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/DebugInfoMetadata.h"
  21 #include "llvm/IR/DerivedTypes.h"
  22 #include "llvm/IR/InlineAsm.h"
  23 #include "llvm/IR/Instructions.h"
  24 #include "llvm/IR/Module.h"
  25 #include "llvm/IR/Operator.h"
  26 #include "llvm/IR/UseListOrder.h"
  27 #include "llvm/IR/ValueSymbolTable.h"
  28 #include "llvm/Support/CommandLine.h"
  29 #include "llvm/Support/ErrorHandling.h"
  30 #include "llvm/Support/MathExtras.h"
  31 #include "llvm/Support/Program.h"
  32 #include "llvm/Support/raw_ostream.h"
  33 #include <cctype>
  34 #include <map>
  35 using namespace llvm;
  36
  37 /// These are manifest constants used by the bitcode writer. They do not need to
  38 /// be kept in sync with the reader, but need to be consistent within this file.
  39 enum {
  40   // VALUE_SYMTAB_BLOCK abbrev id's.
  41   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  42   VST_ENTRY_7_ABBREV,
  43   VST_ENTRY_6_ABBREV,
  44   VST_BBENTRY_6_ABBREV,
  45
  46   // CONSTANTS_BLOCK abbrev id's.
  47   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  48   CONSTANTS_INTEGER_ABBREV,
  49   CONSTANTS_CE_CAST_Abbrev,
  50   CONSTANTS_NULL_Abbrev,
  51
  52   // FUNCTION_BLOCK abbrev id's.
  53   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  54   FUNCTION_INST_BINOP_ABBREV,
  55   FUNCTION_INST_BINOP_FLAGS_ABBREV,
  56   FUNCTION_INST_CAST_ABBREV,
  57   FUNCTION_INST_RET_VOID_ABBREV,
  58   FUNCTION_INST_RET_VAL_ABBREV,
  59   FUNCTION_INST_UNREACHABLE_ABBREV,
  60   FUNCTION_INST_GEP_ABBREV,
  61 };
  62
  63 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
  64   switch (Opcode) {
  65   default: llvm_unreachable("Unknown cast instruction!");
  66   case Instruction::Trunc   : return bitc::CAST_TRUNC;
  67   case Instruction::ZExt    : return bitc::CAST_ZEXT;
  68   case Instruction::SExt    : return bitc::CAST_SEXT;
  69   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
  70   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
  71   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
  72   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
  73   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
  74   case Instruction::FPExt   : return bitc::CAST_FPEXT;
  75   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
  76   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
  77   case Instruction::BitCast : return bitc::CAST_BITCAST;
  78   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
  79   }
  80 }
  81
  82 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
  83   switch (Opcode) {
  84   default: llvm_unreachable("Unknown binary instruction!");
  85   case Instruction::Add:
  86   case Instruction::FAdd: return bitc::BINOP_ADD;
  87   case Instruction::Sub:
  88   case Instruction::FSub: return bitc::BINOP_SUB;
  89   case Instruction::Mul:
  90   case Instruction::FMul: return bitc::BINOP_MUL;
  91   case Instruction::UDiv: return bitc::BINOP_UDIV;
  92   case Instruction::FDiv:
  93   case Instruction::SDiv: return bitc::BINOP_SDIV;
  94   case Instruction::URem: return bitc::BINOP_UREM;
  95   case Instruction::FRem:
  96   case Instruction::SRem: return bitc::BINOP_SREM;
  97   case Instruction::Shl:  return bitc::BINOP_SHL;
  98   case Instruction::LShr: return bitc::BINOP_LSHR;
  99   case Instruction::AShr: return bitc::BINOP_ASHR;
 100   case Instruction::And:  return bitc::BINOP_AND;
 101   case Instruction::Or:   return bitc::BINOP_OR;
 102   case Instruction::Xor:  return bitc::BINOP_XOR;
 103   }
 104 }
 105
 106 static unsigned GetEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
 107   switch (Op) {
 108   default: llvm_unreachable("Unknown RMW operation!");
 109   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
 110   case AtomicRMWInst::Add: return bitc::RMW_ADD;
 111   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
 112   case AtomicRMWInst::And: return bitc::RMW_AND;
 113   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
 114   case AtomicRMWInst::Or: return bitc::RMW_OR;
 115   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
 116   case AtomicRMWInst::Max: return bitc::RMW_MAX;
 117   case AtomicRMWInst::Min: return bitc::RMW_MIN;
 118   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
 119   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
 120   }
 121 }
 122
 123 static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
 124   switch (Ordering) {
 125   case NotAtomic: return bitc::ORDERING_NOTATOMIC;
 126   case Unordered: return bitc::ORDERING_UNORDERED;
 127   case Monotonic: return bitc::ORDERING_MONOTONIC;
 128   case Acquire: return bitc::ORDERING_ACQUIRE;
 129   case Release: return bitc::ORDERING_RELEASE;
 130   case AcquireRelease: return bitc::ORDERING_ACQREL;
 131   case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
 132   }
 133   llvm_unreachable("Invalid ordering");
 134 }
 135
 136 static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
 137   switch (SynchScope) {
 138   case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
 139   case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
 140   }
 141   llvm_unreachable("Invalid synch scope");
 142 }
 143
 144 static void WriteStringRecord(unsigned Code, StringRef Str,
 145                               unsigned AbbrevToUse, BitstreamWriter &Stream) {
 146   SmallVector<unsigned, 64> Vals;
 147
 148   // Code: [strchar x N]
 149   for (unsigned i = 0, e = Str.size(); i != e; ++i) {
 150     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
 151       AbbrevToUse = 0;
 152     Vals.push_back(Str[i]);
 153   }
 154
 155   // Emit the finished record.
 156   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 157 }
 158
 159 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
 160   switch (Kind) {
 161   case Attribute::Alignment:
 162     return bitc::ATTR_KIND_ALIGNMENT;
 163   case Attribute::AlwaysInline:
 164     return bitc::ATTR_KIND_ALWAYS_INLINE;
 165   case Attribute::Builtin:
 166     return bitc::ATTR_KIND_BUILTIN;
 167   case Attribute::ByVal:
 168     return bitc::ATTR_KIND_BY_VAL;
 169   case Attribute::Convergent:
 170     return bitc::ATTR_KIND_CONVERGENT;
 171   case Attribute::InAlloca:
 172     return bitc::ATTR_KIND_IN_ALLOCA;
 173   case Attribute::Cold:
 174     return bitc::ATTR_KIND_COLD;
 175   case Attribute::InlineHint:
 176     return bitc::ATTR_KIND_INLINE_HINT;
 177   case Attribute::InReg:
 178     return bitc::ATTR_KIND_IN_REG;
 179   case Attribute::JumpTable:
 180     return bitc::ATTR_KIND_JUMP_TABLE;
 181   case Attribute::MinSize:
 182     return bitc::ATTR_KIND_MIN_SIZE;
 183   case Attribute::Naked:
 184     return bitc::ATTR_KIND_NAKED;
 185   case Attribute::Nest:
 186     return bitc::ATTR_KIND_NEST;
 187   case Attribute::NoAlias:
 188     return bitc::ATTR_KIND_NO_ALIAS;
 189   case Attribute::NoBuiltin:
 190     return bitc::ATTR_KIND_NO_BUILTIN;
 191   case Attribute::NoCapture:
 192     return bitc::ATTR_KIND_NO_CAPTURE;
 193   case Attribute::NoDuplicate:
 194     return bitc::ATTR_KIND_NO_DUPLICATE;
 195   case Attribute::NoImplicitFloat:
 196     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
 197   case Attribute::NoInline:
 198     return bitc::ATTR_KIND_NO_INLINE;
 199   case Attribute::NonLazyBind:
 200     return bitc::ATTR_KIND_NON_LAZY_BIND;
 201   case Attribute::NonNull:
 202     return bitc::ATTR_KIND_NON_NULL;
 203   case Attribute::Dereferenceable:
 204     return bitc::ATTR_KIND_DEREFERENCEABLE;
 205   case Attribute::DereferenceableOrNull:
 206     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
 207   case Attribute::NoRedZone:
 208     return bitc::ATTR_KIND_NO_RED_ZONE;
 209   case Attribute::NoReturn:
 210     return bitc::ATTR_KIND_NO_RETURN;
 211   case Attribute::NoUnwind:
 212     return bitc::ATTR_KIND_NO_UNWIND;
 213   case Attribute::OptimizeForSize:
 214     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
 215   case Attribute::OptimizeNone:
 216     return bitc::ATTR_KIND_OPTIMIZE_NONE;
 217   case Attribute::ReadNone:
 218     return bitc::ATTR_KIND_READ_NONE;
 219   case Attribute::ReadOnly:
 220     return bitc::ATTR_KIND_READ_ONLY;
 221   case Attribute::Returned:
 222     return bitc::ATTR_KIND_RETURNED;
 223   case Attribute::ReturnsTwice:
 224     return bitc::ATTR_KIND_RETURNS_TWICE;
 225   case Attribute::SExt:
 226     return bitc::ATTR_KIND_S_EXT;
 227   case Attribute::StackAlignment:
 228     return bitc::ATTR_KIND_STACK_ALIGNMENT;
 229   case Attribute::StackProtect:
 230     return bitc::ATTR_KIND_STACK_PROTECT;
 231   case Attribute::StackProtectReq:
 232     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
 233   case Attribute::StackProtectStrong:
 234     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
 235   case Attribute::SafeStack:
 236     return bitc::ATTR_KIND_SAFESTACK;
 237   case Attribute::StructRet:
 238     return bitc::ATTR_KIND_STRUCT_RET;
 239   case Attribute::SanitizeAddress:
 240     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
 241   case Attribute::SanitizeThread:
 242     return bitc::ATTR_KIND_SANITIZE_THREAD;
 243   case Attribute::SanitizeMemory:
 244     return bitc::ATTR_KIND_SANITIZE_MEMORY;
 245   case Attribute::UWTable:
 246     return bitc::ATTR_KIND_UW_TABLE;
 247   case Attribute::ZExt:
 248     return bitc::ATTR_KIND_Z_EXT;
 249   case Attribute::EndAttrKinds:
 250     llvm_unreachable("Can not encode end-attribute kinds marker.");
 251   case Attribute::None:
 252     llvm_unreachable("Can not encode none-attribute.");
 253   }
 254
 255   llvm_unreachable("Trying to encode unknown attribute");
 256 }
 257
 258 static void WriteAttributeGroupTable(const ValueEnumerator &VE,
 259                                      BitstreamWriter &Stream) {
 260   const std::vector<AttributeSet> &AttrGrps = VE.getAttributeGroups();
 261   if (AttrGrps.empty()) return;
 262
 263   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
 264
 265   SmallVector<uint64_t, 64> Record;
 266   for (unsigned i = 0, e = AttrGrps.size(); i != e; ++i) {
 267     AttributeSet AS = AttrGrps[i];
 268     for (unsigned i = 0, e = AS.getNumSlots(); i != e; ++i) {
 269       AttributeSet A = AS.getSlotAttributes(i);
 270
 271       Record.push_back(VE.getAttributeGroupID(A));
 272       Record.push_back(AS.getSlotIndex(i));
 273
 274       for (AttributeSet::iterator I = AS.begin(0), E = AS.end(0);
 275            I != E; ++I) {
 276         Attribute Attr = *I;
 277         if (Attr.isEnumAttribute()) {
 278           Record.push_back(0);
 279           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 280         } else if (Attr.isIntAttribute()) {
 281           Record.push_back(1);
 282           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 283           Record.push_back(Attr.getValueAsInt());
 284         } else {
 285           StringRef Kind = Attr.getKindAsString();
 286           StringRef Val = Attr.getValueAsString();
 287
 288           Record.push_back(Val.empty() ? 3 : 4);
 289           Record.append(Kind.begin(), Kind.end());
 290           Record.push_back(0);
 291           if (!Val.empty()) {
 292             Record.append(Val.begin(), Val.end());
 293             Record.push_back(0);
 294           }
 295         }
 296       }
 297
 298       Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
 299       Record.clear();
 300     }
 301   }
 302
 303   Stream.ExitBlock();
 304 }
 305
 306 static void WriteAttributeTable(const ValueEnumerator &VE,
 307                                 BitstreamWriter &Stream) {
 308   const std::vector<AttributeSet> &Attrs = VE.getAttributes();
 309   if (Attrs.empty()) return;
 310
 311   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 312
 313   SmallVector<uint64_t, 64> Record;
 314   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
 315     const AttributeSet &A = Attrs[i];
 316     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
 317       Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
 318
 319     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 320     Record.clear();
 321   }
 322
 323   Stream.ExitBlock();
 324 }
 325
 326 /// WriteTypeTable - Write out the type table for a module.
 327 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 328   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 329
 330   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
 331   SmallVector<uint64_t, 64> TypeVals;
 332
 333   uint64_t NumBits = VE.computeBitsRequiredForTypeIndicies();
 334
 335   // Abbrev for TYPE_CODE_POINTER.
 336   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 337   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
 338   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 339   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
 340   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
 341
 342   // Abbrev for TYPE_CODE_FUNCTION.
 343   Abbv = new BitCodeAbbrev();
 344   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
 345   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
 346   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 347   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 348
 349   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 350
 351   // Abbrev for TYPE_CODE_STRUCT_ANON.
 352   Abbv = new BitCodeAbbrev();
 353   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
 354   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 355   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 356   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 357
 358   unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
 359
 360   // Abbrev for TYPE_CODE_STRUCT_NAME.
 361   Abbv = new BitCodeAbbrev();
 362   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
 363   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 364   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 365   unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
 366
 367   // Abbrev for TYPE_CODE_STRUCT_NAMED.
 368   Abbv = new BitCodeAbbrev();
 369   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
 370   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 371   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 372   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 373
 374   unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
 375
 376   // Abbrev for TYPE_CODE_ARRAY.
 377   Abbv = new BitCodeAbbrev();
 378   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 379   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 380   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 381
 382   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 383
 384   // Emit an entry count so the reader can reserve space.
 385   TypeVals.push_back(TypeList.size());
 386   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 387   TypeVals.clear();
 388
 389   // Loop over all of the types, emitting each in turn.
 390   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 391     Type *T = TypeList[i];
 392     int AbbrevToUse = 0;
 393     unsigned Code = 0;
 394
 395     switch (T->getTypeID()) {
 396     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
 397     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
 398     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
 399     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
 400     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
 401     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
 402     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 403     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
 404     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
 405     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
 406     case Type::IntegerTyID:
 407       // INTEGER: [width]
 408       Code = bitc::TYPE_CODE_INTEGER;
 409       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 410       break;
 411     case Type::PointerTyID: {
 412       PointerType *PTy = cast<PointerType>(T);
 413       // POINTER: [pointee type, address space]
 414       Code = bitc::TYPE_CODE_POINTER;
 415       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
 416       unsigned AddressSpace = PTy->getAddressSpace();
 417       TypeVals.push_back(AddressSpace);
 418       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
 419       break;
 420     }
 421     case Type::FunctionTyID: {
 422       FunctionType *FT = cast<FunctionType>(T);
 423       // FUNCTION: [isvararg, retty, paramty x N]
 424       Code = bitc::TYPE_CODE_FUNCTION;
 425       TypeVals.push_back(FT->isVarArg());
 426       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 427       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 428         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 429       AbbrevToUse = FunctionAbbrev;
 430       break;
 431     }
 432     case Type::StructTyID: {
 433       StructType *ST = cast<StructType>(T);
 434       // STRUCT: [ispacked, eltty x N]
 435       TypeVals.push_back(ST->isPacked());
 436       // Output all of the element types.
 437       for (StructType::element_iterator I = ST->element_begin(),
 438            E = ST->element_end(); I != E; ++I)
 439         TypeVals.push_back(VE.getTypeID(*I));
 440
 441       if (ST->isLiteral()) {
 442         Code = bitc::TYPE_CODE_STRUCT_ANON;
 443         AbbrevToUse = StructAnonAbbrev;
 444       } else {
 445         if (ST->isOpaque()) {
 446           Code = bitc::TYPE_CODE_OPAQUE;
 447         } else {
 448           Code = bitc::TYPE_CODE_STRUCT_NAMED;
 449           AbbrevToUse = StructNamedAbbrev;
 450         }
 451
 452         // Emit the name if it is present.
 453         if (!ST->getName().empty())
 454           WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
 455                             StructNameAbbrev, Stream);
 456       }
 457       break;
 458     }
 459     case Type::ArrayTyID: {
 460       ArrayType *AT = cast<ArrayType>(T);
 461       // ARRAY: [numelts, eltty]
 462       Code = bitc::TYPE_CODE_ARRAY;
 463       TypeVals.push_back(AT->getNumElements());
 464       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 465       AbbrevToUse = ArrayAbbrev;
 466       break;
 467     }
 468     case Type::VectorTyID: {
 469       VectorType *VT = cast<VectorType>(T);
 470       // VECTOR [numelts, eltty]
 471       Code = bitc::TYPE_CODE_VECTOR;
 472       TypeVals.push_back(VT->getNumElements());
 473       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 474       break;
 475     }
 476     }
 477
 478     // Emit the finished record.
 479     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 480     TypeVals.clear();
 481   }
 482
 483   Stream.ExitBlock();
 484 }
 485
 486 static unsigned getEncodedLinkage(const GlobalValue &GV) {
 487   switch (GV.getLinkage()) {
 488   case GlobalValue::ExternalLinkage:
 489     return 0;
 490   case GlobalValue::WeakAnyLinkage:
 491     return 16;
 492   case GlobalValue::AppendingLinkage:
 493     return 2;
 494   case GlobalValue::InternalLinkage:
 495     return 3;
 496   case GlobalValue::LinkOnceAnyLinkage:
 497     return 18;
 498   case GlobalValue::ExternalWeakLinkage:
 499     return 7;
 500   case GlobalValue::CommonLinkage:
 501     return 8;
 502   case GlobalValue::PrivateLinkage:
 503     return 9;
 504   case GlobalValue::WeakODRLinkage:
 505     return 17;
 506   case GlobalValue::LinkOnceODRLinkage:
 507     return 19;
 508   case GlobalValue::AvailableExternallyLinkage:
 509     return 12;
 510   }
 511   llvm_unreachable("Invalid linkage");
 512 }
 513
 514 static unsigned getEncodedVisibility(const GlobalValue &GV) {
 515   switch (GV.getVisibility()) {
 516   case GlobalValue::DefaultVisibility:   return 0;
 517   case GlobalValue::HiddenVisibility:    return 1;
 518   case GlobalValue::ProtectedVisibility: return 2;
 519   }
 520   llvm_unreachable("Invalid visibility");
 521 }
 522
 523 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
 524   switch (GV.getDLLStorageClass()) {
 525   case GlobalValue::DefaultStorageClass:   return 0;
 526   case GlobalValue::DLLImportStorageClass: return 1;
 527   case GlobalValue::DLLExportStorageClass: return 2;
 528   }
 529   llvm_unreachable("Invalid DLL storage class");
 530 }
 531
 532 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
 533   switch (GV.getThreadLocalMode()) {
 534     case GlobalVariable::NotThreadLocal:         return 0;
 535     case GlobalVariable::GeneralDynamicTLSModel: return 1;
 536     case GlobalVariable::LocalDynamicTLSModel:   return 2;
 537     case GlobalVariable::InitialExecTLSModel:    return 3;
 538     case GlobalVariable::LocalExecTLSModel:      return 4;
 539   }
 540   llvm_unreachable("Invalid TLS model");
 541 }
 542
 543 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
 544   switch (C.getSelectionKind()) {
 545   case Comdat::Any:
 546     return bitc::COMDAT_SELECTION_KIND_ANY;
 547   case Comdat::ExactMatch:
 548     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
 549   case Comdat::Largest:
 550     return bitc::COMDAT_SELECTION_KIND_LARGEST;
 551   case Comdat::NoDuplicates:
 552     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
 553   case Comdat::SameSize:
 554     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
 555   }
 556   llvm_unreachable("Invalid selection kind");
 557 }
 558
 559 static void writeComdats(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 560   SmallVector<uint16_t, 64> Vals;
 561   for (const Comdat *C : VE.getComdats()) {
 562     // COMDAT: [selection_kind, name]
 563     Vals.push_back(getEncodedComdatSelectionKind(*C));
 564     size_t Size = C->getName().size();
 565     assert(isUInt<16>(Size));
 566     Vals.push_back(Size);
 567     for (char Chr : C->getName())
 568       Vals.push_back((unsigned char)Chr);
 569     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
 570     Vals.clear();
 571   }
 572 }
 573
 574 // Emit top-level description of module, including target triple, inline asm,
 575 // descriptors for global variables, and function prototype info.
 576 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 577                             BitstreamWriter &Stream) {
 578   // Emit various pieces of data attached to a module.
 579   if (!M->getTargetTriple().empty())
 580     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 581                       0/*TODO*/, Stream);
 582   const std::string &DL = M->getDataLayoutStr();
 583   if (!DL.empty())
 584     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/, Stream);
 585   if (!M->getModuleInlineAsm().empty())
 586     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 587                       0/*TODO*/, Stream);
 588
 589   // Emit information about sections and GC, computing how many there are. Also
 590   // compute the maximum alignment value.
 591   std::map<std::string, unsigned> SectionMap;
 592   std::map<std::string, unsigned> GCMap;
 593   unsigned MaxAlignment = 0;
 594   unsigned MaxGlobalType = 0;
 595   for (const GlobalValue &GV : M->globals()) {
 596     MaxAlignment = std::max(MaxAlignment, GV.getAlignment());
 597     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
 598     if (GV.hasSection()) {
 599       // Give section names unique ID's.
 600       unsigned &Entry = SectionMap[GV.getSection()];
 601       if (!Entry) {
 602         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
 603                           0/*TODO*/, Stream);
 604         Entry = SectionMap.size();
 605       }
 606     }
 607   }
 608   for (const Function &F : *M) {
 609     MaxAlignment = std::max(MaxAlignment, F.getAlignment());
 610     if (F.hasSection()) {
 611       // Give section names unique ID's.
 612       unsigned &Entry = SectionMap[F.getSection()];
 613       if (!Entry) {
 614         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
 615                           0/*TODO*/, Stream);
 616         Entry = SectionMap.size();
 617       }
 618     }
 619     if (F.hasGC()) {
 620       // Same for GC names.
 621       unsigned &Entry = GCMap[F.getGC()];
 622       if (!Entry) {
 623         WriteStringRecord(bitc::MODULE_CODE_GCNAME, F.getGC(),
 624                           0/*TODO*/, Stream);
 625         Entry = GCMap.size();
 626       }
 627     }
 628   }
 629
 630   // Emit abbrev for globals, now that we know # sections and max alignment.
 631   unsigned SimpleGVarAbbrev = 0;
 632   if (!M->global_empty()) {
 633     // Add an abbrev for common globals with no visibility or thread localness.
 634     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 635     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 636     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 637                               Log2_32_Ceil(MaxGlobalType+1)));
 638     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
 639                                                            //| explicitType << 1
 640                                                            //| constant
 641     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
 642     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
 643     if (MaxAlignment == 0)                                 // Alignment.
 644       Abbv->Add(BitCodeAbbrevOp(0));
 645     else {
 646       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 647       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 648                                Log2_32_Ceil(MaxEncAlignment+1)));
 649     }
 650     if (SectionMap.empty())                                    // Section.
 651       Abbv->Add(BitCodeAbbrevOp(0));
 652     else
 653       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 654                                Log2_32_Ceil(SectionMap.size()+1)));
 655     // Don't bother emitting vis + thread local.
 656     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 657   }
 658
 659   // Emit the global variable information.
 660   SmallVector<unsigned, 64> Vals;
 661   for (const GlobalVariable &GV : M->globals()) {
 662     unsigned AbbrevToUse = 0;
 663
 664     // GLOBALVAR: [type, isconst, initid,
 665     //             linkage, alignment, section, visibility, threadlocal,
 666     //             unnamed_addr, externally_initialized, dllstorageclass,
 667     //             comdat]
 668     Vals.push_back(VE.getTypeID(GV.getValueType()));
 669     Vals.push_back(GV.getType()->getAddressSpace() << 2 | 2 | GV.isConstant());
 670     Vals.push_back(GV.isDeclaration() ? 0 :
 671                    (VE.getValueID(GV.getInitializer()) + 1));
 672     Vals.push_back(getEncodedLinkage(GV));
 673     Vals.push_back(Log2_32(GV.getAlignment())+1);
 674     Vals.push_back(GV.hasSection() ? SectionMap[GV.getSection()] : 0);
 675     if (GV.isThreadLocal() ||
 676         GV.getVisibility() != GlobalValue::DefaultVisibility ||
 677         GV.hasUnnamedAddr() || GV.isExternallyInitialized() ||
 678         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
 679         GV.hasComdat()) {
 680       Vals.push_back(getEncodedVisibility(GV));
 681       Vals.push_back(getEncodedThreadLocalMode(GV));
 682       Vals.push_back(GV.hasUnnamedAddr());
 683       Vals.push_back(GV.isExternallyInitialized());
 684       Vals.push_back(getEncodedDLLStorageClass(GV));
 685       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
 686     } else {
 687       AbbrevToUse = SimpleGVarAbbrev;
 688     }
 689
 690     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 691     Vals.clear();
 692   }
 693
 694   // Emit the function proto information.
 695   for (const Function &F : *M) {
 696     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
 697     //             section, visibility, gc, unnamed_addr, prologuedata,
 698     //             dllstorageclass, comdat, prefixdata, personalityfn]
 699     Vals.push_back(VE.getTypeID(F.getFunctionType()));
 700     Vals.push_back(F.getCallingConv());
 701     Vals.push_back(F.isDeclaration());
 702     Vals.push_back(getEncodedLinkage(F));
 703     Vals.push_back(VE.getAttributeID(F.getAttributes()));
 704     Vals.push_back(Log2_32(F.getAlignment())+1);
 705     Vals.push_back(F.hasSection() ? SectionMap[F.getSection()] : 0);
 706     Vals.push_back(getEncodedVisibility(F));
 707     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
 708     Vals.push_back(F.hasUnnamedAddr());
 709     Vals.push_back(F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1)
 710                                        : 0);
 711     Vals.push_back(getEncodedDLLStorageClass(F));
 712     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
 713     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
 714                                      : 0);
 715     Vals.push_back(
 716         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
 717
 718     unsigned AbbrevToUse = 0;
 719     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 720     Vals.clear();
 721   }
 722
 723   // Emit the alias information.
 724   for (const GlobalAlias &A : M->aliases()) {
 725     // ALIAS: [alias type, aliasee val#, linkage, visibility]
 726     Vals.push_back(VE.getTypeID(A.getType()));
 727     Vals.push_back(VE.getValueID(A.getAliasee()));
 728     Vals.push_back(getEncodedLinkage(A));
 729     Vals.push_back(getEncodedVisibility(A));
 730     Vals.push_back(getEncodedDLLStorageClass(A));
 731     Vals.push_back(getEncodedThreadLocalMode(A));
 732     Vals.push_back(A.hasUnnamedAddr());
 733     unsigned AbbrevToUse = 0;
 734     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 735     Vals.clear();
 736   }
 737 }
 738
 739 static uint64_t GetOptimizationFlags(const Value *V) {
 740   uint64_t Flags = 0;
 741
 742   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
 743     if (OBO->hasNoSignedWrap())
 744       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
 745     if (OBO->hasNoUnsignedWrap())
 746       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
 747   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
 748     if (PEO->isExact())
 749       Flags |= 1 << bitc::PEO_EXACT;
 750   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
 751     if (FPMO->hasUnsafeAlgebra())
 752       Flags |= FastMathFlags::UnsafeAlgebra;
 753     if (FPMO->hasNoNaNs())
 754       Flags |= FastMathFlags::NoNaNs;
 755     if (FPMO->hasNoInfs())
 756       Flags |= FastMathFlags::NoInfs;
 757     if (FPMO->hasNoSignedZeros())
 758       Flags |= FastMathFlags::NoSignedZeros;
 759     if (FPMO->hasAllowReciprocal())
 760       Flags |= FastMathFlags::AllowReciprocal;
 761   }
 762
 763   return Flags;
 764 }
 765
 766 static void WriteValueAsMetadata(const ValueAsMetadata *MD,
 767                                  const ValueEnumerator &VE,
 768                                  BitstreamWriter &Stream,
 769                                  SmallVectorImpl<uint64_t> &Record) {
 770   // Mimic an MDNode with a value as one operand.
 771   Value *V = MD->getValue();
 772   Record.push_back(VE.getTypeID(V->getType()));
 773   Record.push_back(VE.getValueID(V));
 774   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
 775   Record.clear();
 776 }
 777
 778 static void WriteMDTuple(const MDTuple *N, const ValueEnumerator &VE,
 779                          BitstreamWriter &Stream,
 780                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
 781   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
 782     Metadata *MD = N->getOperand(i);
 783     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
 784            "Unexpected function-local metadata");
 785     Record.push_back(VE.getMetadataOrNullID(MD));
 786   }
 787   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
 788                                     : bitc::METADATA_NODE,
 789                     Record, Abbrev);
 790   Record.clear();
 791 }
 792
 793 static void WriteDILocation(const DILocation *N, const ValueEnumerator &VE,
 794                             BitstreamWriter &Stream,
 795                             SmallVectorImpl<uint64_t> &Record,
 796                             unsigned Abbrev) {
 797   Record.push_back(N->isDistinct());
 798   Record.push_back(N->getLine());
 799   Record.push_back(N->getColumn());
 800   Record.push_back(VE.getMetadataID(N->getScope()));
 801   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
 802
 803   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
 804   Record.clear();
 805 }
 806
 807 static void WriteGenericDINode(const GenericDINode *N,
 808                                const ValueEnumerator &VE,
 809                                BitstreamWriter &Stream,
 810                                SmallVectorImpl<uint64_t> &Record,
 811                                unsigned Abbrev) {
 812   Record.push_back(N->isDistinct());
 813   Record.push_back(N->getTag());
 814   Record.push_back(0); // Per-tag version field; unused for now.
 815
 816   for (auto &I : N->operands())
 817     Record.push_back(VE.getMetadataOrNullID(I));
 818
 819   Stream.EmitRecord(bitc::METADATA_GENERIC_DEBUG, Record, Abbrev);
 820   Record.clear();
 821 }
 822
 823 static uint64_t rotateSign(int64_t I) {
 824   uint64_t U = I;
 825   return I < 0 ? ~(U << 1) : U << 1;
 826 }
 827
 828 static void WriteDISubrange(const DISubrange *N, const ValueEnumerator &,
 829                             BitstreamWriter &Stream,
 830                             SmallVectorImpl<uint64_t> &Record,
 831                             unsigned Abbrev) {
 832   Record.push_back(N->isDistinct());
 833   Record.push_back(N->getCount());
 834   Record.push_back(rotateSign(N->getLowerBound()));
 835
 836   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
 837   Record.clear();
 838 }
 839
 840 static void WriteDIEnumerator(const DIEnumerator *N, const ValueEnumerator &VE,
 841                               BitstreamWriter &Stream,
 842                               SmallVectorImpl<uint64_t> &Record,
 843                               unsigned Abbrev) {
 844   Record.push_back(N->isDistinct());
 845   Record.push_back(rotateSign(N->getValue()));
 846   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 847
 848   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
 849   Record.clear();
 850 }
 851
 852 static void WriteDIBasicType(const DIBasicType *N, const ValueEnumerator &VE,
 853                              BitstreamWriter &Stream,
 854                              SmallVectorImpl<uint64_t> &Record,
 855                              unsigned Abbrev) {
 856   Record.push_back(N->isDistinct());
 857   Record.push_back(N->getTag());
 858   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 859   Record.push_back(N->getSizeInBits());
 860   Record.push_back(N->getAlignInBits());
 861   Record.push_back(N->getEncoding());
 862
 863   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
 864   Record.clear();
 865 }
 866
 867 static void WriteDIDerivedType(const DIDerivedType *N,
 868                                const ValueEnumerator &VE,
 869                                BitstreamWriter &Stream,
 870                                SmallVectorImpl<uint64_t> &Record,
 871                                unsigned Abbrev) {
 872   Record.push_back(N->isDistinct());
 873   Record.push_back(N->getTag());
 874   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 875   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 876   Record.push_back(N->getLine());
 877   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 878   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
 879   Record.push_back(N->getSizeInBits());
 880   Record.push_back(N->getAlignInBits());
 881   Record.push_back(N->getOffsetInBits());
 882   Record.push_back(N->getFlags());
 883   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
 884
 885   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
 886   Record.clear();
 887 }
 888
 889 static void WriteDICompositeType(const DICompositeType *N,
 890                                  const ValueEnumerator &VE,
 891                                  BitstreamWriter &Stream,
 892                                  SmallVectorImpl<uint64_t> &Record,
 893                                  unsigned Abbrev) {
 894   Record.push_back(N->isDistinct());
 895   Record.push_back(N->getTag());
 896   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 897   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 898   Record.push_back(N->getLine());
 899   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 900   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
 901   Record.push_back(N->getSizeInBits());
 902   Record.push_back(N->getAlignInBits());
 903   Record.push_back(N->getOffsetInBits());
 904   Record.push_back(N->getFlags());
 905   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
 906   Record.push_back(N->getRuntimeLang());
 907   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
 908   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
 909   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
 910
 911   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
 912   Record.clear();
 913 }
 914
 915 static void WriteDISubroutineType(const DISubroutineType *N,
 916                                   const ValueEnumerator &VE,
 917                                   BitstreamWriter &Stream,
 918                                   SmallVectorImpl<uint64_t> &Record,
 919                                   unsigned Abbrev) {
 920   Record.push_back(N->isDistinct());
 921   Record.push_back(N->getFlags());
 922   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
 923
 924   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
 925   Record.clear();
 926 }
 927
 928 static void WriteDIFile(const DIFile *N, const ValueEnumerator &VE,
 929                         BitstreamWriter &Stream,
 930                         SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
 931   Record.push_back(N->isDistinct());
 932   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
 933   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
 934
 935   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
 936   Record.clear();
 937 }
 938
 939 static void WriteDICompileUnit(const DICompileUnit *N,
 940                                const ValueEnumerator &VE,
 941                                BitstreamWriter &Stream,
 942                                SmallVectorImpl<uint64_t> &Record,
 943                                unsigned Abbrev) {
 944   Record.push_back(N->isDistinct());
 945   Record.push_back(N->getSourceLanguage());
 946   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 947   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
 948   Record.push_back(N->isOptimized());
 949   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
 950   Record.push_back(N->getRuntimeVersion());
 951   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
 952   Record.push_back(N->getEmissionKind());
 953   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
 954   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
 955   Record.push_back(VE.getMetadataOrNullID(N->getSubprograms().get()));
 956   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
 957   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
 958   Record.push_back(N->getDWOId());
 959
 960   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
 961   Record.clear();
 962 }
 963
 964 static void WriteDISubprogram(const DISubprogram *N, const ValueEnumerator &VE,
 965                               BitstreamWriter &Stream,
 966                               SmallVectorImpl<uint64_t> &Record,
 967                               unsigned Abbrev) {
 968   Record.push_back(N->isDistinct());
 969   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 970   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 971   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
 972   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 973   Record.push_back(N->getLine());
 974   Record.push_back(VE.getMetadataOrNullID(N->getType()));
 975   Record.push_back(N->isLocalToUnit());
 976   Record.push_back(N->isDefinition());
 977   Record.push_back(N->getScopeLine());
 978   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
 979   Record.push_back(N->getVirtuality());
 980   Record.push_back(N->getVirtualIndex());
 981   Record.push_back(N->getFlags());
 982   Record.push_back(N->isOptimized());
 983   Record.push_back(VE.getMetadataOrNullID(N->getRawFunction()));
 984   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
 985   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
 986   Record.push_back(VE.getMetadataOrNullID(N->getVariables().get()));
 987
 988   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
 989   Record.clear();
 990 }
 991
 992 static void WriteDILexicalBlock(const DILexicalBlock *N,
 993                                 const ValueEnumerator &VE,
 994                                 BitstreamWriter &Stream,
 995                                 SmallVectorImpl<uint64_t> &Record,
 996                                 unsigned Abbrev) {
 997   Record.push_back(N->isDistinct());
 998   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 999   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1000   Record.push_back(N->getLine());
1001   Record.push_back(N->getColumn());
1002
1003   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
1004   Record.clear();
1005 }
1006
1007 static void WriteDILexicalBlockFile(const DILexicalBlockFile *N,
1008                                     const ValueEnumerator &VE,
1009                                     BitstreamWriter &Stream,
1010                                     SmallVectorImpl<uint64_t> &Record,
1011                                     unsigned Abbrev) {
1012   Record.push_back(N->isDistinct());
1013   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1014   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1015   Record.push_back(N->getDiscriminator());
1016
1017   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
1018   Record.clear();
1019 }
1020
1021 static void WriteDINamespace(const DINamespace *N, const ValueEnumerator &VE,
1022                              BitstreamWriter &Stream,
1023                              SmallVectorImpl<uint64_t> &Record,
1024                              unsigned Abbrev) {
1025   Record.push_back(N->isDistinct());
1026   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1027   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1028   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1029   Record.push_back(N->getLine());
1030
1031   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
1032   Record.clear();
1033 }
1034
1035 static void WriteDIModule(const DIModule *N, const ValueEnumerator &VE,
1036                           BitstreamWriter &Stream,
1037                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
1038   Record.push_back(N->isDistinct());
1039   for (auto &I : N->operands())
1040     Record.push_back(VE.getMetadataOrNullID(I));
1041
1042   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
1043   Record.clear();
1044 }
1045
1046 static void WriteDITemplateTypeParameter(const DITemplateTypeParameter *N,
1047                                          const ValueEnumerator &VE,
1048                                          BitstreamWriter &Stream,
1049                                          SmallVectorImpl<uint64_t> &Record,
1050                                          unsigned Abbrev) {
1051   Record.push_back(N->isDistinct());
1052   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1053   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1054
1055   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
1056   Record.clear();
1057 }
1058
1059 static void WriteDITemplateValueParameter(const DITemplateValueParameter *N,
1060                                           const ValueEnumerator &VE,
1061                                           BitstreamWriter &Stream,
1062                                           SmallVectorImpl<uint64_t> &Record,
1063                                           unsigned Abbrev) {
1064   Record.push_back(N->isDistinct());
1065   Record.push_back(N->getTag());
1066   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1067   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1068   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
1069
1070   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
1071   Record.clear();
1072 }
1073
1074 static void WriteDIGlobalVariable(const DIGlobalVariable *N,
1075                                   const ValueEnumerator &VE,
1076                                   BitstreamWriter &Stream,
1077                                   SmallVectorImpl<uint64_t> &Record,
1078                                   unsigned Abbrev) {
1079   Record.push_back(N->isDistinct());
1080   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1081   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1082   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1083   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1084   Record.push_back(N->getLine());
1085   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1086   Record.push_back(N->isLocalToUnit());
1087   Record.push_back(N->isDefinition());
1088   Record.push_back(VE.getMetadataOrNullID(N->getRawVariable()));
1089   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
1090
1091   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
1092   Record.clear();
1093 }
1094
1095 static void WriteDILocalVariable(const DILocalVariable *N,
1096                                  const ValueEnumerator &VE,
1097                                  BitstreamWriter &Stream,
1098                                  SmallVectorImpl<uint64_t> &Record,
1099                                  unsigned Abbrev) {
1100   Record.push_back(N->isDistinct());
1101   Record.push_back(N->getTag());
1102   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1103   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1104   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1105   Record.push_back(N->getLine());
1106   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1107   Record.push_back(N->getArg());
1108   Record.push_back(N->getFlags());
1109
1110   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
1111   Record.clear();
1112 }
1113
1114 static void WriteDIExpression(const DIExpression *N, const ValueEnumerator &,
1115                               BitstreamWriter &Stream,
1116                               SmallVectorImpl<uint64_t> &Record,
1117                               unsigned Abbrev) {
1118   Record.reserve(N->getElements().size() + 1);
1119
1120   Record.push_back(N->isDistinct());
1121   Record.append(N->elements_begin(), N->elements_end());
1122
1123   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
1124   Record.clear();
1125 }
1126
1127 static void WriteDIObjCProperty(const DIObjCProperty *N,
1128                                 const ValueEnumerator &VE,
1129                                 BitstreamWriter &Stream,
1130                                 SmallVectorImpl<uint64_t> &Record,
1131                                 unsigned Abbrev) {
1132   Record.push_back(N->isDistinct());
1133   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1134   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1135   Record.push_back(N->getLine());
1136   Record.push_back(VE.getMetadataOrNullID(N->getRawSetterName()));
1137   Record.push_back(VE.getMetadataOrNullID(N->getRawGetterName()));
1138   Record.push_back(N->getAttributes());
1139   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1140
1141   Stream.EmitRecord(bitc::METADATA_OBJC_PROPERTY, Record, Abbrev);
1142   Record.clear();
1143 }
1144
1145 static void WriteDIImportedEntity(const DIImportedEntity *N,
1146                                   const ValueEnumerator &VE,
1147                                   BitstreamWriter &Stream,
1148                                   SmallVectorImpl<uint64_t> &Record,
1149                                   unsigned Abbrev) {
1150   Record.push_back(N->isDistinct());
1151   Record.push_back(N->getTag());
1152   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1153   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
1154   Record.push_back(N->getLine());
1155   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1156
1157   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
1158   Record.clear();
1159 }
1160
1161 static void WriteModuleMetadata(const Module *M,
1162                                 const ValueEnumerator &VE,
1163                                 BitstreamWriter &Stream) {
1164   const auto &MDs = VE.getMDs();
1165   if (MDs.empty() && M->named_metadata_empty())
1166     return;
1167
1168   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1169
1170   unsigned MDSAbbrev = 0;
1171   if (VE.hasMDString()) {
1172     // Abbrev for METADATA_STRING.
1173     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1174     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
1175     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1176     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1177     MDSAbbrev = Stream.EmitAbbrev(Abbv);
1178   }
1179
1180   // Initialize MDNode abbreviations.
1181 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
1182 #include "llvm/IR/Metadata.def"
1183
1184   if (VE.hasDILocation()) {
1185     // Abbrev for METADATA_LOCATION.
1186     //
1187     // Assume the column is usually under 128, and always output the inlined-at
1188     // location (it's never more expensive than building an array size 1).
1189     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1190     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1191     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1192     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1193     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1194     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1195     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1196     DILocationAbbrev = Stream.EmitAbbrev(Abbv);
1197   }
1198
1199   if (VE.hasGenericDINode()) {
1200     // Abbrev for METADATA_GENERIC_DEBUG.
1201     //
1202     // Assume the column is usually under 128, and always output the inlined-at
1203     // location (it's never more expensive than building an array size 1).
1204     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1205     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1206     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1207     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1208     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1209     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1210     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1211     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1212     GenericDINodeAbbrev = Stream.EmitAbbrev(Abbv);
1213   }
1214
1215   unsigned NameAbbrev = 0;
1216   if (!M->named_metadata_empty()) {
1217     // Abbrev for METADATA_NAME.
1218     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1219     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
1220     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1221     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1222     NameAbbrev = Stream.EmitAbbrev(Abbv);
1223   }
1224
1225   SmallVector<uint64_t, 64> Record;
1226   for (const Metadata *MD : MDs) {
1227     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
1228       assert(N->isResolved() && "Expected forward references to be resolved");
1229
1230       switch (N->getMetadataID()) {
1231       default:
1232         llvm_unreachable("Invalid MDNode subclass");
1233 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
1234   case Metadata::CLASS##Kind:                                                  \
1235     Write##CLASS(cast<CLASS>(N), VE, Stream, Record, CLASS##Abbrev);           \
1236     continue;
1237 #include "llvm/IR/Metadata.def"
1238       }
1239     }
1240     if (const auto *MDC = dyn_cast<ConstantAsMetadata>(MD)) {
1241       WriteValueAsMetadata(MDC, VE, Stream, Record);
1242       continue;
1243     }
1244     const MDString *MDS = cast<MDString>(MD);
1245     // Code: [strchar x N]
1246     Record.append(MDS->bytes_begin(), MDS->bytes_end());
1247
1248     // Emit the finished record.
1249     Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
1250     Record.clear();
1251   }
1252
1253   // Write named metadata.
1254   for (const NamedMDNode &NMD : M->named_metadata()) {
1255     // Write name.
1256     StringRef Str = NMD.getName();
1257     Record.append(Str.bytes_begin(), Str.bytes_end());
1258     Stream.EmitRecord(bitc::METADATA_NAME, Record, NameAbbrev);
1259     Record.clear();
1260
1261     // Write named metadata operands.
1262     for (const MDNode *N : NMD.operands())
1263       Record.push_back(VE.getMetadataID(N));
1264     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
1265     Record.clear();
1266   }
1267
1268   Stream.ExitBlock();
1269 }
1270
1271 static void WriteFunctionLocalMetadata(const Function &F,
1272                                        const ValueEnumerator &VE,
1273                                        BitstreamWriter &Stream) {
1274   bool StartedMetadataBlock = false;
1275   SmallVector<uint64_t, 64> Record;
1276   const SmallVectorImpl<const LocalAsMetadata *> &MDs =
1277       VE.getFunctionLocalMDs();
1278   for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1279     assert(MDs[i] && "Expected valid function-local metadata");
1280     if (!StartedMetadataBlock) {
1281       Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1282       StartedMetadataBlock = true;
1283     }
1284     WriteValueAsMetadata(MDs[i], VE, Stream, Record);
1285   }
1286
1287   if (StartedMetadataBlock)
1288     Stream.ExitBlock();
1289 }
1290
1291 static void WriteMetadataAttachment(const Function &F,
1292                                     const ValueEnumerator &VE,
1293                                     BitstreamWriter &Stream) {
1294   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
1295
1296   SmallVector<uint64_t, 64> Record;
1297
1298   // Write metadata attachments
1299   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
1300   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
1301   F.getAllMetadata(MDs);
1302   if (!MDs.empty()) {
1303     for (const auto &I : MDs) {
1304       Record.push_back(I.first);
1305       Record.push_back(VE.getMetadataID(I.second));
1306     }
1307     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1308     Record.clear();
1309   }
1310
1311   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1312     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1313          I != E; ++I) {
1314       MDs.clear();
1315       I->getAllMetadataOtherThanDebugLoc(MDs);
1316
1317       // If no metadata, ignore instruction.
1318       if (MDs.empty()) continue;
1319
1320       Record.push_back(VE.getInstructionID(I));
1321
1322       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1323         Record.push_back(MDs[i].first);
1324         Record.push_back(VE.getMetadataID(MDs[i].second));
1325       }
1326       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1327       Record.clear();
1328     }
1329
1330   Stream.ExitBlock();
1331 }
1332
1333 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
1334   SmallVector<uint64_t, 64> Record;
1335
1336   // Write metadata kinds
1337   // METADATA_KIND - [n x [id, name]]
1338   SmallVector<StringRef, 8> Names;
1339   M->getMDKindNames(Names);
1340
1341   if (Names.empty()) return;
1342
1343   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1344
1345   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
1346     Record.push_back(MDKindID);
1347     StringRef KName = Names[MDKindID];
1348     Record.append(KName.begin(), KName.end());
1349
1350     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
1351     Record.clear();
1352   }
1353
1354   Stream.ExitBlock();
1355 }
1356
1357 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
1358   if ((int64_t)V >= 0)
1359     Vals.push_back(V << 1);
1360   else
1361     Vals.push_back((-V << 1) | 1);
1362 }
1363
1364 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
1365                            const ValueEnumerator &VE,
1366                            BitstreamWriter &Stream, bool isGlobal) {
1367   if (FirstVal == LastVal) return;
1368
1369   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
1370
1371   unsigned AggregateAbbrev = 0;
1372   unsigned String8Abbrev = 0;
1373   unsigned CString7Abbrev = 0;
1374   unsigned CString6Abbrev = 0;
1375   // If this is a constant pool for the module, emit module-specific abbrevs.
1376   if (isGlobal) {
1377     // Abbrev for CST_CODE_AGGREGATE.
1378     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1379     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
1380     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1381     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
1382     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
1383
1384     // Abbrev for CST_CODE_STRING.
1385     Abbv = new BitCodeAbbrev();
1386     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
1387     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1388     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1389     String8Abbrev = Stream.EmitAbbrev(Abbv);
1390     // Abbrev for CST_CODE_CSTRING.
1391     Abbv = new BitCodeAbbrev();
1392     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1393     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1394     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1395     CString7Abbrev = Stream.EmitAbbrev(Abbv);
1396     // Abbrev for CST_CODE_CSTRING.
1397     Abbv = new BitCodeAbbrev();
1398     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1399     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1400     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1401     CString6Abbrev = Stream.EmitAbbrev(Abbv);
1402   }
1403
1404   SmallVector<uint64_t, 64> Record;
1405
1406   const ValueEnumerator::ValueList &Vals = VE.getValues();
1407   Type *LastTy = nullptr;
1408   for (unsigned i = FirstVal; i != LastVal; ++i) {
1409     const Value *V = Vals[i].first;
1410     // If we need to switch types, do so now.
1411     if (V->getType() != LastTy) {
1412       LastTy = V->getType();
1413       Record.push_back(VE.getTypeID(LastTy));
1414       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
1415                         CONSTANTS_SETTYPE_ABBREV);
1416       Record.clear();
1417     }
1418
1419     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
1420       Record.push_back(unsigned(IA->hasSideEffects()) |
1421                        unsigned(IA->isAlignStack()) << 1 |
1422                        unsigned(IA->getDialect()&1) << 2);
1423
1424       // Add the asm string.
1425       const std::string &AsmStr = IA->getAsmString();
1426       Record.push_back(AsmStr.size());
1427       Record.append(AsmStr.begin(), AsmStr.end());
1428
1429       // Add the constraint string.
1430       const std::string &ConstraintStr = IA->getConstraintString();
1431       Record.push_back(ConstraintStr.size());
1432       Record.append(ConstraintStr.begin(), ConstraintStr.end());
1433       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
1434       Record.clear();
1435       continue;
1436     }
1437     const Constant *C = cast<Constant>(V);
1438     unsigned Code = -1U;
1439     unsigned AbbrevToUse = 0;
1440     if (C->isNullValue()) {
1441       Code = bitc::CST_CODE_NULL;
1442     } else if (isa<UndefValue>(C)) {
1443       Code = bitc::CST_CODE_UNDEF;
1444     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
1445       if (IV->getBitWidth() <= 64) {
1446         uint64_t V = IV->getSExtValue();
1447         emitSignedInt64(Record, V);
1448         Code = bitc::CST_CODE_INTEGER;
1449         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
1450       } else {                             // Wide integers, > 64 bits in size.
1451         // We have an arbitrary precision integer value to write whose
1452         // bit width is > 64. However, in canonical unsigned integer
1453         // format it is likely that the high bits are going to be zero.
1454         // So, we only write the number of active words.
1455         unsigned NWords = IV->getValue().getActiveWords();
1456         const uint64_t *RawWords = IV->getValue().getRawData();
1457         for (unsigned i = 0; i != NWords; ++i) {
1458           emitSignedInt64(Record, RawWords[i]);
1459         }
1460         Code = bitc::CST_CODE_WIDE_INTEGER;
1461       }
1462     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
1463       Code = bitc::CST_CODE_FLOAT;
1464       Type *Ty = CFP->getType();
1465       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
1466         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
1467       } else if (Ty->isX86_FP80Ty()) {
1468         // api needed to prevent premature destruction
1469         // bits are not in the same order as a normal i80 APInt, compensate.
1470         APInt api = CFP->getValueAPF().bitcastToAPInt();
1471         const uint64_t *p = api.getRawData();
1472         Record.push_back((p[1] << 48) | (p[0] >> 16));
1473         Record.push_back(p[0] & 0xffffLL);
1474       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
1475         APInt api = CFP->getValueAPF().bitcastToAPInt();
1476         const uint64_t *p = api.getRawData();
1477         Record.push_back(p[0]);
1478         Record.push_back(p[1]);
1479       } else {
1480         assert (0 && "Unknown FP type!");
1481       }
1482     } else if (isa<ConstantDataSequential>(C) &&
1483                cast<ConstantDataSequential>(C)->isString()) {
1484       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
1485       // Emit constant strings specially.
1486       unsigned NumElts = Str->getNumElements();
1487       // If this is a null-terminated string, use the denser CSTRING encoding.
1488       if (Str->isCString()) {
1489         Code = bitc::CST_CODE_CSTRING;
1490         --NumElts;  // Don't encode the null, which isn't allowed by char6.
1491       } else {
1492         Code = bitc::CST_CODE_STRING;
1493         AbbrevToUse = String8Abbrev;
1494       }
1495       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
1496       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
1497       for (unsigned i = 0; i != NumElts; ++i) {
1498         unsigned char V = Str->getElementAsInteger(i);
1499         Record.push_back(V);
1500         isCStr7 &= (V & 128) == 0;
1501         if (isCStrChar6)
1502           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
1503       }
1504
1505       if (isCStrChar6)
1506         AbbrevToUse = CString6Abbrev;
1507       else if (isCStr7)
1508         AbbrevToUse = CString7Abbrev;
1509     } else if (const ConstantDataSequential *CDS =
1510                   dyn_cast<ConstantDataSequential>(C)) {
1511       Code = bitc::CST_CODE_DATA;
1512       Type *EltTy = CDS->getType()->getElementType();
1513       if (isa<IntegerType>(EltTy)) {
1514         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
1515           Record.push_back(CDS->getElementAsInteger(i));
1516       } else if (EltTy->isFloatTy()) {
1517         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1518           union { float F; uint32_t I; };
1519           F = CDS->getElementAsFloat(i);
1520           Record.push_back(I);
1521         }
1522       } else {
1523         assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
1524         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1525           union { double F; uint64_t I; };
1526           F = CDS->getElementAsDouble(i);
1527           Record.push_back(I);
1528         }
1529       }
1530     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
1531                isa<ConstantVector>(C)) {
1532       Code = bitc::CST_CODE_AGGREGATE;
1533       for (const Value *Op : C->operands())
1534         Record.push_back(VE.getValueID(Op));
1535       AbbrevToUse = AggregateAbbrev;
1536     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
1537       switch (CE->getOpcode()) {
1538       default:
1539         if (Instruction::isCast(CE->getOpcode())) {
1540           Code = bitc::CST_CODE_CE_CAST;
1541           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
1542           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1543           Record.push_back(VE.getValueID(C->getOperand(0)));
1544           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
1545         } else {
1546           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
1547           Code = bitc::CST_CODE_CE_BINOP;
1548           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
1549           Record.push_back(VE.getValueID(C->getOperand(0)));
1550           Record.push_back(VE.getValueID(C->getOperand(1)));
1551           uint64_t Flags = GetOptimizationFlags(CE);
1552           if (Flags != 0)
1553             Record.push_back(Flags);
1554         }
1555         break;
1556       case Instruction::GetElementPtr: {
1557         Code = bitc::CST_CODE_CE_GEP;
1558         const auto *GO = cast<GEPOperator>(C);
1559         if (GO->isInBounds())
1560           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
1561         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
1562         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
1563           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
1564           Record.push_back(VE.getValueID(C->getOperand(i)));
1565         }
1566         break;
1567       }
1568       case Instruction::Select:
1569         Code = bitc::CST_CODE_CE_SELECT;
1570         Record.push_back(VE.getValueID(C->getOperand(0)));
1571         Record.push_back(VE.getValueID(C->getOperand(1)));
1572         Record.push_back(VE.getValueID(C->getOperand(2)));
1573         break;
1574       case Instruction::ExtractElement:
1575         Code = bitc::CST_CODE_CE_EXTRACTELT;
1576         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1577         Record.push_back(VE.getValueID(C->getOperand(0)));
1578         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
1579         Record.push_back(VE.getValueID(C->getOperand(1)));
1580         break;
1581       case Instruction::InsertElement:
1582         Code = bitc::CST_CODE_CE_INSERTELT;
1583         Record.push_back(VE.getValueID(C->getOperand(0)));
1584         Record.push_back(VE.getValueID(C->getOperand(1)));
1585         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
1586         Record.push_back(VE.getValueID(C->getOperand(2)));
1587         break;
1588       case Instruction::ShuffleVector:
1589         // If the return type and argument types are the same, this is a
1590         // standard shufflevector instruction.  If the types are different,
1591         // then the shuffle is widening or truncating the input vectors, and
1592         // the argument type must also be encoded.
1593         if (C->getType() == C->getOperand(0)->getType()) {
1594           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
1595         } else {
1596           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
1597           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1598         }
1599         Record.push_back(VE.getValueID(C->getOperand(0)));
1600         Record.push_back(VE.getValueID(C->getOperand(1)));
1601         Record.push_back(VE.getValueID(C->getOperand(2)));
1602         break;
1603       case Instruction::ICmp:
1604       case Instruction::FCmp:
1605         Code = bitc::CST_CODE_CE_CMP;
1606         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1607         Record.push_back(VE.getValueID(C->getOperand(0)));
1608         Record.push_back(VE.getValueID(C->getOperand(1)));
1609         Record.push_back(CE->getPredicate());
1610         break;
1611       }
1612     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
1613       Code = bitc::CST_CODE_BLOCKADDRESS;
1614       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
1615       Record.push_back(VE.getValueID(BA->getFunction()));
1616       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
1617     } else {
1618 #ifndef NDEBUG
1619       C->dump();
1620 #endif
1621       llvm_unreachable("Unknown constant!");
1622     }
1623     Stream.EmitRecord(Code, Record, AbbrevToUse);
1624     Record.clear();
1625   }
1626
1627   Stream.ExitBlock();
1628 }
1629
1630 static void WriteModuleConstants(const ValueEnumerator &VE,
1631                                  BitstreamWriter &Stream) {
1632   const ValueEnumerator::ValueList &Vals = VE.getValues();
1633
1634   // Find the first constant to emit, which is the first non-globalvalue value.
1635   // We know globalvalues have been emitted by WriteModuleInfo.
1636   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1637     if (!isa<GlobalValue>(Vals[i].first)) {
1638       WriteConstants(i, Vals.size(), VE, Stream, true);
1639       return;
1640     }
1641   }
1642 }
1643
1644 /// PushValueAndType - The file has to encode both the value and type id for
1645 /// many values, because we need to know what type to create for forward
1646 /// references.  However, most operands are not forward references, so this type
1647 /// field is not needed.
1648 ///
1649 /// This function adds V's value ID to Vals.  If the value ID is higher than the
1650 /// instruction ID, then it is a forward reference, and it also includes the
1651 /// type ID.  The value ID that is written is encoded relative to the InstID.
1652 static bool PushValueAndType(const Value *V, unsigned InstID,
1653                              SmallVectorImpl<unsigned> &Vals,
1654                              ValueEnumerator &VE) {
1655   unsigned ValID = VE.getValueID(V);
1656   // Make encoding relative to the InstID.
1657   Vals.push_back(InstID - ValID);
1658   if (ValID >= InstID) {
1659     Vals.push_back(VE.getTypeID(V->getType()));
1660     return true;
1661   }
1662   return false;
1663 }
1664
1665 /// pushValue - Like PushValueAndType, but where the type of the value is
1666 /// omitted (perhaps it was already encoded in an earlier operand).
1667 static void pushValue(const Value *V, unsigned InstID,
1668                       SmallVectorImpl<unsigned> &Vals,
1669                       ValueEnumerator &VE) {
1670   unsigned ValID = VE.getValueID(V);
1671   Vals.push_back(InstID - ValID);
1672 }
1673
1674 static void pushValueSigned(const Value *V, unsigned InstID,
1675                             SmallVectorImpl<uint64_t> &Vals,
1676                             ValueEnumerator &VE) {
1677   unsigned ValID = VE.getValueID(V);
1678   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
1679   emitSignedInt64(Vals, diff);
1680 }
1681
1682 /// WriteInstruction - Emit an instruction to the specified stream.
1683 static void WriteInstruction(const Instruction &I, unsigned InstID,
1684                              ValueEnumerator &VE, BitstreamWriter &Stream,
1685                              SmallVectorImpl<unsigned> &Vals) {
1686   unsigned Code = 0;
1687   unsigned AbbrevToUse = 0;
1688   VE.setInstructionID(&I);
1689   switch (I.getOpcode()) {
1690   default:
1691     if (Instruction::isCast(I.getOpcode())) {
1692       Code = bitc::FUNC_CODE_INST_CAST;
1693       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1694         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1695       Vals.push_back(VE.getTypeID(I.getType()));
1696       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1697     } else {
1698       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1699       Code = bitc::FUNC_CODE_INST_BINOP;
1700       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1701         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1702       pushValue(I.getOperand(1), InstID, Vals, VE);
1703       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1704       uint64_t Flags = GetOptimizationFlags(&I);
1705       if (Flags != 0) {
1706         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1707           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1708         Vals.push_back(Flags);
1709       }
1710     }
1711     break;
1712
1713   case Instruction::GetElementPtr: {
1714     Code = bitc::FUNC_CODE_INST_GEP;
1715     AbbrevToUse = FUNCTION_INST_GEP_ABBREV;
1716     auto &GEPInst = cast<GetElementPtrInst>(I);
1717     Vals.push_back(GEPInst.isInBounds());
1718     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
1719     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1720       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1721     break;
1722   }
1723   case Instruction::ExtractValue: {
1724     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1725     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1726     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1727     Vals.append(EVI->idx_begin(), EVI->idx_end());
1728     break;
1729   }
1730   case Instruction::InsertValue: {
1731     Code = bitc::FUNC_CODE_INST_INSERTVAL;
1732     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1733     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1734     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1735     Vals.append(IVI->idx_begin(), IVI->idx_end());
1736     break;
1737   }
1738   case Instruction::Select:
1739     Code = bitc::FUNC_CODE_INST_VSELECT;
1740     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1741     pushValue(I.getOperand(2), InstID, Vals, VE);
1742     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1743     break;
1744   case Instruction::ExtractElement:
1745     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1746     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1747     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1748     break;
1749   case Instruction::InsertElement:
1750     Code = bitc::FUNC_CODE_INST_INSERTELT;
1751     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1752     pushValue(I.getOperand(1), InstID, Vals, VE);
1753     PushValueAndType(I.getOperand(2), InstID, Vals, VE);
1754     break;
1755   case Instruction::ShuffleVector:
1756     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1757     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1758     pushValue(I.getOperand(1), InstID, Vals, VE);
1759     pushValue(I.getOperand(2), InstID, Vals, VE);
1760     break;
1761   case Instruction::ICmp:
1762   case Instruction::FCmp:
1763     // compare returning Int1Ty or vector of Int1Ty
1764     Code = bitc::FUNC_CODE_INST_CMP2;
1765     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1766     pushValue(I.getOperand(1), InstID, Vals, VE);
1767     Vals.push_back(cast<CmpInst>(I).getPredicate());
1768     break;
1769
1770   case Instruction::Ret:
1771     {
1772       Code = bitc::FUNC_CODE_INST_RET;
1773       unsigned NumOperands = I.getNumOperands();
1774       if (NumOperands == 0)
1775         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1776       else if (NumOperands == 1) {
1777         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1778           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1779       } else {
1780         for (unsigned i = 0, e = NumOperands; i != e; ++i)
1781           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1782       }
1783     }
1784     break;
1785   case Instruction::Br:
1786     {
1787       Code = bitc::FUNC_CODE_INST_BR;
1788       const BranchInst &II = cast<BranchInst>(I);
1789       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1790       if (II.isConditional()) {
1791         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1792         pushValue(II.getCondition(), InstID, Vals, VE);
1793       }
1794     }
1795     break;
1796   case Instruction::Switch:
1797     {
1798       Code = bitc::FUNC_CODE_INST_SWITCH;
1799       const SwitchInst &SI = cast<SwitchInst>(I);
1800       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
1801       pushValue(SI.getCondition(), InstID, Vals, VE);
1802       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
1803       for (SwitchInst::ConstCaseIt i = SI.case_begin(), e = SI.case_end();
1804            i != e; ++i) {
1805         Vals.push_back(VE.getValueID(i.getCaseValue()));
1806         Vals.push_back(VE.getValueID(i.getCaseSuccessor()));
1807       }
1808     }
1809     break;
1810   case Instruction::IndirectBr:
1811     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1812     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1813     // Encode the address operand as relative, but not the basic blocks.
1814     pushValue(I.getOperand(0), InstID, Vals, VE);
1815     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
1816       Vals.push_back(VE.getValueID(I.getOperand(i)));
1817     break;
1818
1819   case Instruction::Invoke: {
1820     const InvokeInst *II = cast<InvokeInst>(&I);
1821     const Value *Callee = II->getCalledValue();
1822     FunctionType *FTy = II->getFunctionType();
1823     Code = bitc::FUNC_CODE_INST_INVOKE;
1824
1825     Vals.push_back(VE.getAttributeID(II->getAttributes()));
1826     Vals.push_back(II->getCallingConv() | 1 << 13);
1827     Vals.push_back(VE.getValueID(II->getNormalDest()));
1828     Vals.push_back(VE.getValueID(II->getUnwindDest()));
1829     Vals.push_back(VE.getTypeID(FTy));
1830     PushValueAndType(Callee, InstID, Vals, VE);
1831
1832     // Emit value #'s for the fixed parameters.
1833     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1834       pushValue(I.getOperand(i), InstID, Vals, VE);  // fixed param.
1835
1836     // Emit type/value pairs for varargs params.
1837     if (FTy->isVarArg()) {
1838       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1839            i != e; ++i)
1840         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1841     }
1842     break;
1843   }
1844   case Instruction::Resume:
1845     Code = bitc::FUNC_CODE_INST_RESUME;
1846     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1847     break;
1848   case Instruction::CleanupRet: {
1849     Code = bitc::FUNC_CODE_INST_CLEANUPRET;
1850     const auto &CRI = cast<CleanupReturnInst>(I);
1851     Vals.push_back(CRI.hasReturnValue());
1852     Vals.push_back(CRI.hasUnwindDest());
1853     if (CRI.hasReturnValue())
1854       PushValueAndType(CRI.getReturnValue(), InstID, Vals, VE);
1855     if (CRI.hasUnwindDest())
1856       Vals.push_back(VE.getValueID(CRI.getUnwindDest()));
1857     break;
1858   }
1859   case Instruction::CatchRet: {
1860     Code = bitc::FUNC_CODE_INST_CATCHRET;
1861     const auto &CRI = cast<CatchReturnInst>(I);
1862     Vals.push_back(VE.getValueID(CRI.getSuccessor()));
1863     break;
1864   }
1865   case Instruction::CatchBlock: {
1866     Code = bitc::FUNC_CODE_INST_CATCHBLOCK;
1867     const auto &CBI = cast<CatchBlockInst>(I);
1868     Vals.push_back(VE.getTypeID(CBI.getType()));
1869     Vals.push_back(VE.getValueID(CBI.getNormalDest()));
1870     Vals.push_back(VE.getValueID(CBI.getUnwindDest()));
1871     unsigned NumArgOperands = CBI.getNumArgOperands();
1872     Vals.push_back(NumArgOperands);
1873     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
1874       PushValueAndType(CBI.getArgOperand(Op), InstID, Vals, VE);
1875     break;
1876   }
1877   case Instruction::TerminateBlock: {
1878     Code = bitc::FUNC_CODE_INST_TERMINATEBLOCK;
1879     const auto &TBI = cast<TerminateBlockInst>(I);
1880     Vals.push_back(TBI.hasUnwindDest());
1881     if (TBI.hasUnwindDest())
1882       Vals.push_back(VE.getValueID(TBI.getUnwindDest()));
1883     unsigned NumArgOperands = TBI.getNumArgOperands();
1884     Vals.push_back(NumArgOperands);
1885     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
1886       PushValueAndType(TBI.getArgOperand(Op), InstID, Vals, VE);
1887     break;
1888   }
1889   case Instruction::CleanupBlock: {
1890     Code = bitc::FUNC_CODE_INST_CLEANUPBLOCK;
1891     const auto &CBI = cast<CleanupBlockInst>(I);
1892     Vals.push_back(VE.getTypeID(CBI.getType()));
1893     unsigned NumOperands = CBI.getNumOperands();
1894     Vals.push_back(NumOperands);
1895     for (unsigned Op = 0; Op != NumOperands; ++Op)
1896       PushValueAndType(CBI.getOperand(Op), InstID, Vals, VE);
1897     break;
1898   }
1899   case Instruction::CatchEndBlock: {
1900     Code = bitc::FUNC_CODE_INST_CATCHENDBLOCK;
1901     const auto &CEBI = cast<CatchEndBlockInst>(I);
1902     if (CEBI.hasUnwindDest())
1903       Vals.push_back(VE.getValueID(CEBI.getUnwindDest()));
1904     break;
1905   }
1906   case Instruction::Unreachable:
1907     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1908     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1909     break;
1910
1911   case Instruction::PHI: {
1912     const PHINode &PN = cast<PHINode>(I);
1913     Code = bitc::FUNC_CODE_INST_PHI;
1914     // With the newer instruction encoding, forward references could give
1915     // negative valued IDs.  This is most common for PHIs, so we use
1916     // signed VBRs.
1917     SmallVector<uint64_t, 128> Vals64;
1918     Vals64.push_back(VE.getTypeID(PN.getType()));
1919     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1920       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64, VE);
1921       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1922     }
1923     // Emit a Vals64 vector and exit.
1924     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
1925     Vals64.clear();
1926     return;
1927   }
1928
1929   case Instruction::LandingPad: {
1930     const LandingPadInst &LP = cast<LandingPadInst>(I);
1931     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
1932     Vals.push_back(VE.getTypeID(LP.getType()));
1933     Vals.push_back(LP.isCleanup());
1934     Vals.push_back(LP.getNumClauses());
1935     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1936       if (LP.isCatch(I))
1937         Vals.push_back(LandingPadInst::Catch);
1938       else
1939         Vals.push_back(LandingPadInst::Filter);
1940       PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1941     }
1942     break;
1943   }
1944
1945   case Instruction::Alloca: {
1946     Code = bitc::FUNC_CODE_INST_ALLOCA;
1947     const AllocaInst &AI = cast<AllocaInst>(I);
1948     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
1949     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1950     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1951     unsigned AlignRecord = Log2_32(AI.getAlignment()) + 1;
1952     assert(Log2_32(Value::MaximumAlignment) + 1 < 1 << 5 &&
1953            "not enough bits for maximum alignment");
1954     assert(AlignRecord < 1 << 5 && "alignment greater than 1 << 64");
1955     AlignRecord |= AI.isUsedWithInAlloca() << 5;
1956     AlignRecord |= 1 << 6;
1957     Vals.push_back(AlignRecord);
1958     break;
1959   }
1960
1961   case Instruction::Load:
1962     if (cast<LoadInst>(I).isAtomic()) {
1963       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1964       PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1965     } else {
1966       Code = bitc::FUNC_CODE_INST_LOAD;
1967       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1968         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1969     }
1970     Vals.push_back(VE.getTypeID(I.getType()));
1971     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1972     Vals.push_back(cast<LoadInst>(I).isVolatile());
1973     if (cast<LoadInst>(I).isAtomic()) {
1974       Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1975       Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1976     }
1977     break;
1978   case Instruction::Store:
1979     if (cast<StoreInst>(I).isAtomic())
1980       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1981     else
1982       Code = bitc::FUNC_CODE_INST_STORE;
1983     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1984     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // valty + val
1985     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1986     Vals.push_back(cast<StoreInst>(I).isVolatile());
1987     if (cast<StoreInst>(I).isAtomic()) {
1988       Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1989       Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1990     }
1991     break;
1992   case Instruction::AtomicCmpXchg:
1993     Code = bitc::FUNC_CODE_INST_CMPXCHG;
1994     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1995     PushValueAndType(I.getOperand(1), InstID, Vals, VE);         // cmp.
1996     pushValue(I.getOperand(2), InstID, Vals, VE);         // newval.
1997     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1998     Vals.push_back(GetEncodedOrdering(
1999                      cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
2000     Vals.push_back(GetEncodedSynchScope(
2001                      cast<AtomicCmpXchgInst>(I).getSynchScope()));
2002     Vals.push_back(GetEncodedOrdering(
2003                      cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
2004     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
2005     break;
2006   case Instruction::AtomicRMW:
2007     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
2008     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
2009     pushValue(I.getOperand(1), InstID, Vals, VE);         // val.
2010     Vals.push_back(GetEncodedRMWOperation(
2011                      cast<AtomicRMWInst>(I).getOperation()));
2012     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
2013     Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
2014     Vals.push_back(GetEncodedSynchScope(
2015                      cast<AtomicRMWInst>(I).getSynchScope()));
2016     break;
2017   case Instruction::Fence:
2018     Code = bitc::FUNC_CODE_INST_FENCE;
2019     Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
2020     Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
2021     break;
2022   case Instruction::Call: {
2023     const CallInst &CI = cast<CallInst>(I);
2024     FunctionType *FTy = CI.getFunctionType();
2025
2026     Code = bitc::FUNC_CODE_INST_CALL;
2027
2028     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
2029     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()) |
2030                    unsigned(CI.isMustTailCall()) << 14 | 1 << 15);
2031     Vals.push_back(VE.getTypeID(FTy));
2032     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
2033
2034     // Emit value #'s for the fixed parameters.
2035     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
2036       // Check for labels (can happen with asm labels).
2037       if (FTy->getParamType(i)->isLabelTy())
2038         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
2039       else
2040         pushValue(CI.getArgOperand(i), InstID, Vals, VE);  // fixed param.
2041     }
2042
2043     // Emit type/value pairs for varargs params.
2044     if (FTy->isVarArg()) {
2045       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
2046            i != e; ++i)
2047         PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
2048     }
2049     break;
2050   }
2051   case Instruction::VAArg:
2052     Code = bitc::FUNC_CODE_INST_VAARG;
2053     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
2054     pushValue(I.getOperand(0), InstID, Vals, VE); // valist.
2055     Vals.push_back(VE.getTypeID(I.getType())); // restype.
2056     break;
2057   }
2058
2059   Stream.EmitRecord(Code, Vals, AbbrevToUse);
2060   Vals.clear();
2061 }
2062
2063 // Emit names for globals/functions etc.
2064 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
2065                                   const ValueEnumerator &VE,
2066                                   BitstreamWriter &Stream) {
2067   if (VST.empty()) return;
2068   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
2069
2070   // FIXME: Set up the abbrev, we know how many values there are!
2071   // FIXME: We know if the type names can use 7-bit ascii.
2072   SmallVector<unsigned, 64> NameVals;
2073
2074   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
2075        SI != SE; ++SI) {
2076
2077     const ValueName &Name = *SI;
2078
2079     // Figure out the encoding to use for the name.
2080     bool is7Bit = true;
2081     bool isChar6 = true;
2082     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
2083          C != E; ++C) {
2084       if (isChar6)
2085         isChar6 = BitCodeAbbrevOp::isChar6(*C);
2086       if ((unsigned char)*C & 128) {
2087         is7Bit = false;
2088         break;  // don't bother scanning the rest.
2089       }
2090     }
2091
2092     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
2093
2094     // VST_ENTRY:   [valueid, namechar x N]
2095     // VST_BBENTRY: [bbid, namechar x N]
2096     unsigned Code;
2097     if (isa<BasicBlock>(SI->getValue())) {
2098       Code = bitc::VST_CODE_BBENTRY;
2099       if (isChar6)
2100         AbbrevToUse = VST_BBENTRY_6_ABBREV;
2101     } else {
2102       Code = bitc::VST_CODE_ENTRY;
2103       if (isChar6)
2104         AbbrevToUse = VST_ENTRY_6_ABBREV;
2105       else if (is7Bit)
2106         AbbrevToUse = VST_ENTRY_7_ABBREV;
2107     }
2108
2109     NameVals.push_back(VE.getValueID(SI->getValue()));
2110     for (const char *P = Name.getKeyData(),
2111          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
2112       NameVals.push_back((unsigned char)*P);
2113
2114     // Emit the finished record.
2115     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
2116     NameVals.clear();
2117   }
2118   Stream.ExitBlock();
2119 }
2120
2121 static void WriteUseList(ValueEnumerator &VE, UseListOrder &&Order,
2122                          BitstreamWriter &Stream) {
2123   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
2124   unsigned Code;
2125   if (isa<BasicBlock>(Order.V))
2126     Code = bitc::USELIST_CODE_BB;
2127   else
2128     Code = bitc::USELIST_CODE_DEFAULT;
2129
2130   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
2131   Record.push_back(VE.getValueID(Order.V));
2132   Stream.EmitRecord(Code, Record);
2133 }
2134
2135 static void WriteUseListBlock(const Function *F, ValueEnumerator &VE,
2136                               BitstreamWriter &Stream) {
2137   assert(VE.shouldPreserveUseListOrder() &&
2138          "Expected to be preserving use-list order");
2139
2140   auto hasMore = [&]() {
2141     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
2142   };
2143   if (!hasMore())
2144     // Nothing to do.
2145     return;
2146
2147   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
2148   while (hasMore()) {
2149     WriteUseList(VE, std::move(VE.UseListOrders.back()), Stream);
2150     VE.UseListOrders.pop_back();
2151   }
2152   Stream.ExitBlock();
2153 }
2154
2155 /// WriteFunction - Emit a function body to the module stream.
2156 static void WriteFunction(const Function &F, ValueEnumerator &VE,
2157                           BitstreamWriter &Stream) {
2158   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
2159   VE.incorporateFunction(F);
2160
2161   SmallVector<unsigned, 64> Vals;
2162
2163   // Emit the number of basic blocks, so the reader can create them ahead of
2164   // time.
2165   Vals.push_back(VE.getBasicBlocks().size());
2166   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
2167   Vals.clear();
2168
2169   // If there are function-local constants, emit them now.
2170   unsigned CstStart, CstEnd;
2171   VE.getFunctionConstantRange(CstStart, CstEnd);
2172   WriteConstants(CstStart, CstEnd, VE, Stream, false);
2173
2174   // If there is function-local metadata, emit it now.
2175   WriteFunctionLocalMetadata(F, VE, Stream);
2176
2177   // Keep a running idea of what the instruction ID is.
2178   unsigned InstID = CstEnd;
2179
2180   bool NeedsMetadataAttachment = F.hasMetadata();
2181
2182   DILocation *LastDL = nullptr;
2183
2184   // Finally, emit all the instructions, in order.
2185   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
2186     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
2187          I != E; ++I) {
2188       WriteInstruction(*I, InstID, VE, Stream, Vals);
2189
2190       if (!I->getType()->isVoidTy())
2191         ++InstID;
2192
2193       // If the instruction has metadata, write a metadata attachment later.
2194       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
2195
2196       // If the instruction has a debug location, emit it.
2197       DILocation *DL = I->getDebugLoc();
2198       if (!DL)
2199         continue;
2200
2201       if (DL == LastDL) {
2202         // Just repeat the same debug loc as last time.
2203         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
2204         continue;
2205       }
2206
2207       Vals.push_back(DL->getLine());
2208       Vals.push_back(DL->getColumn());
2209       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
2210       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
2211       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
2212       Vals.clear();
2213
2214       LastDL = DL;
2215     }
2216
2217   // Emit names for all the instructions etc.
2218   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
2219
2220   if (NeedsMetadataAttachment)
2221     WriteMetadataAttachment(F, VE, Stream);
2222   if (VE.shouldPreserveUseListOrder())
2223     WriteUseListBlock(&F, VE, Stream);
2224   VE.purgeFunction();
2225   Stream.ExitBlock();
2226 }
2227
2228 // Emit blockinfo, which defines the standard abbreviations etc.
2229 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
2230   // We only want to emit block info records for blocks that have multiple
2231   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
2232   // Other blocks can define their abbrevs inline.
2233   Stream.EnterBlockInfoBlock(2);
2234
2235   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
2236     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2237     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
2238     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2239     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2240     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2241     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2242                                    Abbv) != VST_ENTRY_8_ABBREV)
2243       llvm_unreachable("Unexpected abbrev ordering!");
2244   }
2245
2246   { // 7-bit fixed width VST_ENTRY strings.
2247     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2248     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2249     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2250     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2251     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2252     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2253                                    Abbv) != VST_ENTRY_7_ABBREV)
2254       llvm_unreachable("Unexpected abbrev ordering!");
2255   }
2256   { // 6-bit char6 VST_ENTRY strings.
2257     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2258     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2259     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2260     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2261     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2262     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2263                                    Abbv) != VST_ENTRY_6_ABBREV)
2264       llvm_unreachable("Unexpected abbrev ordering!");
2265   }
2266   { // 6-bit char6 VST_BBENTRY strings.
2267     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2268     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
2269     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2270     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2271     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2272     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2273                                    Abbv) != VST_BBENTRY_6_ABBREV)
2274       llvm_unreachable("Unexpected abbrev ordering!");
2275   }
2276
2277
2278
2279   { // SETTYPE abbrev for CONSTANTS_BLOCK.
2280     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2281     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
2282     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2283                               VE.computeBitsRequiredForTypeIndicies()));
2284     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2285                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
2286       llvm_unreachable("Unexpected abbrev ordering!");
2287   }
2288
2289   { // INTEGER abbrev for CONSTANTS_BLOCK.
2290     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2291     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
2292     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2293     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2294                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
2295       llvm_unreachable("Unexpected abbrev ordering!");
2296   }
2297
2298   { // CE_CAST abbrev for CONSTANTS_BLOCK.
2299     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2300     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
2301     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
2302     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
2303                               VE.computeBitsRequiredForTypeIndicies()));
2304     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
2305
2306     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2307                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
2308       llvm_unreachable("Unexpected abbrev ordering!");
2309   }
2310   { // NULL abbrev for CONSTANTS_BLOCK.
2311     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2312     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
2313     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2314                                    Abbv) != CONSTANTS_NULL_Abbrev)
2315       llvm_unreachable("Unexpected abbrev ordering!");
2316   }
2317
2318   // FIXME: This should only use space for first class types!
2319
2320   { // INST_LOAD abbrev for FUNCTION_BLOCK.
2321     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2322     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
2323     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
2324     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2325                               VE.computeBitsRequiredForTypeIndicies()));
2326     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
2327     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
2328     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2329                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
2330       llvm_unreachable("Unexpected abbrev ordering!");
2331   }
2332   { // INST_BINOP abbrev for FUNCTION_BLOCK.
2333     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2334     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2335     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2336     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2337     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2338     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2339                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
2340       llvm_unreachable("Unexpected abbrev ordering!");
2341   }
2342   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
2343     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2344     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2345     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2346     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2347     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2348     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
2349     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2350                                    Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
2351       llvm_unreachable("Unexpected abbrev ordering!");
2352   }
2353   { // INST_CAST abbrev for FUNCTION_BLOCK.
2354     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2355     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
2356     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
2357     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
2358                               VE.computeBitsRequiredForTypeIndicies()));
2359     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
2360     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2361                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
2362       llvm_unreachable("Unexpected abbrev ordering!");
2363   }
2364
2365   { // INST_RET abbrev for FUNCTION_BLOCK.
2366     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2367     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2368     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2369                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
2370       llvm_unreachable("Unexpected abbrev ordering!");
2371   }
2372   { // INST_RET abbrev for FUNCTION_BLOCK.
2373     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2374     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2375     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
2376     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2377                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
2378       llvm_unreachable("Unexpected abbrev ordering!");
2379   }
2380   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
2381     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2382     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
2383     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2384                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
2385       llvm_unreachable("Unexpected abbrev ordering!");
2386   }
2387   {
2388     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2389     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
2390     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2391     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
2392                               Log2_32_Ceil(VE.getTypes().size() + 1)));
2393     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2394     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2395     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2396         FUNCTION_INST_GEP_ABBREV)
2397       llvm_unreachable("Unexpected abbrev ordering!");
2398   }
2399
2400   Stream.ExitBlock();
2401 }
2402
2403 /// WriteModule - Emit the specified module to the bitstream.
2404 static void WriteModule(const Module *M, BitstreamWriter &Stream,
2405                         bool ShouldPreserveUseListOrder) {
2406   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
2407
2408   SmallVector<unsigned, 1> Vals;
2409   unsigned CurVersion = 1;
2410   Vals.push_back(CurVersion);
2411   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
2412
2413   // Analyze the module, enumerating globals, functions, etc.
2414   ValueEnumerator VE(*M, ShouldPreserveUseListOrder);
2415
2416   // Emit blockinfo, which defines the standard abbreviations etc.
2417   WriteBlockInfo(VE, Stream);
2418
2419   // Emit information about attribute groups.
2420   WriteAttributeGroupTable(VE, Stream);
2421
2422   // Emit information about parameter attributes.
2423   WriteAttributeTable(VE, Stream);
2424
2425   // Emit information describing all of the types in the module.
2426   WriteTypeTable(VE, Stream);
2427
2428   writeComdats(VE, Stream);
2429
2430   // Emit top-level description of module, including target triple, inline asm,
2431   // descriptors for global variables, and function prototype info.
2432   WriteModuleInfo(M, VE, Stream);
2433
2434   // Emit constants.
2435   WriteModuleConstants(VE, Stream);
2436
2437   // Emit metadata.
2438   WriteModuleMetadata(M, VE, Stream);
2439
2440   // Emit metadata.
2441   WriteModuleMetadataStore(M, Stream);
2442
2443   // Emit names for globals/functions etc.
2444   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
2445
2446   // Emit module-level use-lists.
2447   if (VE.shouldPreserveUseListOrder())
2448     WriteUseListBlock(nullptr, VE, Stream);
2449
2450   // Emit function bodies.
2451   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
2452     if (!F->isDeclaration())
2453       WriteFunction(*F, VE, Stream);
2454
2455   Stream.ExitBlock();
2456 }
2457
2458 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
2459 /// header and trailer to make it compatible with the system archiver.  To do
2460 /// this we emit the following header, and then emit a trailer that pads the
2461 /// file out to be a multiple of 16 bytes.
2462 ///
2463 /// struct bc_header {
2464 ///   uint32_t Magic;         // 0x0B17C0DE
2465 ///   uint32_t Version;       // Version, currently always 0.
2466 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
2467 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
2468 ///   uint32_t CPUType;       // CPU specifier.
2469 ///   ... potentially more later ...
2470 /// };
2471 enum {
2472   DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
2473   DarwinBCHeaderSize = 5*4
2474 };
2475
2476 static void WriteInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
2477                                uint32_t &Position) {
2478   support::endian::write32le(&Buffer[Position], Value);
2479   Position += 4;
2480 }
2481
2482 static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
2483                                          const Triple &TT) {
2484   unsigned CPUType = ~0U;
2485
2486   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
2487   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
2488   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
2489   // specific constants here because they are implicitly part of the Darwin ABI.
2490   enum {
2491     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
2492     DARWIN_CPU_TYPE_X86        = 7,
2493     DARWIN_CPU_TYPE_ARM        = 12,
2494     DARWIN_CPU_TYPE_POWERPC    = 18
2495   };
2496
2497   Triple::ArchType Arch = TT.getArch();
2498   if (Arch == Triple::x86_64)
2499     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
2500   else if (Arch == Triple::x86)
2501     CPUType = DARWIN_CPU_TYPE_X86;
2502   else if (Arch == Triple::ppc)
2503     CPUType = DARWIN_CPU_TYPE_POWERPC;
2504   else if (Arch == Triple::ppc64)
2505     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
2506   else if (Arch == Triple::arm || Arch == Triple::thumb)
2507     CPUType = DARWIN_CPU_TYPE_ARM;
2508
2509   // Traditional Bitcode starts after header.
2510   assert(Buffer.size() >= DarwinBCHeaderSize &&
2511          "Expected header size to be reserved");
2512   unsigned BCOffset = DarwinBCHeaderSize;
2513   unsigned BCSize = Buffer.size()-DarwinBCHeaderSize;
2514
2515   // Write the magic and version.
2516   unsigned Position = 0;
2517   WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position);
2518   WriteInt32ToBuffer(0          , Buffer, Position); // Version.
2519   WriteInt32ToBuffer(BCOffset   , Buffer, Position);
2520   WriteInt32ToBuffer(BCSize     , Buffer, Position);
2521   WriteInt32ToBuffer(CPUType    , Buffer, Position);
2522
2523   // If the file is not a multiple of 16 bytes, insert dummy padding.
2524   while (Buffer.size() & 15)
2525     Buffer.push_back(0);
2526 }
2527
2528 /// WriteBitcodeToFile - Write the specified module to the specified output
2529 /// stream.
2530 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out,
2531                               bool ShouldPreserveUseListOrder) {
2532   SmallVector<char, 0> Buffer;
2533   Buffer.reserve(256*1024);
2534
2535   // If this is darwin or another generic macho target, reserve space for the
2536   // header.
2537   Triple TT(M->getTargetTriple());
2538   if (TT.isOSDarwin())
2539     Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0);
2540
2541   // Emit the module into the buffer.
2542   {
2543     BitstreamWriter Stream(Buffer);
2544
2545     // Emit the file header.
2546     Stream.Emit((unsigned)'B', 8);
2547     Stream.Emit((unsigned)'C', 8);
2548     Stream.Emit(0x0, 4);
2549     Stream.Emit(0xC, 4);
2550     Stream.Emit(0xE, 4);
2551     Stream.Emit(0xD, 4);
2552
2553     // Emit the module.
2554     WriteModule(M, Stream, ShouldPreserveUseListOrder);
2555   }
2556
2557   if (TT.isOSDarwin())
2558     EmitDarwinBCHeaderAndTrailer(Buffer, TT);
2559
2560   // Write the generated bitstream to "Out".
2561   Out.write((char*)&Buffer.front(), Buffer.size());
2562 }