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 "ValueEnumerator.h"
  16 #include "llvm/ADT/Triple.h"
  17 #include "llvm/Bitcode/BitstreamWriter.h"
  18 #include "llvm/Bitcode/LLVMBitCodes.h"
  19 #include "llvm/IR/Constants.h"
  20 #include "llvm/IR/DerivedTypes.h"
  21 #include "llvm/IR/InlineAsm.h"
  22 #include "llvm/IR/Instructions.h"
  23 #include "llvm/IR/Module.h"
  24 #include "llvm/IR/Operator.h"
  25 #include "llvm/IR/UseListOrder.h"
  26 #include "llvm/IR/ValueSymbolTable.h"
  27 #include "llvm/Support/CommandLine.h"
  28 #include "llvm/Support/ErrorHandling.h"
  29 #include "llvm/Support/MathExtras.h"
  30 #include "llvm/Support/Program.h"
  31 #include "llvm/Support/raw_ostream.h"
  32 #include <cctype>
  33 #include <map>
  34 using namespace llvm;
  35
  36 /// These are manifest constants used by the bitcode writer. They do not need to
  37 /// be kept in sync with the reader, but need to be consistent within this file.
  38 enum {
  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   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
  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   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   llvm_unreachable("Invalid ordering");
 132 }
 133
 134 static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
 135   switch (SynchScope) {
 136   case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
 137   case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
 138   }
 139   llvm_unreachable("Invalid synch scope");
 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 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
 158   switch (Kind) {
 159   case Attribute::Alignment:
 160     return bitc::ATTR_KIND_ALIGNMENT;
 161   case Attribute::AlwaysInline:
 162     return bitc::ATTR_KIND_ALWAYS_INLINE;
 163   case Attribute::Builtin:
 164     return bitc::ATTR_KIND_BUILTIN;
 165   case Attribute::ByVal:
 166     return bitc::ATTR_KIND_BY_VAL;
 167   case Attribute::InAlloca:
 168     return bitc::ATTR_KIND_IN_ALLOCA;
 169   case Attribute::Cold:
 170     return bitc::ATTR_KIND_COLD;
 171   case Attribute::InlineHint:
 172     return bitc::ATTR_KIND_INLINE_HINT;
 173   case Attribute::InReg:
 174     return bitc::ATTR_KIND_IN_REG;
 175   case Attribute::JumpTable:
 176     return bitc::ATTR_KIND_JUMP_TABLE;
 177   case Attribute::MinSize:
 178     return bitc::ATTR_KIND_MIN_SIZE;
 179   case Attribute::Naked:
 180     return bitc::ATTR_KIND_NAKED;
 181   case Attribute::Nest:
 182     return bitc::ATTR_KIND_NEST;
 183   case Attribute::NoAlias:
 184     return bitc::ATTR_KIND_NO_ALIAS;
 185   case Attribute::NoBuiltin:
 186     return bitc::ATTR_KIND_NO_BUILTIN;
 187   case Attribute::NoCapture:
 188     return bitc::ATTR_KIND_NO_CAPTURE;
 189   case Attribute::NoDuplicate:
 190     return bitc::ATTR_KIND_NO_DUPLICATE;
 191   case Attribute::NoImplicitFloat:
 192     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
 193   case Attribute::NoInline:
 194     return bitc::ATTR_KIND_NO_INLINE;
 195   case Attribute::NonLazyBind:
 196     return bitc::ATTR_KIND_NON_LAZY_BIND;
 197   case Attribute::NonNull:
 198     return bitc::ATTR_KIND_NON_NULL;
 199   case Attribute::Dereferenceable:
 200     return bitc::ATTR_KIND_DEREFERENCEABLE;
 201   case Attribute::NoRedZone:
 202     return bitc::ATTR_KIND_NO_RED_ZONE;
 203   case Attribute::NoReturn:
 204     return bitc::ATTR_KIND_NO_RETURN;
 205   case Attribute::NoUnwind:
 206     return bitc::ATTR_KIND_NO_UNWIND;
 207   case Attribute::OptimizeForSize:
 208     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
 209   case Attribute::OptimizeNone:
 210     return bitc::ATTR_KIND_OPTIMIZE_NONE;
 211   case Attribute::ReadNone:
 212     return bitc::ATTR_KIND_READ_NONE;
 213   case Attribute::ReadOnly:
 214     return bitc::ATTR_KIND_READ_ONLY;
 215   case Attribute::Returned:
 216     return bitc::ATTR_KIND_RETURNED;
 217   case Attribute::ReturnsTwice:
 218     return bitc::ATTR_KIND_RETURNS_TWICE;
 219   case Attribute::SExt:
 220     return bitc::ATTR_KIND_S_EXT;
 221   case Attribute::StackAlignment:
 222     return bitc::ATTR_KIND_STACK_ALIGNMENT;
 223   case Attribute::StackProtect:
 224     return bitc::ATTR_KIND_STACK_PROTECT;
 225   case Attribute::StackProtectReq:
 226     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
 227   case Attribute::StackProtectStrong:
 228     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
 229   case Attribute::StructRet:
 230     return bitc::ATTR_KIND_STRUCT_RET;
 231   case Attribute::SanitizeAddress:
 232     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
 233   case Attribute::SanitizeThread:
 234     return bitc::ATTR_KIND_SANITIZE_THREAD;
 235   case Attribute::SanitizeMemory:
 236     return bitc::ATTR_KIND_SANITIZE_MEMORY;
 237   case Attribute::UWTable:
 238     return bitc::ATTR_KIND_UW_TABLE;
 239   case Attribute::ZExt:
 240     return bitc::ATTR_KIND_Z_EXT;
 241   case Attribute::EndAttrKinds:
 242     llvm_unreachable("Can not encode end-attribute kinds marker.");
 243   case Attribute::None:
 244     llvm_unreachable("Can not encode none-attribute.");
 245   }
 246
 247   llvm_unreachable("Trying to encode unknown attribute");
 248 }
 249
 250 static void WriteAttributeGroupTable(const ValueEnumerator &VE,
 251                                      BitstreamWriter &Stream) {
 252   const std::vector<AttributeSet> &AttrGrps = VE.getAttributeGroups();
 253   if (AttrGrps.empty()) return;
 254
 255   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
 256
 257   SmallVector<uint64_t, 64> Record;
 258   for (unsigned i = 0, e = AttrGrps.size(); i != e; ++i) {
 259     AttributeSet AS = AttrGrps[i];
 260     for (unsigned i = 0, e = AS.getNumSlots(); i != e; ++i) {
 261       AttributeSet A = AS.getSlotAttributes(i);
 262
 263       Record.push_back(VE.getAttributeGroupID(A));
 264       Record.push_back(AS.getSlotIndex(i));
 265
 266       for (AttributeSet::iterator I = AS.begin(0), E = AS.end(0);
 267            I != E; ++I) {
 268         Attribute Attr = *I;
 269         if (Attr.isEnumAttribute()) {
 270           Record.push_back(0);
 271           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 272         } else if (Attr.isIntAttribute()) {
 273           Record.push_back(1);
 274           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 275           Record.push_back(Attr.getValueAsInt());
 276         } else {
 277           StringRef Kind = Attr.getKindAsString();
 278           StringRef Val = Attr.getValueAsString();
 279
 280           Record.push_back(Val.empty() ? 3 : 4);
 281           Record.append(Kind.begin(), Kind.end());
 282           Record.push_back(0);
 283           if (!Val.empty()) {
 284             Record.append(Val.begin(), Val.end());
 285             Record.push_back(0);
 286           }
 287         }
 288       }
 289
 290       Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
 291       Record.clear();
 292     }
 293   }
 294
 295   Stream.ExitBlock();
 296 }
 297
 298 static void WriteAttributeTable(const ValueEnumerator &VE,
 299                                 BitstreamWriter &Stream) {
 300   const std::vector<AttributeSet> &Attrs = VE.getAttributes();
 301   if (Attrs.empty()) return;
 302
 303   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 304
 305   SmallVector<uint64_t, 64> Record;
 306   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
 307     const AttributeSet &A = Attrs[i];
 308     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
 309       Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
 310
 311     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 312     Record.clear();
 313   }
 314
 315   Stream.ExitBlock();
 316 }
 317
 318 /// WriteTypeTable - Write out the type table for a module.
 319 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 320   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 321
 322   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
 323   SmallVector<uint64_t, 64> TypeVals;
 324
 325   uint64_t NumBits = Log2_32_Ceil(VE.getTypes().size()+1);
 326
 327   // Abbrev for TYPE_CODE_POINTER.
 328   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 329   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
 330   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 331   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
 332   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
 333
 334   // Abbrev for TYPE_CODE_FUNCTION.
 335   Abbv = new BitCodeAbbrev();
 336   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
 337   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
 338   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 339   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 340
 341   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 342
 343   // Abbrev for TYPE_CODE_STRUCT_ANON.
 344   Abbv = new BitCodeAbbrev();
 345   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
 346   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 347   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 348   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 349
 350   unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
 351
 352   // Abbrev for TYPE_CODE_STRUCT_NAME.
 353   Abbv = new BitCodeAbbrev();
 354   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
 355   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 356   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 357   unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
 358
 359   // Abbrev for TYPE_CODE_STRUCT_NAMED.
 360   Abbv = new BitCodeAbbrev();
 361   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
 362   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 363   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 364   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 365
 366   unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
 367
 368   // Abbrev for TYPE_CODE_ARRAY.
 369   Abbv = new BitCodeAbbrev();
 370   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 371   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 372   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 373
 374   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 375
 376   // Emit an entry count so the reader can reserve space.
 377   TypeVals.push_back(TypeList.size());
 378   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 379   TypeVals.clear();
 380
 381   // Loop over all of the types, emitting each in turn.
 382   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 383     Type *T = TypeList[i];
 384     int AbbrevToUse = 0;
 385     unsigned Code = 0;
 386
 387     switch (T->getTypeID()) {
 388     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
 389     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
 390     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
 391     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
 392     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
 393     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
 394     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 395     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
 396     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
 397     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
 398     case Type::IntegerTyID:
 399       // INTEGER: [width]
 400       Code = bitc::TYPE_CODE_INTEGER;
 401       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 402       break;
 403     case Type::PointerTyID: {
 404       PointerType *PTy = cast<PointerType>(T);
 405       // POINTER: [pointee type, address space]
 406       Code = bitc::TYPE_CODE_POINTER;
 407       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
 408       unsigned AddressSpace = PTy->getAddressSpace();
 409       TypeVals.push_back(AddressSpace);
 410       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
 411       break;
 412     }
 413     case Type::FunctionTyID: {
 414       FunctionType *FT = cast<FunctionType>(T);
 415       // FUNCTION: [isvararg, retty, paramty x N]
 416       Code = bitc::TYPE_CODE_FUNCTION;
 417       TypeVals.push_back(FT->isVarArg());
 418       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 419       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 420         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 421       AbbrevToUse = FunctionAbbrev;
 422       break;
 423     }
 424     case Type::StructTyID: {
 425       StructType *ST = cast<StructType>(T);
 426       // STRUCT: [ispacked, eltty x N]
 427       TypeVals.push_back(ST->isPacked());
 428       // Output all of the element types.
 429       for (StructType::element_iterator I = ST->element_begin(),
 430            E = ST->element_end(); I != E; ++I)
 431         TypeVals.push_back(VE.getTypeID(*I));
 432
 433       if (ST->isLiteral()) {
 434         Code = bitc::TYPE_CODE_STRUCT_ANON;
 435         AbbrevToUse = StructAnonAbbrev;
 436       } else {
 437         if (ST->isOpaque()) {
 438           Code = bitc::TYPE_CODE_OPAQUE;
 439         } else {
 440           Code = bitc::TYPE_CODE_STRUCT_NAMED;
 441           AbbrevToUse = StructNamedAbbrev;
 442         }
 443
 444         // Emit the name if it is present.
 445         if (!ST->getName().empty())
 446           WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
 447                             StructNameAbbrev, Stream);
 448       }
 449       break;
 450     }
 451     case Type::ArrayTyID: {
 452       ArrayType *AT = cast<ArrayType>(T);
 453       // ARRAY: [numelts, eltty]
 454       Code = bitc::TYPE_CODE_ARRAY;
 455       TypeVals.push_back(AT->getNumElements());
 456       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 457       AbbrevToUse = ArrayAbbrev;
 458       break;
 459     }
 460     case Type::VectorTyID: {
 461       VectorType *VT = cast<VectorType>(T);
 462       // VECTOR [numelts, eltty]
 463       Code = bitc::TYPE_CODE_VECTOR;
 464       TypeVals.push_back(VT->getNumElements());
 465       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 466       break;
 467     }
 468     }
 469
 470     // Emit the finished record.
 471     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 472     TypeVals.clear();
 473   }
 474
 475   Stream.ExitBlock();
 476 }
 477
 478 static unsigned getEncodedLinkage(const GlobalValue &GV) {
 479   switch (GV.getLinkage()) {
 480   case GlobalValue::ExternalLinkage:                 return 0;
 481   case GlobalValue::WeakAnyLinkage:                  return 1;
 482   case GlobalValue::AppendingLinkage:                return 2;
 483   case GlobalValue::InternalLinkage:                 return 3;
 484   case GlobalValue::LinkOnceAnyLinkage:              return 4;
 485   case GlobalValue::ExternalWeakLinkage:             return 7;
 486   case GlobalValue::CommonLinkage:                   return 8;
 487   case GlobalValue::PrivateLinkage:                  return 9;
 488   case GlobalValue::WeakODRLinkage:                  return 10;
 489   case GlobalValue::LinkOnceODRLinkage:              return 11;
 490   case GlobalValue::AvailableExternallyLinkage:      return 12;
 491   }
 492   llvm_unreachable("Invalid linkage");
 493 }
 494
 495 static unsigned getEncodedVisibility(const GlobalValue &GV) {
 496   switch (GV.getVisibility()) {
 497   case GlobalValue::DefaultVisibility:   return 0;
 498   case GlobalValue::HiddenVisibility:    return 1;
 499   case GlobalValue::ProtectedVisibility: return 2;
 500   }
 501   llvm_unreachable("Invalid visibility");
 502 }
 503
 504 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
 505   switch (GV.getDLLStorageClass()) {
 506   case GlobalValue::DefaultStorageClass:   return 0;
 507   case GlobalValue::DLLImportStorageClass: return 1;
 508   case GlobalValue::DLLExportStorageClass: return 2;
 509   }
 510   llvm_unreachable("Invalid DLL storage class");
 511 }
 512
 513 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
 514   switch (GV.getThreadLocalMode()) {
 515     case GlobalVariable::NotThreadLocal:         return 0;
 516     case GlobalVariable::GeneralDynamicTLSModel: return 1;
 517     case GlobalVariable::LocalDynamicTLSModel:   return 2;
 518     case GlobalVariable::InitialExecTLSModel:    return 3;
 519     case GlobalVariable::LocalExecTLSModel:      return 4;
 520   }
 521   llvm_unreachable("Invalid TLS model");
 522 }
 523
 524 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
 525   switch (C.getSelectionKind()) {
 526   case Comdat::Any:
 527     return bitc::COMDAT_SELECTION_KIND_ANY;
 528   case Comdat::ExactMatch:
 529     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
 530   case Comdat::Largest:
 531     return bitc::COMDAT_SELECTION_KIND_LARGEST;
 532   case Comdat::NoDuplicates:
 533     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
 534   case Comdat::SameSize:
 535     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
 536   }
 537   llvm_unreachable("Invalid selection kind");
 538 }
 539
 540 static void writeComdats(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 541   SmallVector<uint8_t, 64> Vals;
 542   for (const Comdat *C : VE.getComdats()) {
 543     // COMDAT: [selection_kind, name]
 544     Vals.push_back(getEncodedComdatSelectionKind(*C));
 545     Vals.push_back(C->getName().size());
 546     for (char Chr : C->getName())
 547       Vals.push_back((unsigned char)Chr);
 548     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
 549     Vals.clear();
 550   }
 551 }
 552
 553 // Emit top-level description of module, including target triple, inline asm,
 554 // descriptors for global variables, and function prototype info.
 555 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 556                             BitstreamWriter &Stream) {
 557   // Emit various pieces of data attached to a module.
 558   if (!M->getTargetTriple().empty())
 559     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 560                       0/*TODO*/, Stream);
 561   const std::string &DL = M->getDataLayoutStr();
 562   if (!DL.empty())
 563     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/, Stream);
 564   if (!M->getModuleInlineAsm().empty())
 565     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 566                       0/*TODO*/, Stream);
 567
 568   // Emit information about sections and GC, computing how many there are. Also
 569   // compute the maximum alignment value.
 570   std::map<std::string, unsigned> SectionMap;
 571   std::map<std::string, unsigned> GCMap;
 572   unsigned MaxAlignment = 0;
 573   unsigned MaxGlobalType = 0;
 574   for (const GlobalValue &GV : M->globals()) {
 575     MaxAlignment = std::max(MaxAlignment, GV.getAlignment());
 576     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getType()));
 577     if (GV.hasSection()) {
 578       // Give section names unique ID's.
 579       unsigned &Entry = SectionMap[GV.getSection()];
 580       if (!Entry) {
 581         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
 582                           0/*TODO*/, Stream);
 583         Entry = SectionMap.size();
 584       }
 585     }
 586   }
 587   for (const Function &F : *M) {
 588     MaxAlignment = std::max(MaxAlignment, F.getAlignment());
 589     if (F.hasSection()) {
 590       // Give section names unique ID's.
 591       unsigned &Entry = SectionMap[F.getSection()];
 592       if (!Entry) {
 593         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
 594                           0/*TODO*/, Stream);
 595         Entry = SectionMap.size();
 596       }
 597     }
 598     if (F.hasGC()) {
 599       // Same for GC names.
 600       unsigned &Entry = GCMap[F.getGC()];
 601       if (!Entry) {
 602         WriteStringRecord(bitc::MODULE_CODE_GCNAME, F.getGC(),
 603                           0/*TODO*/, Stream);
 604         Entry = GCMap.size();
 605       }
 606     }
 607   }
 608
 609   // Emit abbrev for globals, now that we know # sections and max alignment.
 610   unsigned SimpleGVarAbbrev = 0;
 611   if (!M->global_empty()) {
 612     // Add an abbrev for common globals with no visibility or thread localness.
 613     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 614     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 615     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 616                               Log2_32_Ceil(MaxGlobalType+1)));
 617     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
 618     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
 619     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
 620     if (MaxAlignment == 0)                                      // Alignment.
 621       Abbv->Add(BitCodeAbbrevOp(0));
 622     else {
 623       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 624       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 625                                Log2_32_Ceil(MaxEncAlignment+1)));
 626     }
 627     if (SectionMap.empty())                                    // Section.
 628       Abbv->Add(BitCodeAbbrevOp(0));
 629     else
 630       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 631                                Log2_32_Ceil(SectionMap.size()+1)));
 632     // Don't bother emitting vis + thread local.
 633     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 634   }
 635
 636   // Emit the global variable information.
 637   SmallVector<unsigned, 64> Vals;
 638   for (const GlobalVariable &GV : M->globals()) {
 639     unsigned AbbrevToUse = 0;
 640
 641     // GLOBALVAR: [type, isconst, initid,
 642     //             linkage, alignment, section, visibility, threadlocal,
 643     //             unnamed_addr, externally_initialized, dllstorageclass]
 644     Vals.push_back(VE.getTypeID(GV.getType()));
 645     Vals.push_back(GV.isConstant());
 646     Vals.push_back(GV.isDeclaration() ? 0 :
 647                    (VE.getValueID(GV.getInitializer()) + 1));
 648     Vals.push_back(getEncodedLinkage(GV));
 649     Vals.push_back(Log2_32(GV.getAlignment())+1);
 650     Vals.push_back(GV.hasSection() ? SectionMap[GV.getSection()] : 0);
 651     if (GV.isThreadLocal() ||
 652         GV.getVisibility() != GlobalValue::DefaultVisibility ||
 653         GV.hasUnnamedAddr() || GV.isExternallyInitialized() ||
 654         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
 655         GV.hasComdat()) {
 656       Vals.push_back(getEncodedVisibility(GV));
 657       Vals.push_back(getEncodedThreadLocalMode(GV));
 658       Vals.push_back(GV.hasUnnamedAddr());
 659       Vals.push_back(GV.isExternallyInitialized());
 660       Vals.push_back(getEncodedDLLStorageClass(GV));
 661       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
 662     } else {
 663       AbbrevToUse = SimpleGVarAbbrev;
 664     }
 665
 666     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 667     Vals.clear();
 668   }
 669
 670   // Emit the function proto information.
 671   for (const Function &F : *M) {
 672     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
 673     //             section, visibility, gc, unnamed_addr, prefix]
 674     Vals.push_back(VE.getTypeID(F.getType()));
 675     Vals.push_back(F.getCallingConv());
 676     Vals.push_back(F.isDeclaration());
 677     Vals.push_back(getEncodedLinkage(F));
 678     Vals.push_back(VE.getAttributeID(F.getAttributes()));
 679     Vals.push_back(Log2_32(F.getAlignment())+1);
 680     Vals.push_back(F.hasSection() ? SectionMap[F.getSection()] : 0);
 681     Vals.push_back(getEncodedVisibility(F));
 682     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
 683     Vals.push_back(F.hasUnnamedAddr());
 684     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
 685                                       : 0);
 686     Vals.push_back(getEncodedDLLStorageClass(F));
 687     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
 688
 689     unsigned AbbrevToUse = 0;
 690     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 691     Vals.clear();
 692   }
 693
 694   // Emit the alias information.
 695   for (const GlobalAlias &A : M->aliases()) {
 696     // ALIAS: [alias type, aliasee val#, linkage, visibility]
 697     Vals.push_back(VE.getTypeID(A.getType()));
 698     Vals.push_back(VE.getValueID(A.getAliasee()));
 699     Vals.push_back(getEncodedLinkage(A));
 700     Vals.push_back(getEncodedVisibility(A));
 701     Vals.push_back(getEncodedDLLStorageClass(A));
 702     Vals.push_back(getEncodedThreadLocalMode(A));
 703     Vals.push_back(A.hasUnnamedAddr());
 704     unsigned AbbrevToUse = 0;
 705     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 706     Vals.clear();
 707   }
 708 }
 709
 710 static uint64_t GetOptimizationFlags(const Value *V) {
 711   uint64_t Flags = 0;
 712
 713   if (const OverflowingBinaryOperator *OBO =
 714         dyn_cast<OverflowingBinaryOperator>(V)) {
 715     if (OBO->hasNoSignedWrap())
 716       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
 717     if (OBO->hasNoUnsignedWrap())
 718       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
 719   } else if (const PossiblyExactOperator *PEO =
 720                dyn_cast<PossiblyExactOperator>(V)) {
 721     if (PEO->isExact())
 722       Flags |= 1 << bitc::PEO_EXACT;
 723   } else if (const FPMathOperator *FPMO =
 724              dyn_cast<const FPMathOperator>(V)) {
 725     if (FPMO->hasUnsafeAlgebra())
 726       Flags |= FastMathFlags::UnsafeAlgebra;
 727     if (FPMO->hasNoNaNs())
 728       Flags |= FastMathFlags::NoNaNs;
 729     if (FPMO->hasNoInfs())
 730       Flags |= FastMathFlags::NoInfs;
 731     if (FPMO->hasNoSignedZeros())
 732       Flags |= FastMathFlags::NoSignedZeros;
 733     if (FPMO->hasAllowReciprocal())
 734       Flags |= FastMathFlags::AllowReciprocal;
 735   }
 736
 737   return Flags;
 738 }
 739
 740 static void WriteMDNode(const MDNode *N,
 741                         const ValueEnumerator &VE,
 742                         BitstreamWriter &Stream,
 743                         SmallVectorImpl<uint64_t> &Record) {
 744   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
 745     if (N->getOperand(i)) {
 746       Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
 747       Record.push_back(VE.getValueID(N->getOperand(i)));
 748     } else {
 749       Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
 750       Record.push_back(0);
 751     }
 752   }
 753   unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
 754                                            bitc::METADATA_NODE;
 755   Stream.EmitRecord(MDCode, Record, 0);
 756   Record.clear();
 757 }
 758
 759 static void WriteModuleMetadata(const Module *M,
 760                                 const ValueEnumerator &VE,
 761                                 BitstreamWriter &Stream) {
 762   const ValueEnumerator::ValueList &Vals = VE.getMDValues();
 763   bool StartedMetadataBlock = false;
 764   unsigned MDSAbbrev = 0;
 765   SmallVector<uint64_t, 64> Record;
 766   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 767
 768     if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
 769       if (!N->isFunctionLocal() || !N->getFunction()) {
 770         if (!StartedMetadataBlock) {
 771           Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 772           StartedMetadataBlock = true;
 773         }
 774         WriteMDNode(N, VE, Stream, Record);
 775       }
 776     } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
 777       if (!StartedMetadataBlock)  {
 778         Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 779
 780         // Abbrev for METADATA_STRING.
 781         BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 782         Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
 783         Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 784         Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 785         MDSAbbrev = Stream.EmitAbbrev(Abbv);
 786         StartedMetadataBlock = true;
 787       }
 788
 789       // Code: [strchar x N]
 790       Record.append(MDS->begin(), MDS->end());
 791
 792       // Emit the finished record.
 793       Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
 794       Record.clear();
 795     }
 796   }
 797
 798   // Write named metadata.
 799   for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
 800        E = M->named_metadata_end(); I != E; ++I) {
 801     const NamedMDNode *NMD = I;
 802     if (!StartedMetadataBlock)  {
 803       Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 804       StartedMetadataBlock = true;
 805     }
 806
 807     // Write name.
 808     StringRef Str = NMD->getName();
 809     for (unsigned i = 0, e = Str.size(); i != e; ++i)
 810       Record.push_back(Str[i]);
 811     Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
 812     Record.clear();
 813
 814     // Write named metadata operands.
 815     for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
 816       Record.push_back(VE.getValueID(NMD->getOperand(i)));
 817     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
 818     Record.clear();
 819   }
 820
 821   if (StartedMetadataBlock)
 822     Stream.ExitBlock();
 823 }
 824
 825 static void WriteFunctionLocalMetadata(const Function &F,
 826                                        const ValueEnumerator &VE,
 827                                        BitstreamWriter &Stream) {
 828   bool StartedMetadataBlock = false;
 829   SmallVector<uint64_t, 64> Record;
 830   const SmallVectorImpl<const MDNode *> &Vals = VE.getFunctionLocalMDValues();
 831   for (unsigned i = 0, e = Vals.size(); i != e; ++i)
 832     if (const MDNode *N = Vals[i])
 833       if (N->isFunctionLocal() && N->getFunction() == &F) {
 834         if (!StartedMetadataBlock) {
 835           Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 836           StartedMetadataBlock = true;
 837         }
 838         WriteMDNode(N, VE, Stream, Record);
 839       }
 840
 841   if (StartedMetadataBlock)
 842     Stream.ExitBlock();
 843 }
 844
 845 static void WriteMetadataAttachment(const Function &F,
 846                                     const ValueEnumerator &VE,
 847                                     BitstreamWriter &Stream) {
 848   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
 849
 850   SmallVector<uint64_t, 64> Record;
 851
 852   // Write metadata attachments
 853   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
 854   SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
 855
 856   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
 857     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
 858          I != E; ++I) {
 859       MDs.clear();
 860       I->getAllMetadataOtherThanDebugLoc(MDs);
 861
 862       // If no metadata, ignore instruction.
 863       if (MDs.empty()) continue;
 864
 865       Record.push_back(VE.getInstructionID(I));
 866
 867       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
 868         Record.push_back(MDs[i].first);
 869         Record.push_back(VE.getValueID(MDs[i].second));
 870       }
 871       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
 872       Record.clear();
 873     }
 874
 875   Stream.ExitBlock();
 876 }
 877
 878 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
 879   SmallVector<uint64_t, 64> Record;
 880
 881   // Write metadata kinds
 882   // METADATA_KIND - [n x [id, name]]
 883   SmallVector<StringRef, 8> Names;
 884   M->getMDKindNames(Names);
 885
 886   if (Names.empty()) return;
 887
 888   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 889
 890   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
 891     Record.push_back(MDKindID);
 892     StringRef KName = Names[MDKindID];
 893     Record.append(KName.begin(), KName.end());
 894
 895     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
 896     Record.clear();
 897   }
 898
 899   Stream.ExitBlock();
 900 }
 901
 902 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
 903   if ((int64_t)V >= 0)
 904     Vals.push_back(V << 1);
 905   else
 906     Vals.push_back((-V << 1) | 1);
 907 }
 908
 909 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
 910                            const ValueEnumerator &VE,
 911                            BitstreamWriter &Stream, bool isGlobal) {
 912   if (FirstVal == LastVal) return;
 913
 914   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
 915
 916   unsigned AggregateAbbrev = 0;
 917   unsigned String8Abbrev = 0;
 918   unsigned CString7Abbrev = 0;
 919   unsigned CString6Abbrev = 0;
 920   // If this is a constant pool for the module, emit module-specific abbrevs.
 921   if (isGlobal) {
 922     // Abbrev for CST_CODE_AGGREGATE.
 923     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 924     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
 925     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 926     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
 927     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
 928
 929     // Abbrev for CST_CODE_STRING.
 930     Abbv = new BitCodeAbbrev();
 931     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
 932     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 933     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 934     String8Abbrev = Stream.EmitAbbrev(Abbv);
 935     // Abbrev for CST_CODE_CSTRING.
 936     Abbv = new BitCodeAbbrev();
 937     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 938     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 939     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 940     CString7Abbrev = Stream.EmitAbbrev(Abbv);
 941     // Abbrev for CST_CODE_CSTRING.
 942     Abbv = new BitCodeAbbrev();
 943     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 944     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 945     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 946     CString6Abbrev = Stream.EmitAbbrev(Abbv);
 947   }
 948
 949   SmallVector<uint64_t, 64> Record;
 950
 951   const ValueEnumerator::ValueList &Vals = VE.getValues();
 952   Type *LastTy = nullptr;
 953   for (unsigned i = FirstVal; i != LastVal; ++i) {
 954     const Value *V = Vals[i].first;
 955     // If we need to switch types, do so now.
 956     if (V->getType() != LastTy) {
 957       LastTy = V->getType();
 958       Record.push_back(VE.getTypeID(LastTy));
 959       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
 960                         CONSTANTS_SETTYPE_ABBREV);
 961       Record.clear();
 962     }
 963
 964     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
 965       Record.push_back(unsigned(IA->hasSideEffects()) |
 966                        unsigned(IA->isAlignStack()) << 1 |
 967                        unsigned(IA->getDialect()&1) << 2);
 968
 969       // Add the asm string.
 970       const std::string &AsmStr = IA->getAsmString();
 971       Record.push_back(AsmStr.size());
 972       for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
 973         Record.push_back(AsmStr[i]);
 974
 975       // Add the constraint string.
 976       const std::string &ConstraintStr = IA->getConstraintString();
 977       Record.push_back(ConstraintStr.size());
 978       for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
 979         Record.push_back(ConstraintStr[i]);
 980       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
 981       Record.clear();
 982       continue;
 983     }
 984     const Constant *C = cast<Constant>(V);
 985     unsigned Code = -1U;
 986     unsigned AbbrevToUse = 0;
 987     if (C->isNullValue()) {
 988       Code = bitc::CST_CODE_NULL;
 989     } else if (isa<UndefValue>(C)) {
 990       Code = bitc::CST_CODE_UNDEF;
 991     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
 992       if (IV->getBitWidth() <= 64) {
 993         uint64_t V = IV->getSExtValue();
 994         emitSignedInt64(Record, V);
 995         Code = bitc::CST_CODE_INTEGER;
 996         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
 997       } else {                             // Wide integers, > 64 bits in size.
 998         // We have an arbitrary precision integer value to write whose
 999         // bit width is > 64. However, in canonical unsigned integer
1000         // format it is likely that the high bits are going to be zero.
1001         // So, we only write the number of active words.
1002         unsigned NWords = IV->getValue().getActiveWords();
1003         const uint64_t *RawWords = IV->getValue().getRawData();
1004         for (unsigned i = 0; i != NWords; ++i) {
1005           emitSignedInt64(Record, RawWords[i]);
1006         }
1007         Code = bitc::CST_CODE_WIDE_INTEGER;
1008       }
1009     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
1010       Code = bitc::CST_CODE_FLOAT;
1011       Type *Ty = CFP->getType();
1012       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
1013         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
1014       } else if (Ty->isX86_FP80Ty()) {
1015         // api needed to prevent premature destruction
1016         // bits are not in the same order as a normal i80 APInt, compensate.
1017         APInt api = CFP->getValueAPF().bitcastToAPInt();
1018         const uint64_t *p = api.getRawData();
1019         Record.push_back((p[1] << 48) | (p[0] >> 16));
1020         Record.push_back(p[0] & 0xffffLL);
1021       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
1022         APInt api = CFP->getValueAPF().bitcastToAPInt();
1023         const uint64_t *p = api.getRawData();
1024         Record.push_back(p[0]);
1025         Record.push_back(p[1]);
1026       } else {
1027         assert (0 && "Unknown FP type!");
1028       }
1029     } else if (isa<ConstantDataSequential>(C) &&
1030                cast<ConstantDataSequential>(C)->isString()) {
1031       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
1032       // Emit constant strings specially.
1033       unsigned NumElts = Str->getNumElements();
1034       // If this is a null-terminated string, use the denser CSTRING encoding.
1035       if (Str->isCString()) {
1036         Code = bitc::CST_CODE_CSTRING;
1037         --NumElts;  // Don't encode the null, which isn't allowed by char6.
1038       } else {
1039         Code = bitc::CST_CODE_STRING;
1040         AbbrevToUse = String8Abbrev;
1041       }
1042       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
1043       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
1044       for (unsigned i = 0; i != NumElts; ++i) {
1045         unsigned char V = Str->getElementAsInteger(i);
1046         Record.push_back(V);
1047         isCStr7 &= (V & 128) == 0;
1048         if (isCStrChar6)
1049           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
1050       }
1051
1052       if (isCStrChar6)
1053         AbbrevToUse = CString6Abbrev;
1054       else if (isCStr7)
1055         AbbrevToUse = CString7Abbrev;
1056     } else if (const ConstantDataSequential *CDS =
1057                   dyn_cast<ConstantDataSequential>(C)) {
1058       Code = bitc::CST_CODE_DATA;
1059       Type *EltTy = CDS->getType()->getElementType();
1060       if (isa<IntegerType>(EltTy)) {
1061         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
1062           Record.push_back(CDS->getElementAsInteger(i));
1063       } else if (EltTy->isFloatTy()) {
1064         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1065           union { float F; uint32_t I; };
1066           F = CDS->getElementAsFloat(i);
1067           Record.push_back(I);
1068         }
1069       } else {
1070         assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
1071         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1072           union { double F; uint64_t I; };
1073           F = CDS->getElementAsDouble(i);
1074           Record.push_back(I);
1075         }
1076       }
1077     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
1078                isa<ConstantVector>(C)) {
1079       Code = bitc::CST_CODE_AGGREGATE;
1080       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
1081         Record.push_back(VE.getValueID(C->getOperand(i)));
1082       AbbrevToUse = AggregateAbbrev;
1083     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
1084       switch (CE->getOpcode()) {
1085       default:
1086         if (Instruction::isCast(CE->getOpcode())) {
1087           Code = bitc::CST_CODE_CE_CAST;
1088           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
1089           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1090           Record.push_back(VE.getValueID(C->getOperand(0)));
1091           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
1092         } else {
1093           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
1094           Code = bitc::CST_CODE_CE_BINOP;
1095           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
1096           Record.push_back(VE.getValueID(C->getOperand(0)));
1097           Record.push_back(VE.getValueID(C->getOperand(1)));
1098           uint64_t Flags = GetOptimizationFlags(CE);
1099           if (Flags != 0)
1100             Record.push_back(Flags);
1101         }
1102         break;
1103       case Instruction::GetElementPtr:
1104         Code = bitc::CST_CODE_CE_GEP;
1105         if (cast<GEPOperator>(C)->isInBounds())
1106           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
1107         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
1108           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
1109           Record.push_back(VE.getValueID(C->getOperand(i)));
1110         }
1111         break;
1112       case Instruction::Select:
1113         Code = bitc::CST_CODE_CE_SELECT;
1114         Record.push_back(VE.getValueID(C->getOperand(0)));
1115         Record.push_back(VE.getValueID(C->getOperand(1)));
1116         Record.push_back(VE.getValueID(C->getOperand(2)));
1117         break;
1118       case Instruction::ExtractElement:
1119         Code = bitc::CST_CODE_CE_EXTRACTELT;
1120         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1121         Record.push_back(VE.getValueID(C->getOperand(0)));
1122         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
1123         Record.push_back(VE.getValueID(C->getOperand(1)));
1124         break;
1125       case Instruction::InsertElement:
1126         Code = bitc::CST_CODE_CE_INSERTELT;
1127         Record.push_back(VE.getValueID(C->getOperand(0)));
1128         Record.push_back(VE.getValueID(C->getOperand(1)));
1129         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
1130         Record.push_back(VE.getValueID(C->getOperand(2)));
1131         break;
1132       case Instruction::ShuffleVector:
1133         // If the return type and argument types are the same, this is a
1134         // standard shufflevector instruction.  If the types are different,
1135         // then the shuffle is widening or truncating the input vectors, and
1136         // the argument type must also be encoded.
1137         if (C->getType() == C->getOperand(0)->getType()) {
1138           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
1139         } else {
1140           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
1141           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1142         }
1143         Record.push_back(VE.getValueID(C->getOperand(0)));
1144         Record.push_back(VE.getValueID(C->getOperand(1)));
1145         Record.push_back(VE.getValueID(C->getOperand(2)));
1146         break;
1147       case Instruction::ICmp:
1148       case Instruction::FCmp:
1149         Code = bitc::CST_CODE_CE_CMP;
1150         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1151         Record.push_back(VE.getValueID(C->getOperand(0)));
1152         Record.push_back(VE.getValueID(C->getOperand(1)));
1153         Record.push_back(CE->getPredicate());
1154         break;
1155       }
1156     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
1157       Code = bitc::CST_CODE_BLOCKADDRESS;
1158       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
1159       Record.push_back(VE.getValueID(BA->getFunction()));
1160       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
1161     } else {
1162 #ifndef NDEBUG
1163       C->dump();
1164 #endif
1165       llvm_unreachable("Unknown constant!");
1166     }
1167     Stream.EmitRecord(Code, Record, AbbrevToUse);
1168     Record.clear();
1169   }
1170
1171   Stream.ExitBlock();
1172 }
1173
1174 static void WriteModuleConstants(const ValueEnumerator &VE,
1175                                  BitstreamWriter &Stream) {
1176   const ValueEnumerator::ValueList &Vals = VE.getValues();
1177
1178   // Find the first constant to emit, which is the first non-globalvalue value.
1179   // We know globalvalues have been emitted by WriteModuleInfo.
1180   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1181     if (!isa<GlobalValue>(Vals[i].first)) {
1182       WriteConstants(i, Vals.size(), VE, Stream, true);
1183       return;
1184     }
1185   }
1186 }
1187
1188 /// PushValueAndType - The file has to encode both the value and type id for
1189 /// many values, because we need to know what type to create for forward
1190 /// references.  However, most operands are not forward references, so this type
1191 /// field is not needed.
1192 ///
1193 /// This function adds V's value ID to Vals.  If the value ID is higher than the
1194 /// instruction ID, then it is a forward reference, and it also includes the
1195 /// type ID.  The value ID that is written is encoded relative to the InstID.
1196 static bool PushValueAndType(const Value *V, unsigned InstID,
1197                              SmallVectorImpl<unsigned> &Vals,
1198                              ValueEnumerator &VE) {
1199   unsigned ValID = VE.getValueID(V);
1200   // Make encoding relative to the InstID.
1201   Vals.push_back(InstID - ValID);
1202   if (ValID >= InstID) {
1203     Vals.push_back(VE.getTypeID(V->getType()));
1204     return true;
1205   }
1206   return false;
1207 }
1208
1209 /// pushValue - Like PushValueAndType, but where the type of the value is
1210 /// omitted (perhaps it was already encoded in an earlier operand).
1211 static void pushValue(const Value *V, unsigned InstID,
1212                       SmallVectorImpl<unsigned> &Vals,
1213                       ValueEnumerator &VE) {
1214   unsigned ValID = VE.getValueID(V);
1215   Vals.push_back(InstID - ValID);
1216 }
1217
1218 static void pushValueSigned(const Value *V, unsigned InstID,
1219                             SmallVectorImpl<uint64_t> &Vals,
1220                             ValueEnumerator &VE) {
1221   unsigned ValID = VE.getValueID(V);
1222   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
1223   emitSignedInt64(Vals, diff);
1224 }
1225
1226 /// WriteInstruction - Emit an instruction to the specified stream.
1227 static void WriteInstruction(const Instruction &I, unsigned InstID,
1228                              ValueEnumerator &VE, BitstreamWriter &Stream,
1229                              SmallVectorImpl<unsigned> &Vals) {
1230   unsigned Code = 0;
1231   unsigned AbbrevToUse = 0;
1232   VE.setInstructionID(&I);
1233   switch (I.getOpcode()) {
1234   default:
1235     if (Instruction::isCast(I.getOpcode())) {
1236       Code = bitc::FUNC_CODE_INST_CAST;
1237       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1238         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1239       Vals.push_back(VE.getTypeID(I.getType()));
1240       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1241     } else {
1242       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1243       Code = bitc::FUNC_CODE_INST_BINOP;
1244       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1245         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1246       pushValue(I.getOperand(1), InstID, Vals, VE);
1247       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1248       uint64_t Flags = GetOptimizationFlags(&I);
1249       if (Flags != 0) {
1250         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1251           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1252         Vals.push_back(Flags);
1253       }
1254     }
1255     break;
1256
1257   case Instruction::GetElementPtr:
1258     Code = bitc::FUNC_CODE_INST_GEP;
1259     if (cast<GEPOperator>(&I)->isInBounds())
1260       Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
1261     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1262       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1263     break;
1264   case Instruction::ExtractValue: {
1265     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1266     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1267     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1268     for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1269       Vals.push_back(*i);
1270     break;
1271   }
1272   case Instruction::InsertValue: {
1273     Code = bitc::FUNC_CODE_INST_INSERTVAL;
1274     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1275     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1276     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1277     for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1278       Vals.push_back(*i);
1279     break;
1280   }
1281   case Instruction::Select:
1282     Code = bitc::FUNC_CODE_INST_VSELECT;
1283     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1284     pushValue(I.getOperand(2), InstID, Vals, VE);
1285     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1286     break;
1287   case Instruction::ExtractElement:
1288     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1289     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1290     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1291     break;
1292   case Instruction::InsertElement:
1293     Code = bitc::FUNC_CODE_INST_INSERTELT;
1294     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1295     pushValue(I.getOperand(1), InstID, Vals, VE);
1296     PushValueAndType(I.getOperand(2), InstID, Vals, VE);
1297     break;
1298   case Instruction::ShuffleVector:
1299     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1300     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1301     pushValue(I.getOperand(1), InstID, Vals, VE);
1302     pushValue(I.getOperand(2), InstID, Vals, VE);
1303     break;
1304   case Instruction::ICmp:
1305   case Instruction::FCmp:
1306     // compare returning Int1Ty or vector of Int1Ty
1307     Code = bitc::FUNC_CODE_INST_CMP2;
1308     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1309     pushValue(I.getOperand(1), InstID, Vals, VE);
1310     Vals.push_back(cast<CmpInst>(I).getPredicate());
1311     break;
1312
1313   case Instruction::Ret:
1314     {
1315       Code = bitc::FUNC_CODE_INST_RET;
1316       unsigned NumOperands = I.getNumOperands();
1317       if (NumOperands == 0)
1318         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1319       else if (NumOperands == 1) {
1320         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1321           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1322       } else {
1323         for (unsigned i = 0, e = NumOperands; i != e; ++i)
1324           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1325       }
1326     }
1327     break;
1328   case Instruction::Br:
1329     {
1330       Code = bitc::FUNC_CODE_INST_BR;
1331       const BranchInst &II = cast<BranchInst>(I);
1332       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1333       if (II.isConditional()) {
1334         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1335         pushValue(II.getCondition(), InstID, Vals, VE);
1336       }
1337     }
1338     break;
1339   case Instruction::Switch:
1340     {
1341       Code = bitc::FUNC_CODE_INST_SWITCH;
1342       const SwitchInst &SI = cast<SwitchInst>(I);
1343       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
1344       pushValue(SI.getCondition(), InstID, Vals, VE);
1345       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
1346       for (SwitchInst::ConstCaseIt i = SI.case_begin(), e = SI.case_end();
1347            i != e; ++i) {
1348         Vals.push_back(VE.getValueID(i.getCaseValue()));
1349         Vals.push_back(VE.getValueID(i.getCaseSuccessor()));
1350       }
1351     }
1352     break;
1353   case Instruction::IndirectBr:
1354     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1355     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1356     // Encode the address operand as relative, but not the basic blocks.
1357     pushValue(I.getOperand(0), InstID, Vals, VE);
1358     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
1359       Vals.push_back(VE.getValueID(I.getOperand(i)));
1360     break;
1361
1362   case Instruction::Invoke: {
1363     const InvokeInst *II = cast<InvokeInst>(&I);
1364     const Value *Callee(II->getCalledValue());
1365     PointerType *PTy = cast<PointerType>(Callee->getType());
1366     FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1367     Code = bitc::FUNC_CODE_INST_INVOKE;
1368
1369     Vals.push_back(VE.getAttributeID(II->getAttributes()));
1370     Vals.push_back(II->getCallingConv());
1371     Vals.push_back(VE.getValueID(II->getNormalDest()));
1372     Vals.push_back(VE.getValueID(II->getUnwindDest()));
1373     PushValueAndType(Callee, InstID, Vals, VE);
1374
1375     // Emit value #'s for the fixed parameters.
1376     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1377       pushValue(I.getOperand(i), InstID, Vals, VE);  // fixed param.
1378
1379     // Emit type/value pairs for varargs params.
1380     if (FTy->isVarArg()) {
1381       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1382            i != e; ++i)
1383         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1384     }
1385     break;
1386   }
1387   case Instruction::Resume:
1388     Code = bitc::FUNC_CODE_INST_RESUME;
1389     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1390     break;
1391   case Instruction::Unreachable:
1392     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1393     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1394     break;
1395
1396   case Instruction::PHI: {
1397     const PHINode &PN = cast<PHINode>(I);
1398     Code = bitc::FUNC_CODE_INST_PHI;
1399     // With the newer instruction encoding, forward references could give
1400     // negative valued IDs.  This is most common for PHIs, so we use
1401     // signed VBRs.
1402     SmallVector<uint64_t, 128> Vals64;
1403     Vals64.push_back(VE.getTypeID(PN.getType()));
1404     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1405       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64, VE);
1406       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1407     }
1408     // Emit a Vals64 vector and exit.
1409     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
1410     Vals64.clear();
1411     return;
1412   }
1413
1414   case Instruction::LandingPad: {
1415     const LandingPadInst &LP = cast<LandingPadInst>(I);
1416     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
1417     Vals.push_back(VE.getTypeID(LP.getType()));
1418     PushValueAndType(LP.getPersonalityFn(), InstID, Vals, VE);
1419     Vals.push_back(LP.isCleanup());
1420     Vals.push_back(LP.getNumClauses());
1421     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1422       if (LP.isCatch(I))
1423         Vals.push_back(LandingPadInst::Catch);
1424       else
1425         Vals.push_back(LandingPadInst::Filter);
1426       PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1427     }
1428     break;
1429   }
1430
1431   case Instruction::Alloca: {
1432     Code = bitc::FUNC_CODE_INST_ALLOCA;
1433     Vals.push_back(VE.getTypeID(I.getType()));
1434     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1435     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1436     const AllocaInst &AI = cast<AllocaInst>(I);
1437     unsigned AlignRecord = Log2_32(AI.getAlignment()) + 1;
1438     assert(Log2_32(Value::MaximumAlignment) + 1 < 1 << 5 &&
1439            "not enough bits for maximum alignment");
1440     assert(AlignRecord < 1 << 5 && "alignment greater than 1 << 64");
1441     AlignRecord |= AI.isUsedWithInAlloca() << 5;
1442     Vals.push_back(AlignRecord);
1443     break;
1444   }
1445
1446   case Instruction::Load:
1447     if (cast<LoadInst>(I).isAtomic()) {
1448       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1449       PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1450     } else {
1451       Code = bitc::FUNC_CODE_INST_LOAD;
1452       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1453         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1454     }
1455     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1456     Vals.push_back(cast<LoadInst>(I).isVolatile());
1457     if (cast<LoadInst>(I).isAtomic()) {
1458       Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1459       Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1460     }
1461     break;
1462   case Instruction::Store:
1463     if (cast<StoreInst>(I).isAtomic())
1464       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1465     else
1466       Code = bitc::FUNC_CODE_INST_STORE;
1467     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1468     pushValue(I.getOperand(0), InstID, Vals, VE);         // val.
1469     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1470     Vals.push_back(cast<StoreInst>(I).isVolatile());
1471     if (cast<StoreInst>(I).isAtomic()) {
1472       Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1473       Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1474     }
1475     break;
1476   case Instruction::AtomicCmpXchg:
1477     Code = bitc::FUNC_CODE_INST_CMPXCHG;
1478     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1479     pushValue(I.getOperand(1), InstID, Vals, VE);         // cmp.
1480     pushValue(I.getOperand(2), InstID, Vals, VE);         // newval.
1481     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1482     Vals.push_back(GetEncodedOrdering(
1483                      cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
1484     Vals.push_back(GetEncodedSynchScope(
1485                      cast<AtomicCmpXchgInst>(I).getSynchScope()));
1486     Vals.push_back(GetEncodedOrdering(
1487                      cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
1488     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
1489     break;
1490   case Instruction::AtomicRMW:
1491     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
1492     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1493     pushValue(I.getOperand(1), InstID, Vals, VE);         // val.
1494     Vals.push_back(GetEncodedRMWOperation(
1495                      cast<AtomicRMWInst>(I).getOperation()));
1496     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
1497     Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
1498     Vals.push_back(GetEncodedSynchScope(
1499                      cast<AtomicRMWInst>(I).getSynchScope()));
1500     break;
1501   case Instruction::Fence:
1502     Code = bitc::FUNC_CODE_INST_FENCE;
1503     Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
1504     Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
1505     break;
1506   case Instruction::Call: {
1507     const CallInst &CI = cast<CallInst>(I);
1508     PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1509     FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1510
1511     Code = bitc::FUNC_CODE_INST_CALL;
1512
1513     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1514     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()) |
1515                    unsigned(CI.isMustTailCall()) << 14);
1516     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1517
1518     // Emit value #'s for the fixed parameters.
1519     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1520       // Check for labels (can happen with asm labels).
1521       if (FTy->getParamType(i)->isLabelTy())
1522         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
1523       else
1524         pushValue(CI.getArgOperand(i), InstID, Vals, VE);  // fixed param.
1525     }
1526
1527     // Emit type/value pairs for varargs params.
1528     if (FTy->isVarArg()) {
1529       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1530            i != e; ++i)
1531         PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1532     }
1533     break;
1534   }
1535   case Instruction::VAArg:
1536     Code = bitc::FUNC_CODE_INST_VAARG;
1537     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1538     pushValue(I.getOperand(0), InstID, Vals, VE); // valist.
1539     Vals.push_back(VE.getTypeID(I.getType())); // restype.
1540     break;
1541   }
1542
1543   Stream.EmitRecord(Code, Vals, AbbrevToUse);
1544   Vals.clear();
1545 }
1546
1547 // Emit names for globals/functions etc.
1548 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1549                                   const ValueEnumerator &VE,
1550                                   BitstreamWriter &Stream) {
1551   if (VST.empty()) return;
1552   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1553
1554   // FIXME: Set up the abbrev, we know how many values there are!
1555   // FIXME: We know if the type names can use 7-bit ascii.
1556   SmallVector<unsigned, 64> NameVals;
1557
1558   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1559        SI != SE; ++SI) {
1560
1561     const ValueName &Name = *SI;
1562
1563     // Figure out the encoding to use for the name.
1564     bool is7Bit = true;
1565     bool isChar6 = true;
1566     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1567          C != E; ++C) {
1568       if (isChar6)
1569         isChar6 = BitCodeAbbrevOp::isChar6(*C);
1570       if ((unsigned char)*C & 128) {
1571         is7Bit = false;
1572         break;  // don't bother scanning the rest.
1573       }
1574     }
1575
1576     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1577
1578     // VST_ENTRY:   [valueid, namechar x N]
1579     // VST_BBENTRY: [bbid, namechar x N]
1580     unsigned Code;
1581     if (isa<BasicBlock>(SI->getValue())) {
1582       Code = bitc::VST_CODE_BBENTRY;
1583       if (isChar6)
1584         AbbrevToUse = VST_BBENTRY_6_ABBREV;
1585     } else {
1586       Code = bitc::VST_CODE_ENTRY;
1587       if (isChar6)
1588         AbbrevToUse = VST_ENTRY_6_ABBREV;
1589       else if (is7Bit)
1590         AbbrevToUse = VST_ENTRY_7_ABBREV;
1591     }
1592
1593     NameVals.push_back(VE.getValueID(SI->getValue()));
1594     for (const char *P = Name.getKeyData(),
1595          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1596       NameVals.push_back((unsigned char)*P);
1597
1598     // Emit the finished record.
1599     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1600     NameVals.clear();
1601   }
1602   Stream.ExitBlock();
1603 }
1604
1605 /// WriteFunction - Emit a function body to the module stream.
1606 static void WriteFunction(const Function &F, ValueEnumerator &VE,
1607                           BitstreamWriter &Stream) {
1608   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1609   VE.incorporateFunction(F);
1610
1611   SmallVector<unsigned, 64> Vals;
1612
1613   // Emit the number of basic blocks, so the reader can create them ahead of
1614   // time.
1615   Vals.push_back(VE.getBasicBlocks().size());
1616   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1617   Vals.clear();
1618
1619   // If there are function-local constants, emit them now.
1620   unsigned CstStart, CstEnd;
1621   VE.getFunctionConstantRange(CstStart, CstEnd);
1622   WriteConstants(CstStart, CstEnd, VE, Stream, false);
1623
1624   // If there is function-local metadata, emit it now.
1625   WriteFunctionLocalMetadata(F, VE, Stream);
1626
1627   // Keep a running idea of what the instruction ID is.
1628   unsigned InstID = CstEnd;
1629
1630   bool NeedsMetadataAttachment = false;
1631
1632   DebugLoc LastDL;
1633
1634   // Finally, emit all the instructions, in order.
1635   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1636     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1637          I != E; ++I) {
1638       WriteInstruction(*I, InstID, VE, Stream, Vals);
1639
1640       if (!I->getType()->isVoidTy())
1641         ++InstID;
1642
1643       // If the instruction has metadata, write a metadata attachment later.
1644       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1645
1646       // If the instruction has a debug location, emit it.
1647       DebugLoc DL = I->getDebugLoc();
1648       if (DL.isUnknown()) {
1649         // nothing todo.
1650       } else if (DL == LastDL) {
1651         // Just repeat the same debug loc as last time.
1652         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1653       } else {
1654         MDNode *Scope, *IA;
1655         DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1656
1657         Vals.push_back(DL.getLine());
1658         Vals.push_back(DL.getCol());
1659         Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1660         Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1661         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1662         Vals.clear();
1663
1664         LastDL = DL;
1665       }
1666     }
1667
1668   // Emit names for all the instructions etc.
1669   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1670
1671   if (NeedsMetadataAttachment)
1672     WriteMetadataAttachment(F, VE, Stream);
1673   VE.purgeFunction();
1674   Stream.ExitBlock();
1675 }
1676
1677 // Emit blockinfo, which defines the standard abbreviations etc.
1678 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1679   // We only want to emit block info records for blocks that have multiple
1680   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
1681   // Other blocks can define their abbrevs inline.
1682   Stream.EnterBlockInfoBlock(2);
1683
1684   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1685     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1686     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1687     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1688     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1689     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1690     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1691                                    Abbv) != VST_ENTRY_8_ABBREV)
1692       llvm_unreachable("Unexpected abbrev ordering!");
1693   }
1694
1695   { // 7-bit fixed width VST_ENTRY strings.
1696     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1697     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1698     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1699     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1700     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1701     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1702                                    Abbv) != VST_ENTRY_7_ABBREV)
1703       llvm_unreachable("Unexpected abbrev ordering!");
1704   }
1705   { // 6-bit char6 VST_ENTRY strings.
1706     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1707     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1708     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1709     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1710     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1711     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1712                                    Abbv) != VST_ENTRY_6_ABBREV)
1713       llvm_unreachable("Unexpected abbrev ordering!");
1714   }
1715   { // 6-bit char6 VST_BBENTRY strings.
1716     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1717     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1718     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1719     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1720     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1721     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1722                                    Abbv) != VST_BBENTRY_6_ABBREV)
1723       llvm_unreachable("Unexpected abbrev ordering!");
1724   }
1725
1726
1727
1728   { // SETTYPE abbrev for CONSTANTS_BLOCK.
1729     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1730     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1731     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1732                               Log2_32_Ceil(VE.getTypes().size()+1)));
1733     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1734                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
1735       llvm_unreachable("Unexpected abbrev ordering!");
1736   }
1737
1738   { // INTEGER abbrev for CONSTANTS_BLOCK.
1739     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1740     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1741     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1742     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1743                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
1744       llvm_unreachable("Unexpected abbrev ordering!");
1745   }
1746
1747   { // CE_CAST abbrev for CONSTANTS_BLOCK.
1748     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1749     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1750     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1751     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1752                               Log2_32_Ceil(VE.getTypes().size()+1)));
1753     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1754
1755     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1756                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
1757       llvm_unreachable("Unexpected abbrev ordering!");
1758   }
1759   { // NULL abbrev for CONSTANTS_BLOCK.
1760     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1761     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1762     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1763                                    Abbv) != CONSTANTS_NULL_Abbrev)
1764       llvm_unreachable("Unexpected abbrev ordering!");
1765   }
1766
1767   // FIXME: This should only use space for first class types!
1768
1769   { // INST_LOAD abbrev for FUNCTION_BLOCK.
1770     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1771     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1772     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1773     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1774     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1775     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1776                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
1777       llvm_unreachable("Unexpected abbrev ordering!");
1778   }
1779   { // INST_BINOP abbrev for FUNCTION_BLOCK.
1780     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1781     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1782     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1783     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1784     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1785     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1786                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
1787       llvm_unreachable("Unexpected abbrev ordering!");
1788   }
1789   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1790     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1791     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1792     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1793     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1794     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1795     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1796     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1797                                    Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1798       llvm_unreachable("Unexpected abbrev ordering!");
1799   }
1800   { // INST_CAST abbrev for FUNCTION_BLOCK.
1801     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1802     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1803     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1804     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1805                               Log2_32_Ceil(VE.getTypes().size()+1)));
1806     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1807     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1808                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
1809       llvm_unreachable("Unexpected abbrev ordering!");
1810   }
1811
1812   { // INST_RET abbrev for FUNCTION_BLOCK.
1813     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1814     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1815     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1816                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1817       llvm_unreachable("Unexpected abbrev ordering!");
1818   }
1819   { // INST_RET abbrev for FUNCTION_BLOCK.
1820     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1821     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1822     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1823     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1824                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1825       llvm_unreachable("Unexpected abbrev ordering!");
1826   }
1827   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1828     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1829     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1830     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1831                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1832       llvm_unreachable("Unexpected abbrev ordering!");
1833   }
1834
1835   Stream.ExitBlock();
1836 }
1837
1838 // Sort the Users based on the order in which the reader parses the bitcode
1839 // file.
1840 static bool bitcodereader_order(const User *lhs, const User *rhs) {
1841   // TODO: Implement.
1842   return true;
1843 }
1844
1845 static void WriteUseList(const Value *V, const ValueEnumerator &VE,
1846                          BitstreamWriter &Stream) {
1847
1848   // One or zero uses can't get out of order.
1849   if (V->use_empty() || V->hasNUses(1))
1850     return;
1851
1852   // Make a copy of the in-memory use-list for sorting.
1853   SmallVector<const User*, 8> UserList(V->user_begin(), V->user_end());
1854
1855   // Sort the copy based on the order read by the BitcodeReader.
1856   std::sort(UserList.begin(), UserList.end(), bitcodereader_order);
1857
1858   // TODO: Generate a diff between the BitcodeWriter in-memory use-list and the
1859   // sorted list (i.e., the expected BitcodeReader in-memory use-list).
1860
1861   // TODO: Emit the USELIST_CODE_ENTRYs.
1862 }
1863
1864 static void WriteFunctionUseList(const Function *F, ValueEnumerator &VE,
1865                                  BitstreamWriter &Stream) {
1866   VE.incorporateFunction(*F);
1867
1868   for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
1869        AI != AE; ++AI)
1870     WriteUseList(AI, VE, Stream);
1871   for (Function::const_iterator BB = F->begin(), FE = F->end(); BB != FE;
1872        ++BB) {
1873     WriteUseList(BB, VE, Stream);
1874     for (BasicBlock::const_iterator II = BB->begin(), IE = BB->end(); II != IE;
1875          ++II) {
1876       WriteUseList(II, VE, Stream);
1877       for (User::const_op_iterator OI = II->op_begin(), E = II->op_end();
1878            OI != E; ++OI) {
1879         if ((isa<Constant>(*OI) && !isa<GlobalValue>(*OI)) ||
1880             isa<InlineAsm>(*OI))
1881           WriteUseList(*OI, VE, Stream);
1882       }
1883     }
1884   }
1885   VE.purgeFunction();
1886 }
1887
1888 // Emit use-lists.
1889 static void WriteModuleUseLists(const Module *M, ValueEnumerator &VE,
1890                                 BitstreamWriter &Stream) {
1891   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
1892
1893   // XXX: this modifies the module, but in a way that should never change the
1894   // behavior of any pass or codegen in LLVM. The problem is that GVs may
1895   // contain entries in the use_list that do not exist in the Module and are
1896   // not stored in the .bc file.
1897   for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
1898        I != E; ++I)
1899     I->removeDeadConstantUsers();
1900
1901   // Write the global variables.
1902   for (Module::const_global_iterator GI = M->global_begin(),
1903          GE = M->global_end(); GI != GE; ++GI) {
1904     WriteUseList(GI, VE, Stream);
1905
1906     // Write the global variable initializers.
1907     if (GI->hasInitializer())
1908       WriteUseList(GI->getInitializer(), VE, Stream);
1909   }
1910
1911   // Write the functions.
1912   for (Module::const_iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI) {
1913     WriteUseList(FI, VE, Stream);
1914     if (!FI->isDeclaration())
1915       WriteFunctionUseList(FI, VE, Stream);
1916     if (FI->hasPrefixData())
1917       WriteUseList(FI->getPrefixData(), VE, Stream);
1918   }
1919
1920   // Write the aliases.
1921   for (Module::const_alias_iterator AI = M->alias_begin(), AE = M->alias_end();
1922        AI != AE; ++AI) {
1923     WriteUseList(AI, VE, Stream);
1924     WriteUseList(AI->getAliasee(), VE, Stream);
1925   }
1926
1927   Stream.ExitBlock();
1928 }
1929
1930 /// WriteModule - Emit the specified module to the bitstream.
1931 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1932   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1933
1934   SmallVector<unsigned, 1> Vals;
1935   unsigned CurVersion = 1;
1936   Vals.push_back(CurVersion);
1937   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1938
1939   // Analyze the module, enumerating globals, functions, etc.
1940   ValueEnumerator VE(M);
1941
1942   // Emit blockinfo, which defines the standard abbreviations etc.
1943   WriteBlockInfo(VE, Stream);
1944
1945   // Emit information about attribute groups.
1946   WriteAttributeGroupTable(VE, Stream);
1947
1948   // Emit information about parameter attributes.
1949   WriteAttributeTable(VE, Stream);
1950
1951   // Emit information describing all of the types in the module.
1952   WriteTypeTable(VE, Stream);
1953
1954   writeComdats(VE, Stream);
1955
1956   // Emit top-level description of module, including target triple, inline asm,
1957   // descriptors for global variables, and function prototype info.
1958   WriteModuleInfo(M, VE, Stream);
1959
1960   // Emit constants.
1961   WriteModuleConstants(VE, Stream);
1962
1963   // Emit metadata.
1964   WriteModuleMetadata(M, VE, Stream);
1965
1966   // Emit metadata.
1967   WriteModuleMetadataStore(M, Stream);
1968
1969   // Emit names for globals/functions etc.
1970   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1971
1972   // Emit use-lists.
1973   if (shouldPreserveBitcodeUseListOrder())
1974     WriteModuleUseLists(M, VE, Stream);
1975
1976   // Emit function bodies.
1977   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1978     if (!F->isDeclaration())
1979       WriteFunction(*F, VE, Stream);
1980
1981   Stream.ExitBlock();
1982 }
1983
1984 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1985 /// header and trailer to make it compatible with the system archiver.  To do
1986 /// this we emit the following header, and then emit a trailer that pads the
1987 /// file out to be a multiple of 16 bytes.
1988 ///
1989 /// struct bc_header {
1990 ///   uint32_t Magic;         // 0x0B17C0DE
1991 ///   uint32_t Version;       // Version, currently always 0.
1992 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1993 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1994 ///   uint32_t CPUType;       // CPU specifier.
1995 ///   ... potentially more later ...
1996 /// };
1997 enum {
1998   DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1999   DarwinBCHeaderSize = 5*4
2000 };
2001
2002 static void WriteInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
2003                                uint32_t &Position) {
2004   Buffer[Position + 0] = (unsigned char) (Value >>  0);
2005   Buffer[Position + 1] = (unsigned char) (Value >>  8);
2006   Buffer[Position + 2] = (unsigned char) (Value >> 16);
2007   Buffer[Position + 3] = (unsigned char) (Value >> 24);
2008   Position += 4;
2009 }
2010
2011 static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
2012                                          const Triple &TT) {
2013   unsigned CPUType = ~0U;
2014
2015   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
2016   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
2017   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
2018   // specific constants here because they are implicitly part of the Darwin ABI.
2019   enum {
2020     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
2021     DARWIN_CPU_TYPE_X86        = 7,
2022     DARWIN_CPU_TYPE_ARM        = 12,
2023     DARWIN_CPU_TYPE_POWERPC    = 18
2024   };
2025
2026   Triple::ArchType Arch = TT.getArch();
2027   if (Arch == Triple::x86_64)
2028     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
2029   else if (Arch == Triple::x86)
2030     CPUType = DARWIN_CPU_TYPE_X86;
2031   else if (Arch == Triple::ppc)
2032     CPUType = DARWIN_CPU_TYPE_POWERPC;
2033   else if (Arch == Triple::ppc64)
2034     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
2035   else if (Arch == Triple::arm || Arch == Triple::thumb)
2036     CPUType = DARWIN_CPU_TYPE_ARM;
2037
2038   // Traditional Bitcode starts after header.
2039   assert(Buffer.size() >= DarwinBCHeaderSize &&
2040          "Expected header size to be reserved");
2041   unsigned BCOffset = DarwinBCHeaderSize;
2042   unsigned BCSize = Buffer.size()-DarwinBCHeaderSize;
2043
2044   // Write the magic and version.
2045   unsigned Position = 0;
2046   WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position);
2047   WriteInt32ToBuffer(0          , Buffer, Position); // Version.
2048   WriteInt32ToBuffer(BCOffset   , Buffer, Position);
2049   WriteInt32ToBuffer(BCSize     , Buffer, Position);
2050   WriteInt32ToBuffer(CPUType    , Buffer, Position);
2051
2052   // If the file is not a multiple of 16 bytes, insert dummy padding.
2053   while (Buffer.size() & 15)
2054     Buffer.push_back(0);
2055 }
2056
2057 /// WriteBitcodeToFile - Write the specified module to the specified output
2058 /// stream.
2059 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
2060   SmallVector<char, 0> Buffer;
2061   Buffer.reserve(256*1024);
2062
2063   // If this is darwin or another generic macho target, reserve space for the
2064   // header.
2065   Triple TT(M->getTargetTriple());
2066   if (TT.isOSDarwin())
2067     Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0);
2068
2069   // Emit the module into the buffer.
2070   {
2071     BitstreamWriter Stream(Buffer);
2072
2073     // Emit the file header.
2074     Stream.Emit((unsigned)'B', 8);
2075     Stream.Emit((unsigned)'C', 8);
2076     Stream.Emit(0x0, 4);
2077     Stream.Emit(0xC, 4);
2078     Stream.Emit(0xE, 4);
2079     Stream.Emit(0xD, 4);
2080
2081     // Emit the module.
2082     WriteModule(M, Stream);
2083   }
2084
2085   if (TT.isOSDarwin())
2086     EmitDarwinBCHeaderAndTrailer(Buffer, TT);
2087
2088   // Write the generated bitstream to "Out".
2089   Out.write((char*)&Buffer.front(), Buffer.size());
2090 }