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/TypeSymbolTable.h"
  24 #include "llvm/ValueSymbolTable.h"
  25 #include "llvm/Support/MathExtras.h"
  26 using namespace llvm;
  27
  28 /// These are manifest constants used by the bitcode writer. They do not need to
  29 /// be kept in sync with the reader, but need to be consistent within this file.
  30 enum {
  31   CurVersion = 0,
  32
  33   // VALUE_SYMTAB_BLOCK abbrev id's.
  34   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  35   VST_ENTRY_7_ABBREV,
  36   VST_ENTRY_6_ABBREV,
  37   VST_BBENTRY_6_ABBREV,
  38
  39   // CONSTANTS_BLOCK abbrev id's.
  40   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  41   CONSTANTS_INTEGER_ABBREV,
  42   CONSTANTS_CE_CAST_Abbrev,
  43   CONSTANTS_NULL_Abbrev,
  44
  45   // FUNCTION_BLOCK abbrev id's.
  46   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  47   FUNCTION_INST_BINOP_ABBREV,
  48   FUNCTION_INST_CAST_ABBREV,
  49   FUNCTION_INST_RET_VOID_ABBREV,
  50   FUNCTION_INST_RET_VAL_ABBREV,
  51   FUNCTION_INST_UNREACHABLE_ABBREV
  52 };
  53
  54
  55 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
  56   switch (Opcode) {
  57   default: assert(0 && "Unknown cast instruction!");
  58   case Instruction::Trunc   : return bitc::CAST_TRUNC;
  59   case Instruction::ZExt    : return bitc::CAST_ZEXT;
  60   case Instruction::SExt    : return bitc::CAST_SEXT;
  61   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
  62   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
  63   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
  64   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
  65   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
  66   case Instruction::FPExt   : return bitc::CAST_FPEXT;
  67   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
  68   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
  69   case Instruction::BitCast : return bitc::CAST_BITCAST;
  70   }
  71 }
  72
  73 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
  74   switch (Opcode) {
  75   default: assert(0 && "Unknown binary instruction!");
  76   case Instruction::Add:  return bitc::BINOP_ADD;
  77   case Instruction::Sub:  return bitc::BINOP_SUB;
  78   case Instruction::Mul:  return bitc::BINOP_MUL;
  79   case Instruction::UDiv: return bitc::BINOP_UDIV;
  80   case Instruction::FDiv:
  81   case Instruction::SDiv: return bitc::BINOP_SDIV;
  82   case Instruction::URem: return bitc::BINOP_UREM;
  83   case Instruction::FRem:
  84   case Instruction::SRem: return bitc::BINOP_SREM;
  85   case Instruction::Shl:  return bitc::BINOP_SHL;
  86   case Instruction::LShr: return bitc::BINOP_LSHR;
  87   case Instruction::AShr: return bitc::BINOP_ASHR;
  88   case Instruction::And:  return bitc::BINOP_AND;
  89   case Instruction::Or:   return bitc::BINOP_OR;
  90   case Instruction::Xor:  return bitc::BINOP_XOR;
  91   }
  92 }
  93
  94
  95
  96 static void WriteStringRecord(unsigned Code, const std::string &Str,
  97                               unsigned AbbrevToUse, BitstreamWriter &Stream) {
  98   SmallVector<unsigned, 64> Vals;
  99
 100   // Code: [strchar x N]
 101   for (unsigned i = 0, e = Str.size(); i != e; ++i)
 102     Vals.push_back(Str[i]);
 103
 104   // Emit the finished record.
 105   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 106 }
 107
 108 // Emit information about parameter attributes.
 109 static void WriteParamAttrTable(const ValueEnumerator &VE,
 110                                 BitstreamWriter &Stream) {
 111   const std::vector<PAListPtr> &Attrs = VE.getParamAttrs();
 112   if (Attrs.empty()) return;
 113
 114   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 115
 116   SmallVector<uint64_t, 64> Record;
 117   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
 118     const PAListPtr &A = Attrs[i];
 119     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
 120       const ParamAttrsWithIndex &PAWI = A.getSlot(i);
 121       Record.push_back(PAWI.Index);
 122       Record.push_back(PAWI.Attrs);
 123     }
 124
 125     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 126     Record.clear();
 127   }
 128
 129   Stream.ExitBlock();
 130 }
 131
 132 /// WriteTypeTable - Write out the type table for a module.
 133 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 134   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 135
 136   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
 137   SmallVector<uint64_t, 64> TypeVals;
 138
 139   // Abbrev for TYPE_CODE_POINTER.
 140   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 141   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
 142   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 143                             Log2_32_Ceil(VE.getTypes().size()+1)));
 144   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
 145   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
 146
 147   // Abbrev for TYPE_CODE_FUNCTION.
 148   Abbv = new BitCodeAbbrev();
 149   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
 150   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
 151   Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
 152   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 153   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 154                             Log2_32_Ceil(VE.getTypes().size()+1)));
 155   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 156
 157   // Abbrev for TYPE_CODE_STRUCT.
 158   Abbv = new BitCodeAbbrev();
 159   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
 160   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 161   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 162   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 163                             Log2_32_Ceil(VE.getTypes().size()+1)));
 164   unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
 165
 166   // Abbrev for TYPE_CODE_ARRAY.
 167   Abbv = new BitCodeAbbrev();
 168   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 169   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 170   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 171                             Log2_32_Ceil(VE.getTypes().size()+1)));
 172   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 173
 174   // Emit an entry count so the reader can reserve space.
 175   TypeVals.push_back(TypeList.size());
 176   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 177   TypeVals.clear();
 178
 179   // Loop over all of the types, emitting each in turn.
 180   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 181     const Type *T = TypeList[i].first;
 182     int AbbrevToUse = 0;
 183     unsigned Code = 0;
 184
 185     switch (T->getTypeID()) {
 186     default: assert(0 && "Unknown type!");
 187     case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
 188     case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
 189     case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
 190     case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
 191     case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
 192     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 193     case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
 194     case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
 195     case Type::IntegerTyID:
 196       // INTEGER: [width]
 197       Code = bitc::TYPE_CODE_INTEGER;
 198       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 199       break;
 200     case Type::PointerTyID: {
 201       const PointerType *PTy = cast<PointerType>(T);
 202       // POINTER: [pointee type, address space]
 203       Code = bitc::TYPE_CODE_POINTER;
 204       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
 205       unsigned AddressSpace = PTy->getAddressSpace();
 206       TypeVals.push_back(AddressSpace);
 207       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
 208       break;
 209     }
 210     case Type::FunctionTyID: {
 211       const FunctionType *FT = cast<FunctionType>(T);
 212       // FUNCTION: [isvararg, attrid, retty, paramty x N]
 213       Code = bitc::TYPE_CODE_FUNCTION;
 214       TypeVals.push_back(FT->isVarArg());
 215       TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
 216       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 217       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 218         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 219       AbbrevToUse = FunctionAbbrev;
 220       break;
 221     }
 222     case Type::StructTyID: {
 223       const StructType *ST = cast<StructType>(T);
 224       // STRUCT: [ispacked, eltty x N]
 225       Code = bitc::TYPE_CODE_STRUCT;
 226       TypeVals.push_back(ST->isPacked());
 227       // Output all of the element types.
 228       for (StructType::element_iterator I = ST->element_begin(),
 229            E = ST->element_end(); I != E; ++I)
 230         TypeVals.push_back(VE.getTypeID(*I));
 231       AbbrevToUse = StructAbbrev;
 232       break;
 233     }
 234     case Type::ArrayTyID: {
 235       const ArrayType *AT = cast<ArrayType>(T);
 236       // ARRAY: [numelts, eltty]
 237       Code = bitc::TYPE_CODE_ARRAY;
 238       TypeVals.push_back(AT->getNumElements());
 239       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 240       AbbrevToUse = ArrayAbbrev;
 241       break;
 242     }
 243     case Type::VectorTyID: {
 244       const VectorType *VT = cast<VectorType>(T);
 245       // VECTOR [numelts, eltty]
 246       Code = bitc::TYPE_CODE_VECTOR;
 247       TypeVals.push_back(VT->getNumElements());
 248       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 249       break;
 250     }
 251     }
 252
 253     // Emit the finished record.
 254     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 255     TypeVals.clear();
 256   }
 257
 258   Stream.ExitBlock();
 259 }
 260
 261 static unsigned getEncodedLinkage(const GlobalValue *GV) {
 262   switch (GV->getLinkage()) {
 263   default: assert(0 && "Invalid linkage!");
 264   case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
 265   case GlobalValue::ExternalLinkage:     return 0;
 266   case GlobalValue::WeakLinkage:         return 1;
 267   case GlobalValue::AppendingLinkage:    return 2;
 268   case GlobalValue::InternalLinkage:     return 3;
 269   case GlobalValue::LinkOnceLinkage:     return 4;
 270   case GlobalValue::DLLImportLinkage:    return 5;
 271   case GlobalValue::DLLExportLinkage:    return 6;
 272   case GlobalValue::ExternalWeakLinkage: return 7;
 273   }
 274 }
 275
 276 static unsigned getEncodedVisibility(const GlobalValue *GV) {
 277   switch (GV->getVisibility()) {
 278   default: assert(0 && "Invalid visibility!");
 279   case GlobalValue::DefaultVisibility:   return 0;
 280   case GlobalValue::HiddenVisibility:    return 1;
 281   case GlobalValue::ProtectedVisibility: return 2;
 282   }
 283 }
 284
 285 // Emit top-level description of module, including target triple, inline asm,
 286 // descriptors for global variables, and function prototype info.
 287 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 288                             BitstreamWriter &Stream) {
 289   // Emit the list of dependent libraries for the Module.
 290   for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
 291     WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
 292
 293   // Emit various pieces of data attached to a module.
 294   if (!M->getTargetTriple().empty())
 295     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 296                       0/*TODO*/, Stream);
 297   if (!M->getDataLayout().empty())
 298     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
 299                       0/*TODO*/, Stream);
 300   if (!M->getModuleInlineAsm().empty())
 301     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 302                       0/*TODO*/, Stream);
 303
 304   // Emit information about sections and collectors, computing how many there
 305   // are.  Also compute the maximum alignment value.
 306   std::map<std::string, unsigned> SectionMap;
 307   std::map<std::string, unsigned> CollectorMap;
 308   unsigned MaxAlignment = 0;
 309   unsigned MaxGlobalType = 0;
 310   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 311        GV != E; ++GV) {
 312     MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
 313     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
 314
 315     if (!GV->hasSection()) continue;
 316     // Give section names unique ID's.
 317     unsigned &Entry = SectionMap[GV->getSection()];
 318     if (Entry != 0) continue;
 319     WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
 320                       0/*TODO*/, Stream);
 321     Entry = SectionMap.size();
 322   }
 323   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 324     MaxAlignment = std::max(MaxAlignment, F->getAlignment());
 325     if (F->hasSection()) {
 326       // Give section names unique ID's.
 327       unsigned &Entry = SectionMap[F->getSection()];
 328       if (!Entry) {
 329         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
 330                           0/*TODO*/, Stream);
 331         Entry = SectionMap.size();
 332       }
 333     }
 334     if (F->hasCollector()) {
 335       // Same for collector names.
 336       unsigned &Entry = CollectorMap[F->getCollector()];
 337       if (!Entry) {
 338         WriteStringRecord(bitc::MODULE_CODE_COLLECTORNAME, F->getCollector(),
 339                           0/*TODO*/, Stream);
 340         Entry = CollectorMap.size();
 341       }
 342     }
 343   }
 344
 345   // Emit abbrev for globals, now that we know # sections and max alignment.
 346   unsigned SimpleGVarAbbrev = 0;
 347   if (!M->global_empty()) {
 348     // Add an abbrev for common globals with no visibility or thread localness.
 349     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 350     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 351     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 352                               Log2_32_Ceil(MaxGlobalType+1)));
 353     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
 354     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
 355     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));      // Linkage.
 356     if (MaxAlignment == 0)                                      // Alignment.
 357       Abbv->Add(BitCodeAbbrevOp(0));
 358     else {
 359       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 360       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 361                                Log2_32_Ceil(MaxEncAlignment+1)));
 362     }
 363     if (SectionMap.empty())                                    // Section.
 364       Abbv->Add(BitCodeAbbrevOp(0));
 365     else
 366       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 367                                Log2_32_Ceil(SectionMap.size()+1)));
 368     // Don't bother emitting vis + thread local.
 369     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 370   }
 371
 372   // Emit the global variable information.
 373   SmallVector<unsigned, 64> Vals;
 374   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 375        GV != E; ++GV) {
 376     unsigned AbbrevToUse = 0;
 377
 378     // GLOBALVAR: [type, isconst, initid,
 379     //             linkage, alignment, section, visibility, threadlocal]
 380     Vals.push_back(VE.getTypeID(GV->getType()));
 381     Vals.push_back(GV->isConstant());
 382     Vals.push_back(GV->isDeclaration() ? 0 :
 383                    (VE.getValueID(GV->getInitializer()) + 1));
 384     Vals.push_back(getEncodedLinkage(GV));
 385     Vals.push_back(Log2_32(GV->getAlignment())+1);
 386     Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
 387     if (GV->isThreadLocal() ||
 388         GV->getVisibility() != GlobalValue::DefaultVisibility) {
 389       Vals.push_back(getEncodedVisibility(GV));
 390       Vals.push_back(GV->isThreadLocal());
 391     } else {
 392       AbbrevToUse = SimpleGVarAbbrev;
 393     }
 394
 395     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 396     Vals.clear();
 397   }
 398
 399   // Emit the function proto information.
 400   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 401     // FUNCTION:  [type, callingconv, isproto, paramattr,
 402     //             linkage, alignment, section, visibility, collector]
 403     Vals.push_back(VE.getTypeID(F->getType()));
 404     Vals.push_back(F->getCallingConv());
 405     Vals.push_back(F->isDeclaration());
 406     Vals.push_back(getEncodedLinkage(F));
 407     Vals.push_back(VE.getParamAttrID(F->getParamAttrs()));
 408     Vals.push_back(Log2_32(F->getAlignment())+1);
 409     Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
 410     Vals.push_back(getEncodedVisibility(F));
 411     Vals.push_back(F->hasCollector() ? CollectorMap[F->getCollector()] : 0);
 412
 413     unsigned AbbrevToUse = 0;
 414     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 415     Vals.clear();
 416   }
 417
 418
 419   // Emit the alias information.
 420   for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
 421        AI != E; ++AI) {
 422     Vals.push_back(VE.getTypeID(AI->getType()));
 423     Vals.push_back(VE.getValueID(AI->getAliasee()));
 424     Vals.push_back(getEncodedLinkage(AI));
 425     Vals.push_back(getEncodedVisibility(AI));
 426     unsigned AbbrevToUse = 0;
 427     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 428     Vals.clear();
 429   }
 430 }
 431
 432
 433 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
 434                            const ValueEnumerator &VE,
 435                            BitstreamWriter &Stream, bool isGlobal) {
 436   if (FirstVal == LastVal) return;
 437
 438   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
 439
 440   unsigned AggregateAbbrev = 0;
 441   unsigned String8Abbrev = 0;
 442   unsigned CString7Abbrev = 0;
 443   unsigned CString6Abbrev = 0;
 444   // If this is a constant pool for the module, emit module-specific abbrevs.
 445   if (isGlobal) {
 446     // Abbrev for CST_CODE_AGGREGATE.
 447     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 448     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
 449     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 450     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
 451     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
 452
 453     // Abbrev for CST_CODE_STRING.
 454     Abbv = new BitCodeAbbrev();
 455     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
 456     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 457     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 458     String8Abbrev = Stream.EmitAbbrev(Abbv);
 459     // Abbrev for CST_CODE_CSTRING.
 460     Abbv = new BitCodeAbbrev();
 461     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 462     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 463     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 464     CString7Abbrev = Stream.EmitAbbrev(Abbv);
 465     // Abbrev for CST_CODE_CSTRING.
 466     Abbv = new BitCodeAbbrev();
 467     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 468     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 469     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 470     CString6Abbrev = Stream.EmitAbbrev(Abbv);
 471   }
 472
 473   SmallVector<uint64_t, 64> Record;
 474
 475   const ValueEnumerator::ValueList &Vals = VE.getValues();
 476   const Type *LastTy = 0;
 477   for (unsigned i = FirstVal; i != LastVal; ++i) {
 478     const Value *V = Vals[i].first;
 479     // If we need to switch types, do so now.
 480     if (V->getType() != LastTy) {
 481       LastTy = V->getType();
 482       Record.push_back(VE.getTypeID(LastTy));
 483       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
 484                         CONSTANTS_SETTYPE_ABBREV);
 485       Record.clear();
 486     }
 487
 488     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
 489       Record.push_back(unsigned(IA->hasSideEffects()));
 490
 491       // Add the asm string.
 492       const std::string &AsmStr = IA->getAsmString();
 493       Record.push_back(AsmStr.size());
 494       for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
 495         Record.push_back(AsmStr[i]);
 496
 497       // Add the constraint string.
 498       const std::string &ConstraintStr = IA->getConstraintString();
 499       Record.push_back(ConstraintStr.size());
 500       for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
 501         Record.push_back(ConstraintStr[i]);
 502       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
 503       Record.clear();
 504       continue;
 505     }
 506     const Constant *C = cast<Constant>(V);
 507     unsigned Code = -1U;
 508     unsigned AbbrevToUse = 0;
 509     if (C->isNullValue()) {
 510       Code = bitc::CST_CODE_NULL;
 511     } else if (isa<UndefValue>(C)) {
 512       Code = bitc::CST_CODE_UNDEF;
 513     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
 514       if (IV->getBitWidth() <= 64) {
 515         int64_t V = IV->getSExtValue();
 516         if (V >= 0)
 517           Record.push_back(V << 1);
 518         else
 519           Record.push_back((-V << 1) | 1);
 520         Code = bitc::CST_CODE_INTEGER;
 521         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
 522       } else {                             // Wide integers, > 64 bits in size.
 523         // We have an arbitrary precision integer value to write whose
 524         // bit width is > 64. However, in canonical unsigned integer
 525         // format it is likely that the high bits are going to be zero.
 526         // So, we only write the number of active words.
 527         unsigned NWords = IV->getValue().getActiveWords();
 528         const uint64_t *RawWords = IV->getValue().getRawData();
 529         for (unsigned i = 0; i != NWords; ++i) {
 530           int64_t V = RawWords[i];
 531           if (V >= 0)
 532             Record.push_back(V << 1);
 533           else
 534             Record.push_back((-V << 1) | 1);
 535         }
 536         Code = bitc::CST_CODE_WIDE_INTEGER;
 537       }
 538     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
 539       Code = bitc::CST_CODE_FLOAT;
 540       const Type *Ty = CFP->getType();
 541       if (Ty == Type::FloatTy || Ty == Type::DoubleTy) {
 542         Record.push_back(CFP->getValueAPF().convertToAPInt().getZExtValue());
 543       } else if (Ty == Type::X86_FP80Ty) {
 544         // api needed to prevent premature destruction
 545         APInt api = CFP->getValueAPF().convertToAPInt();
 546         const uint64_t *p = api.getRawData();
 547         Record.push_back(p[0]);
 548         Record.push_back((uint16_t)p[1]);
 549       } else if (Ty == Type::FP128Ty || Ty == Type::PPC_FP128Ty) {
 550         APInt api = CFP->getValueAPF().convertToAPInt();
 551         const uint64_t *p = api.getRawData();
 552         Record.push_back(p[0]);
 553         Record.push_back(p[1]);
 554       } else {
 555         assert (0 && "Unknown FP type!");
 556       }
 557     } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
 558       // Emit constant strings specially.
 559       unsigned NumOps = C->getNumOperands();
 560       // If this is a null-terminated string, use the denser CSTRING encoding.
 561       if (C->getOperand(NumOps-1)->isNullValue()) {
 562         Code = bitc::CST_CODE_CSTRING;
 563         --NumOps;  // Don't encode the null, which isn't allowed by char6.
 564       } else {
 565         Code = bitc::CST_CODE_STRING;
 566         AbbrevToUse = String8Abbrev;
 567       }
 568       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
 569       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
 570       for (unsigned i = 0; i != NumOps; ++i) {
 571         unsigned char V = cast<ConstantInt>(C->getOperand(i))->getZExtValue();
 572         Record.push_back(V);
 573         isCStr7 &= (V & 128) == 0;
 574         if (isCStrChar6)
 575           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
 576       }
 577
 578       if (isCStrChar6)
 579         AbbrevToUse = CString6Abbrev;
 580       else if (isCStr7)
 581         AbbrevToUse = CString7Abbrev;
 582     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
 583                isa<ConstantVector>(V)) {
 584       Code = bitc::CST_CODE_AGGREGATE;
 585       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
 586         Record.push_back(VE.getValueID(C->getOperand(i)));
 587       AbbrevToUse = AggregateAbbrev;
 588     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
 589       switch (CE->getOpcode()) {
 590       default:
 591         if (Instruction::isCast(CE->getOpcode())) {
 592           Code = bitc::CST_CODE_CE_CAST;
 593           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
 594           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 595           Record.push_back(VE.getValueID(C->getOperand(0)));
 596           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
 597         } else {
 598           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
 599           Code = bitc::CST_CODE_CE_BINOP;
 600           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
 601           Record.push_back(VE.getValueID(C->getOperand(0)));
 602           Record.push_back(VE.getValueID(C->getOperand(1)));
 603         }
 604         break;
 605       case Instruction::GetElementPtr:
 606         Code = bitc::CST_CODE_CE_GEP;
 607         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
 608           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
 609           Record.push_back(VE.getValueID(C->getOperand(i)));
 610         }
 611         break;
 612       case Instruction::Select:
 613         Code = bitc::CST_CODE_CE_SELECT;
 614         Record.push_back(VE.getValueID(C->getOperand(0)));
 615         Record.push_back(VE.getValueID(C->getOperand(1)));
 616         Record.push_back(VE.getValueID(C->getOperand(2)));
 617         break;
 618       case Instruction::ExtractElement:
 619         Code = bitc::CST_CODE_CE_EXTRACTELT;
 620         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 621         Record.push_back(VE.getValueID(C->getOperand(0)));
 622         Record.push_back(VE.getValueID(C->getOperand(1)));
 623         break;
 624       case Instruction::InsertElement:
 625         Code = bitc::CST_CODE_CE_INSERTELT;
 626         Record.push_back(VE.getValueID(C->getOperand(0)));
 627         Record.push_back(VE.getValueID(C->getOperand(1)));
 628         Record.push_back(VE.getValueID(C->getOperand(2)));
 629         break;
 630       case Instruction::ShuffleVector:
 631         Code = bitc::CST_CODE_CE_SHUFFLEVEC;
 632         Record.push_back(VE.getValueID(C->getOperand(0)));
 633         Record.push_back(VE.getValueID(C->getOperand(1)));
 634         Record.push_back(VE.getValueID(C->getOperand(2)));
 635         break;
 636       case Instruction::ICmp:
 637       case Instruction::FCmp:
 638       case Instruction::VICmp:
 639       case Instruction::VFCmp:
 640         Code = bitc::CST_CODE_CE_CMP;
 641         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 642         Record.push_back(VE.getValueID(C->getOperand(0)));
 643         Record.push_back(VE.getValueID(C->getOperand(1)));
 644         Record.push_back(CE->getPredicate());
 645         break;
 646       }
 647     } else {
 648       assert(0 && "Unknown constant!");
 649     }
 650     Stream.EmitRecord(Code, Record, AbbrevToUse);
 651     Record.clear();
 652   }
 653
 654   Stream.ExitBlock();
 655 }
 656
 657 static void WriteModuleConstants(const ValueEnumerator &VE,
 658                                  BitstreamWriter &Stream) {
 659   const ValueEnumerator::ValueList &Vals = VE.getValues();
 660
 661   // Find the first constant to emit, which is the first non-globalvalue value.
 662   // We know globalvalues have been emitted by WriteModuleInfo.
 663   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 664     if (!isa<GlobalValue>(Vals[i].first)) {
 665       WriteConstants(i, Vals.size(), VE, Stream, true);
 666       return;
 667     }
 668   }
 669 }
 670
 671 /// PushValueAndType - The file has to encode both the value and type id for
 672 /// many values, because we need to know what type to create for forward
 673 /// references.  However, most operands are not forward references, so this type
 674 /// field is not needed.
 675 ///
 676 /// This function adds V's value ID to Vals.  If the value ID is higher than the
 677 /// instruction ID, then it is a forward reference, and it also includes the
 678 /// type ID.
 679 static bool PushValueAndType(Value *V, unsigned InstID,
 680                              SmallVector<unsigned, 64> &Vals,
 681                              ValueEnumerator &VE) {
 682   unsigned ValID = VE.getValueID(V);
 683   Vals.push_back(ValID);
 684   if (ValID >= InstID) {
 685     Vals.push_back(VE.getTypeID(V->getType()));
 686     return true;
 687   }
 688   return false;
 689 }
 690
 691 /// WriteInstruction - Emit an instruction to the specified stream.
 692 static void WriteInstruction(const Instruction &I, unsigned InstID,
 693                              ValueEnumerator &VE, BitstreamWriter &Stream,
 694                              SmallVector<unsigned, 64> &Vals) {
 695   unsigned Code = 0;
 696   unsigned AbbrevToUse = 0;
 697   switch (I.getOpcode()) {
 698   default:
 699     if (Instruction::isCast(I.getOpcode())) {
 700       Code = bitc::FUNC_CODE_INST_CAST;
 701       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 702         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
 703       Vals.push_back(VE.getTypeID(I.getType()));
 704       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
 705     } else {
 706       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
 707       Code = bitc::FUNC_CODE_INST_BINOP;
 708       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 709         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
 710       Vals.push_back(VE.getValueID(I.getOperand(1)));
 711       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
 712     }
 713     break;
 714
 715   case Instruction::GetElementPtr:
 716     Code = bitc::FUNC_CODE_INST_GEP;
 717     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 718       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
 719     break;
 720   case Instruction::Select:
 721     Code = bitc::FUNC_CODE_INST_SELECT;
 722     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
 723     Vals.push_back(VE.getValueID(I.getOperand(2)));
 724     Vals.push_back(VE.getValueID(I.getOperand(0)));
 725     break;
 726   case Instruction::ExtractElement:
 727     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
 728     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 729     Vals.push_back(VE.getValueID(I.getOperand(1)));
 730     break;
 731   case Instruction::InsertElement:
 732     Code = bitc::FUNC_CODE_INST_INSERTELT;
 733     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 734     Vals.push_back(VE.getValueID(I.getOperand(1)));
 735     Vals.push_back(VE.getValueID(I.getOperand(2)));
 736     break;
 737   case Instruction::ShuffleVector:
 738     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
 739     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 740     Vals.push_back(VE.getValueID(I.getOperand(1)));
 741     Vals.push_back(VE.getValueID(I.getOperand(2)));
 742     break;
 743   case Instruction::ICmp:
 744   case Instruction::FCmp:
 745   case Instruction::VICmp:
 746   case Instruction::VFCmp:
 747     Code = bitc::FUNC_CODE_INST_CMP;
 748     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 749     Vals.push_back(VE.getValueID(I.getOperand(1)));
 750     Vals.push_back(cast<CmpInst>(I).getPredicate());
 751     break;
 752   case Instruction::GetResult:
 753     Code = bitc::FUNC_CODE_INST_GETRESULT;
 754     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 755     Vals.push_back(cast<GetResultInst>(I).getIndex());
 756     break;
 757
 758   case Instruction::Ret:
 759     {
 760       Code = bitc::FUNC_CODE_INST_RET;
 761       unsigned NumOperands = I.getNumOperands();
 762       if (NumOperands == 0)
 763         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
 764       else if (NumOperands == 1) {
 765         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 766           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
 767       } else {
 768         for (unsigned i = 0, e = NumOperands; i != e; ++i)
 769           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
 770       }
 771     }
 772     break;
 773   case Instruction::Br:
 774     Code = bitc::FUNC_CODE_INST_BR;
 775     Vals.push_back(VE.getValueID(I.getOperand(0)));
 776     if (cast<BranchInst>(I).isConditional()) {
 777       Vals.push_back(VE.getValueID(I.getOperand(1)));
 778       Vals.push_back(VE.getValueID(I.getOperand(2)));
 779     }
 780     break;
 781   case Instruction::Switch:
 782     Code = bitc::FUNC_CODE_INST_SWITCH;
 783     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 784     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 785       Vals.push_back(VE.getValueID(I.getOperand(i)));
 786     break;
 787   case Instruction::Invoke: {
 788     const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
 789     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
 790     Code = bitc::FUNC_CODE_INST_INVOKE;
 791
 792     const InvokeInst *II = cast<InvokeInst>(&I);
 793     Vals.push_back(VE.getParamAttrID(II->getParamAttrs()));
 794     Vals.push_back(II->getCallingConv());
 795     Vals.push_back(VE.getValueID(I.getOperand(1)));      // normal dest
 796     Vals.push_back(VE.getValueID(I.getOperand(2)));      // unwind dest
 797     PushValueAndType(I.getOperand(0), InstID, Vals, VE); // callee
 798
 799     // Emit value #'s for the fixed parameters.
 800     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
 801       Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
 802
 803     // Emit type/value pairs for varargs params.
 804     if (FTy->isVarArg()) {
 805       for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
 806            i != e; ++i)
 807         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
 808     }
 809     break;
 810   }
 811   case Instruction::Unwind:
 812     Code = bitc::FUNC_CODE_INST_UNWIND;
 813     break;
 814   case Instruction::Unreachable:
 815     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
 816     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
 817     break;
 818
 819   case Instruction::PHI:
 820     Code = bitc::FUNC_CODE_INST_PHI;
 821     Vals.push_back(VE.getTypeID(I.getType()));
 822     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 823       Vals.push_back(VE.getValueID(I.getOperand(i)));
 824     break;
 825
 826   case Instruction::Malloc:
 827     Code = bitc::FUNC_CODE_INST_MALLOC;
 828     Vals.push_back(VE.getTypeID(I.getType()));
 829     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
 830     Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
 831     break;
 832
 833   case Instruction::Free:
 834     Code = bitc::FUNC_CODE_INST_FREE;
 835     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 836     break;
 837
 838   case Instruction::Alloca:
 839     Code = bitc::FUNC_CODE_INST_ALLOCA;
 840     Vals.push_back(VE.getTypeID(I.getType()));
 841     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
 842     Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
 843     break;
 844
 845   case Instruction::Load:
 846     Code = bitc::FUNC_CODE_INST_LOAD;
 847     if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
 848       AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
 849
 850     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
 851     Vals.push_back(cast<LoadInst>(I).isVolatile());
 852     break;
 853   case Instruction::Store:
 854     Code = bitc::FUNC_CODE_INST_STORE2;
 855     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
 856     Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
 857     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
 858     Vals.push_back(cast<StoreInst>(I).isVolatile());
 859     break;
 860   case Instruction::Call: {
 861     const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
 862     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
 863
 864     Code = bitc::FUNC_CODE_INST_CALL;
 865
 866     const CallInst *CI = cast<CallInst>(&I);
 867     Vals.push_back(VE.getParamAttrID(CI->getParamAttrs()));
 868     Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
 869     PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
 870
 871     // Emit value #'s for the fixed parameters.
 872     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
 873       Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
 874
 875     // Emit type/value pairs for varargs params.
 876     if (FTy->isVarArg()) {
 877       unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
 878       for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
 879            i != e; ++i)
 880         PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
 881     }
 882     break;
 883   }
 884   case Instruction::VAArg:
 885     Code = bitc::FUNC_CODE_INST_VAARG;
 886     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
 887     Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
 888     Vals.push_back(VE.getTypeID(I.getType())); // restype.
 889     break;
 890   }
 891
 892   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 893   Vals.clear();
 894 }
 895
 896 // Emit names for globals/functions etc.
 897 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
 898                                   const ValueEnumerator &VE,
 899                                   BitstreamWriter &Stream) {
 900   if (VST.empty()) return;
 901   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
 902
 903   // FIXME: Set up the abbrev, we know how many values there are!
 904   // FIXME: We know if the type names can use 7-bit ascii.
 905   SmallVector<unsigned, 64> NameVals;
 906
 907   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
 908        SI != SE; ++SI) {
 909
 910     const ValueName &Name = *SI;
 911
 912     // Figure out the encoding to use for the name.
 913     bool is7Bit = true;
 914     bool isChar6 = true;
 915     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
 916          C != E; ++C) {
 917       if (isChar6)
 918         isChar6 = BitCodeAbbrevOp::isChar6(*C);
 919       if ((unsigned char)*C & 128) {
 920         is7Bit = false;
 921         break;  // don't bother scanning the rest.
 922       }
 923     }
 924
 925     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
 926
 927     // VST_ENTRY:   [valueid, namechar x N]
 928     // VST_BBENTRY: [bbid, namechar x N]
 929     unsigned Code;
 930     if (isa<BasicBlock>(SI->getValue())) {
 931       Code = bitc::VST_CODE_BBENTRY;
 932       if (isChar6)
 933         AbbrevToUse = VST_BBENTRY_6_ABBREV;
 934     } else {
 935       Code = bitc::VST_CODE_ENTRY;
 936       if (isChar6)
 937         AbbrevToUse = VST_ENTRY_6_ABBREV;
 938       else if (is7Bit)
 939         AbbrevToUse = VST_ENTRY_7_ABBREV;
 940     }
 941
 942     NameVals.push_back(VE.getValueID(SI->getValue()));
 943     for (const char *P = Name.getKeyData(),
 944          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
 945       NameVals.push_back((unsigned char)*P);
 946
 947     // Emit the finished record.
 948     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
 949     NameVals.clear();
 950   }
 951   Stream.ExitBlock();
 952 }
 953
 954 /// WriteFunction - Emit a function body to the module stream.
 955 static void WriteFunction(const Function &F, ValueEnumerator &VE,
 956                           BitstreamWriter &Stream) {
 957   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
 958   VE.incorporateFunction(F);
 959
 960   SmallVector<unsigned, 64> Vals;
 961
 962   // Emit the number of basic blocks, so the reader can create them ahead of
 963   // time.
 964   Vals.push_back(VE.getBasicBlocks().size());
 965   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
 966   Vals.clear();
 967
 968   // If there are function-local constants, emit them now.
 969   unsigned CstStart, CstEnd;
 970   VE.getFunctionConstantRange(CstStart, CstEnd);
 971   WriteConstants(CstStart, CstEnd, VE, Stream, false);
 972
 973   // Keep a running idea of what the instruction ID is.
 974   unsigned InstID = CstEnd;
 975
 976   // Finally, emit all the instructions, in order.
 977   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
 978     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
 979          I != E; ++I) {
 980       WriteInstruction(*I, InstID, VE, Stream, Vals);
 981       if (I->getType() != Type::VoidTy)
 982         ++InstID;
 983     }
 984
 985   // Emit names for all the instructions etc.
 986   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
 987
 988   VE.purgeFunction();
 989   Stream.ExitBlock();
 990 }
 991
 992 /// WriteTypeSymbolTable - Emit a block for the specified type symtab.
 993 static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
 994                                  const ValueEnumerator &VE,
 995                                  BitstreamWriter &Stream) {
 996   if (TST.empty()) return;
 997
 998   Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
 999
1000   // 7-bit fixed width VST_CODE_ENTRY strings.
1001   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1002   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1003   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1004                             Log2_32_Ceil(VE.getTypes().size()+1)));
1005   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1006   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1007   unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1008
1009   SmallVector<unsigned, 64> NameVals;
1010
1011   for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1012        TI != TE; ++TI) {
1013     // TST_ENTRY: [typeid, namechar x N]
1014     NameVals.push_back(VE.getTypeID(TI->second));
1015
1016     const std::string &Str = TI->first;
1017     bool is7Bit = true;
1018     for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1019       NameVals.push_back((unsigned char)Str[i]);
1020       if (Str[i] & 128)
1021         is7Bit = false;
1022     }
1023
1024     // Emit the finished record.
1025     Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1026     NameVals.clear();
1027   }
1028
1029   Stream.ExitBlock();
1030 }
1031
1032 // Emit blockinfo, which defines the standard abbreviations etc.
1033 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1034   // We only want to emit block info records for blocks that have multiple
1035   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1036   // blocks can defined their abbrevs inline.
1037   Stream.EnterBlockInfoBlock(2);
1038
1039   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1040     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1041     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1042     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1043     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1044     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1045     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1046                                    Abbv) != VST_ENTRY_8_ABBREV)
1047       assert(0 && "Unexpected abbrev ordering!");
1048   }
1049
1050   { // 7-bit fixed width VST_ENTRY strings.
1051     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1052     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1053     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1054     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1055     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1056     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1057                                    Abbv) != VST_ENTRY_7_ABBREV)
1058       assert(0 && "Unexpected abbrev ordering!");
1059   }
1060   { // 6-bit char6 VST_ENTRY strings.
1061     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1062     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1063     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1064     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1065     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1066     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1067                                    Abbv) != VST_ENTRY_6_ABBREV)
1068       assert(0 && "Unexpected abbrev ordering!");
1069   }
1070   { // 6-bit char6 VST_BBENTRY strings.
1071     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1072     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1073     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1074     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1075     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1076     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1077                                    Abbv) != VST_BBENTRY_6_ABBREV)
1078       assert(0 && "Unexpected abbrev ordering!");
1079   }
1080
1081
1082
1083   { // SETTYPE abbrev for CONSTANTS_BLOCK.
1084     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1085     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1086     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1087                               Log2_32_Ceil(VE.getTypes().size()+1)));
1088     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1089                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
1090       assert(0 && "Unexpected abbrev ordering!");
1091   }
1092
1093   { // INTEGER abbrev for CONSTANTS_BLOCK.
1094     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1095     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1096     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1097     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1098                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
1099       assert(0 && "Unexpected abbrev ordering!");
1100   }
1101
1102   { // CE_CAST abbrev for CONSTANTS_BLOCK.
1103     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1104     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1105     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1106     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1107                               Log2_32_Ceil(VE.getTypes().size()+1)));
1108     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1109
1110     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1111                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
1112       assert(0 && "Unexpected abbrev ordering!");
1113   }
1114   { // NULL abbrev for CONSTANTS_BLOCK.
1115     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1116     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1117     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1118                                    Abbv) != CONSTANTS_NULL_Abbrev)
1119       assert(0 && "Unexpected abbrev ordering!");
1120   }
1121
1122   // FIXME: This should only use space for first class types!
1123
1124   { // INST_LOAD abbrev for FUNCTION_BLOCK.
1125     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1126     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1127     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1128     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1129     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1130     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1131                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
1132       assert(0 && "Unexpected abbrev ordering!");
1133   }
1134   { // INST_BINOP abbrev for FUNCTION_BLOCK.
1135     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1136     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1137     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1138     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1139     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1140     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1141                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
1142       assert(0 && "Unexpected abbrev ordering!");
1143   }
1144   { // INST_CAST abbrev for FUNCTION_BLOCK.
1145     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1146     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1147     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1148     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1149                               Log2_32_Ceil(VE.getTypes().size()+1)));
1150     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1151     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1152                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
1153       assert(0 && "Unexpected abbrev ordering!");
1154   }
1155
1156   { // INST_RET abbrev for FUNCTION_BLOCK.
1157     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1158     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1159     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1160                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1161       assert(0 && "Unexpected abbrev ordering!");
1162   }
1163   { // INST_RET abbrev for FUNCTION_BLOCK.
1164     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1165     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1166     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1167     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1168                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1169       assert(0 && "Unexpected abbrev ordering!");
1170   }
1171   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1172     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1173     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1174     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1175                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1176       assert(0 && "Unexpected abbrev ordering!");
1177   }
1178
1179   Stream.ExitBlock();
1180 }
1181
1182
1183 /// WriteModule - Emit the specified module to the bitstream.
1184 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1185   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1186
1187   // Emit the version number if it is non-zero.
1188   if (CurVersion) {
1189     SmallVector<unsigned, 1> Vals;
1190     Vals.push_back(CurVersion);
1191     Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1192   }
1193
1194   // Analyze the module, enumerating globals, functions, etc.
1195   ValueEnumerator VE(M);
1196
1197   // Emit blockinfo, which defines the standard abbreviations etc.
1198   WriteBlockInfo(VE, Stream);
1199
1200   // Emit information about parameter attributes.
1201   WriteParamAttrTable(VE, Stream);
1202
1203   // Emit information describing all of the types in the module.
1204   WriteTypeTable(VE, Stream);
1205
1206   // Emit top-level description of module, including target triple, inline asm,
1207   // descriptors for global variables, and function prototype info.
1208   WriteModuleInfo(M, VE, Stream);
1209
1210   // Emit constants.
1211   WriteModuleConstants(VE, Stream);
1212
1213   // If we have any aggregate values in the value table, purge them - these can
1214   // only be used to initialize global variables.  Doing so makes the value
1215   // namespace smaller for code in functions.
1216   int NumNonAggregates = VE.PurgeAggregateValues();
1217   if (NumNonAggregates != -1) {
1218     SmallVector<unsigned, 1> Vals;
1219     Vals.push_back(NumNonAggregates);
1220     Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
1221   }
1222
1223   // Emit function bodies.
1224   for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1225     if (!I->isDeclaration())
1226       WriteFunction(*I, VE, Stream);
1227
1228   // Emit the type symbol table information.
1229   WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1230
1231   // Emit names for globals/functions etc.
1232   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1233
1234   Stream.ExitBlock();
1235 }
1236
1237
1238 /// WriteBitcodeToFile - Write the specified module to the specified output
1239 /// stream.
1240 void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
1241   std::vector<unsigned char> Buffer;
1242   BitstreamWriter Stream(Buffer);
1243
1244   Buffer.reserve(256*1024);
1245
1246   // Emit the file header.
1247   Stream.Emit((unsigned)'B', 8);
1248   Stream.Emit((unsigned)'C', 8);
1249   Stream.Emit(0x0, 4);
1250   Stream.Emit(0xC, 4);
1251   Stream.Emit(0xE, 4);
1252   Stream.Emit(0xD, 4);
1253
1254   // Emit the module.
1255   WriteModule(M, Stream);
1256
1257   // Write the generated bitstream to "Out".
1258   Out.write((char*)&Buffer.front(), Buffer.size());
1259
1260   // Make sure it hits disk now.
1261   Out.flush();
1262 }