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