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/Instructions.h"
  21 #include "llvm/Module.h"
  22 #include "llvm/ParameterAttributes.h"
  23 #include "llvm/TypeSymbolTable.h"
  24 #include "llvm/ValueSymbolTable.h"
  25 #include "llvm/Support/MathExtras.h"
  26 using namespace llvm;
  27
  28 /// These are manifest constants used by the bitcode writer. They do not need to
  29 /// be kept in sync with the reader, but need to be consistent within this file.
  30 enum {
  31   CurVersion = 0,
  32
  33   // VALUE_SYMTAB_BLOCK abbrev id's.
  34   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  35   VST_ENTRY_7_ABBREV,
  36   VST_BBENTRY_7_ABBREV
  37
  38 };
  39
  40
  41 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
  42   switch (Opcode) {
  43   default: assert(0 && "Unknown cast instruction!");
  44   case Instruction::Trunc   : return bitc::CAST_TRUNC;
  45   case Instruction::ZExt    : return bitc::CAST_ZEXT;
  46   case Instruction::SExt    : return bitc::CAST_SEXT;
  47   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
  48   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
  49   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
  50   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
  51   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
  52   case Instruction::FPExt   : return bitc::CAST_FPEXT;
  53   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
  54   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
  55   case Instruction::BitCast : return bitc::CAST_BITCAST;
  56   }
  57 }
  58
  59 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
  60   switch (Opcode) {
  61   default: assert(0 && "Unknown binary instruction!");
  62   case Instruction::Add:  return bitc::BINOP_ADD;
  63   case Instruction::Sub:  return bitc::BINOP_SUB;
  64   case Instruction::Mul:  return bitc::BINOP_MUL;
  65   case Instruction::UDiv: return bitc::BINOP_UDIV;
  66   case Instruction::FDiv:
  67   case Instruction::SDiv: return bitc::BINOP_SDIV;
  68   case Instruction::URem: return bitc::BINOP_UREM;
  69   case Instruction::FRem:
  70   case Instruction::SRem: return bitc::BINOP_SREM;
  71   case Instruction::Shl:  return bitc::BINOP_SHL;
  72   case Instruction::LShr: return bitc::BINOP_LSHR;
  73   case Instruction::AShr: return bitc::BINOP_ASHR;
  74   case Instruction::And:  return bitc::BINOP_AND;
  75   case Instruction::Or:   return bitc::BINOP_OR;
  76   case Instruction::Xor:  return bitc::BINOP_XOR;
  77   }
  78 }
  79
  80
  81
  82 static void WriteStringRecord(unsigned Code, const std::string &Str,
  83                               unsigned AbbrevToUse, BitstreamWriter &Stream) {
  84   SmallVector<unsigned, 64> Vals;
  85
  86   // Code: [strchar x N]
  87   for (unsigned i = 0, e = Str.size(); i != e; ++i)
  88     Vals.push_back(Str[i]);
  89
  90   // Emit the finished record.
  91   Stream.EmitRecord(Code, Vals, AbbrevToUse);
  92 }
  93
  94 // Emit information about parameter attributes.
  95 static void WriteParamAttrTable(const ValueEnumerator &VE,
  96                                 BitstreamWriter &Stream) {
  97   const std::vector<const ParamAttrsList*> &Attrs = VE.getParamAttrs();
  98   if (Attrs.empty()) return;
  99
 100   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 101
 102   SmallVector<uint64_t, 64> Record;
 103   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
 104     const ParamAttrsList *A = Attrs[i];
 105     for (unsigned op = 0, e = A->size(); op != e; ++op) {
 106       Record.push_back(A->getParamIndex(op));
 107       Record.push_back(A->getParamAttrsAtIndex(op));
 108     }
 109
 110     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 111     Record.clear();
 112   }
 113
 114   Stream.ExitBlock();
 115 }
 116
 117 /// WriteTypeTable - Write out the type table for a module.
 118 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 119   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 120
 121   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
 122   SmallVector<uint64_t, 64> TypeVals;
 123
 124   // FIXME: Set up abbrevs now that we know the width of the type fields, etc.
 125
 126   // Emit an entry count so the reader can reserve space.
 127   TypeVals.push_back(TypeList.size());
 128   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 129   TypeVals.clear();
 130
 131   // Loop over all of the types, emitting each in turn.
 132   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 133     const Type *T = TypeList[i].first;
 134     int AbbrevToUse = 0;
 135     unsigned Code = 0;
 136
 137     switch (T->getTypeID()) {
 138     case Type::PackedStructTyID: // FIXME: Delete Type::PackedStructTyID.
 139     default: assert(0 && "Unknown type!");
 140     case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
 141     case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
 142     case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
 143     case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
 144     case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
 145     case Type::IntegerTyID:
 146       // INTEGER: [width]
 147       Code = bitc::TYPE_CODE_INTEGER;
 148       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 149       break;
 150     case Type::PointerTyID:
 151       // POINTER: [pointee type]
 152       Code = bitc::TYPE_CODE_POINTER;
 153       TypeVals.push_back(VE.getTypeID(cast<PointerType>(T)->getElementType()));
 154       break;
 155
 156     case Type::FunctionTyID: {
 157       const FunctionType *FT = cast<FunctionType>(T);
 158       // FUNCTION: [isvararg, attrid, #pararms, paramty x N]
 159       Code = bitc::TYPE_CODE_FUNCTION;
 160       TypeVals.push_back(FT->isVarArg());
 161       TypeVals.push_back(VE.getParamAttrID(FT->getParamAttrs()));
 162       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 163       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 164         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 165       break;
 166     }
 167     case Type::StructTyID: {
 168       const StructType *ST = cast<StructType>(T);
 169       // STRUCT: [ispacked, #elts, eltty x N]
 170       Code = bitc::TYPE_CODE_STRUCT;
 171       TypeVals.push_back(ST->isPacked());
 172       // Output all of the element types.
 173       for (StructType::element_iterator I = ST->element_begin(),
 174            E = ST->element_end(); I != E; ++I)
 175         TypeVals.push_back(VE.getTypeID(*I));
 176       break;
 177     }
 178     case Type::ArrayTyID: {
 179       const ArrayType *AT = cast<ArrayType>(T);
 180       // ARRAY: [numelts, eltty]
 181       Code = bitc::TYPE_CODE_ARRAY;
 182       TypeVals.push_back(AT->getNumElements());
 183       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 184       break;
 185     }
 186     case Type::VectorTyID: {
 187       const VectorType *VT = cast<VectorType>(T);
 188       // VECTOR [numelts, eltty]
 189       Code = bitc::TYPE_CODE_VECTOR;
 190       TypeVals.push_back(VT->getNumElements());
 191       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 192       break;
 193     }
 194     }
 195
 196     // Emit the finished record.
 197     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 198     TypeVals.clear();
 199   }
 200
 201   Stream.ExitBlock();
 202 }
 203
 204 static unsigned getEncodedLinkage(const GlobalValue *GV) {
 205   switch (GV->getLinkage()) {
 206   default: assert(0 && "Invalid linkage!");
 207   case GlobalValue::ExternalLinkage:     return 0;
 208   case GlobalValue::WeakLinkage:         return 1;
 209   case GlobalValue::AppendingLinkage:    return 2;
 210   case GlobalValue::InternalLinkage:     return 3;
 211   case GlobalValue::LinkOnceLinkage:     return 4;
 212   case GlobalValue::DLLImportLinkage:    return 5;
 213   case GlobalValue::DLLExportLinkage:    return 6;
 214   case GlobalValue::ExternalWeakLinkage: return 7;
 215   }
 216 }
 217
 218 static unsigned getEncodedVisibility(const GlobalValue *GV) {
 219   switch (GV->getVisibility()) {
 220   default: assert(0 && "Invalid visibility!");
 221   case GlobalValue::DefaultVisibility:   return 0;
 222   case GlobalValue::HiddenVisibility:    return 1;
 223   case GlobalValue::ProtectedVisibility: return 2;
 224   }
 225 }
 226
 227 // Emit top-level description of module, including target triple, inline asm,
 228 // descriptors for global variables, and function prototype info.
 229 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 230                             BitstreamWriter &Stream) {
 231   // Emit the list of dependent libraries for the Module.
 232   for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
 233     WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
 234
 235   // Emit various pieces of data attached to a module.
 236   if (!M->getTargetTriple().empty())
 237     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 238                       0/*TODO*/, Stream);
 239   if (!M->getDataLayout().empty())
 240     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
 241                       0/*TODO*/, Stream);
 242   if (!M->getModuleInlineAsm().empty())
 243     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 244                       0/*TODO*/, Stream);
 245
 246   // Emit information about sections, computing how many there are.  Also
 247   // compute the maximum alignment value.
 248   std::map<std::string, unsigned> SectionMap;
 249   unsigned MaxAlignment = 0;
 250   unsigned MaxGlobalType = 0;
 251   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 252        GV != E; ++GV) {
 253     MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
 254     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
 255
 256     if (!GV->hasSection()) continue;
 257     // Give section names unique ID's.
 258     unsigned &Entry = SectionMap[GV->getSection()];
 259     if (Entry != 0) continue;
 260     WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
 261                       0/*TODO*/, Stream);
 262     Entry = SectionMap.size();
 263   }
 264   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 265     MaxAlignment = std::max(MaxAlignment, F->getAlignment());
 266     if (!F->hasSection()) continue;
 267     // Give section names unique ID's.
 268     unsigned &Entry = SectionMap[F->getSection()];
 269     if (Entry != 0) continue;
 270     WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
 271                       0/*TODO*/, Stream);
 272     Entry = SectionMap.size();
 273   }
 274
 275   // Emit abbrev for globals, now that we know # sections and max alignment.
 276   unsigned SimpleGVarAbbrev = 0;
 277   if (!M->global_empty()) {
 278     // Add an abbrev for common globals with no visibility or thread localness.
 279     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 280     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 281     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 282                               Log2_32_Ceil(MaxGlobalType+1)));
 283     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
 284     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
 285     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));      // Linkage.
 286     if (MaxAlignment == 0)                                      // Alignment.
 287       Abbv->Add(BitCodeAbbrevOp(0));
 288     else {
 289       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 290       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 291                                Log2_32_Ceil(MaxEncAlignment+1)));
 292     }
 293     if (SectionMap.empty())                                    // Section.
 294       Abbv->Add(BitCodeAbbrevOp(0));
 295     else
 296       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 297                                Log2_32_Ceil(SectionMap.size()+1)));
 298     // Don't bother emitting vis + thread local.
 299     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 300   }
 301
 302   // Emit the global variable information.
 303   SmallVector<unsigned, 64> Vals;
 304   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 305        GV != E; ++GV) {
 306     unsigned AbbrevToUse = 0;
 307
 308     // GLOBALVAR: [type, isconst, initid,
 309     //             linkage, alignment, section, visibility, threadlocal]
 310     Vals.push_back(VE.getTypeID(GV->getType()));
 311     Vals.push_back(GV->isConstant());
 312     Vals.push_back(GV->isDeclaration() ? 0 :
 313                    (VE.getValueID(GV->getInitializer()) + 1));
 314     Vals.push_back(getEncodedLinkage(GV));
 315     Vals.push_back(Log2_32(GV->getAlignment())+1);
 316     Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
 317     if (GV->isThreadLocal() ||
 318         GV->getVisibility() != GlobalValue::DefaultVisibility) {
 319       Vals.push_back(getEncodedVisibility(GV));
 320       Vals.push_back(GV->isThreadLocal());
 321     } else {
 322       AbbrevToUse = SimpleGVarAbbrev;
 323     }
 324
 325     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 326     Vals.clear();
 327   }
 328
 329   // Emit the function proto information.
 330   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 331     // FUNCTION:  [type, callingconv, isproto, linkage, alignment, section,
 332     //             visibility]
 333     Vals.push_back(VE.getTypeID(F->getType()));
 334     Vals.push_back(F->getCallingConv());
 335     Vals.push_back(F->isDeclaration());
 336     Vals.push_back(getEncodedLinkage(F));
 337     Vals.push_back(Log2_32(F->getAlignment())+1);
 338     Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
 339     Vals.push_back(getEncodedVisibility(F));
 340
 341     unsigned AbbrevToUse = 0;
 342     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 343     Vals.clear();
 344   }
 345
 346
 347   // Emit the alias information.
 348   for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
 349        AI != E; ++AI) {
 350     Vals.push_back(VE.getTypeID(AI->getType()));
 351     Vals.push_back(VE.getValueID(AI->getAliasee()));
 352     Vals.push_back(getEncodedLinkage(AI));
 353     unsigned AbbrevToUse = 0;
 354     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 355     Vals.clear();
 356   }
 357 }
 358
 359
 360 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
 361                            const ValueEnumerator &VE,
 362                            BitstreamWriter &Stream) {
 363   if (FirstVal == LastVal) return;
 364
 365   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 2);
 366
 367   // FIXME: Install and use abbrevs to reduce size.  Install them globally so
 368   // they don't need to be reemitted for each function body.
 369
 370   SmallVector<uint64_t, 64> Record;
 371
 372   const ValueEnumerator::ValueList &Vals = VE.getValues();
 373   const Type *LastTy = 0;
 374   for (unsigned i = FirstVal; i != LastVal; ++i) {
 375     const Value *V = Vals[i].first;
 376     // If we need to switch types, do so now.
 377     if (V->getType() != LastTy) {
 378       LastTy = V->getType();
 379       Record.push_back(VE.getTypeID(LastTy));
 380       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record);
 381       Record.clear();
 382     }
 383
 384     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
 385       assert(0 && IA && "FIXME: Inline asm writing unimp!");
 386       continue;
 387     }
 388     const Constant *C = cast<Constant>(V);
 389     unsigned Code = -1U;
 390     unsigned AbbrevToUse = 0;
 391     if (C->isNullValue()) {
 392       Code = bitc::CST_CODE_NULL;
 393     } else if (isa<UndefValue>(C)) {
 394       Code = bitc::CST_CODE_UNDEF;
 395     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
 396       if (IV->getBitWidth() <= 64) {
 397         int64_t V = IV->getSExtValue();
 398         if (V >= 0)
 399           Record.push_back(V << 1);
 400         else
 401           Record.push_back((-V << 1) | 1);
 402         Code = bitc::CST_CODE_INTEGER;
 403       } else {                             // Wide integers, > 64 bits in size.
 404         // We have an arbitrary precision integer value to write whose
 405         // bit width is > 64. However, in canonical unsigned integer
 406         // format it is likely that the high bits are going to be zero.
 407         // So, we only write the number of active words.
 408         unsigned NWords = IV->getValue().getActiveWords();
 409         const uint64_t *RawWords = IV->getValue().getRawData();
 410         for (unsigned i = 0; i != NWords; ++i) {
 411           int64_t V = RawWords[i];
 412           if (V >= 0)
 413             Record.push_back(V << 1);
 414           else
 415             Record.push_back((-V << 1) | 1);
 416         }
 417         Code = bitc::CST_CODE_WIDE_INTEGER;
 418       }
 419     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
 420       Code = bitc::CST_CODE_FLOAT;
 421       if (CFP->getType() == Type::FloatTy) {
 422         Record.push_back(FloatToBits((float)CFP->getValue()));
 423       } else {
 424         assert (CFP->getType() == Type::DoubleTy && "Unknown FP type!");
 425         Record.push_back(DoubleToBits((double)CFP->getValue()));
 426       }
 427     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
 428                isa<ConstantVector>(V)) {
 429       Code = bitc::CST_CODE_AGGREGATE;
 430       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
 431         Record.push_back(VE.getValueID(C->getOperand(i)));
 432     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
 433       switch (CE->getOpcode()) {
 434       default:
 435         if (Instruction::isCast(CE->getOpcode())) {
 436           Code = bitc::CST_CODE_CE_CAST;
 437           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
 438           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 439           Record.push_back(VE.getValueID(C->getOperand(0)));
 440         } else {
 441           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
 442           Code = bitc::CST_CODE_CE_BINOP;
 443           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
 444           Record.push_back(VE.getValueID(C->getOperand(0)));
 445           Record.push_back(VE.getValueID(C->getOperand(1)));
 446         }
 447         break;
 448       case Instruction::GetElementPtr:
 449         Code = bitc::CST_CODE_CE_GEP;
 450         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
 451           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
 452           Record.push_back(VE.getValueID(C->getOperand(i)));
 453         }
 454         break;
 455       case Instruction::Select:
 456         Code = bitc::CST_CODE_CE_SELECT;
 457         Record.push_back(VE.getValueID(C->getOperand(0)));
 458         Record.push_back(VE.getValueID(C->getOperand(1)));
 459         Record.push_back(VE.getValueID(C->getOperand(2)));
 460         break;
 461       case Instruction::ExtractElement:
 462         Code = bitc::CST_CODE_CE_EXTRACTELT;
 463         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 464         Record.push_back(VE.getValueID(C->getOperand(0)));
 465         Record.push_back(VE.getValueID(C->getOperand(1)));
 466         break;
 467       case Instruction::InsertElement:
 468         Code = bitc::CST_CODE_CE_INSERTELT;
 469         Record.push_back(VE.getValueID(C->getOperand(0)));
 470         Record.push_back(VE.getValueID(C->getOperand(1)));
 471         Record.push_back(VE.getValueID(C->getOperand(2)));
 472         break;
 473       case Instruction::ShuffleVector:
 474         Code = bitc::CST_CODE_CE_SHUFFLEVEC;
 475         Record.push_back(VE.getValueID(C->getOperand(0)));
 476         Record.push_back(VE.getValueID(C->getOperand(1)));
 477         Record.push_back(VE.getValueID(C->getOperand(2)));
 478         break;
 479       case Instruction::ICmp:
 480       case Instruction::FCmp:
 481         Code = bitc::CST_CODE_CE_CMP;
 482         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 483         Record.push_back(VE.getValueID(C->getOperand(0)));
 484         Record.push_back(VE.getValueID(C->getOperand(1)));
 485         Record.push_back(CE->getPredicate());
 486         break;
 487       }
 488     } else {
 489       assert(0 && "Unknown constant!");
 490     }
 491     Stream.EmitRecord(Code, Record, AbbrevToUse);
 492     Record.clear();
 493   }
 494
 495   Stream.ExitBlock();
 496 }
 497
 498 static void WriteModuleConstants(const ValueEnumerator &VE,
 499                                  BitstreamWriter &Stream) {
 500   const ValueEnumerator::ValueList &Vals = VE.getValues();
 501
 502   // Find the first constant to emit, which is the first non-globalvalue value.
 503   // We know globalvalues have been emitted by WriteModuleInfo.
 504   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 505     if (!isa<GlobalValue>(Vals[i].first)) {
 506       WriteConstants(i, Vals.size(), VE, Stream);
 507       return;
 508     }
 509   }
 510 }
 511
 512 /// WriteInstruction - Emit an instruction to the specified stream.
 513 static void WriteInstruction(const Instruction &I, ValueEnumerator &VE,
 514                              BitstreamWriter &Stream,
 515                              SmallVector<unsigned, 64> &Vals) {
 516   unsigned Code = 0;
 517   unsigned AbbrevToUse = 0;
 518   switch (I.getOpcode()) {
 519   default:
 520     if (Instruction::isCast(I.getOpcode())) {
 521       Code = bitc::FUNC_CODE_INST_CAST;
 522       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
 523       Vals.push_back(VE.getTypeID(I.getType()));
 524       Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 525       Vals.push_back(VE.getValueID(I.getOperand(0)));
 526     } else {
 527       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
 528       Code = bitc::FUNC_CODE_INST_BINOP;
 529       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
 530       Vals.push_back(VE.getTypeID(I.getType()));
 531       Vals.push_back(VE.getValueID(I.getOperand(0)));
 532       Vals.push_back(VE.getValueID(I.getOperand(1)));
 533     }
 534     break;
 535
 536   case Instruction::GetElementPtr:
 537     Code = bitc::FUNC_CODE_INST_GEP;
 538     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i) {
 539       Vals.push_back(VE.getTypeID(I.getOperand(i)->getType()));
 540       Vals.push_back(VE.getValueID(I.getOperand(i)));
 541     }
 542     break;
 543   case Instruction::Select:
 544     Code = bitc::FUNC_CODE_INST_SELECT;
 545     Vals.push_back(VE.getTypeID(I.getType()));
 546     Vals.push_back(VE.getValueID(I.getOperand(0)));
 547     Vals.push_back(VE.getValueID(I.getOperand(1)));
 548     Vals.push_back(VE.getValueID(I.getOperand(2)));
 549     break;
 550   case Instruction::ExtractElement:
 551     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
 552     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 553     Vals.push_back(VE.getValueID(I.getOperand(0)));
 554     Vals.push_back(VE.getValueID(I.getOperand(1)));
 555     break;
 556   case Instruction::InsertElement:
 557     Code = bitc::FUNC_CODE_INST_INSERTELT;
 558     Vals.push_back(VE.getTypeID(I.getType()));
 559     Vals.push_back(VE.getValueID(I.getOperand(0)));
 560     Vals.push_back(VE.getValueID(I.getOperand(1)));
 561     Vals.push_back(VE.getValueID(I.getOperand(2)));
 562     break;
 563   case Instruction::ShuffleVector:
 564     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
 565     Vals.push_back(VE.getTypeID(I.getType()));
 566     Vals.push_back(VE.getValueID(I.getOperand(0)));
 567     Vals.push_back(VE.getValueID(I.getOperand(1)));
 568     Vals.push_back(VE.getValueID(I.getOperand(2)));
 569     break;
 570   case Instruction::ICmp:
 571   case Instruction::FCmp:
 572     Code = bitc::FUNC_CODE_INST_CMP;
 573     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 574     Vals.push_back(VE.getValueID(I.getOperand(0)));
 575     Vals.push_back(VE.getValueID(I.getOperand(1)));
 576     Vals.push_back(cast<CmpInst>(I).getPredicate());
 577     break;
 578
 579   case Instruction::Ret:
 580     Code = bitc::FUNC_CODE_INST_RET;
 581     if (I.getNumOperands()) {
 582       Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 583       Vals.push_back(VE.getValueID(I.getOperand(0)));
 584     }
 585     break;
 586   case Instruction::Br:
 587     Code = bitc::FUNC_CODE_INST_BR;
 588     Vals.push_back(VE.getValueID(I.getOperand(0)));
 589     if (cast<BranchInst>(I).isConditional()) {
 590       Vals.push_back(VE.getValueID(I.getOperand(1)));
 591       Vals.push_back(VE.getValueID(I.getOperand(2)));
 592     }
 593     break;
 594   case Instruction::Switch:
 595     Code = bitc::FUNC_CODE_INST_SWITCH;
 596     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 597     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 598       Vals.push_back(VE.getValueID(I.getOperand(i)));
 599     break;
 600   case Instruction::Invoke: {
 601     Code = bitc::FUNC_CODE_INST_INVOKE;
 602     Vals.push_back(cast<InvokeInst>(I).getCallingConv());
 603     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 604     Vals.push_back(VE.getValueID(I.getOperand(0)));  // callee
 605     Vals.push_back(VE.getValueID(I.getOperand(1)));  // normal
 606     Vals.push_back(VE.getValueID(I.getOperand(2)));  // unwind
 607
 608     // Emit value #'s for the fixed parameters.
 609     const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
 610     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
 611     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
 612       Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
 613
 614     // Emit type/value pairs for varargs params.
 615     if (FTy->isVarArg()) {
 616       unsigned NumVarargs = I.getNumOperands()-3-FTy->getNumParams();
 617       for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
 618            i != e; ++i) {
 619         Vals.push_back(VE.getTypeID(I.getOperand(i)->getType()));
 620         Vals.push_back(VE.getValueID(I.getOperand(i)));
 621       }
 622     }
 623     break;
 624   }
 625   case Instruction::Unwind:
 626     Code = bitc::FUNC_CODE_INST_UNWIND;
 627     break;
 628   case Instruction::Unreachable:
 629     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
 630     break;
 631
 632   case Instruction::PHI:
 633     Code = bitc::FUNC_CODE_INST_PHI;
 634     Vals.push_back(VE.getTypeID(I.getType()));
 635     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 636       Vals.push_back(VE.getValueID(I.getOperand(i)));
 637     break;
 638
 639   case Instruction::Malloc:
 640     Code = bitc::FUNC_CODE_INST_MALLOC;
 641     Vals.push_back(VE.getTypeID(I.getType()));
 642     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
 643     Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
 644     break;
 645
 646   case Instruction::Free:
 647     Code = bitc::FUNC_CODE_INST_FREE;
 648     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 649     Vals.push_back(VE.getValueID(I.getOperand(0)));
 650     break;
 651
 652   case Instruction::Alloca:
 653     Code = bitc::FUNC_CODE_INST_ALLOCA;
 654     Vals.push_back(VE.getTypeID(I.getType()));
 655     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
 656     Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
 657     break;
 658
 659   case Instruction::Load:
 660     Code = bitc::FUNC_CODE_INST_LOAD;
 661     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 662     Vals.push_back(VE.getValueID(I.getOperand(0))); // ptr.
 663     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
 664     Vals.push_back(cast<LoadInst>(I).isVolatile());
 665     break;
 666   case Instruction::Store:
 667     Code = bitc::FUNC_CODE_INST_STORE;
 668     Vals.push_back(VE.getTypeID(I.getOperand(1)->getType()));   // Pointer
 669     Vals.push_back(VE.getValueID(I.getOperand(0))); // val.
 670     Vals.push_back(VE.getValueID(I.getOperand(1))); // ptr.
 671     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
 672     Vals.push_back(cast<StoreInst>(I).isVolatile());
 673     break;
 674   case Instruction::Call: {
 675     Code = bitc::FUNC_CODE_INST_CALL;
 676     Vals.push_back((cast<CallInst>(I).getCallingConv() << 1) |
 677                    cast<CallInst>(I).isTailCall());
 678     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 679     Vals.push_back(VE.getValueID(I.getOperand(0)));  // callee
 680
 681     // Emit value #'s for the fixed parameters.
 682     const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
 683     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
 684     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
 685       Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
 686
 687     // Emit type/value pairs for varargs params.
 688     if (FTy->isVarArg()) {
 689       unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
 690       for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
 691            i != e; ++i) {
 692         Vals.push_back(VE.getTypeID(I.getOperand(i)->getType()));
 693         Vals.push_back(VE.getValueID(I.getOperand(i)));
 694       }
 695     }
 696     break;
 697   }
 698   case Instruction::VAArg:
 699     Code = bitc::FUNC_CODE_INST_VAARG;
 700     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
 701     Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
 702     Vals.push_back(VE.getTypeID(I.getType())); // restype.
 703     break;
 704   }
 705
 706   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 707   Vals.clear();
 708 }
 709
 710 // Emit names for globals/functions etc.
 711 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
 712                                   const ValueEnumerator &VE,
 713                                   BitstreamWriter &Stream) {
 714   if (VST.empty()) return;
 715   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 3);
 716
 717   { // 8-bit fixed width VST_ENTRY strings.
 718     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 719     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
 720     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
 721     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 722     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 723     if (Stream.EmitAbbrev(Abbv) != VST_ENTRY_8_ABBREV)
 724       assert(0 && "Unexpected abbrev ordering!");
 725   }
 726
 727   { // 7-bit fixed width VST_ENTRY strings.
 728     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 729     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
 730     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
 731     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 732     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 733     if (Stream.EmitAbbrev(Abbv) != VST_ENTRY_7_ABBREV)
 734       assert(0 && "Unexpected abbrev ordering!");
 735   }
 736   { // 7-bit fixed width VST_BBENTRY strings.
 737     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 738     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
 739     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
 740     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 741     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 742     if (Stream.EmitAbbrev(Abbv) != VST_BBENTRY_7_ABBREV)
 743       assert(0 && "Unexpected abbrev ordering!");
 744   }
 745
 746
 747   // FIXME: Set up the abbrev, we know how many values there are!
 748   // FIXME: We know if the type names can use 7-bit ascii.
 749   SmallVector<unsigned, 64> NameVals;
 750
 751   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
 752        SI != SE; ++SI) {
 753
 754     const ValueName &Name = *SI;
 755
 756     // Figure out the encoding to use for the name.
 757     bool is7Bit = true;
 758     for (unsigned i = 0, e = Name.getKeyLength(); i != e; ++i)
 759       if ((unsigned char)Name.getKeyData()[i] & 128) {
 760         is7Bit = false;
 761         break;
 762       }
 763
 764
 765     unsigned AbbrevToUse = 0;
 766
 767     // VST_ENTRY:   [valueid, namelen, namechar x N]
 768     // VST_BBENTRY: [bbid, namelen, namechar x N]
 769     unsigned Code;
 770     if (isa<BasicBlock>(SI->getValue())) {
 771       Code = bitc::VST_CODE_BBENTRY;
 772       if (is7Bit) AbbrevToUse = VST_BBENTRY_7_ABBREV;
 773     } else {
 774       Code = bitc::VST_CODE_ENTRY;
 775       AbbrevToUse = is7Bit ? VST_ENTRY_7_ABBREV : VST_ENTRY_8_ABBREV;
 776     }
 777
 778     NameVals.push_back(VE.getValueID(SI->getValue()));
 779     for (const char *P = Name.getKeyData(),
 780          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
 781       NameVals.push_back((unsigned char)*P);
 782
 783     // Emit the finished record.
 784     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
 785     NameVals.clear();
 786   }
 787   Stream.ExitBlock();
 788 }
 789
 790 /// WriteFunction - Emit a function body to the module stream.
 791 static void WriteFunction(const Function &F, ValueEnumerator &VE,
 792                           BitstreamWriter &Stream) {
 793   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 3);
 794   VE.incorporateFunction(F);
 795
 796   SmallVector<unsigned, 64> Vals;
 797
 798   // Emit the number of basic blocks, so the reader can create them ahead of
 799   // time.
 800   Vals.push_back(VE.getBasicBlocks().size());
 801   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
 802   Vals.clear();
 803
 804   // FIXME: Function attributes?
 805
 806   // If there are function-local constants, emit them now.
 807   unsigned CstStart, CstEnd;
 808   VE.getFunctionConstantRange(CstStart, CstEnd);
 809   WriteConstants(CstStart, CstEnd, VE, Stream);
 810
 811   // Finally, emit all the instructions, in order.
 812   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
 813     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I)
 814       WriteInstruction(*I, VE, Stream, Vals);
 815
 816   // Emit names for all the instructions etc.
 817   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
 818
 819   VE.purgeFunction();
 820   Stream.ExitBlock();
 821 }
 822
 823 /// WriteTypeSymbolTable - Emit a block for the specified type symtab.
 824 static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
 825                                  const ValueEnumerator &VE,
 826                                  BitstreamWriter &Stream) {
 827   if (TST.empty()) return;
 828
 829   Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
 830
 831   // FIXME: Set up the abbrev, we know how many types there are!
 832   // FIXME: We know if the type names can use 7-bit ascii.
 833
 834   SmallVector<unsigned, 64> NameVals;
 835
 836   for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
 837        TI != TE; ++TI) {
 838     unsigned AbbrevToUse = 0;
 839
 840     // TST_ENTRY: [typeid, namelen, namechar x N]
 841     NameVals.push_back(VE.getTypeID(TI->second));
 842
 843     const std::string &Str = TI->first;
 844     for (unsigned i = 0, e = Str.size(); i != e; ++i)
 845       NameVals.push_back(Str[i]);
 846
 847     // Emit the finished record.
 848     Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, AbbrevToUse);
 849     NameVals.clear();
 850   }
 851
 852   Stream.ExitBlock();
 853 }
 854
 855
 856 /// WriteModule - Emit the specified module to the bitstream.
 857 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
 858   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
 859
 860   // Emit the version number if it is non-zero.
 861   if (CurVersion) {
 862     SmallVector<unsigned, 1> Vals;
 863     Vals.push_back(CurVersion);
 864     Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
 865   }
 866
 867   // Analyze the module, enumerating globals, functions, etc.
 868   ValueEnumerator VE(M);
 869
 870   // Emit information about parameter attributes.
 871   WriteParamAttrTable(VE, Stream);
 872
 873   // Emit information describing all of the types in the module.
 874   WriteTypeTable(VE, Stream);
 875
 876   // Emit top-level description of module, including target triple, inline asm,
 877   // descriptors for global variables, and function prototype info.
 878   WriteModuleInfo(M, VE, Stream);
 879
 880   // Emit constants.
 881   WriteModuleConstants(VE, Stream);
 882
 883   // If we have any aggregate values in the value table, purge them - these can
 884   // only be used to initialize global variables.  Doing so makes the value
 885   // namespace smaller for code in functions.
 886   int NumNonAggregates = VE.PurgeAggregateValues();
 887   if (NumNonAggregates != -1) {
 888     SmallVector<unsigned, 1> Vals;
 889     Vals.push_back(NumNonAggregates);
 890     Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
 891   }
 892
 893   // Emit function bodies.
 894   for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
 895     if (!I->isDeclaration())
 896       WriteFunction(*I, VE, Stream);
 897
 898   // Emit the type symbol table information.
 899   WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
 900
 901   // Emit names for globals/functions etc.
 902   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
 903
 904   Stream.ExitBlock();
 905 }
 906
 907 // Emit blockinfo, which defines the standard abbreviations etc.
 908 static void WriteBlockInfo(BitstreamWriter &Stream) {
 909   // We only want to emit block info records for blocks that have multiple
 910   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
 911   // blocks can defined their abbrevs inline.
 912   Stream.EnterSubblock(bitc::BLOCKINFO_BLOCK_ID, 2);
 913
 914 #if 0
 915   // Configure TYPE_SYMTAB_BLOCK's.
 916
 917   // Add an abbrev for VST_ENTRY where the characters each fit in 7 bits.
 918   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 919   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
 920   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8); // Value ID
 921   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3)); // Linkage.
 922
 923   xxx = Stream.EmitAbbrev(Abbv);
 924 #endif
 925   Stream.ExitBlock();
 926 }
 927
 928
 929 /// WriteBitcodeToFile - Write the specified module to the specified output
 930 /// stream.
 931 void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
 932   std::vector<unsigned char> Buffer;
 933   BitstreamWriter Stream(Buffer);
 934
 935   Buffer.reserve(256*1024);
 936
 937   // Emit the file header.
 938   Stream.Emit((unsigned)'B', 8);
 939   Stream.Emit((unsigned)'C', 8);
 940   Stream.Emit(0x0, 4);
 941   Stream.Emit(0xC, 4);
 942   Stream.Emit(0xE, 4);
 943   Stream.Emit(0xD, 4);
 944
 945   // Emit blockinfo, which defines the standard abbreviations etc.
 946   WriteBlockInfo(Stream);
 947
 948   // Emit the module.
 949   WriteModule(M, Stream);
 950
 951   // Write the generated bitstream to "Out".
 952   Out.write((char*)&Buffer.front(), Buffer.size());
 953 }