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::Fixed,
 151                             Log2_32_Ceil(VE.getParamAttrs().size()+1)));
 152   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 153   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 154                             Log2_32_Ceil(VE.getTypes().size()+1)));
 155   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 156
 157   // Abbrev for TYPE_CODE_STRUCT.
 158   Abbv = new BitCodeAbbrev();
 159   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
 160   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 161   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 162   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 163                             Log2_32_Ceil(VE.getTypes().size()+1)));
 164   unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
 165
 166   // Abbrev for TYPE_CODE_ARRAY.
 167   Abbv = new BitCodeAbbrev();
 168   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 169   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 170   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 171                             Log2_32_Ceil(VE.getTypes().size()+1)));
 172   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 173
 174   // Emit an entry count so the reader can reserve space.
 175   TypeVals.push_back(TypeList.size());
 176   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 177   TypeVals.clear();
 178
 179   // Loop over all of the types, emitting each in turn.
 180   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 181     const Type *T = TypeList[i].first;
 182     int AbbrevToUse = 0;
 183     unsigned Code = 0;
 184
 185     switch (T->getTypeID()) {
 186     case Type::PackedStructTyID: // FIXME: Delete Type::PackedStructTyID.
 187     default: assert(0 && "Unknown type!");
 188     case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
 189     case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
 190     case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; 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, attrid, retty, paramty x N]
 208       Code = bitc::TYPE_CODE_FUNCTION;
 209       TypeVals.push_back(FT->isVarArg());
 210       TypeVals.push_back(VE.getParamAttrID(FT->getParamAttrs()));
 211       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 212       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 213         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 214       AbbrevToUse = FunctionAbbrev;
 215       break;
 216     }
 217     case Type::StructTyID: {
 218       const StructType *ST = cast<StructType>(T);
 219       // STRUCT: [ispacked, eltty x N]
 220       Code = bitc::TYPE_CODE_STRUCT;
 221       TypeVals.push_back(ST->isPacked());
 222       // Output all of the element types.
 223       for (StructType::element_iterator I = ST->element_begin(),
 224            E = ST->element_end(); I != E; ++I)
 225         TypeVals.push_back(VE.getTypeID(*I));
 226       AbbrevToUse = StructAbbrev;
 227       break;
 228     }
 229     case Type::ArrayTyID: {
 230       const ArrayType *AT = cast<ArrayType>(T);
 231       // ARRAY: [numelts, eltty]
 232       Code = bitc::TYPE_CODE_ARRAY;
 233       TypeVals.push_back(AT->getNumElements());
 234       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 235       AbbrevToUse = ArrayAbbrev;
 236       break;
 237     }
 238     case Type::VectorTyID: {
 239       const VectorType *VT = cast<VectorType>(T);
 240       // VECTOR [numelts, eltty]
 241       Code = bitc::TYPE_CODE_VECTOR;
 242       TypeVals.push_back(VT->getNumElements());
 243       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 244       break;
 245     }
 246     }
 247
 248     // Emit the finished record.
 249     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 250     TypeVals.clear();
 251   }
 252
 253   Stream.ExitBlock();
 254 }
 255
 256 static unsigned getEncodedLinkage(const GlobalValue *GV) {
 257   switch (GV->getLinkage()) {
 258   default: assert(0 && "Invalid linkage!");
 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, linkage, alignment, section,
 384     //             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
 390     // Note: we emit the param attr ID number for the function type of this
 391     // function.  In the future, we intend for attrs to be properties of
 392     // functions, instead of on the type.  This is to support this future work.
 393     Vals.push_back(VE.getParamAttrID(F->getFunctionType()->getParamAttrs()));
 394
 395     Vals.push_back(Log2_32(F->getAlignment())+1);
 396     Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
 397     Vals.push_back(getEncodedVisibility(F));
 398
 399     unsigned AbbrevToUse = 0;
 400     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 401     Vals.clear();
 402   }
 403
 404
 405   // Emit the alias information.
 406   for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
 407        AI != E; ++AI) {
 408     Vals.push_back(VE.getTypeID(AI->getType()));
 409     Vals.push_back(VE.getValueID(AI->getAliasee()));
 410     Vals.push_back(getEncodedLinkage(AI));
 411     unsigned AbbrevToUse = 0;
 412     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 413     Vals.clear();
 414   }
 415 }
 416
 417
 418 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
 419                            const ValueEnumerator &VE,
 420                            BitstreamWriter &Stream, bool isGlobal) {
 421   if (FirstVal == LastVal) return;
 422
 423   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
 424
 425   unsigned AggregateAbbrev = 0;
 426   unsigned String8Abbrev = 0;
 427   unsigned CString7Abbrev = 0;
 428   unsigned CString6Abbrev = 0;
 429   // If this is a constant pool for the module, emit module-specific abbrevs.
 430   if (isGlobal) {
 431     // Abbrev for CST_CODE_AGGREGATE.
 432     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 433     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
 434     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 435     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
 436     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
 437
 438     // Abbrev for CST_CODE_STRING.
 439     Abbv = new BitCodeAbbrev();
 440     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
 441     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 442     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 443     String8Abbrev = Stream.EmitAbbrev(Abbv);
 444     // Abbrev for CST_CODE_CSTRING.
 445     Abbv = new BitCodeAbbrev();
 446     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 447     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 448     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 449     CString7Abbrev = Stream.EmitAbbrev(Abbv);
 450     // Abbrev for CST_CODE_CSTRING.
 451     Abbv = new BitCodeAbbrev();
 452     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 453     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 454     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 455     CString6Abbrev = Stream.EmitAbbrev(Abbv);
 456   }
 457
 458   SmallVector<uint64_t, 64> Record;
 459
 460   const ValueEnumerator::ValueList &Vals = VE.getValues();
 461   const Type *LastTy = 0;
 462   for (unsigned i = FirstVal; i != LastVal; ++i) {
 463     const Value *V = Vals[i].first;
 464     // If we need to switch types, do so now.
 465     if (V->getType() != LastTy) {
 466       LastTy = V->getType();
 467       Record.push_back(VE.getTypeID(LastTy));
 468       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
 469                         CONSTANTS_SETTYPE_ABBREV);
 470       Record.clear();
 471     }
 472
 473     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
 474       Record.push_back(unsigned(IA->hasSideEffects()));
 475
 476       // Add the asm string.
 477       const std::string &AsmStr = IA->getAsmString();
 478       Record.push_back(AsmStr.size());
 479       for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
 480         Record.push_back(AsmStr[i]);
 481
 482       // Add the constraint string.
 483       const std::string &ConstraintStr = IA->getConstraintString();
 484       Record.push_back(ConstraintStr.size());
 485       for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
 486         Record.push_back(ConstraintStr[i]);
 487       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
 488       Record.clear();
 489       continue;
 490     }
 491     const Constant *C = cast<Constant>(V);
 492     unsigned Code = -1U;
 493     unsigned AbbrevToUse = 0;
 494     if (C->isNullValue()) {
 495       Code = bitc::CST_CODE_NULL;
 496     } else if (isa<UndefValue>(C)) {
 497       Code = bitc::CST_CODE_UNDEF;
 498     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
 499       if (IV->getBitWidth() <= 64) {
 500         int64_t V = IV->getSExtValue();
 501         if (V >= 0)
 502           Record.push_back(V << 1);
 503         else
 504           Record.push_back((-V << 1) | 1);
 505         Code = bitc::CST_CODE_INTEGER;
 506         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
 507       } else {                             // Wide integers, > 64 bits in size.
 508         // We have an arbitrary precision integer value to write whose
 509         // bit width is > 64. However, in canonical unsigned integer
 510         // format it is likely that the high bits are going to be zero.
 511         // So, we only write the number of active words.
 512         unsigned NWords = IV->getValue().getActiveWords();
 513         const uint64_t *RawWords = IV->getValue().getRawData();
 514         for (unsigned i = 0; i != NWords; ++i) {
 515           int64_t V = RawWords[i];
 516           if (V >= 0)
 517             Record.push_back(V << 1);
 518           else
 519             Record.push_back((-V << 1) | 1);
 520         }
 521         Code = bitc::CST_CODE_WIDE_INTEGER;
 522       }
 523     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
 524       Code = bitc::CST_CODE_FLOAT;
 525       if (CFP->getType() == Type::FloatTy) {
 526         Record.push_back(FloatToBits((float)CFP->getValue()));
 527       } else {
 528         assert (CFP->getType() == Type::DoubleTy && "Unknown FP type!");
 529         Record.push_back(DoubleToBits((double)CFP->getValue()));
 530       }
 531     } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
 532       // Emit constant strings specially.
 533       unsigned NumOps = C->getNumOperands();
 534       // If this is a null-terminated string, use the denser CSTRING encoding.
 535       if (C->getOperand(NumOps-1)->isNullValue()) {
 536         Code = bitc::CST_CODE_CSTRING;
 537         --NumOps;  // Don't encode the null, which isn't allowed by char6.
 538       } else {
 539         Code = bitc::CST_CODE_STRING;
 540         AbbrevToUse = String8Abbrev;
 541       }
 542       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
 543       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
 544       for (unsigned i = 0; i != NumOps; ++i) {
 545         unsigned char V = cast<ConstantInt>(C->getOperand(i))->getZExtValue();
 546         Record.push_back(V);
 547         isCStr7 &= (V & 128) == 0;
 548         if (isCStrChar6)
 549           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
 550       }
 551
 552       if (isCStrChar6)
 553         AbbrevToUse = CString6Abbrev;
 554       else if (isCStr7)
 555         AbbrevToUse = CString7Abbrev;
 556     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
 557                isa<ConstantVector>(V)) {
 558       Code = bitc::CST_CODE_AGGREGATE;
 559       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
 560         Record.push_back(VE.getValueID(C->getOperand(i)));
 561       AbbrevToUse = AggregateAbbrev;
 562     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
 563       switch (CE->getOpcode()) {
 564       default:
 565         if (Instruction::isCast(CE->getOpcode())) {
 566           Code = bitc::CST_CODE_CE_CAST;
 567           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
 568           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 569           Record.push_back(VE.getValueID(C->getOperand(0)));
 570           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
 571         } else {
 572           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
 573           Code = bitc::CST_CODE_CE_BINOP;
 574           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
 575           Record.push_back(VE.getValueID(C->getOperand(0)));
 576           Record.push_back(VE.getValueID(C->getOperand(1)));
 577         }
 578         break;
 579       case Instruction::GetElementPtr:
 580         Code = bitc::CST_CODE_CE_GEP;
 581         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
 582           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
 583           Record.push_back(VE.getValueID(C->getOperand(i)));
 584         }
 585         break;
 586       case Instruction::Select:
 587         Code = bitc::CST_CODE_CE_SELECT;
 588         Record.push_back(VE.getValueID(C->getOperand(0)));
 589         Record.push_back(VE.getValueID(C->getOperand(1)));
 590         Record.push_back(VE.getValueID(C->getOperand(2)));
 591         break;
 592       case Instruction::ExtractElement:
 593         Code = bitc::CST_CODE_CE_EXTRACTELT;
 594         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 595         Record.push_back(VE.getValueID(C->getOperand(0)));
 596         Record.push_back(VE.getValueID(C->getOperand(1)));
 597         break;
 598       case Instruction::InsertElement:
 599         Code = bitc::CST_CODE_CE_INSERTELT;
 600         Record.push_back(VE.getValueID(C->getOperand(0)));
 601         Record.push_back(VE.getValueID(C->getOperand(1)));
 602         Record.push_back(VE.getValueID(C->getOperand(2)));
 603         break;
 604       case Instruction::ShuffleVector:
 605         Code = bitc::CST_CODE_CE_SHUFFLEVEC;
 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::ICmp:
 611       case Instruction::FCmp:
 612         Code = bitc::CST_CODE_CE_CMP;
 613         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 614         Record.push_back(VE.getValueID(C->getOperand(0)));
 615         Record.push_back(VE.getValueID(C->getOperand(1)));
 616         Record.push_back(CE->getPredicate());
 617         break;
 618       }
 619     } else {
 620       assert(0 && "Unknown constant!");
 621     }
 622     Stream.EmitRecord(Code, Record, AbbrevToUse);
 623     Record.clear();
 624   }
 625
 626   Stream.ExitBlock();
 627 }
 628
 629 static void WriteModuleConstants(const ValueEnumerator &VE,
 630                                  BitstreamWriter &Stream) {
 631   const ValueEnumerator::ValueList &Vals = VE.getValues();
 632
 633   // Find the first constant to emit, which is the first non-globalvalue value.
 634   // We know globalvalues have been emitted by WriteModuleInfo.
 635   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 636     if (!isa<GlobalValue>(Vals[i].first)) {
 637       WriteConstants(i, Vals.size(), VE, Stream, true);
 638       return;
 639     }
 640   }
 641 }
 642
 643 /// PushValueAndType - The file has to encode both the value and type id for
 644 /// many values, because we need to know what type to create for forward
 645 /// references.  However, most operands are not forward references, so this type
 646 /// field is not needed.
 647 ///
 648 /// This function adds V's value ID to Vals.  If the value ID is higher than the
 649 /// instruction ID, then it is a forward reference, and it also includes the
 650 /// type ID.
 651 static bool PushValueAndType(Value *V, unsigned InstID,
 652                              SmallVector<unsigned, 64> &Vals,
 653                              ValueEnumerator &VE) {
 654   unsigned ValID = VE.getValueID(V);
 655   Vals.push_back(ValID);
 656   if (ValID >= InstID) {
 657     Vals.push_back(VE.getTypeID(V->getType()));
 658     return true;
 659   }
 660   return false;
 661 }
 662
 663 /// WriteInstruction - Emit an instruction to the specified stream.
 664 static void WriteInstruction(const Instruction &I, unsigned InstID,
 665                              ValueEnumerator &VE, BitstreamWriter &Stream,
 666                              SmallVector<unsigned, 64> &Vals) {
 667   unsigned Code = 0;
 668   unsigned AbbrevToUse = 0;
 669   switch (I.getOpcode()) {
 670   default:
 671     if (Instruction::isCast(I.getOpcode())) {
 672       Code = bitc::FUNC_CODE_INST_CAST;
 673       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 674         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
 675       Vals.push_back(VE.getTypeID(I.getType()));
 676       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
 677     } else {
 678       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
 679       Code = bitc::FUNC_CODE_INST_BINOP;
 680       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 681         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
 682       Vals.push_back(VE.getValueID(I.getOperand(1)));
 683       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
 684     }
 685     break;
 686
 687   case Instruction::GetElementPtr:
 688     Code = bitc::FUNC_CODE_INST_GEP;
 689     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 690       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
 691     break;
 692   case Instruction::Select:
 693     Code = bitc::FUNC_CODE_INST_SELECT;
 694     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
 695     Vals.push_back(VE.getValueID(I.getOperand(2)));
 696     Vals.push_back(VE.getValueID(I.getOperand(0)));
 697     break;
 698   case Instruction::ExtractElement:
 699     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
 700     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 701     Vals.push_back(VE.getValueID(I.getOperand(1)));
 702     break;
 703   case Instruction::InsertElement:
 704     Code = bitc::FUNC_CODE_INST_INSERTELT;
 705     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 706     Vals.push_back(VE.getValueID(I.getOperand(1)));
 707     Vals.push_back(VE.getValueID(I.getOperand(2)));
 708     break;
 709   case Instruction::ShuffleVector:
 710     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
 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::ICmp:
 716   case Instruction::FCmp:
 717     Code = bitc::FUNC_CODE_INST_CMP;
 718     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 719     Vals.push_back(VE.getValueID(I.getOperand(1)));
 720     Vals.push_back(cast<CmpInst>(I).getPredicate());
 721     break;
 722
 723   case Instruction::Ret:
 724     Code = bitc::FUNC_CODE_INST_RET;
 725     if (!I.getNumOperands())
 726       AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
 727     else if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 728       AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
 729     break;
 730   case Instruction::Br:
 731     Code = bitc::FUNC_CODE_INST_BR;
 732     Vals.push_back(VE.getValueID(I.getOperand(0)));
 733     if (cast<BranchInst>(I).isConditional()) {
 734       Vals.push_back(VE.getValueID(I.getOperand(1)));
 735       Vals.push_back(VE.getValueID(I.getOperand(2)));
 736     }
 737     break;
 738   case Instruction::Switch:
 739     Code = bitc::FUNC_CODE_INST_SWITCH;
 740     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
 741     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 742       Vals.push_back(VE.getValueID(I.getOperand(i)));
 743     break;
 744   case Instruction::Invoke: {
 745     const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
 746     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
 747     Code = bitc::FUNC_CODE_INST_INVOKE;
 748
 749     // Note: we emit the param attr ID number for the function type of this
 750     // function.  In the future, we intend for attrs to be properties of
 751     // functions, instead of on the type.  This is to support this future work.
 752     Vals.push_back(VE.getParamAttrID(FTy->getParamAttrs()));
 753
 754     Vals.push_back(cast<InvokeInst>(I).getCallingConv());
 755     Vals.push_back(VE.getValueID(I.getOperand(1)));      // normal dest
 756     Vals.push_back(VE.getValueID(I.getOperand(2)));      // unwind dest
 757     PushValueAndType(I.getOperand(0), InstID, Vals, VE); // callee
 758
 759     // Emit value #'s for the fixed parameters.
 760     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
 761       Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
 762
 763     // Emit type/value pairs for varargs params.
 764     if (FTy->isVarArg()) {
 765       for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
 766            i != e; ++i)
 767         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
 768     }
 769     break;
 770   }
 771   case Instruction::Unwind:
 772     Code = bitc::FUNC_CODE_INST_UNWIND;
 773     break;
 774   case Instruction::Unreachable:
 775     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
 776     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
 777     break;
 778
 779   case Instruction::PHI:
 780     Code = bitc::FUNC_CODE_INST_PHI;
 781     Vals.push_back(VE.getTypeID(I.getType()));
 782     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 783       Vals.push_back(VE.getValueID(I.getOperand(i)));
 784     break;
 785
 786   case Instruction::Malloc:
 787     Code = bitc::FUNC_CODE_INST_MALLOC;
 788     Vals.push_back(VE.getTypeID(I.getType()));
 789     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
 790     Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
 791     break;
 792
 793   case Instruction::Free:
 794     Code = bitc::FUNC_CODE_INST_FREE;
 795     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 796     break;
 797
 798   case Instruction::Alloca:
 799     Code = bitc::FUNC_CODE_INST_ALLOCA;
 800     Vals.push_back(VE.getTypeID(I.getType()));
 801     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
 802     Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
 803     break;
 804
 805   case Instruction::Load:
 806     Code = bitc::FUNC_CODE_INST_LOAD;
 807     if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
 808       AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
 809
 810     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
 811     Vals.push_back(cast<LoadInst>(I).isVolatile());
 812     break;
 813   case Instruction::Store:
 814     Code = bitc::FUNC_CODE_INST_STORE;
 815     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // val.
 816     Vals.push_back(VE.getValueID(I.getOperand(1)));       // ptr.
 817     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
 818     Vals.push_back(cast<StoreInst>(I).isVolatile());
 819     break;
 820   case Instruction::Call: {
 821     const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
 822     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
 823
 824     Code = bitc::FUNC_CODE_INST_CALL;
 825
 826     // Note: we emit the param attr ID number for the function type of this
 827     // function.  In the future, we intend for attrs to be properties of
 828     // functions, instead of on the type.  This is to support this future work.
 829     Vals.push_back(VE.getParamAttrID(FTy->getParamAttrs()));
 830
 831     Vals.push_back((cast<CallInst>(I).getCallingConv() << 1) |
 832                    unsigned(cast<CallInst>(I).isTailCall()));
 833     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // Callee
 834
 835     // Emit value #'s for the fixed parameters.
 836     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
 837       Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
 838
 839     // Emit type/value pairs for varargs params.
 840     if (FTy->isVarArg()) {
 841       unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
 842       for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
 843            i != e; ++i)
 844         PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
 845     }
 846     break;
 847   }
 848   case Instruction::VAArg:
 849     Code = bitc::FUNC_CODE_INST_VAARG;
 850     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
 851     Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
 852     Vals.push_back(VE.getTypeID(I.getType())); // restype.
 853     break;
 854   }
 855
 856   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 857   Vals.clear();
 858 }
 859
 860 // Emit names for globals/functions etc.
 861 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
 862                                   const ValueEnumerator &VE,
 863                                   BitstreamWriter &Stream) {
 864   if (VST.empty()) return;
 865   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
 866
 867   // FIXME: Set up the abbrev, we know how many values there are!
 868   // FIXME: We know if the type names can use 7-bit ascii.
 869   SmallVector<unsigned, 64> NameVals;
 870
 871   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
 872        SI != SE; ++SI) {
 873
 874     const ValueName &Name = *SI;
 875
 876     // Figure out the encoding to use for the name.
 877     bool is7Bit = true;
 878     bool isChar6 = true;
 879     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
 880          C != E; ++C) {
 881       if (isChar6)
 882         isChar6 = BitCodeAbbrevOp::isChar6(*C);
 883       if ((unsigned char)*C & 128) {
 884         is7Bit = false;
 885         break;  // don't bother scanning the rest.
 886       }
 887     }
 888
 889     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
 890
 891     // VST_ENTRY:   [valueid, namechar x N]
 892     // VST_BBENTRY: [bbid, namechar x N]
 893     unsigned Code;
 894     if (isa<BasicBlock>(SI->getValue())) {
 895       Code = bitc::VST_CODE_BBENTRY;
 896       if (isChar6)
 897         AbbrevToUse = VST_BBENTRY_6_ABBREV;
 898     } else {
 899       Code = bitc::VST_CODE_ENTRY;
 900       if (isChar6)
 901         AbbrevToUse = VST_ENTRY_6_ABBREV;
 902       else if (is7Bit)
 903         AbbrevToUse = VST_ENTRY_7_ABBREV;
 904     }
 905
 906     NameVals.push_back(VE.getValueID(SI->getValue()));
 907     for (const char *P = Name.getKeyData(),
 908          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
 909       NameVals.push_back((unsigned char)*P);
 910
 911     // Emit the finished record.
 912     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
 913     NameVals.clear();
 914   }
 915   Stream.ExitBlock();
 916 }
 917
 918 /// WriteFunction - Emit a function body to the module stream.
 919 static void WriteFunction(const Function &F, ValueEnumerator &VE,
 920                           BitstreamWriter &Stream) {
 921   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
 922   VE.incorporateFunction(F);
 923
 924   SmallVector<unsigned, 64> Vals;
 925
 926   // Emit the number of basic blocks, so the reader can create them ahead of
 927   // time.
 928   Vals.push_back(VE.getBasicBlocks().size());
 929   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
 930   Vals.clear();
 931
 932   // If there are function-local constants, emit them now.
 933   unsigned CstStart, CstEnd;
 934   VE.getFunctionConstantRange(CstStart, CstEnd);
 935   WriteConstants(CstStart, CstEnd, VE, Stream, false);
 936
 937   // Keep a running idea of what the instruction ID is.
 938   unsigned InstID = CstEnd;
 939
 940   // Finally, emit all the instructions, in order.
 941   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
 942     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
 943          I != E; ++I) {
 944       WriteInstruction(*I, InstID, VE, Stream, Vals);
 945       if (I->getType() != Type::VoidTy)
 946         ++InstID;
 947     }
 948
 949   // Emit names for all the instructions etc.
 950   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
 951
 952   VE.purgeFunction();
 953   Stream.ExitBlock();
 954 }
 955
 956 /// WriteTypeSymbolTable - Emit a block for the specified type symtab.
 957 static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
 958                                  const ValueEnumerator &VE,
 959                                  BitstreamWriter &Stream) {
 960   if (TST.empty()) return;
 961
 962   Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
 963
 964   // 7-bit fixed width VST_CODE_ENTRY strings.
 965   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 966   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
 967   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 968                             Log2_32_Ceil(VE.getTypes().size()+1)));
 969   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 970   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 971   unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
 972
 973   SmallVector<unsigned, 64> NameVals;
 974
 975   for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
 976        TI != TE; ++TI) {
 977     // TST_ENTRY: [typeid, namechar x N]
 978     NameVals.push_back(VE.getTypeID(TI->second));
 979
 980     const std::string &Str = TI->first;
 981     bool is7Bit = true;
 982     for (unsigned i = 0, e = Str.size(); i != e; ++i) {
 983       NameVals.push_back((unsigned char)Str[i]);
 984       if (Str[i] & 128)
 985         is7Bit = false;
 986     }
 987
 988     // Emit the finished record.
 989     Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
 990     NameVals.clear();
 991   }
 992
 993   Stream.ExitBlock();
 994 }
 995
 996 // Emit blockinfo, which defines the standard abbreviations etc.
 997 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 998   // We only want to emit block info records for blocks that have multiple
 999   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1000   // blocks can defined their abbrevs inline.
1001   Stream.EnterBlockInfoBlock(2);
1002
1003   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1004     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1005     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1006     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1007     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1008     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1009     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1010                                    Abbv) != VST_ENTRY_8_ABBREV)
1011       assert(0 && "Unexpected abbrev ordering!");
1012   }
1013
1014   { // 7-bit fixed width VST_ENTRY strings.
1015     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1016     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1017     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1018     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1019     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1020     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1021                                    Abbv) != VST_ENTRY_7_ABBREV)
1022       assert(0 && "Unexpected abbrev ordering!");
1023   }
1024   { // 6-bit char6 VST_ENTRY strings.
1025     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1026     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1027     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1028     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1029     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1030     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1031                                    Abbv) != VST_ENTRY_6_ABBREV)
1032       assert(0 && "Unexpected abbrev ordering!");
1033   }
1034   { // 6-bit char6 VST_BBENTRY strings.
1035     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1036     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1037     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1038     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1039     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1040     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1041                                    Abbv) != VST_BBENTRY_6_ABBREV)
1042       assert(0 && "Unexpected abbrev ordering!");
1043   }
1044
1045
1046
1047   { // SETTYPE abbrev for CONSTANTS_BLOCK.
1048     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1049     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1050     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1051                               Log2_32_Ceil(VE.getTypes().size()+1)));
1052     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1053                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
1054       assert(0 && "Unexpected abbrev ordering!");
1055   }
1056
1057   { // INTEGER abbrev for CONSTANTS_BLOCK.
1058     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1059     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1060     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1061     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1062                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
1063       assert(0 && "Unexpected abbrev ordering!");
1064   }
1065
1066   { // CE_CAST abbrev for CONSTANTS_BLOCK.
1067     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1068     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1069     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1070     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1071                               Log2_32_Ceil(VE.getTypes().size()+1)));
1072     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1073
1074     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1075                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
1076       assert(0 && "Unexpected abbrev ordering!");
1077   }
1078   { // NULL abbrev for CONSTANTS_BLOCK.
1079     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1080     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1081     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1082                                    Abbv) != CONSTANTS_NULL_Abbrev)
1083       assert(0 && "Unexpected abbrev ordering!");
1084   }
1085
1086   // FIXME: This should only use space for first class types!
1087
1088   { // INST_LOAD abbrev for FUNCTION_BLOCK.
1089     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1090     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1091     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1092     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1093     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1094     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1095                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
1096       assert(0 && "Unexpected abbrev ordering!");
1097   }
1098   { // INST_BINOP abbrev for FUNCTION_BLOCK.
1099     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1100     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1101     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1102     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1103     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1104     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1105                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
1106       assert(0 && "Unexpected abbrev ordering!");
1107   }
1108   { // INST_CAST abbrev for FUNCTION_BLOCK.
1109     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1110     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1111     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1112     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1113                               Log2_32_Ceil(VE.getTypes().size()+1)));
1114     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1115     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1116                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
1117       assert(0 && "Unexpected abbrev ordering!");
1118   }
1119
1120   { // INST_RET abbrev for FUNCTION_BLOCK.
1121     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1122     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1123     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1124                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1125       assert(0 && "Unexpected abbrev ordering!");
1126   }
1127   { // INST_RET abbrev for FUNCTION_BLOCK.
1128     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1129     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1130     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1131     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1132                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1133       assert(0 && "Unexpected abbrev ordering!");
1134   }
1135   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1136     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1137     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1138     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1139                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1140       assert(0 && "Unexpected abbrev ordering!");
1141   }
1142
1143   Stream.ExitBlock();
1144 }
1145
1146
1147 /// WriteModule - Emit the specified module to the bitstream.
1148 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1149   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1150
1151   // Emit the version number if it is non-zero.
1152   if (CurVersion) {
1153     SmallVector<unsigned, 1> Vals;
1154     Vals.push_back(CurVersion);
1155     Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1156   }
1157
1158   // Analyze the module, enumerating globals, functions, etc.
1159   ValueEnumerator VE(M);
1160
1161   // Emit blockinfo, which defines the standard abbreviations etc.
1162   WriteBlockInfo(VE, Stream);
1163
1164   // Emit information about parameter attributes.
1165   WriteParamAttrTable(VE, Stream);
1166
1167   // Emit information describing all of the types in the module.
1168   WriteTypeTable(VE, Stream);
1169
1170   // Emit top-level description of module, including target triple, inline asm,
1171   // descriptors for global variables, and function prototype info.
1172   WriteModuleInfo(M, VE, Stream);
1173
1174   // Emit constants.
1175   WriteModuleConstants(VE, Stream);
1176
1177   // If we have any aggregate values in the value table, purge them - these can
1178   // only be used to initialize global variables.  Doing so makes the value
1179   // namespace smaller for code in functions.
1180   int NumNonAggregates = VE.PurgeAggregateValues();
1181   if (NumNonAggregates != -1) {
1182     SmallVector<unsigned, 1> Vals;
1183     Vals.push_back(NumNonAggregates);
1184     Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
1185   }
1186
1187   // Emit function bodies.
1188   for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1189     if (!I->isDeclaration())
1190       WriteFunction(*I, VE, Stream);
1191
1192   // Emit the type symbol table information.
1193   WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1194
1195   // Emit names for globals/functions etc.
1196   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1197
1198   Stream.ExitBlock();
1199 }
1200
1201
1202 /// WriteBitcodeToFile - Write the specified module to the specified output
1203 /// stream.
1204 void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
1205   std::vector<unsigned char> Buffer;
1206   BitstreamWriter Stream(Buffer);
1207
1208   Buffer.reserve(256*1024);
1209
1210   // Emit the file header.
1211   Stream.Emit((unsigned)'B', 8);
1212   Stream.Emit((unsigned)'C', 8);
1213   Stream.Emit(0x0, 4);
1214   Stream.Emit(0xC, 4);
1215   Stream.Emit(0xE, 4);
1216   Stream.Emit(0xD, 4);
1217
1218   // Emit the module.
1219   WriteModule(M, Stream);
1220
1221   // Write the generated bitstream to "Out".
1222   Out.write((char*)&Buffer.front(), Buffer.size());
1223
1224   // Make sure it hits disk now.
1225   Out.flush();
1226 }