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