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