contrib/llvm/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/ValueSymbolTable.h"
  25 #include "llvm/ADT/Triple.h"
  26 #include "llvm/Support/ErrorHandling.h"
  27 #include "llvm/Support/MathExtras.h"
  28 #include "llvm/Support/raw_ostream.h"
  29 #include "llvm/Support/Program.h"
  30 #include <cctype>
  31 #include <map>
  32 using namespace llvm;
  33
  34 /// These are manifest constants used by the bitcode writer. They do not need to
  35 /// be kept in sync with the reader, but need to be consistent within this file.
  36 enum {
  37   CurVersion = 0,
  38
  39   // VALUE_SYMTAB_BLOCK abbrev id's.
  40   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  41   VST_ENTRY_7_ABBREV,
  42   VST_ENTRY_6_ABBREV,
  43   VST_BBENTRY_6_ABBREV,
  44
  45   // CONSTANTS_BLOCK abbrev id's.
  46   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  47   CONSTANTS_INTEGER_ABBREV,
  48   CONSTANTS_CE_CAST_Abbrev,
  49   CONSTANTS_NULL_Abbrev,
  50
  51   // FUNCTION_BLOCK abbrev id's.
  52   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  53   FUNCTION_INST_BINOP_ABBREV,
  54   FUNCTION_INST_BINOP_FLAGS_ABBREV,
  55   FUNCTION_INST_CAST_ABBREV,
  56   FUNCTION_INST_RET_VOID_ABBREV,
  57   FUNCTION_INST_RET_VAL_ABBREV,
  58   FUNCTION_INST_UNREACHABLE_ABBREV
  59 };
  60
  61 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
  62   switch (Opcode) {
  63   default: llvm_unreachable("Unknown cast instruction!");
  64   case Instruction::Trunc   : return bitc::CAST_TRUNC;
  65   case Instruction::ZExt    : return bitc::CAST_ZEXT;
  66   case Instruction::SExt    : return bitc::CAST_SEXT;
  67   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
  68   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
  69   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
  70   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
  71   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
  72   case Instruction::FPExt   : return bitc::CAST_FPEXT;
  73   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
  74   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
  75   case Instruction::BitCast : return bitc::CAST_BITCAST;
  76   }
  77 }
  78
  79 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
  80   switch (Opcode) {
  81   default: llvm_unreachable("Unknown binary instruction!");
  82   case Instruction::Add:
  83   case Instruction::FAdd: return bitc::BINOP_ADD;
  84   case Instruction::Sub:
  85   case Instruction::FSub: return bitc::BINOP_SUB;
  86   case Instruction::Mul:
  87   case Instruction::FMul: return bitc::BINOP_MUL;
  88   case Instruction::UDiv: return bitc::BINOP_UDIV;
  89   case Instruction::FDiv:
  90   case Instruction::SDiv: return bitc::BINOP_SDIV;
  91   case Instruction::URem: return bitc::BINOP_UREM;
  92   case Instruction::FRem:
  93   case Instruction::SRem: return bitc::BINOP_SREM;
  94   case Instruction::Shl:  return bitc::BINOP_SHL;
  95   case Instruction::LShr: return bitc::BINOP_LSHR;
  96   case Instruction::AShr: return bitc::BINOP_ASHR;
  97   case Instruction::And:  return bitc::BINOP_AND;
  98   case Instruction::Or:   return bitc::BINOP_OR;
  99   case Instruction::Xor:  return bitc::BINOP_XOR;
 100   }
 101 }
 102
 103 static unsigned GetEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
 104   switch (Op) {
 105   default: llvm_unreachable("Unknown RMW operation!");
 106   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
 107   case AtomicRMWInst::Add: return bitc::RMW_ADD;
 108   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
 109   case AtomicRMWInst::And: return bitc::RMW_AND;
 110   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
 111   case AtomicRMWInst::Or: return bitc::RMW_OR;
 112   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
 113   case AtomicRMWInst::Max: return bitc::RMW_MAX;
 114   case AtomicRMWInst::Min: return bitc::RMW_MIN;
 115   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
 116   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
 117   }
 118 }
 119
 120 static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
 121   switch (Ordering) {
 122   default: llvm_unreachable("Unknown atomic ordering");
 123   case NotAtomic: return bitc::ORDERING_NOTATOMIC;
 124   case Unordered: return bitc::ORDERING_UNORDERED;
 125   case Monotonic: return bitc::ORDERING_MONOTONIC;
 126   case Acquire: return bitc::ORDERING_ACQUIRE;
 127   case Release: return bitc::ORDERING_RELEASE;
 128   case AcquireRelease: return bitc::ORDERING_ACQREL;
 129   case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
 130   }
 131 }
 132
 133 static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
 134   switch (SynchScope) {
 135   default: llvm_unreachable("Unknown synchronization scope");
 136   case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
 137   case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
 138   }
 139 }
 140
 141 static void WriteStringRecord(unsigned Code, StringRef Str,
 142                               unsigned AbbrevToUse, BitstreamWriter &Stream) {
 143   SmallVector<unsigned, 64> Vals;
 144
 145   // Code: [strchar x N]
 146   for (unsigned i = 0, e = Str.size(); i != e; ++i) {
 147     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
 148       AbbrevToUse = 0;
 149     Vals.push_back(Str[i]);
 150   }
 151
 152   // Emit the finished record.
 153   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 154 }
 155
 156 // Emit information about parameter attributes.
 157 static void WriteAttributeTable(const ValueEnumerator &VE,
 158                                 BitstreamWriter &Stream) {
 159   const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
 160   if (Attrs.empty()) return;
 161
 162   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 163
 164   SmallVector<uint64_t, 64> Record;
 165   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
 166     const AttrListPtr &A = Attrs[i];
 167     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
 168       const AttributeWithIndex &PAWI = A.getSlot(i);
 169       Record.push_back(PAWI.Index);
 170
 171       // FIXME: remove in LLVM 3.0
 172       // Store the alignment in the bitcode as a 16-bit raw value instead of a
 173       // 5-bit log2 encoded value. Shift the bits above the alignment up by
 174       // 11 bits.
 175       uint64_t FauxAttr = PAWI.Attrs & 0xffff;
 176       if (PAWI.Attrs & Attribute::Alignment)
 177         FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
 178       FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
 179
 180       Record.push_back(FauxAttr);
 181     }
 182
 183     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 184     Record.clear();
 185   }
 186
 187   Stream.ExitBlock();
 188 }
 189
 190 /// WriteTypeTable - Write out the type table for a module.
 191 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 192   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 193
 194   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
 195   SmallVector<uint64_t, 64> TypeVals;
 196
 197   // Abbrev for TYPE_CODE_POINTER.
 198   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 199   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
 200   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 201                             Log2_32_Ceil(VE.getTypes().size()+1)));
 202   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
 203   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
 204
 205   // Abbrev for TYPE_CODE_FUNCTION.
 206   Abbv = new BitCodeAbbrev();
 207   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
 208   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
 209   Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
 210   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 211   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 212                             Log2_32_Ceil(VE.getTypes().size()+1)));
 213   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 214
 215   // Abbrev for TYPE_CODE_STRUCT_ANON.
 216   Abbv = new BitCodeAbbrev();
 217   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
 218   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 219   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 220   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 221                             Log2_32_Ceil(VE.getTypes().size()+1)));
 222   unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
 223
 224   // Abbrev for TYPE_CODE_STRUCT_NAME.
 225   Abbv = new BitCodeAbbrev();
 226   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
 227   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 228   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 229   unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
 230
 231   // Abbrev for TYPE_CODE_STRUCT_NAMED.
 232   Abbv = new BitCodeAbbrev();
 233   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
 234   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 235   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 236   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 237                             Log2_32_Ceil(VE.getTypes().size()+1)));
 238   unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
 239
 240   // Abbrev for TYPE_CODE_ARRAY.
 241   Abbv = new BitCodeAbbrev();
 242   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 243   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 244   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 245                             Log2_32_Ceil(VE.getTypes().size()+1)));
 246   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 247
 248   // Emit an entry count so the reader can reserve space.
 249   TypeVals.push_back(TypeList.size());
 250   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 251   TypeVals.clear();
 252
 253   // Loop over all of the types, emitting each in turn.
 254   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 255     Type *T = TypeList[i];
 256     int AbbrevToUse = 0;
 257     unsigned Code = 0;
 258
 259     switch (T->getTypeID()) {
 260     default: llvm_unreachable("Unknown type!");
 261     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;   break;
 262     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;  break;
 263     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE; break;
 264     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80; break;
 265     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128; break;
 266     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 267     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;  break;
 268     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA; break;
 269     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX; break;
 270     case Type::IntegerTyID:
 271       // INTEGER: [width]
 272       Code = bitc::TYPE_CODE_INTEGER;
 273       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 274       break;
 275     case Type::PointerTyID: {
 276       PointerType *PTy = cast<PointerType>(T);
 277       // POINTER: [pointee type, address space]
 278       Code = bitc::TYPE_CODE_POINTER;
 279       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
 280       unsigned AddressSpace = PTy->getAddressSpace();
 281       TypeVals.push_back(AddressSpace);
 282       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
 283       break;
 284     }
 285     case Type::FunctionTyID: {
 286       FunctionType *FT = cast<FunctionType>(T);
 287       // FUNCTION: [isvararg, attrid, retty, paramty x N]
 288       Code = bitc::TYPE_CODE_FUNCTION;
 289       TypeVals.push_back(FT->isVarArg());
 290       TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
 291       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 292       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 293         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 294       AbbrevToUse = FunctionAbbrev;
 295       break;
 296     }
 297     case Type::StructTyID: {
 298       StructType *ST = cast<StructType>(T);
 299       // STRUCT: [ispacked, eltty x N]
 300       TypeVals.push_back(ST->isPacked());
 301       // Output all of the element types.
 302       for (StructType::element_iterator I = ST->element_begin(),
 303            E = ST->element_end(); I != E; ++I)
 304         TypeVals.push_back(VE.getTypeID(*I));
 305
 306       if (ST->isLiteral()) {
 307         Code = bitc::TYPE_CODE_STRUCT_ANON;
 308         AbbrevToUse = StructAnonAbbrev;
 309       } else {
 310         if (ST->isOpaque()) {
 311           Code = bitc::TYPE_CODE_OPAQUE;
 312         } else {
 313           Code = bitc::TYPE_CODE_STRUCT_NAMED;
 314           AbbrevToUse = StructNamedAbbrev;
 315         }
 316
 317         // Emit the name if it is present.
 318         if (!ST->getName().empty())
 319           WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
 320                             StructNameAbbrev, Stream);
 321       }
 322       break;
 323     }
 324     case Type::ArrayTyID: {
 325       ArrayType *AT = cast<ArrayType>(T);
 326       // ARRAY: [numelts, eltty]
 327       Code = bitc::TYPE_CODE_ARRAY;
 328       TypeVals.push_back(AT->getNumElements());
 329       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 330       AbbrevToUse = ArrayAbbrev;
 331       break;
 332     }
 333     case Type::VectorTyID: {
 334       VectorType *VT = cast<VectorType>(T);
 335       // VECTOR [numelts, eltty]
 336       Code = bitc::TYPE_CODE_VECTOR;
 337       TypeVals.push_back(VT->getNumElements());
 338       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 339       break;
 340     }
 341     }
 342
 343     // Emit the finished record.
 344     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 345     TypeVals.clear();
 346   }
 347
 348   Stream.ExitBlock();
 349 }
 350
 351 static unsigned getEncodedLinkage(const GlobalValue *GV) {
 352   switch (GV->getLinkage()) {
 353   default: llvm_unreachable("Invalid linkage!");
 354   case GlobalValue::ExternalLinkage:                 return 0;
 355   case GlobalValue::WeakAnyLinkage:                  return 1;
 356   case GlobalValue::AppendingLinkage:                return 2;
 357   case GlobalValue::InternalLinkage:                 return 3;
 358   case GlobalValue::LinkOnceAnyLinkage:              return 4;
 359   case GlobalValue::DLLImportLinkage:                return 5;
 360   case GlobalValue::DLLExportLinkage:                return 6;
 361   case GlobalValue::ExternalWeakLinkage:             return 7;
 362   case GlobalValue::CommonLinkage:                   return 8;
 363   case GlobalValue::PrivateLinkage:                  return 9;
 364   case GlobalValue::WeakODRLinkage:                  return 10;
 365   case GlobalValue::LinkOnceODRLinkage:              return 11;
 366   case GlobalValue::AvailableExternallyLinkage:      return 12;
 367   case GlobalValue::LinkerPrivateLinkage:            return 13;
 368   case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
 369   case GlobalValue::LinkerPrivateWeakDefAutoLinkage: return 15;
 370   }
 371 }
 372
 373 static unsigned getEncodedVisibility(const GlobalValue *GV) {
 374   switch (GV->getVisibility()) {
 375   default: llvm_unreachable("Invalid visibility!");
 376   case GlobalValue::DefaultVisibility:   return 0;
 377   case GlobalValue::HiddenVisibility:    return 1;
 378   case GlobalValue::ProtectedVisibility: return 2;
 379   }
 380 }
 381
 382 // Emit top-level description of module, including target triple, inline asm,
 383 // descriptors for global variables, and function prototype info.
 384 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 385                             BitstreamWriter &Stream) {
 386   // Emit the list of dependent libraries for the Module.
 387   for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
 388     WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
 389
 390   // Emit various pieces of data attached to a module.
 391   if (!M->getTargetTriple().empty())
 392     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 393                       0/*TODO*/, Stream);
 394   if (!M->getDataLayout().empty())
 395     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
 396                       0/*TODO*/, Stream);
 397   if (!M->getModuleInlineAsm().empty())
 398     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 399                       0/*TODO*/, Stream);
 400
 401   // Emit information about sections and GC, computing how many there are. Also
 402   // compute the maximum alignment value.
 403   std::map<std::string, unsigned> SectionMap;
 404   std::map<std::string, unsigned> GCMap;
 405   unsigned MaxAlignment = 0;
 406   unsigned MaxGlobalType = 0;
 407   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 408        GV != E; ++GV) {
 409     MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
 410     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
 411     if (GV->hasSection()) {
 412       // Give section names unique ID's.
 413       unsigned &Entry = SectionMap[GV->getSection()];
 414       if (!Entry) {
 415         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
 416                           0/*TODO*/, Stream);
 417         Entry = SectionMap.size();
 418       }
 419     }
 420   }
 421   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 422     MaxAlignment = std::max(MaxAlignment, F->getAlignment());
 423     if (F->hasSection()) {
 424       // Give section names unique ID's.
 425       unsigned &Entry = SectionMap[F->getSection()];
 426       if (!Entry) {
 427         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
 428                           0/*TODO*/, Stream);
 429         Entry = SectionMap.size();
 430       }
 431     }
 432     if (F->hasGC()) {
 433       // Same for GC names.
 434       unsigned &Entry = GCMap[F->getGC()];
 435       if (!Entry) {
 436         WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
 437                           0/*TODO*/, Stream);
 438         Entry = GCMap.size();
 439       }
 440     }
 441   }
 442
 443   // Emit abbrev for globals, now that we know # sections and max alignment.
 444   unsigned SimpleGVarAbbrev = 0;
 445   if (!M->global_empty()) {
 446     // Add an abbrev for common globals with no visibility or thread localness.
 447     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 448     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 449     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 450                               Log2_32_Ceil(MaxGlobalType+1)));
 451     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
 452     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
 453     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
 454     if (MaxAlignment == 0)                                      // Alignment.
 455       Abbv->Add(BitCodeAbbrevOp(0));
 456     else {
 457       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 458       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 459                                Log2_32_Ceil(MaxEncAlignment+1)));
 460     }
 461     if (SectionMap.empty())                                    // Section.
 462       Abbv->Add(BitCodeAbbrevOp(0));
 463     else
 464       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 465                                Log2_32_Ceil(SectionMap.size()+1)));
 466     // Don't bother emitting vis + thread local.
 467     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 468   }
 469
 470   // Emit the global variable information.
 471   SmallVector<unsigned, 64> Vals;
 472   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 473        GV != E; ++GV) {
 474     unsigned AbbrevToUse = 0;
 475
 476     // GLOBALVAR: [type, isconst, initid,
 477     //             linkage, alignment, section, visibility, threadlocal,
 478     //             unnamed_addr]
 479     Vals.push_back(VE.getTypeID(GV->getType()));
 480     Vals.push_back(GV->isConstant());
 481     Vals.push_back(GV->isDeclaration() ? 0 :
 482                    (VE.getValueID(GV->getInitializer()) + 1));
 483     Vals.push_back(getEncodedLinkage(GV));
 484     Vals.push_back(Log2_32(GV->getAlignment())+1);
 485     Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
 486     if (GV->isThreadLocal() ||
 487         GV->getVisibility() != GlobalValue::DefaultVisibility ||
 488         GV->hasUnnamedAddr()) {
 489       Vals.push_back(getEncodedVisibility(GV));
 490       Vals.push_back(GV->isThreadLocal());
 491       Vals.push_back(GV->hasUnnamedAddr());
 492     } else {
 493       AbbrevToUse = SimpleGVarAbbrev;
 494     }
 495
 496     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 497     Vals.clear();
 498   }
 499
 500   // Emit the function proto information.
 501   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 502     // FUNCTION:  [type, callingconv, isproto, paramattr,
 503     //             linkage, alignment, section, visibility, gc, unnamed_addr]
 504     Vals.push_back(VE.getTypeID(F->getType()));
 505     Vals.push_back(F->getCallingConv());
 506     Vals.push_back(F->isDeclaration());
 507     Vals.push_back(getEncodedLinkage(F));
 508     Vals.push_back(VE.getAttributeID(F->getAttributes()));
 509     Vals.push_back(Log2_32(F->getAlignment())+1);
 510     Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
 511     Vals.push_back(getEncodedVisibility(F));
 512     Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
 513     Vals.push_back(F->hasUnnamedAddr());
 514
 515     unsigned AbbrevToUse = 0;
 516     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 517     Vals.clear();
 518   }
 519
 520   // Emit the alias information.
 521   for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
 522        AI != E; ++AI) {
 523     Vals.push_back(VE.getTypeID(AI->getType()));
 524     Vals.push_back(VE.getValueID(AI->getAliasee()));
 525     Vals.push_back(getEncodedLinkage(AI));
 526     Vals.push_back(getEncodedVisibility(AI));
 527     unsigned AbbrevToUse = 0;
 528     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 529     Vals.clear();
 530   }
 531 }
 532
 533 static uint64_t GetOptimizationFlags(const Value *V) {
 534   uint64_t Flags = 0;
 535
 536   if (const OverflowingBinaryOperator *OBO =
 537         dyn_cast<OverflowingBinaryOperator>(V)) {
 538     if (OBO->hasNoSignedWrap())
 539       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
 540     if (OBO->hasNoUnsignedWrap())
 541       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
 542   } else if (const PossiblyExactOperator *PEO =
 543                dyn_cast<PossiblyExactOperator>(V)) {
 544     if (PEO->isExact())
 545       Flags |= 1 << bitc::PEO_EXACT;
 546   }
 547
 548   return Flags;
 549 }
 550
 551 static void WriteMDNode(const MDNode *N,
 552                         const ValueEnumerator &VE,
 553                         BitstreamWriter &Stream,
 554                         SmallVector<uint64_t, 64> &Record) {
 555   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
 556     if (N->getOperand(i)) {
 557       Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
 558       Record.push_back(VE.getValueID(N->getOperand(i)));
 559     } else {
 560       Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
 561       Record.push_back(0);
 562     }
 563   }
 564   unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
 565                                            bitc::METADATA_NODE;
 566   Stream.EmitRecord(MDCode, Record, 0);
 567   Record.clear();
 568 }
 569
 570 static void WriteModuleMetadata(const Module *M,
 571                                 const ValueEnumerator &VE,
 572                                 BitstreamWriter &Stream) {
 573   const ValueEnumerator::ValueList &Vals = VE.getMDValues();
 574   bool StartedMetadataBlock = false;
 575   unsigned MDSAbbrev = 0;
 576   SmallVector<uint64_t, 64> Record;
 577   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 578
 579     if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
 580       if (!N->isFunctionLocal() || !N->getFunction()) {
 581         if (!StartedMetadataBlock) {
 582           Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 583           StartedMetadataBlock = true;
 584         }
 585         WriteMDNode(N, VE, Stream, Record);
 586       }
 587     } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
 588       if (!StartedMetadataBlock)  {
 589         Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 590
 591         // Abbrev for METADATA_STRING.
 592         BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 593         Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
 594         Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 595         Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 596         MDSAbbrev = Stream.EmitAbbrev(Abbv);
 597         StartedMetadataBlock = true;
 598       }
 599
 600       // Code: [strchar x N]
 601       Record.append(MDS->begin(), MDS->end());
 602
 603       // Emit the finished record.
 604       Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
 605       Record.clear();
 606     }
 607   }
 608
 609   // Write named metadata.
 610   for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
 611        E = M->named_metadata_end(); I != E; ++I) {
 612     const NamedMDNode *NMD = I;
 613     if (!StartedMetadataBlock)  {
 614       Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 615       StartedMetadataBlock = true;
 616     }
 617
 618     // Write name.
 619     StringRef Str = NMD->getName();
 620     for (unsigned i = 0, e = Str.size(); i != e; ++i)
 621       Record.push_back(Str[i]);
 622     Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
 623     Record.clear();
 624
 625     // Write named metadata operands.
 626     for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
 627       Record.push_back(VE.getValueID(NMD->getOperand(i)));
 628     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
 629     Record.clear();
 630   }
 631
 632   if (StartedMetadataBlock)
 633     Stream.ExitBlock();
 634 }
 635
 636 static void WriteFunctionLocalMetadata(const Function &F,
 637                                        const ValueEnumerator &VE,
 638                                        BitstreamWriter &Stream) {
 639   bool StartedMetadataBlock = false;
 640   SmallVector<uint64_t, 64> Record;
 641   const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
 642   for (unsigned i = 0, e = Vals.size(); i != e; ++i)
 643     if (const MDNode *N = Vals[i])
 644       if (N->isFunctionLocal() && N->getFunction() == &F) {
 645         if (!StartedMetadataBlock) {
 646           Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 647           StartedMetadataBlock = true;
 648         }
 649         WriteMDNode(N, VE, Stream, Record);
 650       }
 651
 652   if (StartedMetadataBlock)
 653     Stream.ExitBlock();
 654 }
 655
 656 static void WriteMetadataAttachment(const Function &F,
 657                                     const ValueEnumerator &VE,
 658                                     BitstreamWriter &Stream) {
 659   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
 660
 661   SmallVector<uint64_t, 64> Record;
 662
 663   // Write metadata attachments
 664   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
 665   SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
 666
 667   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
 668     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
 669          I != E; ++I) {
 670       MDs.clear();
 671       I->getAllMetadataOtherThanDebugLoc(MDs);
 672
 673       // If no metadata, ignore instruction.
 674       if (MDs.empty()) continue;
 675
 676       Record.push_back(VE.getInstructionID(I));
 677
 678       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
 679         Record.push_back(MDs[i].first);
 680         Record.push_back(VE.getValueID(MDs[i].second));
 681       }
 682       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
 683       Record.clear();
 684     }
 685
 686   Stream.ExitBlock();
 687 }
 688
 689 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
 690   SmallVector<uint64_t, 64> Record;
 691
 692   // Write metadata kinds
 693   // METADATA_KIND - [n x [id, name]]
 694   SmallVector<StringRef, 4> Names;
 695   M->getMDKindNames(Names);
 696
 697   if (Names.empty()) return;
 698
 699   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 700
 701   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
 702     Record.push_back(MDKindID);
 703     StringRef KName = Names[MDKindID];
 704     Record.append(KName.begin(), KName.end());
 705
 706     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
 707     Record.clear();
 708   }
 709
 710   Stream.ExitBlock();
 711 }
 712
 713 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
 714                            const ValueEnumerator &VE,
 715                            BitstreamWriter &Stream, bool isGlobal) {
 716   if (FirstVal == LastVal) return;
 717
 718   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
 719
 720   unsigned AggregateAbbrev = 0;
 721   unsigned String8Abbrev = 0;
 722   unsigned CString7Abbrev = 0;
 723   unsigned CString6Abbrev = 0;
 724   // If this is a constant pool for the module, emit module-specific abbrevs.
 725   if (isGlobal) {
 726     // Abbrev for CST_CODE_AGGREGATE.
 727     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 728     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
 729     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 730     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
 731     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
 732
 733     // Abbrev for CST_CODE_STRING.
 734     Abbv = new BitCodeAbbrev();
 735     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
 736     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 737     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 738     String8Abbrev = Stream.EmitAbbrev(Abbv);
 739     // Abbrev for CST_CODE_CSTRING.
 740     Abbv = new BitCodeAbbrev();
 741     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 742     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 743     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 744     CString7Abbrev = Stream.EmitAbbrev(Abbv);
 745     // Abbrev for CST_CODE_CSTRING.
 746     Abbv = new BitCodeAbbrev();
 747     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 748     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 749     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 750     CString6Abbrev = Stream.EmitAbbrev(Abbv);
 751   }
 752
 753   SmallVector<uint64_t, 64> Record;
 754
 755   const ValueEnumerator::ValueList &Vals = VE.getValues();
 756   Type *LastTy = 0;
 757   for (unsigned i = FirstVal; i != LastVal; ++i) {
 758     const Value *V = Vals[i].first;
 759     // If we need to switch types, do so now.
 760     if (V->getType() != LastTy) {
 761       LastTy = V->getType();
 762       Record.push_back(VE.getTypeID(LastTy));
 763       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
 764                         CONSTANTS_SETTYPE_ABBREV);
 765       Record.clear();
 766     }
 767
 768     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
 769       Record.push_back(unsigned(IA->hasSideEffects()) |
 770                        unsigned(IA->isAlignStack()) << 1);
 771
 772       // Add the asm string.
 773       const std::string &AsmStr = IA->getAsmString();
 774       Record.push_back(AsmStr.size());
 775       for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
 776         Record.push_back(AsmStr[i]);
 777
 778       // Add the constraint string.
 779       const std::string &ConstraintStr = IA->getConstraintString();
 780       Record.push_back(ConstraintStr.size());
 781       for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
 782         Record.push_back(ConstraintStr[i]);
 783       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
 784       Record.clear();
 785       continue;
 786     }
 787     const Constant *C = cast<Constant>(V);
 788     unsigned Code = -1U;
 789     unsigned AbbrevToUse = 0;
 790     if (C->isNullValue()) {
 791       Code = bitc::CST_CODE_NULL;
 792     } else if (isa<UndefValue>(C)) {
 793       Code = bitc::CST_CODE_UNDEF;
 794     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
 795       if (IV->getBitWidth() <= 64) {
 796         uint64_t V = IV->getSExtValue();
 797         if ((int64_t)V >= 0)
 798           Record.push_back(V << 1);
 799         else
 800           Record.push_back((-V << 1) | 1);
 801         Code = bitc::CST_CODE_INTEGER;
 802         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
 803       } else {                             // Wide integers, > 64 bits in size.
 804         // We have an arbitrary precision integer value to write whose
 805         // bit width is > 64. However, in canonical unsigned integer
 806         // format it is likely that the high bits are going to be zero.
 807         // So, we only write the number of active words.
 808         unsigned NWords = IV->getValue().getActiveWords();
 809         const uint64_t *RawWords = IV->getValue().getRawData();
 810         for (unsigned i = 0; i != NWords; ++i) {
 811           int64_t V = RawWords[i];
 812           if (V >= 0)
 813             Record.push_back(V << 1);
 814           else
 815             Record.push_back((-V << 1) | 1);
 816         }
 817         Code = bitc::CST_CODE_WIDE_INTEGER;
 818       }
 819     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
 820       Code = bitc::CST_CODE_FLOAT;
 821       Type *Ty = CFP->getType();
 822       if (Ty->isFloatTy() || Ty->isDoubleTy()) {
 823         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
 824       } else if (Ty->isX86_FP80Ty()) {
 825         // api needed to prevent premature destruction
 826         // bits are not in the same order as a normal i80 APInt, compensate.
 827         APInt api = CFP->getValueAPF().bitcastToAPInt();
 828         const uint64_t *p = api.getRawData();
 829         Record.push_back((p[1] << 48) | (p[0] >> 16));
 830         Record.push_back(p[0] & 0xffffLL);
 831       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
 832         APInt api = CFP->getValueAPF().bitcastToAPInt();
 833         const uint64_t *p = api.getRawData();
 834         Record.push_back(p[0]);
 835         Record.push_back(p[1]);
 836       } else {
 837         assert (0 && "Unknown FP type!");
 838       }
 839     } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
 840       const ConstantArray *CA = cast<ConstantArray>(C);
 841       // Emit constant strings specially.
 842       unsigned NumOps = CA->getNumOperands();
 843       // If this is a null-terminated string, use the denser CSTRING encoding.
 844       if (CA->getOperand(NumOps-1)->isNullValue()) {
 845         Code = bitc::CST_CODE_CSTRING;
 846         --NumOps;  // Don't encode the null, which isn't allowed by char6.
 847       } else {
 848         Code = bitc::CST_CODE_STRING;
 849         AbbrevToUse = String8Abbrev;
 850       }
 851       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
 852       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
 853       for (unsigned i = 0; i != NumOps; ++i) {
 854         unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
 855         Record.push_back(V);
 856         isCStr7 &= (V & 128) == 0;
 857         if (isCStrChar6)
 858           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
 859       }
 860
 861       if (isCStrChar6)
 862         AbbrevToUse = CString6Abbrev;
 863       else if (isCStr7)
 864         AbbrevToUse = CString7Abbrev;
 865     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
 866                isa<ConstantVector>(V)) {
 867       Code = bitc::CST_CODE_AGGREGATE;
 868       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
 869         Record.push_back(VE.getValueID(C->getOperand(i)));
 870       AbbrevToUse = AggregateAbbrev;
 871     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
 872       switch (CE->getOpcode()) {
 873       default:
 874         if (Instruction::isCast(CE->getOpcode())) {
 875           Code = bitc::CST_CODE_CE_CAST;
 876           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
 877           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 878           Record.push_back(VE.getValueID(C->getOperand(0)));
 879           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
 880         } else {
 881           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
 882           Code = bitc::CST_CODE_CE_BINOP;
 883           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
 884           Record.push_back(VE.getValueID(C->getOperand(0)));
 885           Record.push_back(VE.getValueID(C->getOperand(1)));
 886           uint64_t Flags = GetOptimizationFlags(CE);
 887           if (Flags != 0)
 888             Record.push_back(Flags);
 889         }
 890         break;
 891       case Instruction::GetElementPtr:
 892         Code = bitc::CST_CODE_CE_GEP;
 893         if (cast<GEPOperator>(C)->isInBounds())
 894           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
 895         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
 896           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
 897           Record.push_back(VE.getValueID(C->getOperand(i)));
 898         }
 899         break;
 900       case Instruction::Select:
 901         Code = bitc::CST_CODE_CE_SELECT;
 902         Record.push_back(VE.getValueID(C->getOperand(0)));
 903         Record.push_back(VE.getValueID(C->getOperand(1)));
 904         Record.push_back(VE.getValueID(C->getOperand(2)));
 905         break;
 906       case Instruction::ExtractElement:
 907         Code = bitc::CST_CODE_CE_EXTRACTELT;
 908         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 909         Record.push_back(VE.getValueID(C->getOperand(0)));
 910         Record.push_back(VE.getValueID(C->getOperand(1)));
 911         break;
 912       case Instruction::InsertElement:
 913         Code = bitc::CST_CODE_CE_INSERTELT;
 914         Record.push_back(VE.getValueID(C->getOperand(0)));
 915         Record.push_back(VE.getValueID(C->getOperand(1)));
 916         Record.push_back(VE.getValueID(C->getOperand(2)));
 917         break;
 918       case Instruction::ShuffleVector:
 919         // If the return type and argument types are the same, this is a
 920         // standard shufflevector instruction.  If the types are different,
 921         // then the shuffle is widening or truncating the input vectors, and
 922         // the argument type must also be encoded.
 923         if (C->getType() == C->getOperand(0)->getType()) {
 924           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
 925         } else {
 926           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
 927           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 928         }
 929         Record.push_back(VE.getValueID(C->getOperand(0)));
 930         Record.push_back(VE.getValueID(C->getOperand(1)));
 931         Record.push_back(VE.getValueID(C->getOperand(2)));
 932         break;
 933       case Instruction::ICmp:
 934       case Instruction::FCmp:
 935         Code = bitc::CST_CODE_CE_CMP;
 936         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
 937         Record.push_back(VE.getValueID(C->getOperand(0)));
 938         Record.push_back(VE.getValueID(C->getOperand(1)));
 939         Record.push_back(CE->getPredicate());
 940         break;
 941       }
 942     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
 943       Code = bitc::CST_CODE_BLOCKADDRESS;
 944       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
 945       Record.push_back(VE.getValueID(BA->getFunction()));
 946       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
 947     } else {
 948 #ifndef NDEBUG
 949       C->dump();
 950 #endif
 951       llvm_unreachable("Unknown constant!");
 952     }
 953     Stream.EmitRecord(Code, Record, AbbrevToUse);
 954     Record.clear();
 955   }
 956
 957   Stream.ExitBlock();
 958 }
 959
 960 static void WriteModuleConstants(const ValueEnumerator &VE,
 961                                  BitstreamWriter &Stream) {
 962   const ValueEnumerator::ValueList &Vals = VE.getValues();
 963
 964   // Find the first constant to emit, which is the first non-globalvalue value.
 965   // We know globalvalues have been emitted by WriteModuleInfo.
 966   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 967     if (!isa<GlobalValue>(Vals[i].first)) {
 968       WriteConstants(i, Vals.size(), VE, Stream, true);
 969       return;
 970     }
 971   }
 972 }
 973
 974 /// PushValueAndType - The file has to encode both the value and type id for
 975 /// many values, because we need to know what type to create for forward
 976 /// references.  However, most operands are not forward references, so this type
 977 /// field is not needed.
 978 ///
 979 /// This function adds V's value ID to Vals.  If the value ID is higher than the
 980 /// instruction ID, then it is a forward reference, and it also includes the
 981 /// type ID.
 982 static bool PushValueAndType(const Value *V, unsigned InstID,
 983                              SmallVector<unsigned, 64> &Vals,
 984                              ValueEnumerator &VE) {
 985   unsigned ValID = VE.getValueID(V);
 986   Vals.push_back(ValID);
 987   if (ValID >= InstID) {
 988     Vals.push_back(VE.getTypeID(V->getType()));
 989     return true;
 990   }
 991   return false;
 992 }
 993
 994 /// WriteInstruction - Emit an instruction to the specified stream.
 995 static void WriteInstruction(const Instruction &I, unsigned InstID,
 996                              ValueEnumerator &VE, BitstreamWriter &Stream,
 997                              SmallVector<unsigned, 64> &Vals) {
 998   unsigned Code = 0;
 999   unsigned AbbrevToUse = 0;
1000   VE.setInstructionID(&I);
1001   switch (I.getOpcode()) {
1002   default:
1003     if (Instruction::isCast(I.getOpcode())) {
1004       Code = bitc::FUNC_CODE_INST_CAST;
1005       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1006         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1007       Vals.push_back(VE.getTypeID(I.getType()));
1008       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1009     } else {
1010       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1011       Code = bitc::FUNC_CODE_INST_BINOP;
1012       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1013         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1014       Vals.push_back(VE.getValueID(I.getOperand(1)));
1015       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1016       uint64_t Flags = GetOptimizationFlags(&I);
1017       if (Flags != 0) {
1018         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1019           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1020         Vals.push_back(Flags);
1021       }
1022     }
1023     break;
1024
1025   case Instruction::GetElementPtr:
1026     Code = bitc::FUNC_CODE_INST_GEP;
1027     if (cast<GEPOperator>(&I)->isInBounds())
1028       Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
1029     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1030       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1031     break;
1032   case Instruction::ExtractValue: {
1033     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1034     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1035     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1036     for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1037       Vals.push_back(*i);
1038     break;
1039   }
1040   case Instruction::InsertValue: {
1041     Code = bitc::FUNC_CODE_INST_INSERTVAL;
1042     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1043     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1044     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1045     for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1046       Vals.push_back(*i);
1047     break;
1048   }
1049   case Instruction::Select:
1050     Code = bitc::FUNC_CODE_INST_VSELECT;
1051     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1052     Vals.push_back(VE.getValueID(I.getOperand(2)));
1053     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1054     break;
1055   case Instruction::ExtractElement:
1056     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1057     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1058     Vals.push_back(VE.getValueID(I.getOperand(1)));
1059     break;
1060   case Instruction::InsertElement:
1061     Code = bitc::FUNC_CODE_INST_INSERTELT;
1062     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1063     Vals.push_back(VE.getValueID(I.getOperand(1)));
1064     Vals.push_back(VE.getValueID(I.getOperand(2)));
1065     break;
1066   case Instruction::ShuffleVector:
1067     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1068     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1069     Vals.push_back(VE.getValueID(I.getOperand(1)));
1070     Vals.push_back(VE.getValueID(I.getOperand(2)));
1071     break;
1072   case Instruction::ICmp:
1073   case Instruction::FCmp:
1074     // compare returning Int1Ty or vector of Int1Ty
1075     Code = bitc::FUNC_CODE_INST_CMP2;
1076     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1077     Vals.push_back(VE.getValueID(I.getOperand(1)));
1078     Vals.push_back(cast<CmpInst>(I).getPredicate());
1079     break;
1080
1081   case Instruction::Ret:
1082     {
1083       Code = bitc::FUNC_CODE_INST_RET;
1084       unsigned NumOperands = I.getNumOperands();
1085       if (NumOperands == 0)
1086         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1087       else if (NumOperands == 1) {
1088         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1089           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1090       } else {
1091         for (unsigned i = 0, e = NumOperands; i != e; ++i)
1092           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1093       }
1094     }
1095     break;
1096   case Instruction::Br:
1097     {
1098       Code = bitc::FUNC_CODE_INST_BR;
1099       BranchInst &II = cast<BranchInst>(I);
1100       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1101       if (II.isConditional()) {
1102         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1103         Vals.push_back(VE.getValueID(II.getCondition()));
1104       }
1105     }
1106     break;
1107   case Instruction::Switch:
1108     Code = bitc::FUNC_CODE_INST_SWITCH;
1109     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1110     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1111       Vals.push_back(VE.getValueID(I.getOperand(i)));
1112     break;
1113   case Instruction::IndirectBr:
1114     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1115     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1116     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1117       Vals.push_back(VE.getValueID(I.getOperand(i)));
1118     break;
1119
1120   case Instruction::Invoke: {
1121     const InvokeInst *II = cast<InvokeInst>(&I);
1122     const Value *Callee(II->getCalledValue());
1123     PointerType *PTy = cast<PointerType>(Callee->getType());
1124     FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1125     Code = bitc::FUNC_CODE_INST_INVOKE;
1126
1127     Vals.push_back(VE.getAttributeID(II->getAttributes()));
1128     Vals.push_back(II->getCallingConv());
1129     Vals.push_back(VE.getValueID(II->getNormalDest()));
1130     Vals.push_back(VE.getValueID(II->getUnwindDest()));
1131     PushValueAndType(Callee, InstID, Vals, VE);
1132
1133     // Emit value #'s for the fixed parameters.
1134     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1135       Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1136
1137     // Emit type/value pairs for varargs params.
1138     if (FTy->isVarArg()) {
1139       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1140            i != e; ++i)
1141         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1142     }
1143     break;
1144   }
1145   case Instruction::Resume:
1146     Code = bitc::FUNC_CODE_INST_RESUME;
1147     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1148     break;
1149   case Instruction::Unwind:
1150     Code = bitc::FUNC_CODE_INST_UNWIND;
1151     break;
1152   case Instruction::Unreachable:
1153     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1154     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1155     break;
1156
1157   case Instruction::PHI: {
1158     const PHINode &PN = cast<PHINode>(I);
1159     Code = bitc::FUNC_CODE_INST_PHI;
1160     Vals.push_back(VE.getTypeID(PN.getType()));
1161     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1162       Vals.push_back(VE.getValueID(PN.getIncomingValue(i)));
1163       Vals.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1164     }
1165     break;
1166   }
1167
1168   case Instruction::LandingPad: {
1169     const LandingPadInst &LP = cast<LandingPadInst>(I);
1170     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
1171     Vals.push_back(VE.getTypeID(LP.getType()));
1172     PushValueAndType(LP.getPersonalityFn(), InstID, Vals, VE);
1173     Vals.push_back(LP.isCleanup());
1174     Vals.push_back(LP.getNumClauses());
1175     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1176       if (LP.isCatch(I))
1177         Vals.push_back(LandingPadInst::Catch);
1178       else
1179         Vals.push_back(LandingPadInst::Filter);
1180       PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1181     }
1182     break;
1183   }
1184
1185   case Instruction::Alloca:
1186     Code = bitc::FUNC_CODE_INST_ALLOCA;
1187     Vals.push_back(VE.getTypeID(I.getType()));
1188     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1189     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1190     Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1191     break;
1192
1193   case Instruction::Load:
1194     if (cast<LoadInst>(I).isAtomic()) {
1195       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1196       PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1197     } else {
1198       Code = bitc::FUNC_CODE_INST_LOAD;
1199       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1200         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1201     }
1202     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1203     Vals.push_back(cast<LoadInst>(I).isVolatile());
1204     if (cast<LoadInst>(I).isAtomic()) {
1205       Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1206       Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1207     }
1208     break;
1209   case Instruction::Store:
1210     if (cast<StoreInst>(I).isAtomic())
1211       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1212     else
1213       Code = bitc::FUNC_CODE_INST_STORE;
1214     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1215     Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1216     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1217     Vals.push_back(cast<StoreInst>(I).isVolatile());
1218     if (cast<StoreInst>(I).isAtomic()) {
1219       Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1220       Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1221     }
1222     break;
1223   case Instruction::AtomicCmpXchg:
1224     Code = bitc::FUNC_CODE_INST_CMPXCHG;
1225     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1226     Vals.push_back(VE.getValueID(I.getOperand(1)));       // cmp.
1227     Vals.push_back(VE.getValueID(I.getOperand(2)));       // newval.
1228     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1229     Vals.push_back(GetEncodedOrdering(
1230                      cast<AtomicCmpXchgInst>(I).getOrdering()));
1231     Vals.push_back(GetEncodedSynchScope(
1232                      cast<AtomicCmpXchgInst>(I).getSynchScope()));
1233     break;
1234   case Instruction::AtomicRMW:
1235     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
1236     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1237     Vals.push_back(VE.getValueID(I.getOperand(1)));       // val.
1238     Vals.push_back(GetEncodedRMWOperation(
1239                      cast<AtomicRMWInst>(I).getOperation()));
1240     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
1241     Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
1242     Vals.push_back(GetEncodedSynchScope(
1243                      cast<AtomicRMWInst>(I).getSynchScope()));
1244     break;
1245   case Instruction::Fence:
1246     Code = bitc::FUNC_CODE_INST_FENCE;
1247     Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
1248     Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
1249     break;
1250   case Instruction::Call: {
1251     const CallInst &CI = cast<CallInst>(I);
1252     PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1253     FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1254
1255     Code = bitc::FUNC_CODE_INST_CALL;
1256
1257     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1258     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1259     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1260
1261     // Emit value #'s for the fixed parameters.
1262     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1263       Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1264
1265     // Emit type/value pairs for varargs params.
1266     if (FTy->isVarArg()) {
1267       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1268            i != e; ++i)
1269         PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1270     }
1271     break;
1272   }
1273   case Instruction::VAArg:
1274     Code = bitc::FUNC_CODE_INST_VAARG;
1275     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1276     Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1277     Vals.push_back(VE.getTypeID(I.getType())); // restype.
1278     break;
1279   }
1280
1281   Stream.EmitRecord(Code, Vals, AbbrevToUse);
1282   Vals.clear();
1283 }
1284
1285 // Emit names for globals/functions etc.
1286 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1287                                   const ValueEnumerator &VE,
1288                                   BitstreamWriter &Stream) {
1289   if (VST.empty()) return;
1290   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1291
1292   // FIXME: Set up the abbrev, we know how many values there are!
1293   // FIXME: We know if the type names can use 7-bit ascii.
1294   SmallVector<unsigned, 64> NameVals;
1295
1296   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1297        SI != SE; ++SI) {
1298
1299     const ValueName &Name = *SI;
1300
1301     // Figure out the encoding to use for the name.
1302     bool is7Bit = true;
1303     bool isChar6 = true;
1304     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1305          C != E; ++C) {
1306       if (isChar6)
1307         isChar6 = BitCodeAbbrevOp::isChar6(*C);
1308       if ((unsigned char)*C & 128) {
1309         is7Bit = false;
1310         break;  // don't bother scanning the rest.
1311       }
1312     }
1313
1314     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1315
1316     // VST_ENTRY:   [valueid, namechar x N]
1317     // VST_BBENTRY: [bbid, namechar x N]
1318     unsigned Code;
1319     if (isa<BasicBlock>(SI->getValue())) {
1320       Code = bitc::VST_CODE_BBENTRY;
1321       if (isChar6)
1322         AbbrevToUse = VST_BBENTRY_6_ABBREV;
1323     } else {
1324       Code = bitc::VST_CODE_ENTRY;
1325       if (isChar6)
1326         AbbrevToUse = VST_ENTRY_6_ABBREV;
1327       else if (is7Bit)
1328         AbbrevToUse = VST_ENTRY_7_ABBREV;
1329     }
1330
1331     NameVals.push_back(VE.getValueID(SI->getValue()));
1332     for (const char *P = Name.getKeyData(),
1333          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1334       NameVals.push_back((unsigned char)*P);
1335
1336     // Emit the finished record.
1337     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1338     NameVals.clear();
1339   }
1340   Stream.ExitBlock();
1341 }
1342
1343 /// WriteFunction - Emit a function body to the module stream.
1344 static void WriteFunction(const Function &F, ValueEnumerator &VE,
1345                           BitstreamWriter &Stream) {
1346   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1347   VE.incorporateFunction(F);
1348
1349   SmallVector<unsigned, 64> Vals;
1350
1351   // Emit the number of basic blocks, so the reader can create them ahead of
1352   // time.
1353   Vals.push_back(VE.getBasicBlocks().size());
1354   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1355   Vals.clear();
1356
1357   // If there are function-local constants, emit them now.
1358   unsigned CstStart, CstEnd;
1359   VE.getFunctionConstantRange(CstStart, CstEnd);
1360   WriteConstants(CstStart, CstEnd, VE, Stream, false);
1361
1362   // If there is function-local metadata, emit it now.
1363   WriteFunctionLocalMetadata(F, VE, Stream);
1364
1365   // Keep a running idea of what the instruction ID is.
1366   unsigned InstID = CstEnd;
1367
1368   bool NeedsMetadataAttachment = false;
1369
1370   DebugLoc LastDL;
1371
1372   // Finally, emit all the instructions, in order.
1373   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1374     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1375          I != E; ++I) {
1376       WriteInstruction(*I, InstID, VE, Stream, Vals);
1377
1378       if (!I->getType()->isVoidTy())
1379         ++InstID;
1380
1381       // If the instruction has metadata, write a metadata attachment later.
1382       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1383
1384       // If the instruction has a debug location, emit it.
1385       DebugLoc DL = I->getDebugLoc();
1386       if (DL.isUnknown()) {
1387         // nothing todo.
1388       } else if (DL == LastDL) {
1389         // Just repeat the same debug loc as last time.
1390         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1391       } else {
1392         MDNode *Scope, *IA;
1393         DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1394
1395         Vals.push_back(DL.getLine());
1396         Vals.push_back(DL.getCol());
1397         Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1398         Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1399         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1400         Vals.clear();
1401
1402         LastDL = DL;
1403       }
1404     }
1405
1406   // Emit names for all the instructions etc.
1407   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1408
1409   if (NeedsMetadataAttachment)
1410     WriteMetadataAttachment(F, VE, Stream);
1411   VE.purgeFunction();
1412   Stream.ExitBlock();
1413 }
1414
1415 // Emit blockinfo, which defines the standard abbreviations etc.
1416 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1417   // We only want to emit block info records for blocks that have multiple
1418   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1419   // blocks can defined their abbrevs inline.
1420   Stream.EnterBlockInfoBlock(2);
1421
1422   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1423     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1424     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1425     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1426     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1427     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1428     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1429                                    Abbv) != VST_ENTRY_8_ABBREV)
1430       llvm_unreachable("Unexpected abbrev ordering!");
1431   }
1432
1433   { // 7-bit fixed width VST_ENTRY strings.
1434     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1435     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1436     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1437     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1438     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1439     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1440                                    Abbv) != VST_ENTRY_7_ABBREV)
1441       llvm_unreachable("Unexpected abbrev ordering!");
1442   }
1443   { // 6-bit char6 VST_ENTRY strings.
1444     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1445     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1446     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1447     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1448     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1449     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1450                                    Abbv) != VST_ENTRY_6_ABBREV)
1451       llvm_unreachable("Unexpected abbrev ordering!");
1452   }
1453   { // 6-bit char6 VST_BBENTRY strings.
1454     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1455     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1456     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1457     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1458     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1459     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1460                                    Abbv) != VST_BBENTRY_6_ABBREV)
1461       llvm_unreachable("Unexpected abbrev ordering!");
1462   }
1463
1464
1465
1466   { // SETTYPE abbrev for CONSTANTS_BLOCK.
1467     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1468     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1469     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1470                               Log2_32_Ceil(VE.getTypes().size()+1)));
1471     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1472                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
1473       llvm_unreachable("Unexpected abbrev ordering!");
1474   }
1475
1476   { // INTEGER abbrev for CONSTANTS_BLOCK.
1477     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1478     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1479     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1480     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1481                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
1482       llvm_unreachable("Unexpected abbrev ordering!");
1483   }
1484
1485   { // CE_CAST abbrev for CONSTANTS_BLOCK.
1486     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1487     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1488     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1489     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1490                               Log2_32_Ceil(VE.getTypes().size()+1)));
1491     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1492
1493     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1494                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
1495       llvm_unreachable("Unexpected abbrev ordering!");
1496   }
1497   { // NULL abbrev for CONSTANTS_BLOCK.
1498     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1499     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1500     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1501                                    Abbv) != CONSTANTS_NULL_Abbrev)
1502       llvm_unreachable("Unexpected abbrev ordering!");
1503   }
1504
1505   // FIXME: This should only use space for first class types!
1506
1507   { // INST_LOAD abbrev for FUNCTION_BLOCK.
1508     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1509     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1510     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1511     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1512     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1513     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1514                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
1515       llvm_unreachable("Unexpected abbrev ordering!");
1516   }
1517   { // INST_BINOP abbrev for FUNCTION_BLOCK.
1518     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1519     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1520     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1521     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1522     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1523     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1524                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
1525       llvm_unreachable("Unexpected abbrev ordering!");
1526   }
1527   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1528     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1529     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1530     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1531     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1532     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1533     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1534     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1535                                    Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1536       llvm_unreachable("Unexpected abbrev ordering!");
1537   }
1538   { // INST_CAST abbrev for FUNCTION_BLOCK.
1539     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1540     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1541     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1542     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1543                               Log2_32_Ceil(VE.getTypes().size()+1)));
1544     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1545     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1546                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
1547       llvm_unreachable("Unexpected abbrev ordering!");
1548   }
1549
1550   { // INST_RET abbrev for FUNCTION_BLOCK.
1551     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1552     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1553     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1554                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1555       llvm_unreachable("Unexpected abbrev ordering!");
1556   }
1557   { // INST_RET abbrev for FUNCTION_BLOCK.
1558     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1559     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1560     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1561     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1562                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1563       llvm_unreachable("Unexpected abbrev ordering!");
1564   }
1565   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1566     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1567     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1568     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1569                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1570       llvm_unreachable("Unexpected abbrev ordering!");
1571   }
1572
1573   Stream.ExitBlock();
1574 }
1575
1576
1577 /// WriteModule - Emit the specified module to the bitstream.
1578 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1579   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1580
1581   // Emit the version number if it is non-zero.
1582   if (CurVersion) {
1583     SmallVector<unsigned, 1> Vals;
1584     Vals.push_back(CurVersion);
1585     Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1586   }
1587
1588   // Analyze the module, enumerating globals, functions, etc.
1589   ValueEnumerator VE(M);
1590
1591   // Emit blockinfo, which defines the standard abbreviations etc.
1592   WriteBlockInfo(VE, Stream);
1593
1594   // Emit information about parameter attributes.
1595   WriteAttributeTable(VE, Stream);
1596
1597   // Emit information describing all of the types in the module.
1598   WriteTypeTable(VE, Stream);
1599
1600   // Emit top-level description of module, including target triple, inline asm,
1601   // descriptors for global variables, and function prototype info.
1602   WriteModuleInfo(M, VE, Stream);
1603
1604   // Emit constants.
1605   WriteModuleConstants(VE, Stream);
1606
1607   // Emit metadata.
1608   WriteModuleMetadata(M, VE, Stream);
1609
1610   // Emit function bodies.
1611   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1612     if (!F->isDeclaration())
1613       WriteFunction(*F, VE, Stream);
1614
1615   // Emit metadata.
1616   WriteModuleMetadataStore(M, Stream);
1617
1618   // Emit names for globals/functions etc.
1619   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1620
1621   Stream.ExitBlock();
1622 }
1623
1624 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1625 /// header and trailer to make it compatible with the system archiver.  To do
1626 /// this we emit the following header, and then emit a trailer that pads the
1627 /// file out to be a multiple of 16 bytes.
1628 ///
1629 /// struct bc_header {
1630 ///   uint32_t Magic;         // 0x0B17C0DE
1631 ///   uint32_t Version;       // Version, currently always 0.
1632 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1633 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1634 ///   uint32_t CPUType;       // CPU specifier.
1635 ///   ... potentially more later ...
1636 /// };
1637 enum {
1638   DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1639   DarwinBCHeaderSize = 5*4
1640 };
1641
1642 static void EmitDarwinBCHeader(BitstreamWriter &Stream, const Triple &TT) {
1643   unsigned CPUType = ~0U;
1644
1645   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1646   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1647   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1648   // specific constants here because they are implicitly part of the Darwin ABI.
1649   enum {
1650     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1651     DARWIN_CPU_TYPE_X86        = 7,
1652     DARWIN_CPU_TYPE_ARM        = 12,
1653     DARWIN_CPU_TYPE_POWERPC    = 18
1654   };
1655
1656   Triple::ArchType Arch = TT.getArch();
1657   if (Arch == Triple::x86_64)
1658     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1659   else if (Arch == Triple::x86)
1660     CPUType = DARWIN_CPU_TYPE_X86;
1661   else if (Arch == Triple::ppc)
1662     CPUType = DARWIN_CPU_TYPE_POWERPC;
1663   else if (Arch == Triple::ppc64)
1664     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1665   else if (Arch == Triple::arm || Arch == Triple::thumb)
1666     CPUType = DARWIN_CPU_TYPE_ARM;
1667
1668   // Traditional Bitcode starts after header.
1669   unsigned BCOffset = DarwinBCHeaderSize;
1670
1671   Stream.Emit(0x0B17C0DE, 32);
1672   Stream.Emit(0         , 32);  // Version.
1673   Stream.Emit(BCOffset  , 32);
1674   Stream.Emit(0         , 32);  // Filled in later.
1675   Stream.Emit(CPUType   , 32);
1676 }
1677
1678 /// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1679 /// finalize the header.
1680 static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1681   // Update the size field in the header.
1682   Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1683
1684   // If the file is not a multiple of 16 bytes, insert dummy padding.
1685   while (BufferSize & 15) {
1686     Stream.Emit(0, 8);
1687     ++BufferSize;
1688   }
1689 }
1690
1691
1692 /// WriteBitcodeToFile - Write the specified module to the specified output
1693 /// stream.
1694 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1695   std::vector<unsigned char> Buffer;
1696   BitstreamWriter Stream(Buffer);
1697
1698   Buffer.reserve(256*1024);
1699
1700   WriteBitcodeToStream( M, Stream );
1701
1702   // Write the generated bitstream to "Out".
1703   Out.write((char*)&Buffer.front(), Buffer.size());
1704 }
1705
1706 /// WriteBitcodeToStream - Write the specified module to the specified output
1707 /// stream.
1708 void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1709   // If this is darwin or another generic macho target, emit a file header and
1710   // trailer if needed.
1711   Triple TT(M->getTargetTriple());
1712   if (TT.isOSDarwin())
1713     EmitDarwinBCHeader(Stream, TT);
1714
1715   // Emit the file header.
1716   Stream.Emit((unsigned)'B', 8);
1717   Stream.Emit((unsigned)'C', 8);
1718   Stream.Emit(0x0, 4);
1719   Stream.Emit(0xC, 4);
1720   Stream.Emit(0xE, 4);
1721   Stream.Emit(0xD, 4);
1722
1723   // Emit the module.
1724   WriteModule(M, Stream);
1725
1726   if (TT.isOSDarwin())
1727     EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1728 }