lib/Bitcode/Writer/BitcodeWriter.cpp

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