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