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   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
 145
 146   // Abbrev for TYPE_CODE_FUNCTION.
 147   Abbv = new BitCodeAbbrev();
 148   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
 149   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
 150   Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
 151   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 152   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 153                             Log2_32_Ceil(VE.getTypes().size()+1)));
 154   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 155
 156   // Abbrev for TYPE_CODE_STRUCT.
 157   Abbv = new BitCodeAbbrev();
 158   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
 159   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 160   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 161   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 162                             Log2_32_Ceil(VE.getTypes().size()+1)));
 163   unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
 164
 165   // Abbrev for TYPE_CODE_ARRAY.
 166   Abbv = new BitCodeAbbrev();
 167   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 168   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 169   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 170                             Log2_32_Ceil(VE.getTypes().size()+1)));
 171   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 172
 173   // Emit an entry count so the reader can reserve space.
 174   TypeVals.push_back(TypeList.size());
 175   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 176   TypeVals.clear();
 177
 178   // Loop over all of the types, emitting each in turn.
 179   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 180     const Type *T = TypeList[i].first;
 181     int AbbrevToUse = 0;
 182     unsigned Code = 0;
 183
 184     switch (T->getTypeID()) {
 185     default: assert(0 && "Unknown type!");
 186     case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
 187     case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
 188     case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
 189     case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
 190     case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
 191     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 192     case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
 193     case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
 194     case Type::IntegerTyID:
 195       // INTEGER: [width]
 196       Code = bitc::TYPE_CODE_INTEGER;
 197       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 198       break;
 199     case Type::PointerTyID: {
 200       const PointerType *PTy = cast<PointerType>(T);
 201       // POINTER: [pointee type] or [pointee type, address space]
 202       Code = bitc::TYPE_CODE_POINTER;
 203       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
 204       if (unsigned AddressSpace = PTy->getAddressSpace())
 205         TypeVals.push_back(AddressSpace);
 206       else
 207         AbbrevToUse = PtrAbbrev;
 208       break;
 209     }
 210
 211     case Type::FunctionTyID: {
 212       const FunctionType *FT = cast<FunctionType>(T);
 213       // FUNCTION: [isvararg, attrid, retty, paramty x N]
 214       Code = bitc::TYPE_CODE_FUNCTION;
 215       TypeVals.push_back(FT->isVarArg());
 216       TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
 217       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 218       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 219         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 220       AbbrevToUse = FunctionAbbrev;
 221       break;
 222     }
 223     case Type::StructTyID: {
 224       const StructType *ST = cast<StructType>(T);
 225       // STRUCT: [ispacked, eltty x N]
 226       Code = bitc::TYPE_CODE_STRUCT;
 227       TypeVals.push_back(ST->isPacked());
 228       // Output all of the element types.
 229       for (StructType::element_iterator I = ST->element_begin(),
 230            E = ST->element_end(); I != E; ++I)
 231         TypeVals.push_back(VE.getTypeID(*I));
 232       AbbrevToUse = StructAbbrev;
 233       break;
 234     }
 235     case Type::ArrayTyID: {
 236       const ArrayType *AT = cast<ArrayType>(T);
 237       // ARRAY: [numelts, eltty]
 238       Code = bitc::TYPE_CODE_ARRAY;
 239       TypeVals.push_back(AT->getNumElements());
 240       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 241       AbbrevToUse = ArrayAbbrev;
 242       break;
 243     }
 244     case Type::VectorTyID: {
 245       const VectorType *VT = cast<VectorType>(T);
 246       // VECTOR [numelts, eltty]
 247       Code = bitc::TYPE_CODE_VECTOR;
 248       TypeVals.push_back(VT->getNumElements());
 249       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 250       break;
 251     }
 252     }
 253
 254     // Emit the finished record.
 255     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 256     TypeVals.clear();
 257   }
 258
 259   Stream.ExitBlock();
 260 }
 261
 262 static unsigned getEncodedLinkage(const GlobalValue *GV) {
 263   switch (GV->getLinkage()) {
 264   default: assert(0 && "Invalid linkage!");
 265   case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
 266   case GlobalValue::ExternalLinkage:     return 0;
 267   case GlobalValue::WeakLinkage:         return 1;
 268   case GlobalValue::AppendingLinkage:    return 2;
 269   case GlobalValue::InternalLinkage:     return 3;
 270   case GlobalValue::LinkOnceLinkage:     return 4;
 271   case GlobalValue::DLLImportLinkage:    return 5;
 272   case GlobalValue::DLLExportLinkage:    return 6;
 273   case GlobalValue::ExternalWeakLinkage: return 7;
 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, 3));      // 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     unsigned AbbrevToUse = 0;
 427     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 428     Vals.clear();
 429   }
 430 }
 431
 432
 433 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
 434                            const ValueEnumerator &VE,
 435                            BitstreamWriter &Stream, bool isGlobal) {
 436   if (FirstVal == LastVal) return;
 437
 438   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
 439
 440   unsigned AggregateAbbrev = 0;
 441   unsigned String8Abbrev = 0;
 442   unsigned CString7Abbrev = 0;
 443   unsigned CString6Abbrev = 0;
 444   // If this is a constant pool for the module, emit module-specific abbrevs.
 445   if (isGlobal) {
 446     // Abbrev for CST_CODE_AGGREGATE.
 447     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 448     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
 449     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 450     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
 451     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
 452
 453     // Abbrev for CST_CODE_STRING.
 454     Abbv = new BitCodeAbbrev();
 455     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
 456     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 457     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 458     String8Abbrev = Stream.EmitAbbrev(Abbv);
 459     // Abbrev for CST_CODE_CSTRING.
 460     Abbv = new BitCodeAbbrev();
 461     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 462     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 463     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 464     CString7Abbrev = Stream.EmitAbbrev(Abbv);
 465     // Abbrev for CST_CODE_CSTRING.
 466     Abbv = new BitCodeAbbrev();
 467     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 468     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 469     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 470     CString6Abbrev = Stream.EmitAbbrev(Abbv);
 471   }
 472
 473   SmallVector<uint64_t, 64> Record;
 474
 475   const ValueEnumerator::ValueList &Vals = VE.getValues();
 476   const Type *LastTy = 0;
 477   for (unsigned i = FirstVal; i != LastVal; ++i) {
 478     const Value *V = Vals[i].first;
 479     // If we need to switch types, do so now.
 480     if (V->getType() != LastTy) {
 481       LastTy = V->getType();
 482       Record.push_back(VE.getTypeID(LastTy));
 483       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
 484                         CONSTANTS_SETTYPE_ABBREV);
 485       Record.clear();
 486     }
 487
 488     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
 489       Record.push_back(unsigned(IA->hasSideEffects()));
 490
 491       // Add the asm string.
 492       const std::string &AsmStr = IA->getAsmString();
 493       Record.push_back(AsmStr.size());
 494       for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
 495         Record.push_back(AsmStr[i]);
 496
 497       // Add the constraint string.
 498       const std::string &ConstraintStr = IA->getConstraintString();
 499       Record.push_back(ConstraintStr.size());
 500       for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
 501         Record.push_back(ConstraintStr[i]);
 502       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
 503       Record.clear();
 504       continue;
 505     }
 506     const Constant *C = cast<Constant>(V);
 507     unsigned Code = -1U;
 508     unsigned AbbrevToUse = 0;
 509     if (C->isNullValue()) {
 510       Code = bitc::CST_CODE_NULL;
 511     } else if (isa<UndefValue>(C)) {
 512       Code = bitc::CST_CODE_UNDEF;
 513     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
 514       if (IV->getBitWidth() <= 64) {
 515         int64_t V = IV->getSExtValue();
 516         if (V >= 0)
 517           Record.push_back(V << 1);
 518         else
 519           Record.push_back((-V << 1) | 1);
 520         Code = bitc::CST_CODE_INTEGER;
 521         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
 522       } else {                             // Wide integers, > 64 bits in size.
 523         // We have an arbitrary precision integer value to write whose
 524         // bit width is > 64. However, in canonical unsigned integer
 525         // format it is likely that the high bits are going to be zero.
 526         // So, we only write the number of active words.
 527         unsigned NWords = IV->getValue().getActiveWords();
 528         const uint64_t *RawWords = IV->getValue().getRawData();
 529         for (unsigned i = 0; i != NWords; ++i) {
 530           int64_t V = RawWords[i];
 531           if (V >= 0)
 532             Record.push_back(V << 1);
 533           else
 534             Record.push_back((-V << 1) | 1);
 535         }
 536         Code = bitc::CST_CODE_WIDE_INTEGER;
 537       }
 538     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
 539       Code = bitc::CST_CODE_FLOAT;
 540       const Type *Ty = CFP->getType();
 541       if (Ty == Type::FloatTy || Ty == Type::DoubleTy) {
 542         Record.push_back(CFP->getValueAPF().convertToAPInt().getZExtValue());
 543       } else if (Ty == Type::X86_FP80Ty) {
 544         // api needed to prevent premature destruction
 545         APInt api = CFP->getValueAPF().convertToAPInt();
 546         const uint64_t *p = api.getRawData();
 547         Record.push_back(p[0]);
 548         Record.push_back((uint16_t)p[1]);
 549       } else if (Ty == Type::FP128Ty || Ty == Type::PPC_FP128Ty) {
 550         APInt api = CFP->getValueAPF().convertToAPInt();
 551         const uint64_t *p = api.getRawData();
 552         Record.push_back(p[0]);
 553         Record.push_back(p[1]);
 554       } else {
 555         assert (0 && "Unknown FP type!");
 556       }
 557     } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
 558       // Emit constant strings specially.
 559       unsigned NumOps = C->getNumOperands();
 560       // If this is a null-terminated string, use the denser CSTRING encoding.
 561       if (C->getOperand(NumOps-1)->isNullValue()) {
 562         Code = bitc::CST_CODE_CSTRING;
 563         --NumOps;  // Don't encode the null, which isn't allowed by char6.
 564       } else {
 565         Code = bitc::CST_CODE_STRING;
 566         AbbrevToUse = String8Abbrev;
 567       }
 568       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
 569       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
 570       for (unsigned i = 0; i != NumOps; ++i) {
 571         unsigned char V = cast<ConstantInt>(C->getOperand(i))->getZExtValue();
 572         Record.push_back(V);
 573         isCStr7 &= (V & 128) == 0;
 574         if (isCStrChar6)
 575           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
 576       }
 577
 578       if (isCStrChar6)
 579         AbbrevToUse = CString6Abbrev;
 580       else if (isCStr7)
 581         AbbrevToUse = CString7Abbrev;
 582     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
 583                isa<ConstantVector>(V)) {
 584       Code = bitc::CST_CODE_AGGREGATE;
 585       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
 586         Record.push_back(VE.getValueID(C->getOperand(i)));
 587       AbbrevToUse = AggregateAbbrev;
 588     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
 589       switch (CE->getOpcode()) {
 590       default:
 591         if (Instruction::isCast(CE->getOpcode())) {
 592           Code = bitc::CST_CODE_CE_CAST;
 593           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
 594           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 595           Record.push_back(VE.getValueID(C->getOperand(0)));
 596           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
 597         } else {
 598           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
 599           Code = bitc::CST_CODE_CE_BINOP;
 600           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
 601           Record.push_back(VE.getValueID(C->getOperand(0)));
 602           Record.push_back(VE.getValueID(C->getOperand(1)));
 603         }
 604         break;
 605       case Instruction::GetElementPtr:
 606         Code = bitc::CST_CODE_CE_GEP;
 607         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
 608           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
 609           Record.push_back(VE.getValueID(C->getOperand(i)));
 610         }
 611         break;
 612       case Instruction::Select:
 613         Code = bitc::CST_CODE_CE_SELECT;
 614         Record.push_back(VE.getValueID(C->getOperand(0)));
 615         Record.push_back(VE.getValueID(C->getOperand(1)));
 616         Record.push_back(VE.getValueID(C->getOperand(2)));
 617         break;
 618       case Instruction::ExtractElement:
 619         Code = bitc::CST_CODE_CE_EXTRACTELT;
 620         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 621         Record.push_back(VE.getValueID(C->getOperand(0)));
 622         Record.push_back(VE.getValueID(C->getOperand(1)));
 623         break;
 624       case Instruction::InsertElement:
 625         Code = bitc::CST_CODE_CE_INSERTELT;
 626         Record.push_back(VE.getValueID(C->getOperand(0)));
 627         Record.push_back(VE.getValueID(C->getOperand(1)));
 628         Record.push_back(VE.getValueID(C->getOperand(2)));
 629         break;
 630       case Instruction::ShuffleVector:
 631         Code = bitc::CST_CODE_CE_SHUFFLEVEC;
 632         Record.push_back(VE.getValueID(C->getOperand(0)));
 633         Record.push_back(VE.getValueID(C->getOperand(1)));
 634         Record.push_back(VE.getValueID(C->getOperand(2)));
 635         break;
 636       case Instruction::ICmp:
 637       case Instruction::FCmp:
 638         Code = bitc::CST_CODE_CE_CMP;
 639         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 640         Record.push_back(VE.getValueID(C->getOperand(0)));
 641         Record.push_back(VE.getValueID(C->getOperand(1)));
 642         Record.push_back(CE->getPredicate());
 643         break;
 644       }
 645     } else {
 646       assert(0 && "Unknown constant!");
 647     }
 648     Stream.EmitRecord(Code, Record, AbbrevToUse);
 649     Record.clear();
 650   }
 651
 652   Stream.ExitBlock();
 653 }
 654
 655 static void WriteModuleConstants(const ValueEnumerator &VE,
 656                                  BitstreamWriter &Stream) {
 657   const ValueEnumerator::ValueList &Vals = VE.getValues();
 658
 659   // Find the first constant to emit, which is the first non-globalvalue value.
 660   // We know globalvalues have been emitted by WriteModuleInfo.
 661   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 662     if (!isa<GlobalValue>(Vals[i].first)) {
 663       WriteConstants(i, Vals.size(), VE, Stream, true);
 664       return;
 665     }
 666   }
 667 }
 668
 669 /// PushValueAndType - The file has to encode both the value and type id for
 670 /// many values, because we need to know what type to create for forward
 671 /// references.  However, most operands are not forward references, so this type
 672 /// field is not needed.
 673 ///
 674 /// This function adds V's value ID to Vals.  If the value ID is higher than the
 675 /// instruction ID, then it is a forward reference, and it also includes the
 676 /// type ID.
 677 static bool PushValueAndType(Value *V, unsigned InstID,
 678                              SmallVector<unsigned, 64> &Vals,
 679                              ValueEnumerator &VE) {
 680   unsigned ValID = VE.getValueID(V);
 681   Vals.push_back(ValID);
 682   if (ValID >= InstID) {
 683     Vals.push_back(VE.getTypeID(V->getType()));
 684     return true;
 685   }
 686   return false;
 687 }
 688
 689 /// WriteInstruction - Emit an instruction to the specified stream.
 690 static void WriteInstruction(const Instruction &I, unsigned InstID,
 691                              ValueEnumerator &VE, BitstreamWriter &Stream,
 692                              SmallVector<unsigned, 64> &Vals) {
 693   unsigned Code = 0;
 694   unsigned AbbrevToUse = 0;
 695   switch (I.getOpcode()) {
 696   default:
 697     if (Instruction::isCast(I.getOpcode())) {
 698       Code = bitc::FUNC_CODE_INST_CAST;
 699       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 700         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
 701       Vals.push_back(VE.getTypeID(I.getType()));
 702       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
 703     } else {
 704       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
 705       Code = bitc::FUNC_CODE_INST_BINOP;
 706       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 707         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
 708       Vals.push_back(VE.getValueID(I.getOperand(1)));
 709       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
 710     }
 711     break;
 712
 713   case Instruction::GetElementPtr:
 714     Code = bitc::FUNC_CODE_INST_GEP;
 715     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 716       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
 717     break;
 718   case Instruction::Select:
 719     Code = bitc::FUNC_CODE_INST_SELECT;
 720     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
 721     Vals.push_back(VE.getValueID(I.getOperand(2)));
 722     Vals.push_back(VE.getValueID(I.getOperand(0)));
 723     break;
 724   case Instruction::ExtractElement:
 725     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
 726     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 727     Vals.push_back(VE.getValueID(I.getOperand(1)));
 728     break;
 729   case Instruction::InsertElement:
 730     Code = bitc::FUNC_CODE_INST_INSERTELT;
 731     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 732     Vals.push_back(VE.getValueID(I.getOperand(1)));
 733     Vals.push_back(VE.getValueID(I.getOperand(2)));
 734     break;
 735   case Instruction::ShuffleVector:
 736     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
 737     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 738     Vals.push_back(VE.getValueID(I.getOperand(1)));
 739     Vals.push_back(VE.getValueID(I.getOperand(2)));
 740     break;
 741   case Instruction::ICmp:
 742   case Instruction::FCmp:
 743     Code = bitc::FUNC_CODE_INST_CMP;
 744     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 745     Vals.push_back(VE.getValueID(I.getOperand(1)));
 746     Vals.push_back(cast<CmpInst>(I).getPredicate());
 747     break;
 748
 749   case Instruction::Ret:
 750     Code = bitc::FUNC_CODE_INST_RET;
 751     if (!I.getNumOperands())
 752       AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
 753     else if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 754       AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
 755     break;
 756   case Instruction::Br:
 757     Code = bitc::FUNC_CODE_INST_BR;
 758     Vals.push_back(VE.getValueID(I.getOperand(0)));
 759     if (cast<BranchInst>(I).isConditional()) {
 760       Vals.push_back(VE.getValueID(I.getOperand(1)));
 761       Vals.push_back(VE.getValueID(I.getOperand(2)));
 762     }
 763     break;
 764   case Instruction::Switch:
 765     Code = bitc::FUNC_CODE_INST_SWITCH;
 766     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 767     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 768       Vals.push_back(VE.getValueID(I.getOperand(i)));
 769     break;
 770   case Instruction::Invoke: {
 771     const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
 772     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
 773     Code = bitc::FUNC_CODE_INST_INVOKE;
 774
 775     const InvokeInst *II = cast<InvokeInst>(&I);
 776     Vals.push_back(VE.getParamAttrID(II->getParamAttrs()));
 777     Vals.push_back(II->getCallingConv());
 778     Vals.push_back(VE.getValueID(I.getOperand(1)));      // normal dest
 779     Vals.push_back(VE.getValueID(I.getOperand(2)));      // unwind dest
 780     PushValueAndType(I.getOperand(0), InstID, Vals, VE); // callee
 781
 782     // Emit value #'s for the fixed parameters.
 783     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
 784       Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
 785
 786     // Emit type/value pairs for varargs params.
 787     if (FTy->isVarArg()) {
 788       for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
 789            i != e; ++i)
 790         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
 791     }
 792     break;
 793   }
 794   case Instruction::Unwind:
 795     Code = bitc::FUNC_CODE_INST_UNWIND;
 796     break;
 797   case Instruction::Unreachable:
 798     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
 799     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
 800     break;
 801
 802   case Instruction::PHI:
 803     Code = bitc::FUNC_CODE_INST_PHI;
 804     Vals.push_back(VE.getTypeID(I.getType()));
 805     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 806       Vals.push_back(VE.getValueID(I.getOperand(i)));
 807     break;
 808
 809   case Instruction::Malloc:
 810     Code = bitc::FUNC_CODE_INST_MALLOC;
 811     Vals.push_back(VE.getTypeID(I.getType()));
 812     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
 813     Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
 814     break;
 815
 816   case Instruction::Free:
 817     Code = bitc::FUNC_CODE_INST_FREE;
 818     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 819     break;
 820
 821   case Instruction::Alloca:
 822     Code = bitc::FUNC_CODE_INST_ALLOCA;
 823     Vals.push_back(VE.getTypeID(I.getType()));
 824     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
 825     Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
 826     break;
 827
 828   case Instruction::Load:
 829     Code = bitc::FUNC_CODE_INST_LOAD;
 830     if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
 831       AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
 832
 833     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
 834     Vals.push_back(cast<LoadInst>(I).isVolatile());
 835     break;
 836   case Instruction::Store:
 837     Code = bitc::FUNC_CODE_INST_STORE2;
 838     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
 839     Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
 840     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
 841     Vals.push_back(cast<StoreInst>(I).isVolatile());
 842     break;
 843   case Instruction::Call: {
 844     const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
 845     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
 846
 847     Code = bitc::FUNC_CODE_INST_CALL;
 848
 849     const CallInst *CI = cast<CallInst>(&I);
 850     Vals.push_back(VE.getParamAttrID(CI->getParamAttrs()));
 851     Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
 852     PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
 853
 854     // Emit value #'s for the fixed parameters.
 855     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
 856       Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
 857
 858     // Emit type/value pairs for varargs params.
 859     if (FTy->isVarArg()) {
 860       unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
 861       for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
 862            i != e; ++i)
 863         PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
 864     }
 865     break;
 866   }
 867   case Instruction::VAArg:
 868     Code = bitc::FUNC_CODE_INST_VAARG;
 869     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
 870     Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
 871     Vals.push_back(VE.getTypeID(I.getType())); // restype.
 872     break;
 873   }
 874
 875   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 876   Vals.clear();
 877 }
 878
 879 // Emit names for globals/functions etc.
 880 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
 881                                   const ValueEnumerator &VE,
 882                                   BitstreamWriter &Stream) {
 883   if (VST.empty()) return;
 884   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
 885
 886   // FIXME: Set up the abbrev, we know how many values there are!
 887   // FIXME: We know if the type names can use 7-bit ascii.
 888   SmallVector<unsigned, 64> NameVals;
 889
 890   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
 891        SI != SE; ++SI) {
 892
 893     const ValueName &Name = *SI;
 894
 895     // Figure out the encoding to use for the name.
 896     bool is7Bit = true;
 897     bool isChar6 = true;
 898     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
 899          C != E; ++C) {
 900       if (isChar6)
 901         isChar6 = BitCodeAbbrevOp::isChar6(*C);
 902       if ((unsigned char)*C & 128) {
 903         is7Bit = false;
 904         break;  // don't bother scanning the rest.
 905       }
 906     }
 907
 908     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
 909
 910     // VST_ENTRY:   [valueid, namechar x N]
 911     // VST_BBENTRY: [bbid, namechar x N]
 912     unsigned Code;
 913     if (isa<BasicBlock>(SI->getValue())) {
 914       Code = bitc::VST_CODE_BBENTRY;
 915       if (isChar6)
 916         AbbrevToUse = VST_BBENTRY_6_ABBREV;
 917     } else {
 918       Code = bitc::VST_CODE_ENTRY;
 919       if (isChar6)
 920         AbbrevToUse = VST_ENTRY_6_ABBREV;
 921       else if (is7Bit)
 922         AbbrevToUse = VST_ENTRY_7_ABBREV;
 923     }
 924
 925     NameVals.push_back(VE.getValueID(SI->getValue()));
 926     for (const char *P = Name.getKeyData(),
 927          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
 928       NameVals.push_back((unsigned char)*P);
 929
 930     // Emit the finished record.
 931     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
 932     NameVals.clear();
 933   }
 934   Stream.ExitBlock();
 935 }
 936
 937 /// WriteFunction - Emit a function body to the module stream.
 938 static void WriteFunction(const Function &F, ValueEnumerator &VE,
 939                           BitstreamWriter &Stream) {
 940   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
 941   VE.incorporateFunction(F);
 942
 943   SmallVector<unsigned, 64> Vals;
 944
 945   // Emit the number of basic blocks, so the reader can create them ahead of
 946   // time.
 947   Vals.push_back(VE.getBasicBlocks().size());
 948   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
 949   Vals.clear();
 950
 951   // If there are function-local constants, emit them now.
 952   unsigned CstStart, CstEnd;
 953   VE.getFunctionConstantRange(CstStart, CstEnd);
 954   WriteConstants(CstStart, CstEnd, VE, Stream, false);
 955
 956   // Keep a running idea of what the instruction ID is.
 957   unsigned InstID = CstEnd;
 958
 959   // Finally, emit all the instructions, in order.
 960   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
 961     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
 962          I != E; ++I) {
 963       WriteInstruction(*I, InstID, VE, Stream, Vals);
 964       if (I->getType() != Type::VoidTy)
 965         ++InstID;
 966     }
 967
 968   // Emit names for all the instructions etc.
 969   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
 970
 971   VE.purgeFunction();
 972   Stream.ExitBlock();
 973 }
 974
 975 /// WriteTypeSymbolTable - Emit a block for the specified type symtab.
 976 static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
 977                                  const ValueEnumerator &VE,
 978                                  BitstreamWriter &Stream) {
 979   if (TST.empty()) return;
 980
 981   Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
 982
 983   // 7-bit fixed width VST_CODE_ENTRY strings.
 984   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 985   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
 986   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 987                             Log2_32_Ceil(VE.getTypes().size()+1)));
 988   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 989   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 990   unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
 991
 992   SmallVector<unsigned, 64> NameVals;
 993
 994   for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
 995        TI != TE; ++TI) {
 996     // TST_ENTRY: [typeid, namechar x N]
 997     NameVals.push_back(VE.getTypeID(TI->second));
 998
 999     const std::string &Str = TI->first;
1000     bool is7Bit = true;
1001     for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1002       NameVals.push_back((unsigned char)Str[i]);
1003       if (Str[i] & 128)
1004         is7Bit = false;
1005     }
1006
1007     // Emit the finished record.
1008     Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1009     NameVals.clear();
1010   }
1011
1012   Stream.ExitBlock();
1013 }
1014
1015 // Emit blockinfo, which defines the standard abbreviations etc.
1016 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1017   // We only want to emit block info records for blocks that have multiple
1018   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1019   // blocks can defined their abbrevs inline.
1020   Stream.EnterBlockInfoBlock(2);
1021
1022   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1023     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1024     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1025     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1026     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1027     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1028     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1029                                    Abbv) != VST_ENTRY_8_ABBREV)
1030       assert(0 && "Unexpected abbrev ordering!");
1031   }
1032
1033   { // 7-bit fixed width VST_ENTRY strings.
1034     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1035     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1036     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1037     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1038     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1039     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1040                                    Abbv) != VST_ENTRY_7_ABBREV)
1041       assert(0 && "Unexpected abbrev ordering!");
1042   }
1043   { // 6-bit char6 VST_ENTRY strings.
1044     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1045     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1046     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1047     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1048     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1049     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1050                                    Abbv) != VST_ENTRY_6_ABBREV)
1051       assert(0 && "Unexpected abbrev ordering!");
1052   }
1053   { // 6-bit char6 VST_BBENTRY strings.
1054     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1055     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1056     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1057     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1058     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1059     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1060                                    Abbv) != VST_BBENTRY_6_ABBREV)
1061       assert(0 && "Unexpected abbrev ordering!");
1062   }
1063
1064
1065
1066   { // SETTYPE abbrev for CONSTANTS_BLOCK.
1067     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1068     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1069     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1070                               Log2_32_Ceil(VE.getTypes().size()+1)));
1071     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1072                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
1073       assert(0 && "Unexpected abbrev ordering!");
1074   }
1075
1076   { // INTEGER abbrev for CONSTANTS_BLOCK.
1077     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1078     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1079     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1080     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1081                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
1082       assert(0 && "Unexpected abbrev ordering!");
1083   }
1084
1085   { // CE_CAST abbrev for CONSTANTS_BLOCK.
1086     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1087     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1088     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1089     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1090                               Log2_32_Ceil(VE.getTypes().size()+1)));
1091     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1092
1093     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1094                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
1095       assert(0 && "Unexpected abbrev ordering!");
1096   }
1097   { // NULL abbrev for CONSTANTS_BLOCK.
1098     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1099     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1100     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1101                                    Abbv) != CONSTANTS_NULL_Abbrev)
1102       assert(0 && "Unexpected abbrev ordering!");
1103   }
1104
1105   // FIXME: This should only use space for first class types!
1106
1107   { // INST_LOAD abbrev for FUNCTION_BLOCK.
1108     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1109     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1110     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1111     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1112     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1113     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1114                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
1115       assert(0 && "Unexpected abbrev ordering!");
1116   }
1117   { // INST_BINOP abbrev for FUNCTION_BLOCK.
1118     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1119     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1120     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1121     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1122     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1123     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1124                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
1125       assert(0 && "Unexpected abbrev ordering!");
1126   }
1127   { // INST_CAST abbrev for FUNCTION_BLOCK.
1128     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1129     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1130     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1131     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1132                               Log2_32_Ceil(VE.getTypes().size()+1)));
1133     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1134     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1135                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
1136       assert(0 && "Unexpected abbrev ordering!");
1137   }
1138
1139   { // INST_RET abbrev for FUNCTION_BLOCK.
1140     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1141     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1142     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1143                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1144       assert(0 && "Unexpected abbrev ordering!");
1145   }
1146   { // INST_RET abbrev for FUNCTION_BLOCK.
1147     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1148     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1149     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1150     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1151                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1152       assert(0 && "Unexpected abbrev ordering!");
1153   }
1154   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1155     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1156     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1157     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1158                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1159       assert(0 && "Unexpected abbrev ordering!");
1160   }
1161
1162   Stream.ExitBlock();
1163 }
1164
1165
1166 /// WriteModule - Emit the specified module to the bitstream.
1167 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1168   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1169
1170   // Emit the version number if it is non-zero.
1171   if (CurVersion) {
1172     SmallVector<unsigned, 1> Vals;
1173     Vals.push_back(CurVersion);
1174     Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1175   }
1176
1177   // Analyze the module, enumerating globals, functions, etc.
1178   ValueEnumerator VE(M);
1179
1180   // Emit blockinfo, which defines the standard abbreviations etc.
1181   WriteBlockInfo(VE, Stream);
1182
1183   // Emit information about parameter attributes.
1184   WriteParamAttrTable(VE, Stream);
1185
1186   // Emit information describing all of the types in the module.
1187   WriteTypeTable(VE, Stream);
1188
1189   // Emit top-level description of module, including target triple, inline asm,
1190   // descriptors for global variables, and function prototype info.
1191   WriteModuleInfo(M, VE, Stream);
1192
1193   // Emit constants.
1194   WriteModuleConstants(VE, Stream);
1195
1196   // If we have any aggregate values in the value table, purge them - these can
1197   // only be used to initialize global variables.  Doing so makes the value
1198   // namespace smaller for code in functions.
1199   int NumNonAggregates = VE.PurgeAggregateValues();
1200   if (NumNonAggregates != -1) {
1201     SmallVector<unsigned, 1> Vals;
1202     Vals.push_back(NumNonAggregates);
1203     Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
1204   }
1205
1206   // Emit function bodies.
1207   for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1208     if (!I->isDeclaration())
1209       WriteFunction(*I, VE, Stream);
1210
1211   // Emit the type symbol table information.
1212   WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1213
1214   // Emit names for globals/functions etc.
1215   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1216
1217   Stream.ExitBlock();
1218 }
1219
1220
1221 /// WriteBitcodeToFile - Write the specified module to the specified output
1222 /// stream.
1223 void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
1224   std::vector<unsigned char> Buffer;
1225   BitstreamWriter Stream(Buffer);
1226
1227   Buffer.reserve(256*1024);
1228
1229   // Emit the file header.
1230   Stream.Emit((unsigned)'B', 8);
1231   Stream.Emit((unsigned)'C', 8);
1232   Stream.Emit(0x0, 4);
1233   Stream.Emit(0xC, 4);
1234   Stream.Emit(0xE, 4);
1235   Stream.Emit(0xD, 4);
1236
1237   // Emit the module.
1238   WriteModule(M, Stream);
1239
1240   // Write the generated bitstream to "Out".
1241   Out.write((char*)&Buffer.front(), Buffer.size());
1242
1243   // Make sure it hits disk now.
1244   Out.flush();
1245 }