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   case GlobalValue::CommonLinkage:       return 8;
 274   }
 275 }
 276
 277 static unsigned getEncodedVisibility(const GlobalValue *GV) {
 278   switch (GV->getVisibility()) {
 279   default: assert(0 && "Invalid visibility!");
 280   case GlobalValue::DefaultVisibility:   return 0;
 281   case GlobalValue::HiddenVisibility:    return 1;
 282   case GlobalValue::ProtectedVisibility: return 2;
 283   }
 284 }
 285
 286 // Emit top-level description of module, including target triple, inline asm,
 287 // descriptors for global variables, and function prototype info.
 288 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 289                             BitstreamWriter &Stream) {
 290   // Emit the list of dependent libraries for the Module.
 291   for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
 292     WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
 293
 294   // Emit various pieces of data attached to a module.
 295   if (!M->getTargetTriple().empty())
 296     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 297                       0/*TODO*/, Stream);
 298   if (!M->getDataLayout().empty())
 299     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
 300                       0/*TODO*/, Stream);
 301   if (!M->getModuleInlineAsm().empty())
 302     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 303                       0/*TODO*/, Stream);
 304
 305   // Emit information about sections and collectors, computing how many there
 306   // are.  Also compute the maximum alignment value.
 307   std::map<std::string, unsigned> SectionMap;
 308   std::map<std::string, unsigned> CollectorMap;
 309   unsigned MaxAlignment = 0;
 310   unsigned MaxGlobalType = 0;
 311   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 312        GV != E; ++GV) {
 313     MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
 314     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
 315
 316     if (!GV->hasSection()) continue;
 317     // Give section names unique ID's.
 318     unsigned &Entry = SectionMap[GV->getSection()];
 319     if (Entry != 0) continue;
 320     WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
 321                       0/*TODO*/, Stream);
 322     Entry = SectionMap.size();
 323   }
 324   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 325     MaxAlignment = std::max(MaxAlignment, F->getAlignment());
 326     if (F->hasSection()) {
 327       // Give section names unique ID's.
 328       unsigned &Entry = SectionMap[F->getSection()];
 329       if (!Entry) {
 330         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
 331                           0/*TODO*/, Stream);
 332         Entry = SectionMap.size();
 333       }
 334     }
 335     if (F->hasCollector()) {
 336       // Same for collector names.
 337       unsigned &Entry = CollectorMap[F->getCollector()];
 338       if (!Entry) {
 339         WriteStringRecord(bitc::MODULE_CODE_COLLECTORNAME, F->getCollector(),
 340                           0/*TODO*/, Stream);
 341         Entry = CollectorMap.size();
 342       }
 343     }
 344   }
 345
 346   // Emit abbrev for globals, now that we know # sections and max alignment.
 347   unsigned SimpleGVarAbbrev = 0;
 348   if (!M->global_empty()) {
 349     // Add an abbrev for common globals with no visibility or thread localness.
 350     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 351     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 352     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 353                               Log2_32_Ceil(MaxGlobalType+1)));
 354     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
 355     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
 356     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
 357     if (MaxAlignment == 0)                                      // Alignment.
 358       Abbv->Add(BitCodeAbbrevOp(0));
 359     else {
 360       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 361       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 362                                Log2_32_Ceil(MaxEncAlignment+1)));
 363     }
 364     if (SectionMap.empty())                                    // Section.
 365       Abbv->Add(BitCodeAbbrevOp(0));
 366     else
 367       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 368                                Log2_32_Ceil(SectionMap.size()+1)));
 369     // Don't bother emitting vis + thread local.
 370     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 371   }
 372
 373   // Emit the global variable information.
 374   SmallVector<unsigned, 64> Vals;
 375   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 376        GV != E; ++GV) {
 377     unsigned AbbrevToUse = 0;
 378
 379     // GLOBALVAR: [type, isconst, initid,
 380     //             linkage, alignment, section, visibility, threadlocal]
 381     Vals.push_back(VE.getTypeID(GV->getType()));
 382     Vals.push_back(GV->isConstant());
 383     Vals.push_back(GV->isDeclaration() ? 0 :
 384                    (VE.getValueID(GV->getInitializer()) + 1));
 385     Vals.push_back(getEncodedLinkage(GV));
 386     Vals.push_back(Log2_32(GV->getAlignment())+1);
 387     Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
 388     if (GV->isThreadLocal() ||
 389         GV->getVisibility() != GlobalValue::DefaultVisibility) {
 390       Vals.push_back(getEncodedVisibility(GV));
 391       Vals.push_back(GV->isThreadLocal());
 392     } else {
 393       AbbrevToUse = SimpleGVarAbbrev;
 394     }
 395
 396     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 397     Vals.clear();
 398   }
 399
 400   // Emit the function proto information.
 401   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 402     // FUNCTION:  [type, callingconv, isproto, paramattr,
 403     //             linkage, alignment, section, visibility, collector]
 404     Vals.push_back(VE.getTypeID(F->getType()));
 405     Vals.push_back(F->getCallingConv());
 406     Vals.push_back(F->isDeclaration());
 407     Vals.push_back(getEncodedLinkage(F));
 408     Vals.push_back(VE.getParamAttrID(F->getParamAttrs()));
 409     Vals.push_back(Log2_32(F->getAlignment())+1);
 410     Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
 411     Vals.push_back(getEncodedVisibility(F));
 412     Vals.push_back(F->hasCollector() ? CollectorMap[F->getCollector()] : 0);
 413
 414     unsigned AbbrevToUse = 0;
 415     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 416     Vals.clear();
 417   }
 418
 419
 420   // Emit the alias information.
 421   for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
 422        AI != E; ++AI) {
 423     Vals.push_back(VE.getTypeID(AI->getType()));
 424     Vals.push_back(VE.getValueID(AI->getAliasee()));
 425     Vals.push_back(getEncodedLinkage(AI));
 426     Vals.push_back(getEncodedVisibility(AI));
 427     unsigned AbbrevToUse = 0;
 428     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 429     Vals.clear();
 430   }
 431 }
 432
 433
 434 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
 435                            const ValueEnumerator &VE,
 436                            BitstreamWriter &Stream, bool isGlobal) {
 437   if (FirstVal == LastVal) return;
 438
 439   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
 440
 441   unsigned AggregateAbbrev = 0;
 442   unsigned String8Abbrev = 0;
 443   unsigned CString7Abbrev = 0;
 444   unsigned CString6Abbrev = 0;
 445   // If this is a constant pool for the module, emit module-specific abbrevs.
 446   if (isGlobal) {
 447     // Abbrev for CST_CODE_AGGREGATE.
 448     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 449     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
 450     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 451     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
 452     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
 453
 454     // Abbrev for CST_CODE_STRING.
 455     Abbv = new BitCodeAbbrev();
 456     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
 457     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 458     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 459     String8Abbrev = Stream.EmitAbbrev(Abbv);
 460     // Abbrev for CST_CODE_CSTRING.
 461     Abbv = new BitCodeAbbrev();
 462     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 463     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 464     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 465     CString7Abbrev = Stream.EmitAbbrev(Abbv);
 466     // Abbrev for CST_CODE_CSTRING.
 467     Abbv = new BitCodeAbbrev();
 468     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 469     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 470     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 471     CString6Abbrev = Stream.EmitAbbrev(Abbv);
 472   }
 473
 474   SmallVector<uint64_t, 64> Record;
 475
 476   const ValueEnumerator::ValueList &Vals = VE.getValues();
 477   const Type *LastTy = 0;
 478   for (unsigned i = FirstVal; i != LastVal; ++i) {
 479     const Value *V = Vals[i].first;
 480     // If we need to switch types, do so now.
 481     if (V->getType() != LastTy) {
 482       LastTy = V->getType();
 483       Record.push_back(VE.getTypeID(LastTy));
 484       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
 485                         CONSTANTS_SETTYPE_ABBREV);
 486       Record.clear();
 487     }
 488
 489     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
 490       Record.push_back(unsigned(IA->hasSideEffects()));
 491
 492       // Add the asm string.
 493       const std::string &AsmStr = IA->getAsmString();
 494       Record.push_back(AsmStr.size());
 495       for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
 496         Record.push_back(AsmStr[i]);
 497
 498       // Add the constraint string.
 499       const std::string &ConstraintStr = IA->getConstraintString();
 500       Record.push_back(ConstraintStr.size());
 501       for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
 502         Record.push_back(ConstraintStr[i]);
 503       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
 504       Record.clear();
 505       continue;
 506     }
 507     const Constant *C = cast<Constant>(V);
 508     unsigned Code = -1U;
 509     unsigned AbbrevToUse = 0;
 510     if (C->isNullValue()) {
 511       Code = bitc::CST_CODE_NULL;
 512     } else if (isa<UndefValue>(C)) {
 513       Code = bitc::CST_CODE_UNDEF;
 514     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
 515       if (IV->getBitWidth() <= 64) {
 516         int64_t V = IV->getSExtValue();
 517         if (V >= 0)
 518           Record.push_back(V << 1);
 519         else
 520           Record.push_back((-V << 1) | 1);
 521         Code = bitc::CST_CODE_INTEGER;
 522         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
 523       } else {                             // Wide integers, > 64 bits in size.
 524         // We have an arbitrary precision integer value to write whose
 525         // bit width is > 64. However, in canonical unsigned integer
 526         // format it is likely that the high bits are going to be zero.
 527         // So, we only write the number of active words.
 528         unsigned NWords = IV->getValue().getActiveWords();
 529         const uint64_t *RawWords = IV->getValue().getRawData();
 530         for (unsigned i = 0; i != NWords; ++i) {
 531           int64_t V = RawWords[i];
 532           if (V >= 0)
 533             Record.push_back(V << 1);
 534           else
 535             Record.push_back((-V << 1) | 1);
 536         }
 537         Code = bitc::CST_CODE_WIDE_INTEGER;
 538       }
 539     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
 540       Code = bitc::CST_CODE_FLOAT;
 541       const Type *Ty = CFP->getType();
 542       if (Ty == Type::FloatTy || Ty == Type::DoubleTy) {
 543         Record.push_back(CFP->getValueAPF().convertToAPInt().getZExtValue());
 544       } else if (Ty == Type::X86_FP80Ty) {
 545         // api needed to prevent premature destruction
 546         APInt api = CFP->getValueAPF().convertToAPInt();
 547         const uint64_t *p = api.getRawData();
 548         Record.push_back(p[0]);
 549         Record.push_back((uint16_t)p[1]);
 550       } else if (Ty == Type::FP128Ty || Ty == Type::PPC_FP128Ty) {
 551         APInt api = CFP->getValueAPF().convertToAPInt();
 552         const uint64_t *p = api.getRawData();
 553         Record.push_back(p[0]);
 554         Record.push_back(p[1]);
 555       } else {
 556         assert (0 && "Unknown FP type!");
 557       }
 558     } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
 559       // Emit constant strings specially.
 560       unsigned NumOps = C->getNumOperands();
 561       // If this is a null-terminated string, use the denser CSTRING encoding.
 562       if (C->getOperand(NumOps-1)->isNullValue()) {
 563         Code = bitc::CST_CODE_CSTRING;
 564         --NumOps;  // Don't encode the null, which isn't allowed by char6.
 565       } else {
 566         Code = bitc::CST_CODE_STRING;
 567         AbbrevToUse = String8Abbrev;
 568       }
 569       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
 570       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
 571       for (unsigned i = 0; i != NumOps; ++i) {
 572         unsigned char V = cast<ConstantInt>(C->getOperand(i))->getZExtValue();
 573         Record.push_back(V);
 574         isCStr7 &= (V & 128) == 0;
 575         if (isCStrChar6)
 576           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
 577       }
 578
 579       if (isCStrChar6)
 580         AbbrevToUse = CString6Abbrev;
 581       else if (isCStr7)
 582         AbbrevToUse = CString7Abbrev;
 583     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
 584                isa<ConstantVector>(V)) {
 585       Code = bitc::CST_CODE_AGGREGATE;
 586       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
 587         Record.push_back(VE.getValueID(C->getOperand(i)));
 588       AbbrevToUse = AggregateAbbrev;
 589     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
 590       switch (CE->getOpcode()) {
 591       default:
 592         if (Instruction::isCast(CE->getOpcode())) {
 593           Code = bitc::CST_CODE_CE_CAST;
 594           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
 595           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 596           Record.push_back(VE.getValueID(C->getOperand(0)));
 597           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
 598         } else {
 599           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
 600           Code = bitc::CST_CODE_CE_BINOP;
 601           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
 602           Record.push_back(VE.getValueID(C->getOperand(0)));
 603           Record.push_back(VE.getValueID(C->getOperand(1)));
 604         }
 605         break;
 606       case Instruction::GetElementPtr:
 607         Code = bitc::CST_CODE_CE_GEP;
 608         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
 609           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
 610           Record.push_back(VE.getValueID(C->getOperand(i)));
 611         }
 612         break;
 613       case Instruction::Select:
 614         Code = bitc::CST_CODE_CE_SELECT;
 615         Record.push_back(VE.getValueID(C->getOperand(0)));
 616         Record.push_back(VE.getValueID(C->getOperand(1)));
 617         Record.push_back(VE.getValueID(C->getOperand(2)));
 618         break;
 619       case Instruction::ExtractElement:
 620         Code = bitc::CST_CODE_CE_EXTRACTELT;
 621         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 622         Record.push_back(VE.getValueID(C->getOperand(0)));
 623         Record.push_back(VE.getValueID(C->getOperand(1)));
 624         break;
 625       case Instruction::InsertElement:
 626         Code = bitc::CST_CODE_CE_INSERTELT;
 627         Record.push_back(VE.getValueID(C->getOperand(0)));
 628         Record.push_back(VE.getValueID(C->getOperand(1)));
 629         Record.push_back(VE.getValueID(C->getOperand(2)));
 630         break;
 631       case Instruction::ShuffleVector:
 632         Code = bitc::CST_CODE_CE_SHUFFLEVEC;
 633         Record.push_back(VE.getValueID(C->getOperand(0)));
 634         Record.push_back(VE.getValueID(C->getOperand(1)));
 635         Record.push_back(VE.getValueID(C->getOperand(2)));
 636         break;
 637       case Instruction::ICmp:
 638       case Instruction::FCmp:
 639       case Instruction::VICmp:
 640       case Instruction::VFCmp:
 641         Code = bitc::CST_CODE_CE_CMP;
 642         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 643         Record.push_back(VE.getValueID(C->getOperand(0)));
 644         Record.push_back(VE.getValueID(C->getOperand(1)));
 645         Record.push_back(CE->getPredicate());
 646         break;
 647       }
 648     } else {
 649       assert(0 && "Unknown constant!");
 650     }
 651     Stream.EmitRecord(Code, Record, AbbrevToUse);
 652     Record.clear();
 653   }
 654
 655   Stream.ExitBlock();
 656 }
 657
 658 static void WriteModuleConstants(const ValueEnumerator &VE,
 659                                  BitstreamWriter &Stream) {
 660   const ValueEnumerator::ValueList &Vals = VE.getValues();
 661
 662   // Find the first constant to emit, which is the first non-globalvalue value.
 663   // We know globalvalues have been emitted by WriteModuleInfo.
 664   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 665     if (!isa<GlobalValue>(Vals[i].first)) {
 666       WriteConstants(i, Vals.size(), VE, Stream, true);
 667       return;
 668     }
 669   }
 670 }
 671
 672 /// PushValueAndType - The file has to encode both the value and type id for
 673 /// many values, because we need to know what type to create for forward
 674 /// references.  However, most operands are not forward references, so this type
 675 /// field is not needed.
 676 ///
 677 /// This function adds V's value ID to Vals.  If the value ID is higher than the
 678 /// instruction ID, then it is a forward reference, and it also includes the
 679 /// type ID.
 680 static bool PushValueAndType(Value *V, unsigned InstID,
 681                              SmallVector<unsigned, 64> &Vals,
 682                              ValueEnumerator &VE) {
 683   unsigned ValID = VE.getValueID(V);
 684   Vals.push_back(ValID);
 685   if (ValID >= InstID) {
 686     Vals.push_back(VE.getTypeID(V->getType()));
 687     return true;
 688   }
 689   return false;
 690 }
 691
 692 /// WriteInstruction - Emit an instruction to the specified stream.
 693 static void WriteInstruction(const Instruction &I, unsigned InstID,
 694                              ValueEnumerator &VE, BitstreamWriter &Stream,
 695                              SmallVector<unsigned, 64> &Vals) {
 696   unsigned Code = 0;
 697   unsigned AbbrevToUse = 0;
 698   switch (I.getOpcode()) {
 699   default:
 700     if (Instruction::isCast(I.getOpcode())) {
 701       Code = bitc::FUNC_CODE_INST_CAST;
 702       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 703         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
 704       Vals.push_back(VE.getTypeID(I.getType()));
 705       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
 706     } else {
 707       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
 708       Code = bitc::FUNC_CODE_INST_BINOP;
 709       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 710         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
 711       Vals.push_back(VE.getValueID(I.getOperand(1)));
 712       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
 713     }
 714     break;
 715
 716   case Instruction::GetElementPtr:
 717     Code = bitc::FUNC_CODE_INST_GEP;
 718     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 719       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
 720     break;
 721   case Instruction::Select:
 722     Code = bitc::FUNC_CODE_INST_SELECT;
 723     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
 724     Vals.push_back(VE.getValueID(I.getOperand(2)));
 725     Vals.push_back(VE.getValueID(I.getOperand(0)));
 726     break;
 727   case Instruction::ExtractElement:
 728     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
 729     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 730     Vals.push_back(VE.getValueID(I.getOperand(1)));
 731     break;
 732   case Instruction::InsertElement:
 733     Code = bitc::FUNC_CODE_INST_INSERTELT;
 734     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 735     Vals.push_back(VE.getValueID(I.getOperand(1)));
 736     Vals.push_back(VE.getValueID(I.getOperand(2)));
 737     break;
 738   case Instruction::ShuffleVector:
 739     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
 740     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 741     Vals.push_back(VE.getValueID(I.getOperand(1)));
 742     Vals.push_back(VE.getValueID(I.getOperand(2)));
 743     break;
 744   case Instruction::ICmp:
 745   case Instruction::FCmp:
 746   case Instruction::VICmp:
 747   case Instruction::VFCmp:
 748     Code = bitc::FUNC_CODE_INST_CMP;
 749     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 750     Vals.push_back(VE.getValueID(I.getOperand(1)));
 751     Vals.push_back(cast<CmpInst>(I).getPredicate());
 752     break;
 753   case Instruction::GetResult:
 754     Code = bitc::FUNC_CODE_INST_GETRESULT;
 755     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 756     Vals.push_back(cast<GetResultInst>(I).getIndex());
 757     break;
 758
 759   case Instruction::Ret:
 760     {
 761       Code = bitc::FUNC_CODE_INST_RET;
 762       unsigned NumOperands = I.getNumOperands();
 763       if (NumOperands == 0)
 764         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
 765       else if (NumOperands == 1) {
 766         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 767           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
 768       } else {
 769         for (unsigned i = 0, e = NumOperands; i != e; ++i)
 770           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
 771       }
 772     }
 773     break;
 774   case Instruction::Br:
 775     Code = bitc::FUNC_CODE_INST_BR;
 776     Vals.push_back(VE.getValueID(I.getOperand(0)));
 777     if (cast<BranchInst>(I).isConditional()) {
 778       Vals.push_back(VE.getValueID(I.getOperand(1)));
 779       Vals.push_back(VE.getValueID(I.getOperand(2)));
 780     }
 781     break;
 782   case Instruction::Switch:
 783     Code = bitc::FUNC_CODE_INST_SWITCH;
 784     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 785     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 786       Vals.push_back(VE.getValueID(I.getOperand(i)));
 787     break;
 788   case Instruction::Invoke: {
 789     const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
 790     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
 791     Code = bitc::FUNC_CODE_INST_INVOKE;
 792
 793     const InvokeInst *II = cast<InvokeInst>(&I);
 794     Vals.push_back(VE.getParamAttrID(II->getParamAttrs()));
 795     Vals.push_back(II->getCallingConv());
 796     Vals.push_back(VE.getValueID(I.getOperand(1)));      // normal dest
 797     Vals.push_back(VE.getValueID(I.getOperand(2)));      // unwind dest
 798     PushValueAndType(I.getOperand(0), InstID, Vals, VE); // callee
 799
 800     // Emit value #'s for the fixed parameters.
 801     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
 802       Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
 803
 804     // Emit type/value pairs for varargs params.
 805     if (FTy->isVarArg()) {
 806       for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
 807            i != e; ++i)
 808         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
 809     }
 810     break;
 811   }
 812   case Instruction::Unwind:
 813     Code = bitc::FUNC_CODE_INST_UNWIND;
 814     break;
 815   case Instruction::Unreachable:
 816     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
 817     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
 818     break;
 819
 820   case Instruction::PHI:
 821     Code = bitc::FUNC_CODE_INST_PHI;
 822     Vals.push_back(VE.getTypeID(I.getType()));
 823     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 824       Vals.push_back(VE.getValueID(I.getOperand(i)));
 825     break;
 826
 827   case Instruction::Malloc:
 828     Code = bitc::FUNC_CODE_INST_MALLOC;
 829     Vals.push_back(VE.getTypeID(I.getType()));
 830     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
 831     Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
 832     break;
 833
 834   case Instruction::Free:
 835     Code = bitc::FUNC_CODE_INST_FREE;
 836     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 837     break;
 838
 839   case Instruction::Alloca:
 840     Code = bitc::FUNC_CODE_INST_ALLOCA;
 841     Vals.push_back(VE.getTypeID(I.getType()));
 842     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
 843     Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
 844     break;
 845
 846   case Instruction::Load:
 847     Code = bitc::FUNC_CODE_INST_LOAD;
 848     if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
 849       AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
 850
 851     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
 852     Vals.push_back(cast<LoadInst>(I).isVolatile());
 853     break;
 854   case Instruction::Store:
 855     Code = bitc::FUNC_CODE_INST_STORE2;
 856     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
 857     Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
 858     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
 859     Vals.push_back(cast<StoreInst>(I).isVolatile());
 860     break;
 861   case Instruction::Call: {
 862     const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
 863     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
 864
 865     Code = bitc::FUNC_CODE_INST_CALL;
 866
 867     const CallInst *CI = cast<CallInst>(&I);
 868     Vals.push_back(VE.getParamAttrID(CI->getParamAttrs()));
 869     Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
 870     PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
 871
 872     // Emit value #'s for the fixed parameters.
 873     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
 874       Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
 875
 876     // Emit type/value pairs for varargs params.
 877     if (FTy->isVarArg()) {
 878       unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
 879       for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
 880            i != e; ++i)
 881         PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
 882     }
 883     break;
 884   }
 885   case Instruction::VAArg:
 886     Code = bitc::FUNC_CODE_INST_VAARG;
 887     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
 888     Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
 889     Vals.push_back(VE.getTypeID(I.getType())); // restype.
 890     break;
 891   }
 892
 893   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 894   Vals.clear();
 895 }
 896
 897 // Emit names for globals/functions etc.
 898 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
 899                                   const ValueEnumerator &VE,
 900                                   BitstreamWriter &Stream) {
 901   if (VST.empty()) return;
 902   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
 903
 904   // FIXME: Set up the abbrev, we know how many values there are!
 905   // FIXME: We know if the type names can use 7-bit ascii.
 906   SmallVector<unsigned, 64> NameVals;
 907
 908   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
 909        SI != SE; ++SI) {
 910
 911     const ValueName &Name = *SI;
 912
 913     // Figure out the encoding to use for the name.
 914     bool is7Bit = true;
 915     bool isChar6 = true;
 916     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
 917          C != E; ++C) {
 918       if (isChar6)
 919         isChar6 = BitCodeAbbrevOp::isChar6(*C);
 920       if ((unsigned char)*C & 128) {
 921         is7Bit = false;
 922         break;  // don't bother scanning the rest.
 923       }
 924     }
 925
 926     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
 927
 928     // VST_ENTRY:   [valueid, namechar x N]
 929     // VST_BBENTRY: [bbid, namechar x N]
 930     unsigned Code;
 931     if (isa<BasicBlock>(SI->getValue())) {
 932       Code = bitc::VST_CODE_BBENTRY;
 933       if (isChar6)
 934         AbbrevToUse = VST_BBENTRY_6_ABBREV;
 935     } else {
 936       Code = bitc::VST_CODE_ENTRY;
 937       if (isChar6)
 938         AbbrevToUse = VST_ENTRY_6_ABBREV;
 939       else if (is7Bit)
 940         AbbrevToUse = VST_ENTRY_7_ABBREV;
 941     }
 942
 943     NameVals.push_back(VE.getValueID(SI->getValue()));
 944     for (const char *P = Name.getKeyData(),
 945          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
 946       NameVals.push_back((unsigned char)*P);
 947
 948     // Emit the finished record.
 949     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
 950     NameVals.clear();
 951   }
 952   Stream.ExitBlock();
 953 }
 954
 955 /// WriteFunction - Emit a function body to the module stream.
 956 static void WriteFunction(const Function &F, ValueEnumerator &VE,
 957                           BitstreamWriter &Stream) {
 958   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
 959   VE.incorporateFunction(F);
 960
 961   SmallVector<unsigned, 64> Vals;
 962
 963   // Emit the number of basic blocks, so the reader can create them ahead of
 964   // time.
 965   Vals.push_back(VE.getBasicBlocks().size());
 966   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
 967   Vals.clear();
 968
 969   // If there are function-local constants, emit them now.
 970   unsigned CstStart, CstEnd;
 971   VE.getFunctionConstantRange(CstStart, CstEnd);
 972   WriteConstants(CstStart, CstEnd, VE, Stream, false);
 973
 974   // Keep a running idea of what the instruction ID is.
 975   unsigned InstID = CstEnd;
 976
 977   // Finally, emit all the instructions, in order.
 978   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
 979     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
 980          I != E; ++I) {
 981       WriteInstruction(*I, InstID, VE, Stream, Vals);
 982       if (I->getType() != Type::VoidTy)
 983         ++InstID;
 984     }
 985
 986   // Emit names for all the instructions etc.
 987   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
 988
 989   VE.purgeFunction();
 990   Stream.ExitBlock();
 991 }
 992
 993 /// WriteTypeSymbolTable - Emit a block for the specified type symtab.
 994 static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
 995                                  const ValueEnumerator &VE,
 996                                  BitstreamWriter &Stream) {
 997   if (TST.empty()) return;
 998
 999   Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1000
1001   // 7-bit fixed width VST_CODE_ENTRY strings.
1002   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1003   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1004   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1005                             Log2_32_Ceil(VE.getTypes().size()+1)));
1006   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1007   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1008   unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1009
1010   SmallVector<unsigned, 64> NameVals;
1011
1012   for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1013        TI != TE; ++TI) {
1014     // TST_ENTRY: [typeid, namechar x N]
1015     NameVals.push_back(VE.getTypeID(TI->second));
1016
1017     const std::string &Str = TI->first;
1018     bool is7Bit = true;
1019     for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1020       NameVals.push_back((unsigned char)Str[i]);
1021       if (Str[i] & 128)
1022         is7Bit = false;
1023     }
1024
1025     // Emit the finished record.
1026     Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1027     NameVals.clear();
1028   }
1029
1030   Stream.ExitBlock();
1031 }
1032
1033 // Emit blockinfo, which defines the standard abbreviations etc.
1034 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1035   // We only want to emit block info records for blocks that have multiple
1036   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1037   // blocks can defined their abbrevs inline.
1038   Stream.EnterBlockInfoBlock(2);
1039
1040   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1041     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1042     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1043     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1044     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1045     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1046     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1047                                    Abbv) != VST_ENTRY_8_ABBREV)
1048       assert(0 && "Unexpected abbrev ordering!");
1049   }
1050
1051   { // 7-bit fixed width VST_ENTRY strings.
1052     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1053     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1054     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1055     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1056     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1057     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1058                                    Abbv) != VST_ENTRY_7_ABBREV)
1059       assert(0 && "Unexpected abbrev ordering!");
1060   }
1061   { // 6-bit char6 VST_ENTRY strings.
1062     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1063     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1064     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1065     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1066     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1067     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1068                                    Abbv) != VST_ENTRY_6_ABBREV)
1069       assert(0 && "Unexpected abbrev ordering!");
1070   }
1071   { // 6-bit char6 VST_BBENTRY strings.
1072     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1073     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1074     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1075     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1076     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1077     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1078                                    Abbv) != VST_BBENTRY_6_ABBREV)
1079       assert(0 && "Unexpected abbrev ordering!");
1080   }
1081
1082
1083
1084   { // SETTYPE abbrev for CONSTANTS_BLOCK.
1085     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1086     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1087     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1088                               Log2_32_Ceil(VE.getTypes().size()+1)));
1089     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1090                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
1091       assert(0 && "Unexpected abbrev ordering!");
1092   }
1093
1094   { // INTEGER abbrev for CONSTANTS_BLOCK.
1095     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1096     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1097     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1098     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1099                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
1100       assert(0 && "Unexpected abbrev ordering!");
1101   }
1102
1103   { // CE_CAST abbrev for CONSTANTS_BLOCK.
1104     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1105     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1106     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1107     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1108                               Log2_32_Ceil(VE.getTypes().size()+1)));
1109     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1110
1111     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1112                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
1113       assert(0 && "Unexpected abbrev ordering!");
1114   }
1115   { // NULL abbrev for CONSTANTS_BLOCK.
1116     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1117     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1118     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1119                                    Abbv) != CONSTANTS_NULL_Abbrev)
1120       assert(0 && "Unexpected abbrev ordering!");
1121   }
1122
1123   // FIXME: This should only use space for first class types!
1124
1125   { // INST_LOAD abbrev for FUNCTION_BLOCK.
1126     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1127     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1128     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1129     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1130     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1131     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1132                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
1133       assert(0 && "Unexpected abbrev ordering!");
1134   }
1135   { // INST_BINOP abbrev for FUNCTION_BLOCK.
1136     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1137     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1138     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1139     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1140     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1141     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1142                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
1143       assert(0 && "Unexpected abbrev ordering!");
1144   }
1145   { // INST_CAST abbrev for FUNCTION_BLOCK.
1146     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1147     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1148     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1149     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1150                               Log2_32_Ceil(VE.getTypes().size()+1)));
1151     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1152     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1153                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
1154       assert(0 && "Unexpected abbrev ordering!");
1155   }
1156
1157   { // INST_RET abbrev for FUNCTION_BLOCK.
1158     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1159     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1160     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1161                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1162       assert(0 && "Unexpected abbrev ordering!");
1163   }
1164   { // INST_RET abbrev for FUNCTION_BLOCK.
1165     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1166     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1167     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1168     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1169                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1170       assert(0 && "Unexpected abbrev ordering!");
1171   }
1172   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1173     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1174     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1175     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1176                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1177       assert(0 && "Unexpected abbrev ordering!");
1178   }
1179
1180   Stream.ExitBlock();
1181 }
1182
1183
1184 /// WriteModule - Emit the specified module to the bitstream.
1185 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1186   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1187
1188   // Emit the version number if it is non-zero.
1189   if (CurVersion) {
1190     SmallVector<unsigned, 1> Vals;
1191     Vals.push_back(CurVersion);
1192     Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1193   }
1194
1195   // Analyze the module, enumerating globals, functions, etc.
1196   ValueEnumerator VE(M);
1197
1198   // Emit blockinfo, which defines the standard abbreviations etc.
1199   WriteBlockInfo(VE, Stream);
1200
1201   // Emit information about parameter attributes.
1202   WriteParamAttrTable(VE, Stream);
1203
1204   // Emit information describing all of the types in the module.
1205   WriteTypeTable(VE, Stream);
1206
1207   // Emit top-level description of module, including target triple, inline asm,
1208   // descriptors for global variables, and function prototype info.
1209   WriteModuleInfo(M, VE, Stream);
1210
1211   // Emit constants.
1212   WriteModuleConstants(VE, Stream);
1213
1214   // If we have any aggregate values in the value table, purge them - these can
1215   // only be used to initialize global variables.  Doing so makes the value
1216   // namespace smaller for code in functions.
1217   int NumNonAggregates = VE.PurgeAggregateValues();
1218   if (NumNonAggregates != -1) {
1219     SmallVector<unsigned, 1> Vals;
1220     Vals.push_back(NumNonAggregates);
1221     Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
1222   }
1223
1224   // Emit function bodies.
1225   for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1226     if (!I->isDeclaration())
1227       WriteFunction(*I, VE, Stream);
1228
1229   // Emit the type symbol table information.
1230   WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1231
1232   // Emit names for globals/functions etc.
1233   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1234
1235   Stream.ExitBlock();
1236 }
1237
1238
1239 /// WriteBitcodeToFile - Write the specified module to the specified output
1240 /// stream.
1241 void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
1242   std::vector<unsigned char> Buffer;
1243   BitstreamWriter Stream(Buffer);
1244
1245   Buffer.reserve(256*1024);
1246
1247   // Emit the file header.
1248   Stream.Emit((unsigned)'B', 8);
1249   Stream.Emit((unsigned)'C', 8);
1250   Stream.Emit(0x0, 4);
1251   Stream.Emit(0xC, 4);
1252   Stream.Emit(0xE, 4);
1253   Stream.Emit(0xD, 4);
1254
1255   // Emit the module.
1256   WriteModule(M, Stream);
1257
1258   // Write the generated bitstream to "Out".
1259   Out.write((char*)&Buffer.front(), Buffer.size());
1260
1261   // Make sure it hits disk now.
1262   Out.flush();
1263 }