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::ExtractValue: {
 614         Code = bitc::CST_CODE_CE_EXTRACTVAL;
 615         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 616         Record.push_back(VE.getValueID(C->getOperand(0)));
 617         const SmallVector<unsigned, 4> &Indices = CE->getIndices();
 618         for (unsigned i = 0, e = Indices.size(); i != e; ++i)
 619           Record.push_back(Indices[i]);
 620         break;
 621       }
 622       case Instruction::InsertValue: {
 623         Code = bitc::CST_CODE_CE_INSERTVAL;
 624         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 625         Record.push_back(VE.getValueID(C->getOperand(0)));
 626         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
 627         Record.push_back(VE.getValueID(C->getOperand(1)));
 628         const SmallVector<unsigned, 4> &Indices = CE->getIndices();
 629         for (unsigned i = 0, e = Indices.size(); i != e; ++i)
 630           Record.push_back(Indices[i]);
 631         break;
 632       }
 633       case Instruction::Select:
 634         Code = bitc::CST_CODE_CE_SELECT;
 635         Record.push_back(VE.getValueID(C->getOperand(0)));
 636         Record.push_back(VE.getValueID(C->getOperand(1)));
 637         Record.push_back(VE.getValueID(C->getOperand(2)));
 638         break;
 639       case Instruction::ExtractElement:
 640         Code = bitc::CST_CODE_CE_EXTRACTELT;
 641         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 642         Record.push_back(VE.getValueID(C->getOperand(0)));
 643         Record.push_back(VE.getValueID(C->getOperand(1)));
 644         break;
 645       case Instruction::InsertElement:
 646         Code = bitc::CST_CODE_CE_INSERTELT;
 647         Record.push_back(VE.getValueID(C->getOperand(0)));
 648         Record.push_back(VE.getValueID(C->getOperand(1)));
 649         Record.push_back(VE.getValueID(C->getOperand(2)));
 650         break;
 651       case Instruction::ShuffleVector:
 652         Code = bitc::CST_CODE_CE_SHUFFLEVEC;
 653         Record.push_back(VE.getValueID(C->getOperand(0)));
 654         Record.push_back(VE.getValueID(C->getOperand(1)));
 655         Record.push_back(VE.getValueID(C->getOperand(2)));
 656         break;
 657       case Instruction::ICmp:
 658       case Instruction::FCmp:
 659       case Instruction::VICmp:
 660       case Instruction::VFCmp:
 661         Code = bitc::CST_CODE_CE_CMP;
 662         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 663         Record.push_back(VE.getValueID(C->getOperand(0)));
 664         Record.push_back(VE.getValueID(C->getOperand(1)));
 665         Record.push_back(CE->getPredicate());
 666         break;
 667       }
 668     } else {
 669       assert(0 && "Unknown constant!");
 670     }
 671     Stream.EmitRecord(Code, Record, AbbrevToUse);
 672     Record.clear();
 673   }
 674
 675   Stream.ExitBlock();
 676 }
 677
 678 static void WriteModuleConstants(const ValueEnumerator &VE,
 679                                  BitstreamWriter &Stream) {
 680   const ValueEnumerator::ValueList &Vals = VE.getValues();
 681
 682   // Find the first constant to emit, which is the first non-globalvalue value.
 683   // We know globalvalues have been emitted by WriteModuleInfo.
 684   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 685     if (!isa<GlobalValue>(Vals[i].first)) {
 686       WriteConstants(i, Vals.size(), VE, Stream, true);
 687       return;
 688     }
 689   }
 690 }
 691
 692 /// PushValueAndType - The file has to encode both the value and type id for
 693 /// many values, because we need to know what type to create for forward
 694 /// references.  However, most operands are not forward references, so this type
 695 /// field is not needed.
 696 ///
 697 /// This function adds V's value ID to Vals.  If the value ID is higher than the
 698 /// instruction ID, then it is a forward reference, and it also includes the
 699 /// type ID.
 700 static bool PushValueAndType(Value *V, unsigned InstID,
 701                              SmallVector<unsigned, 64> &Vals,
 702                              ValueEnumerator &VE) {
 703   unsigned ValID = VE.getValueID(V);
 704   Vals.push_back(ValID);
 705   if (ValID >= InstID) {
 706     Vals.push_back(VE.getTypeID(V->getType()));
 707     return true;
 708   }
 709   return false;
 710 }
 711
 712 /// WriteInstruction - Emit an instruction to the specified stream.
 713 static void WriteInstruction(const Instruction &I, unsigned InstID,
 714                              ValueEnumerator &VE, BitstreamWriter &Stream,
 715                              SmallVector<unsigned, 64> &Vals) {
 716   unsigned Code = 0;
 717   unsigned AbbrevToUse = 0;
 718   switch (I.getOpcode()) {
 719   default:
 720     if (Instruction::isCast(I.getOpcode())) {
 721       Code = bitc::FUNC_CODE_INST_CAST;
 722       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 723         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
 724       Vals.push_back(VE.getTypeID(I.getType()));
 725       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
 726     } else {
 727       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
 728       Code = bitc::FUNC_CODE_INST_BINOP;
 729       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 730         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
 731       Vals.push_back(VE.getValueID(I.getOperand(1)));
 732       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
 733     }
 734     break;
 735
 736   case Instruction::GetElementPtr:
 737     Code = bitc::FUNC_CODE_INST_GEP;
 738     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 739       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
 740     break;
 741   case Instruction::ExtractValue:
 742     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
 743     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 744       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
 745     break;
 746   case Instruction::InsertValue:
 747     Code = bitc::FUNC_CODE_INST_INSERTVAL;
 748     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 749       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
 750     break;
 751   case Instruction::Select:
 752     Code = bitc::FUNC_CODE_INST_SELECT;
 753     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
 754     Vals.push_back(VE.getValueID(I.getOperand(2)));
 755     Vals.push_back(VE.getValueID(I.getOperand(0)));
 756     break;
 757   case Instruction::ExtractElement:
 758     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
 759     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 760     Vals.push_back(VE.getValueID(I.getOperand(1)));
 761     break;
 762   case Instruction::InsertElement:
 763     Code = bitc::FUNC_CODE_INST_INSERTELT;
 764     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 765     Vals.push_back(VE.getValueID(I.getOperand(1)));
 766     Vals.push_back(VE.getValueID(I.getOperand(2)));
 767     break;
 768   case Instruction::ShuffleVector:
 769     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
 770     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 771     Vals.push_back(VE.getValueID(I.getOperand(1)));
 772     Vals.push_back(VE.getValueID(I.getOperand(2)));
 773     break;
 774   case Instruction::ICmp:
 775   case Instruction::FCmp:
 776   case Instruction::VICmp:
 777   case Instruction::VFCmp:
 778     Code = bitc::FUNC_CODE_INST_CMP;
 779     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 780     Vals.push_back(VE.getValueID(I.getOperand(1)));
 781     Vals.push_back(cast<CmpInst>(I).getPredicate());
 782     break;
 783   case Instruction::GetResult:
 784     Code = bitc::FUNC_CODE_INST_GETRESULT;
 785     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 786     Vals.push_back(cast<GetResultInst>(I).getIndex());
 787     break;
 788
 789   case Instruction::Ret:
 790     {
 791       Code = bitc::FUNC_CODE_INST_RET;
 792       unsigned NumOperands = I.getNumOperands();
 793       if (NumOperands == 0)
 794         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
 795       else if (NumOperands == 1) {
 796         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 797           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
 798       } else {
 799         for (unsigned i = 0, e = NumOperands; i != e; ++i)
 800           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
 801       }
 802     }
 803     break;
 804   case Instruction::Br:
 805     Code = bitc::FUNC_CODE_INST_BR;
 806     Vals.push_back(VE.getValueID(I.getOperand(0)));
 807     if (cast<BranchInst>(I).isConditional()) {
 808       Vals.push_back(VE.getValueID(I.getOperand(1)));
 809       Vals.push_back(VE.getValueID(I.getOperand(2)));
 810     }
 811     break;
 812   case Instruction::Switch:
 813     Code = bitc::FUNC_CODE_INST_SWITCH;
 814     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 815     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 816       Vals.push_back(VE.getValueID(I.getOperand(i)));
 817     break;
 818   case Instruction::Invoke: {
 819     const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
 820     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
 821     Code = bitc::FUNC_CODE_INST_INVOKE;
 822
 823     const InvokeInst *II = cast<InvokeInst>(&I);
 824     Vals.push_back(VE.getParamAttrID(II->getParamAttrs()));
 825     Vals.push_back(II->getCallingConv());
 826     Vals.push_back(VE.getValueID(I.getOperand(1)));      // normal dest
 827     Vals.push_back(VE.getValueID(I.getOperand(2)));      // unwind dest
 828     PushValueAndType(I.getOperand(0), InstID, Vals, VE); // callee
 829
 830     // Emit value #'s for the fixed parameters.
 831     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
 832       Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
 833
 834     // Emit type/value pairs for varargs params.
 835     if (FTy->isVarArg()) {
 836       for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
 837            i != e; ++i)
 838         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
 839     }
 840     break;
 841   }
 842   case Instruction::Unwind:
 843     Code = bitc::FUNC_CODE_INST_UNWIND;
 844     break;
 845   case Instruction::Unreachable:
 846     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
 847     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
 848     break;
 849
 850   case Instruction::PHI:
 851     Code = bitc::FUNC_CODE_INST_PHI;
 852     Vals.push_back(VE.getTypeID(I.getType()));
 853     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 854       Vals.push_back(VE.getValueID(I.getOperand(i)));
 855     break;
 856
 857   case Instruction::Malloc:
 858     Code = bitc::FUNC_CODE_INST_MALLOC;
 859     Vals.push_back(VE.getTypeID(I.getType()));
 860     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
 861     Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
 862     break;
 863
 864   case Instruction::Free:
 865     Code = bitc::FUNC_CODE_INST_FREE;
 866     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 867     break;
 868
 869   case Instruction::Alloca:
 870     Code = bitc::FUNC_CODE_INST_ALLOCA;
 871     Vals.push_back(VE.getTypeID(I.getType()));
 872     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
 873     Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
 874     break;
 875
 876   case Instruction::Load:
 877     Code = bitc::FUNC_CODE_INST_LOAD;
 878     if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
 879       AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
 880
 881     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
 882     Vals.push_back(cast<LoadInst>(I).isVolatile());
 883     break;
 884   case Instruction::Store:
 885     Code = bitc::FUNC_CODE_INST_STORE2;
 886     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
 887     Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
 888     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
 889     Vals.push_back(cast<StoreInst>(I).isVolatile());
 890     break;
 891   case Instruction::Call: {
 892     const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
 893     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
 894
 895     Code = bitc::FUNC_CODE_INST_CALL;
 896
 897     const CallInst *CI = cast<CallInst>(&I);
 898     Vals.push_back(VE.getParamAttrID(CI->getParamAttrs()));
 899     Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
 900     PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
 901
 902     // Emit value #'s for the fixed parameters.
 903     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
 904       Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
 905
 906     // Emit type/value pairs for varargs params.
 907     if (FTy->isVarArg()) {
 908       unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
 909       for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
 910            i != e; ++i)
 911         PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
 912     }
 913     break;
 914   }
 915   case Instruction::VAArg:
 916     Code = bitc::FUNC_CODE_INST_VAARG;
 917     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
 918     Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
 919     Vals.push_back(VE.getTypeID(I.getType())); // restype.
 920     break;
 921   }
 922
 923   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 924   Vals.clear();
 925 }
 926
 927 // Emit names for globals/functions etc.
 928 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
 929                                   const ValueEnumerator &VE,
 930                                   BitstreamWriter &Stream) {
 931   if (VST.empty()) return;
 932   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
 933
 934   // FIXME: Set up the abbrev, we know how many values there are!
 935   // FIXME: We know if the type names can use 7-bit ascii.
 936   SmallVector<unsigned, 64> NameVals;
 937
 938   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
 939        SI != SE; ++SI) {
 940
 941     const ValueName &Name = *SI;
 942
 943     // Figure out the encoding to use for the name.
 944     bool is7Bit = true;
 945     bool isChar6 = true;
 946     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
 947          C != E; ++C) {
 948       if (isChar6)
 949         isChar6 = BitCodeAbbrevOp::isChar6(*C);
 950       if ((unsigned char)*C & 128) {
 951         is7Bit = false;
 952         break;  // don't bother scanning the rest.
 953       }
 954     }
 955
 956     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
 957
 958     // VST_ENTRY:   [valueid, namechar x N]
 959     // VST_BBENTRY: [bbid, namechar x N]
 960     unsigned Code;
 961     if (isa<BasicBlock>(SI->getValue())) {
 962       Code = bitc::VST_CODE_BBENTRY;
 963       if (isChar6)
 964         AbbrevToUse = VST_BBENTRY_6_ABBREV;
 965     } else {
 966       Code = bitc::VST_CODE_ENTRY;
 967       if (isChar6)
 968         AbbrevToUse = VST_ENTRY_6_ABBREV;
 969       else if (is7Bit)
 970         AbbrevToUse = VST_ENTRY_7_ABBREV;
 971     }
 972
 973     NameVals.push_back(VE.getValueID(SI->getValue()));
 974     for (const char *P = Name.getKeyData(),
 975          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
 976       NameVals.push_back((unsigned char)*P);
 977
 978     // Emit the finished record.
 979     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
 980     NameVals.clear();
 981   }
 982   Stream.ExitBlock();
 983 }
 984
 985 /// WriteFunction - Emit a function body to the module stream.
 986 static void WriteFunction(const Function &F, ValueEnumerator &VE,
 987                           BitstreamWriter &Stream) {
 988   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
 989   VE.incorporateFunction(F);
 990
 991   SmallVector<unsigned, 64> Vals;
 992
 993   // Emit the number of basic blocks, so the reader can create them ahead of
 994   // time.
 995   Vals.push_back(VE.getBasicBlocks().size());
 996   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
 997   Vals.clear();
 998
 999   // If there are function-local constants, emit them now.
1000   unsigned CstStart, CstEnd;
1001   VE.getFunctionConstantRange(CstStart, CstEnd);
1002   WriteConstants(CstStart, CstEnd, VE, Stream, false);
1003
1004   // Keep a running idea of what the instruction ID is.
1005   unsigned InstID = CstEnd;
1006
1007   // Finally, emit all the instructions, in order.
1008   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1009     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1010          I != E; ++I) {
1011       WriteInstruction(*I, InstID, VE, Stream, Vals);
1012       if (I->getType() != Type::VoidTy)
1013         ++InstID;
1014     }
1015
1016   // Emit names for all the instructions etc.
1017   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1018
1019   VE.purgeFunction();
1020   Stream.ExitBlock();
1021 }
1022
1023 /// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1024 static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1025                                  const ValueEnumerator &VE,
1026                                  BitstreamWriter &Stream) {
1027   if (TST.empty()) return;
1028
1029   Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1030
1031   // 7-bit fixed width VST_CODE_ENTRY strings.
1032   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1033   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1034   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1035                             Log2_32_Ceil(VE.getTypes().size()+1)));
1036   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1037   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1038   unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1039
1040   SmallVector<unsigned, 64> NameVals;
1041
1042   for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1043        TI != TE; ++TI) {
1044     // TST_ENTRY: [typeid, namechar x N]
1045     NameVals.push_back(VE.getTypeID(TI->second));
1046
1047     const std::string &Str = TI->first;
1048     bool is7Bit = true;
1049     for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1050       NameVals.push_back((unsigned char)Str[i]);
1051       if (Str[i] & 128)
1052         is7Bit = false;
1053     }
1054
1055     // Emit the finished record.
1056     Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1057     NameVals.clear();
1058   }
1059
1060   Stream.ExitBlock();
1061 }
1062
1063 // Emit blockinfo, which defines the standard abbreviations etc.
1064 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1065   // We only want to emit block info records for blocks that have multiple
1066   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1067   // blocks can defined their abbrevs inline.
1068   Stream.EnterBlockInfoBlock(2);
1069
1070   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1071     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1072     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1073     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1074     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1075     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1076     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1077                                    Abbv) != VST_ENTRY_8_ABBREV)
1078       assert(0 && "Unexpected abbrev ordering!");
1079   }
1080
1081   { // 7-bit fixed width VST_ENTRY strings.
1082     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1083     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1084     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1085     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1086     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1087     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1088                                    Abbv) != VST_ENTRY_7_ABBREV)
1089       assert(0 && "Unexpected abbrev ordering!");
1090   }
1091   { // 6-bit char6 VST_ENTRY strings.
1092     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1093     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1094     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1095     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1096     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1097     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1098                                    Abbv) != VST_ENTRY_6_ABBREV)
1099       assert(0 && "Unexpected abbrev ordering!");
1100   }
1101   { // 6-bit char6 VST_BBENTRY strings.
1102     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1103     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1104     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1105     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1106     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1107     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1108                                    Abbv) != VST_BBENTRY_6_ABBREV)
1109       assert(0 && "Unexpected abbrev ordering!");
1110   }
1111
1112
1113
1114   { // SETTYPE abbrev for CONSTANTS_BLOCK.
1115     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1116     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1117     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1118                               Log2_32_Ceil(VE.getTypes().size()+1)));
1119     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1120                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
1121       assert(0 && "Unexpected abbrev ordering!");
1122   }
1123
1124   { // INTEGER abbrev for CONSTANTS_BLOCK.
1125     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1126     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1127     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1128     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1129                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
1130       assert(0 && "Unexpected abbrev ordering!");
1131   }
1132
1133   { // CE_CAST abbrev for CONSTANTS_BLOCK.
1134     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1135     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1136     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1137     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1138                               Log2_32_Ceil(VE.getTypes().size()+1)));
1139     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1140
1141     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1142                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
1143       assert(0 && "Unexpected abbrev ordering!");
1144   }
1145   { // NULL abbrev for CONSTANTS_BLOCK.
1146     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1147     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1148     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1149                                    Abbv) != CONSTANTS_NULL_Abbrev)
1150       assert(0 && "Unexpected abbrev ordering!");
1151   }
1152
1153   // FIXME: This should only use space for first class types!
1154
1155   { // INST_LOAD abbrev for FUNCTION_BLOCK.
1156     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1157     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1158     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1159     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1160     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1161     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1162                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
1163       assert(0 && "Unexpected abbrev ordering!");
1164   }
1165   { // INST_BINOP abbrev for FUNCTION_BLOCK.
1166     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1167     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1168     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1169     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1170     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1171     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1172                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
1173       assert(0 && "Unexpected abbrev ordering!");
1174   }
1175   { // INST_CAST abbrev for FUNCTION_BLOCK.
1176     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1177     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1178     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1179     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1180                               Log2_32_Ceil(VE.getTypes().size()+1)));
1181     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1182     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1183                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
1184       assert(0 && "Unexpected abbrev ordering!");
1185   }
1186
1187   { // INST_RET abbrev for FUNCTION_BLOCK.
1188     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1189     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1190     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1191                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1192       assert(0 && "Unexpected abbrev ordering!");
1193   }
1194   { // INST_RET abbrev for FUNCTION_BLOCK.
1195     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1196     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1197     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1198     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1199                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1200       assert(0 && "Unexpected abbrev ordering!");
1201   }
1202   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1203     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1204     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1205     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1206                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1207       assert(0 && "Unexpected abbrev ordering!");
1208   }
1209
1210   Stream.ExitBlock();
1211 }
1212
1213
1214 /// WriteModule - Emit the specified module to the bitstream.
1215 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1216   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1217
1218   // Emit the version number if it is non-zero.
1219   if (CurVersion) {
1220     SmallVector<unsigned, 1> Vals;
1221     Vals.push_back(CurVersion);
1222     Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1223   }
1224
1225   // Analyze the module, enumerating globals, functions, etc.
1226   ValueEnumerator VE(M);
1227
1228   // Emit blockinfo, which defines the standard abbreviations etc.
1229   WriteBlockInfo(VE, Stream);
1230
1231   // Emit information about parameter attributes.
1232   WriteParamAttrTable(VE, Stream);
1233
1234   // Emit information describing all of the types in the module.
1235   WriteTypeTable(VE, Stream);
1236
1237   // Emit top-level description of module, including target triple, inline asm,
1238   // descriptors for global variables, and function prototype info.
1239   WriteModuleInfo(M, VE, Stream);
1240
1241   // Emit constants.
1242   WriteModuleConstants(VE, Stream);
1243
1244   // If we have any aggregate values in the value table, purge them - these can
1245   // only be used to initialize global variables.  Doing so makes the value
1246   // namespace smaller for code in functions.
1247   int NumNonAggregates = VE.PurgeAggregateValues();
1248   if (NumNonAggregates != -1) {
1249     SmallVector<unsigned, 1> Vals;
1250     Vals.push_back(NumNonAggregates);
1251     Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
1252   }
1253
1254   // Emit function bodies.
1255   for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1256     if (!I->isDeclaration())
1257       WriteFunction(*I, VE, Stream);
1258
1259   // Emit the type symbol table information.
1260   WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1261
1262   // Emit names for globals/functions etc.
1263   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1264
1265   Stream.ExitBlock();
1266 }
1267
1268
1269 /// WriteBitcodeToFile - Write the specified module to the specified output
1270 /// stream.
1271 void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
1272   std::vector<unsigned char> Buffer;
1273   BitstreamWriter Stream(Buffer);
1274
1275   Buffer.reserve(256*1024);
1276
1277   // Emit the file header.
1278   Stream.Emit((unsigned)'B', 8);
1279   Stream.Emit((unsigned)'C', 8);
1280   Stream.Emit(0x0, 4);
1281   Stream.Emit(0xC, 4);
1282   Stream.Emit(0xE, 4);
1283   Stream.Emit(0xD, 4);
1284
1285   // Emit the module.
1286   WriteModule(M, Stream);
1287
1288   // Write the generated bitstream to "Out".
1289   Out.write((char*)&Buffer.front(), Buffer.size());
1290
1291   // Make sure it hits disk now.
1292   Out.flush();
1293 }