lib/Bitcode/Writer/BitcodeWriter.cpp

   1 //===--- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ----------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // 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/Operator.h"
  24 #include "llvm/TypeSymbolTable.h"
  25 #include "llvm/ValueSymbolTable.h"
  26 #include "llvm/Support/ErrorHandling.h"
  27 #include "llvm/Support/MathExtras.h"
  28 #include "llvm/Support/raw_ostream.h"
  29 #include "llvm/System/Program.h"
  30 using namespace llvm;
  31
  32 /// These are manifest constants used by the bitcode writer. They do not need to
  33 /// be kept in sync with the reader, but need to be consistent within this file.
  34 enum {
  35   CurVersion = 0,
  36
  37   // VALUE_SYMTAB_BLOCK abbrev id's.
  38   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  39   VST_ENTRY_7_ABBREV,
  40   VST_ENTRY_6_ABBREV,
  41   VST_BBENTRY_6_ABBREV,
  42
  43   // CONSTANTS_BLOCK abbrev id's.
  44   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  45   CONSTANTS_INTEGER_ABBREV,
  46   CONSTANTS_CE_CAST_Abbrev,
  47   CONSTANTS_NULL_Abbrev,
  48
  49   // FUNCTION_BLOCK abbrev id's.
  50   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  51   FUNCTION_INST_BINOP_ABBREV,
  52   FUNCTION_INST_BINOP_FLAGS_ABBREV,
  53   FUNCTION_INST_CAST_ABBREV,
  54   FUNCTION_INST_RET_VOID_ABBREV,
  55   FUNCTION_INST_RET_VAL_ABBREV,
  56   FUNCTION_INST_UNREACHABLE_ABBREV
  57 };
  58
  59
  60 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
  61   switch (Opcode) {
  62   default: llvm_unreachable("Unknown cast instruction!");
  63   case Instruction::Trunc   : return bitc::CAST_TRUNC;
  64   case Instruction::ZExt    : return bitc::CAST_ZEXT;
  65   case Instruction::SExt    : return bitc::CAST_SEXT;
  66   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
  67   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
  68   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
  69   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
  70   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
  71   case Instruction::FPExt   : return bitc::CAST_FPEXT;
  72   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
  73   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
  74   case Instruction::BitCast : return bitc::CAST_BITCAST;
  75   }
  76 }
  77
  78 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
  79   switch (Opcode) {
  80   default: llvm_unreachable("Unknown binary instruction!");
  81   case Instruction::Add:
  82   case Instruction::FAdd: return bitc::BINOP_ADD;
  83   case Instruction::Sub:
  84   case Instruction::FSub: return bitc::BINOP_SUB;
  85   case Instruction::Mul:
  86   case Instruction::FMul: return bitc::BINOP_MUL;
  87   case Instruction::UDiv: return bitc::BINOP_UDIV;
  88   case Instruction::FDiv:
  89   case Instruction::SDiv: return bitc::BINOP_SDIV;
  90   case Instruction::URem: return bitc::BINOP_UREM;
  91   case Instruction::FRem:
  92   case Instruction::SRem: return bitc::BINOP_SREM;
  93   case Instruction::Shl:  return bitc::BINOP_SHL;
  94   case Instruction::LShr: return bitc::BINOP_LSHR;
  95   case Instruction::AShr: return bitc::BINOP_ASHR;
  96   case Instruction::And:  return bitc::BINOP_AND;
  97   case Instruction::Or:   return bitc::BINOP_OR;
  98   case Instruction::Xor:  return bitc::BINOP_XOR;
  99   }
 100 }
 101
 102
 103
 104 static void WriteStringRecord(unsigned Code, const std::string &Str,
 105                               unsigned AbbrevToUse, BitstreamWriter &Stream) {
 106   SmallVector<unsigned, 64> Vals;
 107
 108   // Code: [strchar x N]
 109   for (unsigned i = 0, e = Str.size(); i != e; ++i)
 110     Vals.push_back(Str[i]);
 111
 112   // Emit the finished record.
 113   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 114 }
 115
 116 // Emit information about parameter attributes.
 117 static void WriteAttributeTable(const ValueEnumerator &VE,
 118                                 BitstreamWriter &Stream) {
 119   const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
 120   if (Attrs.empty()) return;
 121
 122   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 123
 124   SmallVector<uint64_t, 64> Record;
 125   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
 126     const AttrListPtr &A = Attrs[i];
 127     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
 128       const AttributeWithIndex &PAWI = A.getSlot(i);
 129       Record.push_back(PAWI.Index);
 130
 131       // FIXME: remove in LLVM 3.0
 132       // Store the alignment in the bitcode as a 16-bit raw value instead of a
 133       // 5-bit log2 encoded value. Shift the bits above the alignment up by
 134       // 11 bits.
 135       uint64_t FauxAttr = PAWI.Attrs & 0xffff;
 136       if (PAWI.Attrs & Attribute::Alignment)
 137         FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
 138       FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
 139
 140       Record.push_back(FauxAttr);
 141     }
 142
 143     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 144     Record.clear();
 145   }
 146
 147   Stream.ExitBlock();
 148 }
 149
 150 /// WriteTypeTable - Write out the type table for a module.
 151 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 152   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 153
 154   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
 155   SmallVector<uint64_t, 64> TypeVals;
 156
 157   // Abbrev for TYPE_CODE_POINTER.
 158   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 159   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
 160   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 161                             Log2_32_Ceil(VE.getTypes().size()+1)));
 162   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
 163   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
 164
 165   // Abbrev for TYPE_CODE_FUNCTION.
 166   Abbv = new BitCodeAbbrev();
 167   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
 168   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
 169   Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
 170   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 171   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 172                             Log2_32_Ceil(VE.getTypes().size()+1)));
 173   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 174
 175   // Abbrev for TYPE_CODE_STRUCT.
 176   Abbv = new BitCodeAbbrev();
 177   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
 178   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 179   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 180   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 181                             Log2_32_Ceil(VE.getTypes().size()+1)));
 182   unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
 183
 184   // Abbrev for TYPE_CODE_UNION.
 185   Abbv = new BitCodeAbbrev();
 186   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_UNION));
 187   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 188   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 189                             Log2_32_Ceil(VE.getTypes().size()+1)));
 190   unsigned UnionAbbrev = Stream.EmitAbbrev(Abbv);
 191
 192   // Abbrev for TYPE_CODE_ARRAY.
 193   Abbv = new BitCodeAbbrev();
 194   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 195   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 196   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 197                             Log2_32_Ceil(VE.getTypes().size()+1)));
 198   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 199
 200   // Emit an entry count so the reader can reserve space.
 201   TypeVals.push_back(TypeList.size());
 202   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 203   TypeVals.clear();
 204
 205   // Loop over all of the types, emitting each in turn.
 206   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 207     const Type *T = TypeList[i].first;
 208     int AbbrevToUse = 0;
 209     unsigned Code = 0;
 210
 211     switch (T->getTypeID()) {
 212     default: llvm_unreachable("Unknown type!");
 213     case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
 214     case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
 215     case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
 216     case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
 217     case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
 218     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 219     case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
 220     case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
 221     case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
 222     case Type::IntegerTyID:
 223       // INTEGER: [width]
 224       Code = bitc::TYPE_CODE_INTEGER;
 225       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 226       break;
 227     case Type::PointerTyID: {
 228       const PointerType *PTy = cast<PointerType>(T);
 229       // POINTER: [pointee type, address space]
 230       Code = bitc::TYPE_CODE_POINTER;
 231       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
 232       unsigned AddressSpace = PTy->getAddressSpace();
 233       TypeVals.push_back(AddressSpace);
 234       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
 235       break;
 236     }
 237     case Type::FunctionTyID: {
 238       const FunctionType *FT = cast<FunctionType>(T);
 239       // FUNCTION: [isvararg, attrid, retty, paramty x N]
 240       Code = bitc::TYPE_CODE_FUNCTION;
 241       TypeVals.push_back(FT->isVarArg());
 242       TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
 243       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 244       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 245         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 246       AbbrevToUse = FunctionAbbrev;
 247       break;
 248     }
 249     case Type::StructTyID: {
 250       const StructType *ST = cast<StructType>(T);
 251       // STRUCT: [ispacked, eltty x N]
 252       Code = bitc::TYPE_CODE_STRUCT;
 253       TypeVals.push_back(ST->isPacked());
 254       // Output all of the element types.
 255       for (StructType::element_iterator I = ST->element_begin(),
 256            E = ST->element_end(); I != E; ++I)
 257         TypeVals.push_back(VE.getTypeID(*I));
 258       AbbrevToUse = StructAbbrev;
 259       break;
 260     }
 261     case Type::UnionTyID: {
 262       const UnionType *UT = cast<UnionType>(T);
 263       // UNION: [eltty x N]
 264       Code = bitc::TYPE_CODE_UNION;
 265       // Output all of the element types.
 266       for (UnionType::element_iterator I = UT->element_begin(),
 267            E = UT->element_end(); I != E; ++I)
 268         TypeVals.push_back(VE.getTypeID(*I));
 269       AbbrevToUse = UnionAbbrev;
 270       break;
 271     }
 272     case Type::ArrayTyID: {
 273       const ArrayType *AT = cast<ArrayType>(T);
 274       // ARRAY: [numelts, eltty]
 275       Code = bitc::TYPE_CODE_ARRAY;
 276       TypeVals.push_back(AT->getNumElements());
 277       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 278       AbbrevToUse = ArrayAbbrev;
 279       break;
 280     }
 281     case Type::VectorTyID: {
 282       const VectorType *VT = cast<VectorType>(T);
 283       // VECTOR [numelts, eltty]
 284       Code = bitc::TYPE_CODE_VECTOR;
 285       TypeVals.push_back(VT->getNumElements());
 286       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 287       break;
 288     }
 289     }
 290
 291     // Emit the finished record.
 292     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 293     TypeVals.clear();
 294   }
 295
 296   Stream.ExitBlock();
 297 }
 298
 299 static unsigned getEncodedLinkage(const GlobalValue *GV) {
 300   switch (GV->getLinkage()) {
 301   default: llvm_unreachable("Invalid linkage!");
 302   case GlobalValue::ExternalLinkage:            return 0;
 303   case GlobalValue::WeakAnyLinkage:             return 1;
 304   case GlobalValue::AppendingLinkage:           return 2;
 305   case GlobalValue::InternalLinkage:            return 3;
 306   case GlobalValue::LinkOnceAnyLinkage:         return 4;
 307   case GlobalValue::DLLImportLinkage:           return 5;
 308   case GlobalValue::DLLExportLinkage:           return 6;
 309   case GlobalValue::ExternalWeakLinkage:        return 7;
 310   case GlobalValue::CommonLinkage:              return 8;
 311   case GlobalValue::PrivateLinkage:             return 9;
 312   case GlobalValue::WeakODRLinkage:             return 10;
 313   case GlobalValue::LinkOnceODRLinkage:         return 11;
 314   case GlobalValue::AvailableExternallyLinkage: return 12;
 315   case GlobalValue::LinkerPrivateLinkage:       return 13;
 316   }
 317 }
 318
 319 static unsigned getEncodedVisibility(const GlobalValue *GV) {
 320   switch (GV->getVisibility()) {
 321   default: llvm_unreachable("Invalid visibility!");
 322   case GlobalValue::DefaultVisibility:   return 0;
 323   case GlobalValue::HiddenVisibility:    return 1;
 324   case GlobalValue::ProtectedVisibility: return 2;
 325   }
 326 }
 327
 328 // Emit top-level description of module, including target triple, inline asm,
 329 // descriptors for global variables, and function prototype info.
 330 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 331                             BitstreamWriter &Stream) {
 332   // Emit the list of dependent libraries for the Module.
 333   for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
 334     WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
 335
 336   // Emit various pieces of data attached to a module.
 337   if (!M->getTargetTriple().empty())
 338     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 339                       0/*TODO*/, Stream);
 340   if (!M->getDataLayout().empty())
 341     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
 342                       0/*TODO*/, Stream);
 343   if (!M->getModuleInlineAsm().empty())
 344     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 345                       0/*TODO*/, Stream);
 346
 347   // Emit information about sections and GC, computing how many there are. Also
 348   // compute the maximum alignment value.
 349   std::map<std::string, unsigned> SectionMap;
 350   std::map<std::string, unsigned> GCMap;
 351   unsigned MaxAlignment = 0;
 352   unsigned MaxGlobalType = 0;
 353   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 354        GV != E; ++GV) {
 355     MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
 356     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
 357
 358     if (!GV->hasSection()) continue;
 359     // Give section names unique ID's.
 360     unsigned &Entry = SectionMap[GV->getSection()];
 361     if (Entry != 0) continue;
 362     WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
 363                       0/*TODO*/, Stream);
 364     Entry = SectionMap.size();
 365   }
 366   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 367     MaxAlignment = std::max(MaxAlignment, F->getAlignment());
 368     if (F->hasSection()) {
 369       // Give section names unique ID's.
 370       unsigned &Entry = SectionMap[F->getSection()];
 371       if (!Entry) {
 372         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
 373                           0/*TODO*/, Stream);
 374         Entry = SectionMap.size();
 375       }
 376     }
 377     if (F->hasGC()) {
 378       // Same for GC names.
 379       unsigned &Entry = GCMap[F->getGC()];
 380       if (!Entry) {
 381         WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
 382                           0/*TODO*/, Stream);
 383         Entry = GCMap.size();
 384       }
 385     }
 386   }
 387
 388   // Emit abbrev for globals, now that we know # sections and max alignment.
 389   unsigned SimpleGVarAbbrev = 0;
 390   if (!M->global_empty()) {
 391     // Add an abbrev for common globals with no visibility or thread localness.
 392     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 393     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 394     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 395                               Log2_32_Ceil(MaxGlobalType+1)));
 396     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
 397     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
 398     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
 399     if (MaxAlignment == 0)                                      // Alignment.
 400       Abbv->Add(BitCodeAbbrevOp(0));
 401     else {
 402       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 403       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 404                                Log2_32_Ceil(MaxEncAlignment+1)));
 405     }
 406     if (SectionMap.empty())                                    // Section.
 407       Abbv->Add(BitCodeAbbrevOp(0));
 408     else
 409       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 410                                Log2_32_Ceil(SectionMap.size()+1)));
 411     // Don't bother emitting vis + thread local.
 412     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 413   }
 414
 415   // Emit the global variable information.
 416   SmallVector<unsigned, 64> Vals;
 417   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 418        GV != E; ++GV) {
 419     unsigned AbbrevToUse = 0;
 420
 421     // GLOBALVAR: [type, isconst, initid,
 422     //             linkage, alignment, section, visibility, threadlocal]
 423     Vals.push_back(VE.getTypeID(GV->getType()));
 424     Vals.push_back(GV->isConstant());
 425     Vals.push_back(GV->isDeclaration() ? 0 :
 426                    (VE.getValueID(GV->getInitializer()) + 1));
 427     Vals.push_back(getEncodedLinkage(GV));
 428     Vals.push_back(Log2_32(GV->getAlignment())+1);
 429     Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
 430     if (GV->isThreadLocal() ||
 431         GV->getVisibility() != GlobalValue::DefaultVisibility) {
 432       Vals.push_back(getEncodedVisibility(GV));
 433       Vals.push_back(GV->isThreadLocal());
 434     } else {
 435       AbbrevToUse = SimpleGVarAbbrev;
 436     }
 437
 438     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 439     Vals.clear();
 440   }
 441
 442   // Emit the function proto information.
 443   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 444     // FUNCTION:  [type, callingconv, isproto, paramattr,
 445     //             linkage, alignment, section, visibility, gc]
 446     Vals.push_back(VE.getTypeID(F->getType()));
 447     Vals.push_back(F->getCallingConv());
 448     Vals.push_back(F->isDeclaration());
 449     Vals.push_back(getEncodedLinkage(F));
 450     Vals.push_back(VE.getAttributeID(F->getAttributes()));
 451     Vals.push_back(Log2_32(F->getAlignment())+1);
 452     Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
 453     Vals.push_back(getEncodedVisibility(F));
 454     Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
 455
 456     unsigned AbbrevToUse = 0;
 457     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 458     Vals.clear();
 459   }
 460
 461
 462   // Emit the alias information.
 463   for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
 464        AI != E; ++AI) {
 465     Vals.push_back(VE.getTypeID(AI->getType()));
 466     Vals.push_back(VE.getValueID(AI->getAliasee()));
 467     Vals.push_back(getEncodedLinkage(AI));
 468     Vals.push_back(getEncodedVisibility(AI));
 469     unsigned AbbrevToUse = 0;
 470     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 471     Vals.clear();
 472   }
 473 }
 474
 475 static uint64_t GetOptimizationFlags(const Value *V) {
 476   uint64_t Flags = 0;
 477
 478   if (const OverflowingBinaryOperator *OBO =
 479         dyn_cast<OverflowingBinaryOperator>(V)) {
 480     if (OBO->hasNoSignedWrap())
 481       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
 482     if (OBO->hasNoUnsignedWrap())
 483       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
 484   } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
 485     if (Div->isExact())
 486       Flags |= 1 << bitc::SDIV_EXACT;
 487   }
 488
 489   return Flags;
 490 }
 491
 492 static void WriteMDNode(const MDNode *N,
 493                         const ValueEnumerator &VE,
 494                         BitstreamWriter &Stream,
 495                         SmallVector<uint64_t, 64> &Record) {
 496   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
 497     if (N->getOperand(i)) {
 498       Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
 499       Record.push_back(VE.getValueID(N->getOperand(i)));
 500     } else {
 501       Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
 502       Record.push_back(0);
 503     }
 504   }
 505   unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
 506                                            bitc::METADATA_NODE;
 507   Stream.EmitRecord(MDCode, Record, 0);
 508   Record.clear();
 509 }
 510
 511 static void WriteModuleMetadata(const ValueEnumerator &VE,
 512                                 BitstreamWriter &Stream) {
 513   const ValueEnumerator::ValueList &Vals = VE.getMDValues();
 514   bool StartedMetadataBlock = false;
 515   unsigned MDSAbbrev = 0;
 516   SmallVector<uint64_t, 64> Record;
 517   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 518
 519     if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
 520       if (!N->isFunctionLocal() || !N->getFunction()) {
 521         if (!StartedMetadataBlock) {
 522           Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 523           StartedMetadataBlock = true;
 524         }
 525         WriteMDNode(N, VE, Stream, Record);
 526       }
 527     } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
 528       if (!StartedMetadataBlock)  {
 529         Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 530
 531         // Abbrev for METADATA_STRING.
 532         BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 533         Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
 534         Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 535         Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 536         MDSAbbrev = Stream.EmitAbbrev(Abbv);
 537         StartedMetadataBlock = true;
 538       }
 539
 540       // Code: [strchar x N]
 541       Record.append(MDS->begin(), MDS->end());
 542
 543       // Emit the finished record.
 544       Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
 545       Record.clear();
 546     } else if (const NamedMDNode *NMD = dyn_cast<NamedMDNode>(Vals[i].first)) {
 547       if (!StartedMetadataBlock)  {
 548         Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 549         StartedMetadataBlock = true;
 550       }
 551
 552       // Write name.
 553       StringRef Str = NMD->getName();
 554       for (unsigned i = 0, e = Str.size(); i != e; ++i)
 555         Record.push_back(Str[i]);
 556       Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
 557       Record.clear();
 558
 559       // Write named metadata operands.
 560       for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
 561         if (NMD->getOperand(i))
 562           Record.push_back(VE.getValueID(NMD->getOperand(i)));
 563         else
 564           Record.push_back(~0U);
 565       }
 566       Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
 567       Record.clear();
 568     }
 569   }
 570
 571   if (StartedMetadataBlock)
 572     Stream.ExitBlock();
 573 }
 574
 575 static void WriteFunctionLocalMetadata(const Function &F,
 576                                        const ValueEnumerator &VE,
 577                                        BitstreamWriter &Stream) {
 578   bool StartedMetadataBlock = false;
 579   SmallVector<uint64_t, 64> Record;
 580   const ValueEnumerator::ValueList &Vals = VE.getMDValues();
 581
 582   for (unsigned i = 0, e = Vals.size(); i != e; ++i)
 583     if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first))
 584       if (N->isFunctionLocal() && N->getFunction() == &F) {
 585         if (!StartedMetadataBlock) {
 586           Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 587           StartedMetadataBlock = true;
 588         }
 589         WriteMDNode(N, VE, Stream, Record);
 590       }
 591
 592   if (StartedMetadataBlock)
 593     Stream.ExitBlock();
 594 }
 595
 596 static void WriteMetadataAttachment(const Function &F,
 597                                     const ValueEnumerator &VE,
 598                                     BitstreamWriter &Stream) {
 599   bool StartedMetadataBlock = false;
 600   SmallVector<uint64_t, 64> Record;
 601
 602   // Write metadata attachments
 603   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
 604   SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
 605
 606   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
 607     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
 608          I != E; ++I) {
 609       MDs.clear();
 610       I->getAllMetadata(MDs);
 611
 612       // If no metadata, ignore instruction.
 613       if (MDs.empty()) continue;
 614
 615       Record.push_back(VE.getInstructionID(I));
 616
 617       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
 618         Record.push_back(MDs[i].first);
 619         Record.push_back(VE.getValueID(MDs[i].second));
 620       }
 621       if (!StartedMetadataBlock)  {
 622         Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
 623         StartedMetadataBlock = true;
 624       }
 625       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
 626       Record.clear();
 627     }
 628
 629   if (StartedMetadataBlock)
 630     Stream.ExitBlock();
 631 }
 632
 633 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
 634   SmallVector<uint64_t, 64> Record;
 635
 636   // Write metadata kinds
 637   // METADATA_KIND - [n x [id, name]]
 638   SmallVector<StringRef, 4> Names;
 639   M->getMDKindNames(Names);
 640
 641   assert(Names[0] == "" && "MDKind #0 is invalid");
 642   if (Names.size() == 1) return;
 643
 644   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 645
 646   for (unsigned MDKindID = 1, e = Names.size(); MDKindID != e; ++MDKindID) {
 647     Record.push_back(MDKindID);
 648     StringRef KName = Names[MDKindID];
 649     Record.append(KName.begin(), KName.end());
 650
 651     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
 652     Record.clear();
 653   }
 654
 655   Stream.ExitBlock();
 656 }
 657
 658 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
 659                            const ValueEnumerator &VE,
 660                            BitstreamWriter &Stream, bool isGlobal) {
 661   if (FirstVal == LastVal) return;
 662
 663   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
 664
 665   unsigned AggregateAbbrev = 0;
 666   unsigned String8Abbrev = 0;
 667   unsigned CString7Abbrev = 0;
 668   unsigned CString6Abbrev = 0;
 669   // If this is a constant pool for the module, emit module-specific abbrevs.
 670   if (isGlobal) {
 671     // Abbrev for CST_CODE_AGGREGATE.
 672     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 673     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
 674     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 675     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
 676     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
 677
 678     // Abbrev for CST_CODE_STRING.
 679     Abbv = new BitCodeAbbrev();
 680     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
 681     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 682     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 683     String8Abbrev = Stream.EmitAbbrev(Abbv);
 684     // Abbrev for CST_CODE_CSTRING.
 685     Abbv = new BitCodeAbbrev();
 686     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 687     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 688     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 689     CString7Abbrev = Stream.EmitAbbrev(Abbv);
 690     // Abbrev for CST_CODE_CSTRING.
 691     Abbv = new BitCodeAbbrev();
 692     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 693     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 694     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 695     CString6Abbrev = Stream.EmitAbbrev(Abbv);
 696   }
 697
 698   SmallVector<uint64_t, 64> Record;
 699
 700   const ValueEnumerator::ValueList &Vals = VE.getValues();
 701   const Type *LastTy = 0;
 702   for (unsigned i = FirstVal; i != LastVal; ++i) {
 703     const Value *V = Vals[i].first;
 704     // If we need to switch types, do so now.
 705     if (V->getType() != LastTy) {
 706       LastTy = V->getType();
 707       Record.push_back(VE.getTypeID(LastTy));
 708       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
 709                         CONSTANTS_SETTYPE_ABBREV);
 710       Record.clear();
 711     }
 712
 713     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
 714       Record.push_back(unsigned(IA->hasSideEffects()) |
 715                        unsigned(IA->isAlignStack()) << 1);
 716
 717       // Add the asm string.
 718       const std::string &AsmStr = IA->getAsmString();
 719       Record.push_back(AsmStr.size());
 720       for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
 721         Record.push_back(AsmStr[i]);
 722
 723       // Add the constraint string.
 724       const std::string &ConstraintStr = IA->getConstraintString();
 725       Record.push_back(ConstraintStr.size());
 726       for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
 727         Record.push_back(ConstraintStr[i]);
 728       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
 729       Record.clear();
 730       continue;
 731     }
 732     const Constant *C = cast<Constant>(V);
 733     unsigned Code = -1U;
 734     unsigned AbbrevToUse = 0;
 735     if (C->isNullValue()) {
 736       Code = bitc::CST_CODE_NULL;
 737     } else if (isa<UndefValue>(C)) {
 738       Code = bitc::CST_CODE_UNDEF;
 739     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
 740       if (IV->getBitWidth() <= 64) {
 741         int64_t V = IV->getSExtValue();
 742         if (V >= 0)
 743           Record.push_back(V << 1);
 744         else
 745           Record.push_back((-V << 1) | 1);
 746         Code = bitc::CST_CODE_INTEGER;
 747         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
 748       } else {                             // Wide integers, > 64 bits in size.
 749         // We have an arbitrary precision integer value to write whose
 750         // bit width is > 64. However, in canonical unsigned integer
 751         // format it is likely that the high bits are going to be zero.
 752         // So, we only write the number of active words.
 753         unsigned NWords = IV->getValue().getActiveWords();
 754         const uint64_t *RawWords = IV->getValue().getRawData();
 755         for (unsigned i = 0; i != NWords; ++i) {
 756           int64_t V = RawWords[i];
 757           if (V >= 0)
 758             Record.push_back(V << 1);
 759           else
 760             Record.push_back((-V << 1) | 1);
 761         }
 762         Code = bitc::CST_CODE_WIDE_INTEGER;
 763       }
 764     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
 765       Code = bitc::CST_CODE_FLOAT;
 766       const Type *Ty = CFP->getType();
 767       if (Ty->isFloatTy() || Ty->isDoubleTy()) {
 768         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
 769       } else if (Ty->isX86_FP80Ty()) {
 770         // api needed to prevent premature destruction
 771         // bits are not in the same order as a normal i80 APInt, compensate.
 772         APInt api = CFP->getValueAPF().bitcastToAPInt();
 773         const uint64_t *p = api.getRawData();
 774         Record.push_back((p[1] << 48) | (p[0] >> 16));
 775         Record.push_back(p[0] & 0xffffLL);
 776       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
 777         APInt api = CFP->getValueAPF().bitcastToAPInt();
 778         const uint64_t *p = api.getRawData();
 779         Record.push_back(p[0]);
 780         Record.push_back(p[1]);
 781       } else {
 782         assert (0 && "Unknown FP type!");
 783       }
 784     } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
 785       const ConstantArray *CA = cast<ConstantArray>(C);
 786       // Emit constant strings specially.
 787       unsigned NumOps = CA->getNumOperands();
 788       // If this is a null-terminated string, use the denser CSTRING encoding.
 789       if (CA->getOperand(NumOps-1)->isNullValue()) {
 790         Code = bitc::CST_CODE_CSTRING;
 791         --NumOps;  // Don't encode the null, which isn't allowed by char6.
 792       } else {
 793         Code = bitc::CST_CODE_STRING;
 794         AbbrevToUse = String8Abbrev;
 795       }
 796       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
 797       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
 798       for (unsigned i = 0; i != NumOps; ++i) {
 799         unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
 800         Record.push_back(V);
 801         isCStr7 &= (V & 128) == 0;
 802         if (isCStrChar6)
 803           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
 804       }
 805
 806       if (isCStrChar6)
 807         AbbrevToUse = CString6Abbrev;
 808       else if (isCStr7)
 809         AbbrevToUse = CString7Abbrev;
 810     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
 811                isa<ConstantVector>(V)) {
 812       Code = bitc::CST_CODE_AGGREGATE;
 813       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
 814         Record.push_back(VE.getValueID(C->getOperand(i)));
 815       AbbrevToUse = AggregateAbbrev;
 816     } else if (isa<ConstantUnion>(C)) {
 817       Code = bitc::CST_CODE_AGGREGATE;
 818
 819       // Unions only have one entry but we must send type along with it.
 820       const Type *EntryKind = C->getOperand(0)->getType();
 821
 822       const UnionType *UnTy = cast<UnionType>(C->getType());
 823       int UnionIndex = UnTy->getElementTypeIndex(EntryKind);
 824       assert(UnionIndex != -1 && "Constant union contains invalid entry");
 825
 826       Record.push_back(UnionIndex);
 827       Record.push_back(VE.getValueID(C->getOperand(0)));
 828
 829       AbbrevToUse = AggregateAbbrev;
 830     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
 831       switch (CE->getOpcode()) {
 832       default:
 833         if (Instruction::isCast(CE->getOpcode())) {
 834           Code = bitc::CST_CODE_CE_CAST;
 835           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
 836           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 837           Record.push_back(VE.getValueID(C->getOperand(0)));
 838           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
 839         } else {
 840           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
 841           Code = bitc::CST_CODE_CE_BINOP;
 842           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
 843           Record.push_back(VE.getValueID(C->getOperand(0)));
 844           Record.push_back(VE.getValueID(C->getOperand(1)));
 845           uint64_t Flags = GetOptimizationFlags(CE);
 846           if (Flags != 0)
 847             Record.push_back(Flags);
 848         }
 849         break;
 850       case Instruction::GetElementPtr:
 851         Code = bitc::CST_CODE_CE_GEP;
 852         if (cast<GEPOperator>(C)->isInBounds())
 853           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
 854         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
 855           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
 856           Record.push_back(VE.getValueID(C->getOperand(i)));
 857         }
 858         break;
 859       case Instruction::Select:
 860         Code = bitc::CST_CODE_CE_SELECT;
 861         Record.push_back(VE.getValueID(C->getOperand(0)));
 862         Record.push_back(VE.getValueID(C->getOperand(1)));
 863         Record.push_back(VE.getValueID(C->getOperand(2)));
 864         break;
 865       case Instruction::ExtractElement:
 866         Code = bitc::CST_CODE_CE_EXTRACTELT;
 867         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 868         Record.push_back(VE.getValueID(C->getOperand(0)));
 869         Record.push_back(VE.getValueID(C->getOperand(1)));
 870         break;
 871       case Instruction::InsertElement:
 872         Code = bitc::CST_CODE_CE_INSERTELT;
 873         Record.push_back(VE.getValueID(C->getOperand(0)));
 874         Record.push_back(VE.getValueID(C->getOperand(1)));
 875         Record.push_back(VE.getValueID(C->getOperand(2)));
 876         break;
 877       case Instruction::ShuffleVector:
 878         // If the return type and argument types are the same, this is a
 879         // standard shufflevector instruction.  If the types are different,
 880         // then the shuffle is widening or truncating the input vectors, and
 881         // the argument type must also be encoded.
 882         if (C->getType() == C->getOperand(0)->getType()) {
 883           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
 884         } else {
 885           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
 886           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 887         }
 888         Record.push_back(VE.getValueID(C->getOperand(0)));
 889         Record.push_back(VE.getValueID(C->getOperand(1)));
 890         Record.push_back(VE.getValueID(C->getOperand(2)));
 891         break;
 892       case Instruction::ICmp:
 893       case Instruction::FCmp:
 894         Code = bitc::CST_CODE_CE_CMP;
 895         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 896         Record.push_back(VE.getValueID(C->getOperand(0)));
 897         Record.push_back(VE.getValueID(C->getOperand(1)));
 898         Record.push_back(CE->getPredicate());
 899         break;
 900       }
 901     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
 902       assert(BA->getFunction() == BA->getBasicBlock()->getParent() &&
 903              "Malformed blockaddress");
 904       Code = bitc::CST_CODE_BLOCKADDRESS;
 905       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
 906       Record.push_back(VE.getValueID(BA->getFunction()));
 907       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
 908     } else {
 909       llvm_unreachable("Unknown constant!");
 910     }
 911     Stream.EmitRecord(Code, Record, AbbrevToUse);
 912     Record.clear();
 913   }
 914
 915   Stream.ExitBlock();
 916 }
 917
 918 static void WriteModuleConstants(const ValueEnumerator &VE,
 919                                  BitstreamWriter &Stream) {
 920   const ValueEnumerator::ValueList &Vals = VE.getValues();
 921
 922   // Find the first constant to emit, which is the first non-globalvalue value.
 923   // We know globalvalues have been emitted by WriteModuleInfo.
 924   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 925     if (!isa<GlobalValue>(Vals[i].first)) {
 926       WriteConstants(i, Vals.size(), VE, Stream, true);
 927       return;
 928     }
 929   }
 930 }
 931
 932 /// PushValueAndType - The file has to encode both the value and type id for
 933 /// many values, because we need to know what type to create for forward
 934 /// references.  However, most operands are not forward references, so this type
 935 /// field is not needed.
 936 ///
 937 /// This function adds V's value ID to Vals.  If the value ID is higher than the
 938 /// instruction ID, then it is a forward reference, and it also includes the
 939 /// type ID.
 940 static bool PushValueAndType(const Value *V, unsigned InstID,
 941                              SmallVector<unsigned, 64> &Vals,
 942                              ValueEnumerator &VE) {
 943   unsigned ValID = VE.getValueID(V);
 944   Vals.push_back(ValID);
 945   if (ValID >= InstID) {
 946     Vals.push_back(VE.getTypeID(V->getType()));
 947     return true;
 948   }
 949   return false;
 950 }
 951
 952 /// WriteInstruction - Emit an instruction to the specified stream.
 953 static void WriteInstruction(const Instruction &I, unsigned InstID,
 954                              ValueEnumerator &VE, BitstreamWriter &Stream,
 955                              SmallVector<unsigned, 64> &Vals) {
 956   unsigned Code = 0;
 957   unsigned AbbrevToUse = 0;
 958   VE.setInstructionID(&I);
 959   switch (I.getOpcode()) {
 960   default:
 961     if (Instruction::isCast(I.getOpcode())) {
 962       Code = bitc::FUNC_CODE_INST_CAST;
 963       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 964         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
 965       Vals.push_back(VE.getTypeID(I.getType()));
 966       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
 967     } else {
 968       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
 969       Code = bitc::FUNC_CODE_INST_BINOP;
 970       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
 971         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
 972       Vals.push_back(VE.getValueID(I.getOperand(1)));
 973       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
 974       uint64_t Flags = GetOptimizationFlags(&I);
 975       if (Flags != 0) {
 976         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
 977           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
 978         Vals.push_back(Flags);
 979       }
 980     }
 981     break;
 982
 983   case Instruction::GetElementPtr:
 984     Code = bitc::FUNC_CODE_INST_GEP;
 985     if (cast<GEPOperator>(&I)->isInBounds())
 986       Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
 987     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
 988       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
 989     break;
 990   case Instruction::ExtractValue: {
 991     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
 992     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
 993     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
 994     for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
 995       Vals.push_back(*i);
 996     break;
 997   }
 998   case Instruction::InsertValue: {
 999     Code = bitc::FUNC_CODE_INST_INSERTVAL;
1000     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1001     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1002     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1003     for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1004       Vals.push_back(*i);
1005     break;
1006   }
1007   case Instruction::Select:
1008     Code = bitc::FUNC_CODE_INST_VSELECT;
1009     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1010     Vals.push_back(VE.getValueID(I.getOperand(2)));
1011     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1012     break;
1013   case Instruction::ExtractElement:
1014     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1015     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1016     Vals.push_back(VE.getValueID(I.getOperand(1)));
1017     break;
1018   case Instruction::InsertElement:
1019     Code = bitc::FUNC_CODE_INST_INSERTELT;
1020     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1021     Vals.push_back(VE.getValueID(I.getOperand(1)));
1022     Vals.push_back(VE.getValueID(I.getOperand(2)));
1023     break;
1024   case Instruction::ShuffleVector:
1025     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1026     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1027     Vals.push_back(VE.getValueID(I.getOperand(1)));
1028     Vals.push_back(VE.getValueID(I.getOperand(2)));
1029     break;
1030   case Instruction::ICmp:
1031   case Instruction::FCmp:
1032     // compare returning Int1Ty or vector of Int1Ty
1033     Code = bitc::FUNC_CODE_INST_CMP2;
1034     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1035     Vals.push_back(VE.getValueID(I.getOperand(1)));
1036     Vals.push_back(cast<CmpInst>(I).getPredicate());
1037     break;
1038
1039   case Instruction::Ret:
1040     {
1041       Code = bitc::FUNC_CODE_INST_RET;
1042       unsigned NumOperands = I.getNumOperands();
1043       if (NumOperands == 0)
1044         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1045       else if (NumOperands == 1) {
1046         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1047           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1048       } else {
1049         for (unsigned i = 0, e = NumOperands; i != e; ++i)
1050           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1051       }
1052     }
1053     break;
1054   case Instruction::Br:
1055     {
1056       Code = bitc::FUNC_CODE_INST_BR;
1057       BranchInst &II = cast<BranchInst>(I);
1058       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1059       if (II.isConditional()) {
1060         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1061         Vals.push_back(VE.getValueID(II.getCondition()));
1062       }
1063     }
1064     break;
1065   case Instruction::Switch:
1066     Code = bitc::FUNC_CODE_INST_SWITCH;
1067     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1068     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1069       Vals.push_back(VE.getValueID(I.getOperand(i)));
1070     break;
1071   case Instruction::IndirectBr:
1072     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1073     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1074     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1075       Vals.push_back(VE.getValueID(I.getOperand(i)));
1076     break;
1077
1078   case Instruction::Invoke: {
1079     const InvokeInst *II = cast<InvokeInst>(&I);
1080     const Value *Callee(II->getCalledValue());
1081     const PointerType *PTy = cast<PointerType>(Callee->getType());
1082     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1083     Code = bitc::FUNC_CODE_INST_INVOKE;
1084
1085     Vals.push_back(VE.getAttributeID(II->getAttributes()));
1086     Vals.push_back(II->getCallingConv());
1087     Vals.push_back(VE.getValueID(II->getNormalDest()));
1088     Vals.push_back(VE.getValueID(II->getUnwindDest()));
1089     PushValueAndType(Callee, InstID, Vals, VE);
1090
1091     // Emit value #'s for the fixed parameters.
1092     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1093       Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1094
1095     // Emit type/value pairs for varargs params.
1096     if (FTy->isVarArg()) {
1097       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1098            i != e; ++i)
1099         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1100     }
1101     break;
1102   }
1103   case Instruction::Unwind:
1104     Code = bitc::FUNC_CODE_INST_UNWIND;
1105     break;
1106   case Instruction::Unreachable:
1107     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1108     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1109     break;
1110
1111   case Instruction::PHI:
1112     Code = bitc::FUNC_CODE_INST_PHI;
1113     Vals.push_back(VE.getTypeID(I.getType()));
1114     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1115       Vals.push_back(VE.getValueID(I.getOperand(i)));
1116     break;
1117
1118   case Instruction::Alloca:
1119     Code = bitc::FUNC_CODE_INST_ALLOCA;
1120     Vals.push_back(VE.getTypeID(I.getType()));
1121     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1122     Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1123     break;
1124
1125   case Instruction::Load:
1126     Code = bitc::FUNC_CODE_INST_LOAD;
1127     if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1128       AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1129
1130     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1131     Vals.push_back(cast<LoadInst>(I).isVolatile());
1132     break;
1133   case Instruction::Store:
1134     Code = bitc::FUNC_CODE_INST_STORE2;
1135     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1136     Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1137     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1138     Vals.push_back(cast<StoreInst>(I).isVolatile());
1139     break;
1140   case Instruction::Call: {
1141     const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
1142     const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1143
1144     Code = bitc::FUNC_CODE_INST_CALL;
1145
1146     const CallInst *CI = cast<CallInst>(&I);
1147     Vals.push_back(VE.getAttributeID(CI->getAttributes()));
1148     Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
1149     PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
1150
1151     // Emit value #'s for the fixed parameters.
1152     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1153       Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
1154
1155     // Emit type/value pairs for varargs params.
1156     if (FTy->isVarArg()) {
1157       unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
1158       for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
1159            i != e; ++i)
1160         PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
1161     }
1162     break;
1163   }
1164   case Instruction::VAArg:
1165     Code = bitc::FUNC_CODE_INST_VAARG;
1166     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1167     Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1168     Vals.push_back(VE.getTypeID(I.getType())); // restype.
1169     break;
1170   }
1171
1172   Stream.EmitRecord(Code, Vals, AbbrevToUse);
1173   Vals.clear();
1174 }
1175
1176 // Emit names for globals/functions etc.
1177 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1178                                   const ValueEnumerator &VE,
1179                                   BitstreamWriter &Stream) {
1180   if (VST.empty()) return;
1181   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1182
1183   // FIXME: Set up the abbrev, we know how many values there are!
1184   // FIXME: We know if the type names can use 7-bit ascii.
1185   SmallVector<unsigned, 64> NameVals;
1186
1187   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1188        SI != SE; ++SI) {
1189
1190     const ValueName &Name = *SI;
1191
1192     // Figure out the encoding to use for the name.
1193     bool is7Bit = true;
1194     bool isChar6 = true;
1195     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1196          C != E; ++C) {
1197       if (isChar6)
1198         isChar6 = BitCodeAbbrevOp::isChar6(*C);
1199       if ((unsigned char)*C & 128) {
1200         is7Bit = false;
1201         break;  // don't bother scanning the rest.
1202       }
1203     }
1204
1205     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1206
1207     // VST_ENTRY:   [valueid, namechar x N]
1208     // VST_BBENTRY: [bbid, namechar x N]
1209     unsigned Code;
1210     if (isa<BasicBlock>(SI->getValue())) {
1211       Code = bitc::VST_CODE_BBENTRY;
1212       if (isChar6)
1213         AbbrevToUse = VST_BBENTRY_6_ABBREV;
1214     } else {
1215       Code = bitc::VST_CODE_ENTRY;
1216       if (isChar6)
1217         AbbrevToUse = VST_ENTRY_6_ABBREV;
1218       else if (is7Bit)
1219         AbbrevToUse = VST_ENTRY_7_ABBREV;
1220     }
1221
1222     NameVals.push_back(VE.getValueID(SI->getValue()));
1223     for (const char *P = Name.getKeyData(),
1224          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1225       NameVals.push_back((unsigned char)*P);
1226
1227     // Emit the finished record.
1228     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1229     NameVals.clear();
1230   }
1231   Stream.ExitBlock();
1232 }
1233
1234 /// WriteFunction - Emit a function body to the module stream.
1235 static void WriteFunction(const Function &F, ValueEnumerator &VE,
1236                           BitstreamWriter &Stream) {
1237   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1238   VE.incorporateFunction(F);
1239
1240   SmallVector<unsigned, 64> Vals;
1241
1242   // Emit the number of basic blocks, so the reader can create them ahead of
1243   // time.
1244   Vals.push_back(VE.getBasicBlocks().size());
1245   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1246   Vals.clear();
1247
1248   // If there are function-local constants, emit them now.
1249   unsigned CstStart, CstEnd;
1250   VE.getFunctionConstantRange(CstStart, CstEnd);
1251   WriteConstants(CstStart, CstEnd, VE, Stream, false);
1252
1253   // If there is function-local metadata, emit it now.
1254   WriteFunctionLocalMetadata(F, VE, Stream);
1255
1256   // Keep a running idea of what the instruction ID is.
1257   unsigned InstID = CstEnd;
1258
1259   // Finally, emit all the instructions, in order.
1260   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1261     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1262          I != E; ++I) {
1263       WriteInstruction(*I, InstID, VE, Stream, Vals);
1264       if (!I->getType()->isVoidTy())
1265         ++InstID;
1266     }
1267
1268   // Emit names for all the instructions etc.
1269   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1270
1271   WriteMetadataAttachment(F, VE, Stream);
1272   VE.purgeFunction();
1273   Stream.ExitBlock();
1274 }
1275
1276 /// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1277 static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1278                                  const ValueEnumerator &VE,
1279                                  BitstreamWriter &Stream) {
1280   if (TST.empty()) return;
1281
1282   Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1283
1284   // 7-bit fixed width VST_CODE_ENTRY strings.
1285   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1286   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1287   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1288                             Log2_32_Ceil(VE.getTypes().size()+1)));
1289   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1290   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1291   unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1292
1293   SmallVector<unsigned, 64> NameVals;
1294
1295   for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1296        TI != TE; ++TI) {
1297     // TST_ENTRY: [typeid, namechar x N]
1298     NameVals.push_back(VE.getTypeID(TI->second));
1299
1300     const std::string &Str = TI->first;
1301     bool is7Bit = true;
1302     for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1303       NameVals.push_back((unsigned char)Str[i]);
1304       if (Str[i] & 128)
1305         is7Bit = false;
1306     }
1307
1308     // Emit the finished record.
1309     Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1310     NameVals.clear();
1311   }
1312
1313   Stream.ExitBlock();
1314 }
1315
1316 // Emit blockinfo, which defines the standard abbreviations etc.
1317 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1318   // We only want to emit block info records for blocks that have multiple
1319   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1320   // blocks can defined their abbrevs inline.
1321   Stream.EnterBlockInfoBlock(2);
1322
1323   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1324     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1325     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1326     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1327     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1328     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1329     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1330                                    Abbv) != VST_ENTRY_8_ABBREV)
1331       llvm_unreachable("Unexpected abbrev ordering!");
1332   }
1333
1334   { // 7-bit fixed width VST_ENTRY strings.
1335     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1336     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1337     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1338     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1339     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1340     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1341                                    Abbv) != VST_ENTRY_7_ABBREV)
1342       llvm_unreachable("Unexpected abbrev ordering!");
1343   }
1344   { // 6-bit char6 VST_ENTRY strings.
1345     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1346     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1347     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1348     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1349     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1350     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1351                                    Abbv) != VST_ENTRY_6_ABBREV)
1352       llvm_unreachable("Unexpected abbrev ordering!");
1353   }
1354   { // 6-bit char6 VST_BBENTRY strings.
1355     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1356     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1357     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1358     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1359     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1360     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1361                                    Abbv) != VST_BBENTRY_6_ABBREV)
1362       llvm_unreachable("Unexpected abbrev ordering!");
1363   }
1364
1365
1366
1367   { // SETTYPE abbrev for CONSTANTS_BLOCK.
1368     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1369     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1370     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1371                               Log2_32_Ceil(VE.getTypes().size()+1)));
1372     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1373                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
1374       llvm_unreachable("Unexpected abbrev ordering!");
1375   }
1376
1377   { // INTEGER abbrev for CONSTANTS_BLOCK.
1378     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1379     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1380     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1381     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1382                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
1383       llvm_unreachable("Unexpected abbrev ordering!");
1384   }
1385
1386   { // CE_CAST abbrev for CONSTANTS_BLOCK.
1387     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1388     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1389     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1390     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1391                               Log2_32_Ceil(VE.getTypes().size()+1)));
1392     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1393
1394     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1395                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
1396       llvm_unreachable("Unexpected abbrev ordering!");
1397   }
1398   { // NULL abbrev for CONSTANTS_BLOCK.
1399     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1400     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1401     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1402                                    Abbv) != CONSTANTS_NULL_Abbrev)
1403       llvm_unreachable("Unexpected abbrev ordering!");
1404   }
1405
1406   // FIXME: This should only use space for first class types!
1407
1408   { // INST_LOAD abbrev for FUNCTION_BLOCK.
1409     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1410     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1411     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1412     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1413     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1414     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1415                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
1416       llvm_unreachable("Unexpected abbrev ordering!");
1417   }
1418   { // INST_BINOP abbrev for FUNCTION_BLOCK.
1419     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1420     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1421     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1422     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1423     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1424     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1425                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
1426       llvm_unreachable("Unexpected abbrev ordering!");
1427   }
1428   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1429     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1430     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1431     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1432     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1433     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1434     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1435     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1436                                    Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1437       llvm_unreachable("Unexpected abbrev ordering!");
1438   }
1439   { // INST_CAST abbrev for FUNCTION_BLOCK.
1440     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1441     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1442     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1443     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1444                               Log2_32_Ceil(VE.getTypes().size()+1)));
1445     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1446     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1447                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
1448       llvm_unreachable("Unexpected abbrev ordering!");
1449   }
1450
1451   { // INST_RET abbrev for FUNCTION_BLOCK.
1452     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1453     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1454     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1455                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1456       llvm_unreachable("Unexpected abbrev ordering!");
1457   }
1458   { // INST_RET abbrev for FUNCTION_BLOCK.
1459     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1460     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1461     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1462     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1463                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1464       llvm_unreachable("Unexpected abbrev ordering!");
1465   }
1466   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1467     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1468     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1469     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1470                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1471       llvm_unreachable("Unexpected abbrev ordering!");
1472   }
1473
1474   Stream.ExitBlock();
1475 }
1476
1477
1478 /// WriteModule - Emit the specified module to the bitstream.
1479 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1480   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1481
1482   // Emit the version number if it is non-zero.
1483   if (CurVersion) {
1484     SmallVector<unsigned, 1> Vals;
1485     Vals.push_back(CurVersion);
1486     Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1487   }
1488
1489   // Analyze the module, enumerating globals, functions, etc.
1490   ValueEnumerator VE(M);
1491
1492   // Emit blockinfo, which defines the standard abbreviations etc.
1493   WriteBlockInfo(VE, Stream);
1494
1495   // Emit information about parameter attributes.
1496   WriteAttributeTable(VE, Stream);
1497
1498   // Emit information describing all of the types in the module.
1499   WriteTypeTable(VE, Stream);
1500
1501   // Emit top-level description of module, including target triple, inline asm,
1502   // descriptors for global variables, and function prototype info.
1503   WriteModuleInfo(M, VE, Stream);
1504
1505   // Emit constants.
1506   WriteModuleConstants(VE, Stream);
1507
1508   // Emit metadata.
1509   WriteModuleMetadata(VE, Stream);
1510
1511   // Emit function bodies.
1512   for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1513     if (!I->isDeclaration())
1514       WriteFunction(*I, VE, Stream);
1515
1516   // Emit metadata.
1517   WriteModuleMetadataStore(M, Stream);
1518
1519   // Emit the type symbol table information.
1520   WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1521
1522   // Emit names for globals/functions etc.
1523   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1524
1525   Stream.ExitBlock();
1526 }
1527
1528 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1529 /// header and trailer to make it compatible with the system archiver.  To do
1530 /// this we emit the following header, and then emit a trailer that pads the
1531 /// file out to be a multiple of 16 bytes.
1532 ///
1533 /// struct bc_header {
1534 ///   uint32_t Magic;         // 0x0B17C0DE
1535 ///   uint32_t Version;       // Version, currently always 0.
1536 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1537 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1538 ///   uint32_t CPUType;       // CPU specifier.
1539 ///   ... potentially more later ...
1540 /// };
1541 enum {
1542   DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1543   DarwinBCHeaderSize = 5*4
1544 };
1545
1546 /// isARMTriplet - Return true if the triplet looks like:
1547 /// arm-*, thumb-*, armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*.
1548 static bool isARMTriplet(const std::string &TT) {
1549   size_t Pos = 0;
1550   size_t Size = TT.size();
1551   if (Size >= 6 &&
1552       TT[0] == 't' && TT[1] == 'h' && TT[2] == 'u' &&
1553       TT[3] == 'm' && TT[4] == 'b')
1554     Pos = 5;
1555   else if (Size >= 4 && TT[0] == 'a' && TT[1] == 'r' && TT[2] == 'm')
1556     Pos = 3;
1557   else
1558     return false;
1559
1560   if (TT[Pos] == '-')
1561     return true;
1562   else if (TT[Pos] == 'v') {
1563     if (Size >= Pos+4 &&
1564         TT[Pos+1] == '6' && TT[Pos+2] == 't' && TT[Pos+3] == '2')
1565       return true;
1566     else if (Size >= Pos+4 &&
1567              TT[Pos+1] == '5' && TT[Pos+2] == 't' && TT[Pos+3] == 'e')
1568       return true;
1569   } else
1570     return false;
1571   while (++Pos < Size && TT[Pos] != '-') {
1572     if (!isdigit(TT[Pos]))
1573       return false;
1574   }
1575   return true;
1576 }
1577
1578 static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1579                                const std::string &TT) {
1580   unsigned CPUType = ~0U;
1581
1582   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1583   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1584   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1585   // specific constants here because they are implicitly part of the Darwin ABI.
1586   enum {
1587     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1588     DARWIN_CPU_TYPE_X86        = 7,
1589     DARWIN_CPU_TYPE_ARM        = 12,
1590     DARWIN_CPU_TYPE_POWERPC    = 18
1591   };
1592
1593   if (TT.find("x86_64-") == 0)
1594     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1595   else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1596            TT[4] == '-' && TT[1] - '3' < 6)
1597     CPUType = DARWIN_CPU_TYPE_X86;
1598   else if (TT.find("powerpc-") == 0)
1599     CPUType = DARWIN_CPU_TYPE_POWERPC;
1600   else if (TT.find("powerpc64-") == 0)
1601     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1602   else if (isARMTriplet(TT))
1603     CPUType = DARWIN_CPU_TYPE_ARM;
1604
1605   // Traditional Bitcode starts after header.
1606   unsigned BCOffset = DarwinBCHeaderSize;
1607
1608   Stream.Emit(0x0B17C0DE, 32);
1609   Stream.Emit(0         , 32);  // Version.
1610   Stream.Emit(BCOffset  , 32);
1611   Stream.Emit(0         , 32);  // Filled in later.
1612   Stream.Emit(CPUType   , 32);
1613 }
1614
1615 /// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1616 /// finalize the header.
1617 static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1618   // Update the size field in the header.
1619   Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1620
1621   // If the file is not a multiple of 16 bytes, insert dummy padding.
1622   while (BufferSize & 15) {
1623     Stream.Emit(0, 8);
1624     ++BufferSize;
1625   }
1626 }
1627
1628
1629 /// WriteBitcodeToFile - Write the specified module to the specified output
1630 /// stream.
1631 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1632   std::vector<unsigned char> Buffer;
1633   BitstreamWriter Stream(Buffer);
1634
1635   Buffer.reserve(256*1024);
1636
1637   WriteBitcodeToStream( M, Stream );
1638
1639   // If writing to stdout, set binary mode.
1640   if (&llvm::outs() == &Out)
1641     sys::Program::ChangeStdoutToBinary();
1642
1643   // Write the generated bitstream to "Out".
1644   Out.write((char*)&Buffer.front(), Buffer.size());
1645
1646   // Make sure it hits disk now.
1647   Out.flush();
1648 }
1649
1650 /// WriteBitcodeToStream - Write the specified module to the specified output
1651 /// stream.
1652 void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1653   // If this is darwin, emit a file header and trailer if needed.
1654   bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1655   if (isDarwin)
1656     EmitDarwinBCHeader(Stream, M->getTargetTriple());
1657
1658   // Emit the file header.
1659   Stream.Emit((unsigned)'B', 8);
1660   Stream.Emit((unsigned)'C', 8);
1661   Stream.Emit(0x0, 4);
1662   Stream.Emit(0xC, 4);
1663   Stream.Emit(0xE, 4);
1664   Stream.Emit(0xD, 4);
1665
1666   // Emit the module.
1667   WriteModule(M, Stream);
1668
1669   if (isDarwin)
1670     EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1671 }