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/STLExtras.h"
  17 #include "llvm/ADT/Triple.h"
  18 #include "llvm/Bitcode/BitstreamWriter.h"
  19 #include "llvm/Bitcode/LLVMBitCodes.h"
  20 #include "llvm/IR/CallSite.h"
  21 #include "llvm/IR/Constants.h"
  22 #include "llvm/IR/DebugInfoMetadata.h"
  23 #include "llvm/IR/DerivedTypes.h"
  24 #include "llvm/IR/InlineAsm.h"
  25 #include "llvm/IR/Instructions.h"
  26 #include "llvm/IR/LLVMContext.h"
  27 #include "llvm/IR/IntrinsicInst.h"
  28 #include "llvm/IR/Module.h"
  29 #include "llvm/IR/Operator.h"
  30 #include "llvm/IR/UseListOrder.h"
  31 #include "llvm/IR/ValueSymbolTable.h"
  32 #include "llvm/Support/CommandLine.h"
  33 #include "llvm/Support/ErrorHandling.h"
  34 #include "llvm/Support/MathExtras.h"
  35 #include "llvm/Support/Program.h"
  36 #include "llvm/Support/raw_ostream.h"
  37 #include <cctype>
  38 #include <map>
  39 using namespace llvm;
  40
  41 /// These are manifest constants used by the bitcode writer. They do not need to
  42 /// be kept in sync with the reader, but need to be consistent within this file.
  43 enum {
  44   // VALUE_SYMTAB_BLOCK abbrev id's.
  45   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  46   VST_ENTRY_7_ABBREV,
  47   VST_ENTRY_6_ABBREV,
  48   VST_BBENTRY_6_ABBREV,
  49
  50   // CONSTANTS_BLOCK abbrev id's.
  51   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  52   CONSTANTS_INTEGER_ABBREV,
  53   CONSTANTS_CE_CAST_Abbrev,
  54   CONSTANTS_NULL_Abbrev,
  55
  56   // FUNCTION_BLOCK abbrev id's.
  57   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  58   FUNCTION_INST_BINOP_ABBREV,
  59   FUNCTION_INST_BINOP_FLAGS_ABBREV,
  60   FUNCTION_INST_CAST_ABBREV,
  61   FUNCTION_INST_RET_VOID_ABBREV,
  62   FUNCTION_INST_RET_VAL_ABBREV,
  63   FUNCTION_INST_UNREACHABLE_ABBREV,
  64   FUNCTION_INST_GEP_ABBREV,
  65 };
  66
  67 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
  68   switch (Opcode) {
  69   default: llvm_unreachable("Unknown cast instruction!");
  70   case Instruction::Trunc   : return bitc::CAST_TRUNC;
  71   case Instruction::ZExt    : return bitc::CAST_ZEXT;
  72   case Instruction::SExt    : return bitc::CAST_SEXT;
  73   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
  74   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
  75   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
  76   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
  77   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
  78   case Instruction::FPExt   : return bitc::CAST_FPEXT;
  79   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
  80   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
  81   case Instruction::BitCast : return bitc::CAST_BITCAST;
  82   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
  83   }
  84 }
  85
  86 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
  87   switch (Opcode) {
  88   default: llvm_unreachable("Unknown binary instruction!");
  89   case Instruction::Add:
  90   case Instruction::FAdd: return bitc::BINOP_ADD;
  91   case Instruction::Sub:
  92   case Instruction::FSub: return bitc::BINOP_SUB;
  93   case Instruction::Mul:
  94   case Instruction::FMul: return bitc::BINOP_MUL;
  95   case Instruction::UDiv: return bitc::BINOP_UDIV;
  96   case Instruction::FDiv:
  97   case Instruction::SDiv: return bitc::BINOP_SDIV;
  98   case Instruction::URem: return bitc::BINOP_UREM;
  99   case Instruction::FRem:
 100   case Instruction::SRem: return bitc::BINOP_SREM;
 101   case Instruction::Shl:  return bitc::BINOP_SHL;
 102   case Instruction::LShr: return bitc::BINOP_LSHR;
 103   case Instruction::AShr: return bitc::BINOP_ASHR;
 104   case Instruction::And:  return bitc::BINOP_AND;
 105   case Instruction::Or:   return bitc::BINOP_OR;
 106   case Instruction::Xor:  return bitc::BINOP_XOR;
 107   }
 108 }
 109
 110 static unsigned GetEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
 111   switch (Op) {
 112   default: llvm_unreachable("Unknown RMW operation!");
 113   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
 114   case AtomicRMWInst::Add: return bitc::RMW_ADD;
 115   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
 116   case AtomicRMWInst::And: return bitc::RMW_AND;
 117   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
 118   case AtomicRMWInst::Or: return bitc::RMW_OR;
 119   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
 120   case AtomicRMWInst::Max: return bitc::RMW_MAX;
 121   case AtomicRMWInst::Min: return bitc::RMW_MIN;
 122   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
 123   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
 124   }
 125 }
 126
 127 static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
 128   switch (Ordering) {
 129   case NotAtomic: return bitc::ORDERING_NOTATOMIC;
 130   case Unordered: return bitc::ORDERING_UNORDERED;
 131   case Monotonic: return bitc::ORDERING_MONOTONIC;
 132   case Acquire: return bitc::ORDERING_ACQUIRE;
 133   case Release: return bitc::ORDERING_RELEASE;
 134   case AcquireRelease: return bitc::ORDERING_ACQREL;
 135   case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
 136   }
 137   llvm_unreachable("Invalid ordering");
 138 }
 139
 140 static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
 141   switch (SynchScope) {
 142   case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
 143   case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
 144   }
 145   llvm_unreachable("Invalid synch scope");
 146 }
 147
 148 static void WriteStringRecord(unsigned Code, StringRef Str,
 149                               unsigned AbbrevToUse, BitstreamWriter &Stream) {
 150   SmallVector<unsigned, 64> Vals;
 151
 152   // Code: [strchar x N]
 153   for (unsigned i = 0, e = Str.size(); i != e; ++i) {
 154     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
 155       AbbrevToUse = 0;
 156     Vals.push_back(Str[i]);
 157   }
 158
 159   // Emit the finished record.
 160   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 161 }
 162
 163 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
 164   switch (Kind) {
 165   case Attribute::Alignment:
 166     return bitc::ATTR_KIND_ALIGNMENT;
 167   case Attribute::AlwaysInline:
 168     return bitc::ATTR_KIND_ALWAYS_INLINE;
 169   case Attribute::ArgMemOnly:
 170     return bitc::ATTR_KIND_ARGMEMONLY;
 171   case Attribute::Builtin:
 172     return bitc::ATTR_KIND_BUILTIN;
 173   case Attribute::ByVal:
 174     return bitc::ATTR_KIND_BY_VAL;
 175   case Attribute::Convergent:
 176     return bitc::ATTR_KIND_CONVERGENT;
 177   case Attribute::InAlloca:
 178     return bitc::ATTR_KIND_IN_ALLOCA;
 179   case Attribute::Cold:
 180     return bitc::ATTR_KIND_COLD;
 181   case Attribute::InlineHint:
 182     return bitc::ATTR_KIND_INLINE_HINT;
 183   case Attribute::InReg:
 184     return bitc::ATTR_KIND_IN_REG;
 185   case Attribute::JumpTable:
 186     return bitc::ATTR_KIND_JUMP_TABLE;
 187   case Attribute::MinSize:
 188     return bitc::ATTR_KIND_MIN_SIZE;
 189   case Attribute::Naked:
 190     return bitc::ATTR_KIND_NAKED;
 191   case Attribute::Nest:
 192     return bitc::ATTR_KIND_NEST;
 193   case Attribute::NoAlias:
 194     return bitc::ATTR_KIND_NO_ALIAS;
 195   case Attribute::NoBuiltin:
 196     return bitc::ATTR_KIND_NO_BUILTIN;
 197   case Attribute::NoCapture:
 198     return bitc::ATTR_KIND_NO_CAPTURE;
 199   case Attribute::NoDuplicate:
 200     return bitc::ATTR_KIND_NO_DUPLICATE;
 201   case Attribute::NoImplicitFloat:
 202     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
 203   case Attribute::NoInline:
 204     return bitc::ATTR_KIND_NO_INLINE;
 205   case Attribute::NoRecurse:
 206     return bitc::ATTR_KIND_NO_RECURSE;
 207   case Attribute::NonLazyBind:
 208     return bitc::ATTR_KIND_NON_LAZY_BIND;
 209   case Attribute::NonNull:
 210     return bitc::ATTR_KIND_NON_NULL;
 211   case Attribute::Dereferenceable:
 212     return bitc::ATTR_KIND_DEREFERENCEABLE;
 213   case Attribute::DereferenceableOrNull:
 214     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
 215   case Attribute::NoRedZone:
 216     return bitc::ATTR_KIND_NO_RED_ZONE;
 217   case Attribute::NoReturn:
 218     return bitc::ATTR_KIND_NO_RETURN;
 219   case Attribute::NoUnwind:
 220     return bitc::ATTR_KIND_NO_UNWIND;
 221   case Attribute::OptimizeForSize:
 222     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
 223   case Attribute::OptimizeNone:
 224     return bitc::ATTR_KIND_OPTIMIZE_NONE;
 225   case Attribute::ReadNone:
 226     return bitc::ATTR_KIND_READ_NONE;
 227   case Attribute::ReadOnly:
 228     return bitc::ATTR_KIND_READ_ONLY;
 229   case Attribute::Returned:
 230     return bitc::ATTR_KIND_RETURNED;
 231   case Attribute::ReturnsTwice:
 232     return bitc::ATTR_KIND_RETURNS_TWICE;
 233   case Attribute::SExt:
 234     return bitc::ATTR_KIND_S_EXT;
 235   case Attribute::StackAlignment:
 236     return bitc::ATTR_KIND_STACK_ALIGNMENT;
 237   case Attribute::StackProtect:
 238     return bitc::ATTR_KIND_STACK_PROTECT;
 239   case Attribute::StackProtectReq:
 240     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
 241   case Attribute::StackProtectStrong:
 242     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
 243   case Attribute::SafeStack:
 244     return bitc::ATTR_KIND_SAFESTACK;
 245   case Attribute::StructRet:
 246     return bitc::ATTR_KIND_STRUCT_RET;
 247   case Attribute::SanitizeAddress:
 248     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
 249   case Attribute::SanitizeThread:
 250     return bitc::ATTR_KIND_SANITIZE_THREAD;
 251   case Attribute::SanitizeMemory:
 252     return bitc::ATTR_KIND_SANITIZE_MEMORY;
 253   case Attribute::UWTable:
 254     return bitc::ATTR_KIND_UW_TABLE;
 255   case Attribute::ZExt:
 256     return bitc::ATTR_KIND_Z_EXT;
 257   case Attribute::EndAttrKinds:
 258     llvm_unreachable("Can not encode end-attribute kinds marker.");
 259   case Attribute::None:
 260     llvm_unreachable("Can not encode none-attribute.");
 261   }
 262
 263   llvm_unreachable("Trying to encode unknown attribute");
 264 }
 265
 266 static void WriteAttributeGroupTable(const ValueEnumerator &VE,
 267                                      BitstreamWriter &Stream) {
 268   const std::vector<AttributeSet> &AttrGrps = VE.getAttributeGroups();
 269   if (AttrGrps.empty()) return;
 270
 271   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
 272
 273   SmallVector<uint64_t, 64> Record;
 274   for (unsigned i = 0, e = AttrGrps.size(); i != e; ++i) {
 275     AttributeSet AS = AttrGrps[i];
 276     for (unsigned i = 0, e = AS.getNumSlots(); i != e; ++i) {
 277       AttributeSet A = AS.getSlotAttributes(i);
 278
 279       Record.push_back(VE.getAttributeGroupID(A));
 280       Record.push_back(AS.getSlotIndex(i));
 281
 282       for (AttributeSet::iterator I = AS.begin(0), E = AS.end(0);
 283            I != E; ++I) {
 284         Attribute Attr = *I;
 285         if (Attr.isEnumAttribute()) {
 286           Record.push_back(0);
 287           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 288         } else if (Attr.isIntAttribute()) {
 289           Record.push_back(1);
 290           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 291           Record.push_back(Attr.getValueAsInt());
 292         } else {
 293           StringRef Kind = Attr.getKindAsString();
 294           StringRef Val = Attr.getValueAsString();
 295
 296           Record.push_back(Val.empty() ? 3 : 4);
 297           Record.append(Kind.begin(), Kind.end());
 298           Record.push_back(0);
 299           if (!Val.empty()) {
 300             Record.append(Val.begin(), Val.end());
 301             Record.push_back(0);
 302           }
 303         }
 304       }
 305
 306       Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
 307       Record.clear();
 308     }
 309   }
 310
 311   Stream.ExitBlock();
 312 }
 313
 314 static void WriteAttributeTable(const ValueEnumerator &VE,
 315                                 BitstreamWriter &Stream) {
 316   const std::vector<AttributeSet> &Attrs = VE.getAttributes();
 317   if (Attrs.empty()) return;
 318
 319   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 320
 321   SmallVector<uint64_t, 64> Record;
 322   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
 323     const AttributeSet &A = Attrs[i];
 324     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
 325       Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
 326
 327     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 328     Record.clear();
 329   }
 330
 331   Stream.ExitBlock();
 332 }
 333
 334 /// WriteTypeTable - Write out the type table for a module.
 335 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 336   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 337
 338   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
 339   SmallVector<uint64_t, 64> TypeVals;
 340
 341   uint64_t NumBits = VE.computeBitsRequiredForTypeIndicies();
 342
 343   // Abbrev for TYPE_CODE_POINTER.
 344   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 345   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
 346   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 347   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
 348   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
 349
 350   // Abbrev for TYPE_CODE_FUNCTION.
 351   Abbv = new BitCodeAbbrev();
 352   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
 353   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
 354   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 355   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 356
 357   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 358
 359   // Abbrev for TYPE_CODE_STRUCT_ANON.
 360   Abbv = new BitCodeAbbrev();
 361   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
 362   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 363   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 364   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 365
 366   unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
 367
 368   // Abbrev for TYPE_CODE_STRUCT_NAME.
 369   Abbv = new BitCodeAbbrev();
 370   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
 371   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 372   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 373   unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
 374
 375   // Abbrev for TYPE_CODE_STRUCT_NAMED.
 376   Abbv = new BitCodeAbbrev();
 377   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
 378   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 379   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 380   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 381
 382   unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
 383
 384   // Abbrev for TYPE_CODE_ARRAY.
 385   Abbv = new BitCodeAbbrev();
 386   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 387   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 388   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 389
 390   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 391
 392   // Emit an entry count so the reader can reserve space.
 393   TypeVals.push_back(TypeList.size());
 394   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 395   TypeVals.clear();
 396
 397   // Loop over all of the types, emitting each in turn.
 398   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 399     Type *T = TypeList[i];
 400     int AbbrevToUse = 0;
 401     unsigned Code = 0;
 402
 403     switch (T->getTypeID()) {
 404     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
 405     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
 406     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
 407     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
 408     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
 409     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
 410     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 411     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
 412     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
 413     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
 414     case Type::TokenTyID:     Code = bitc::TYPE_CODE_TOKEN;     break;
 415     case Type::IntegerTyID:
 416       // INTEGER: [width]
 417       Code = bitc::TYPE_CODE_INTEGER;
 418       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 419       break;
 420     case Type::PointerTyID: {
 421       PointerType *PTy = cast<PointerType>(T);
 422       // POINTER: [pointee type, address space]
 423       Code = bitc::TYPE_CODE_POINTER;
 424       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
 425       unsigned AddressSpace = PTy->getAddressSpace();
 426       TypeVals.push_back(AddressSpace);
 427       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
 428       break;
 429     }
 430     case Type::FunctionTyID: {
 431       FunctionType *FT = cast<FunctionType>(T);
 432       // FUNCTION: [isvararg, retty, paramty x N]
 433       Code = bitc::TYPE_CODE_FUNCTION;
 434       TypeVals.push_back(FT->isVarArg());
 435       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 436       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 437         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 438       AbbrevToUse = FunctionAbbrev;
 439       break;
 440     }
 441     case Type::StructTyID: {
 442       StructType *ST = cast<StructType>(T);
 443       // STRUCT: [ispacked, eltty x N]
 444       TypeVals.push_back(ST->isPacked());
 445       // Output all of the element types.
 446       for (StructType::element_iterator I = ST->element_begin(),
 447            E = ST->element_end(); I != E; ++I)
 448         TypeVals.push_back(VE.getTypeID(*I));
 449
 450       if (ST->isLiteral()) {
 451         Code = bitc::TYPE_CODE_STRUCT_ANON;
 452         AbbrevToUse = StructAnonAbbrev;
 453       } else {
 454         if (ST->isOpaque()) {
 455           Code = bitc::TYPE_CODE_OPAQUE;
 456         } else {
 457           Code = bitc::TYPE_CODE_STRUCT_NAMED;
 458           AbbrevToUse = StructNamedAbbrev;
 459         }
 460
 461         // Emit the name if it is present.
 462         if (!ST->getName().empty())
 463           WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
 464                             StructNameAbbrev, Stream);
 465       }
 466       break;
 467     }
 468     case Type::ArrayTyID: {
 469       ArrayType *AT = cast<ArrayType>(T);
 470       // ARRAY: [numelts, eltty]
 471       Code = bitc::TYPE_CODE_ARRAY;
 472       TypeVals.push_back(AT->getNumElements());
 473       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 474       AbbrevToUse = ArrayAbbrev;
 475       break;
 476     }
 477     case Type::VectorTyID: {
 478       VectorType *VT = cast<VectorType>(T);
 479       // VECTOR [numelts, eltty]
 480       Code = bitc::TYPE_CODE_VECTOR;
 481       TypeVals.push_back(VT->getNumElements());
 482       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 483       break;
 484     }
 485     }
 486
 487     // Emit the finished record.
 488     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 489     TypeVals.clear();
 490   }
 491
 492   Stream.ExitBlock();
 493 }
 494
 495 static unsigned getEncodedLinkage(const GlobalValue &GV) {
 496   switch (GV.getLinkage()) {
 497   case GlobalValue::ExternalLinkage:
 498     return 0;
 499   case GlobalValue::WeakAnyLinkage:
 500     return 16;
 501   case GlobalValue::AppendingLinkage:
 502     return 2;
 503   case GlobalValue::InternalLinkage:
 504     return 3;
 505   case GlobalValue::LinkOnceAnyLinkage:
 506     return 18;
 507   case GlobalValue::ExternalWeakLinkage:
 508     return 7;
 509   case GlobalValue::CommonLinkage:
 510     return 8;
 511   case GlobalValue::PrivateLinkage:
 512     return 9;
 513   case GlobalValue::WeakODRLinkage:
 514     return 17;
 515   case GlobalValue::LinkOnceODRLinkage:
 516     return 19;
 517   case GlobalValue::AvailableExternallyLinkage:
 518     return 12;
 519   }
 520   llvm_unreachable("Invalid linkage");
 521 }
 522
 523 static unsigned getEncodedVisibility(const GlobalValue &GV) {
 524   switch (GV.getVisibility()) {
 525   case GlobalValue::DefaultVisibility:   return 0;
 526   case GlobalValue::HiddenVisibility:    return 1;
 527   case GlobalValue::ProtectedVisibility: return 2;
 528   }
 529   llvm_unreachable("Invalid visibility");
 530 }
 531
 532 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
 533   switch (GV.getDLLStorageClass()) {
 534   case GlobalValue::DefaultStorageClass:   return 0;
 535   case GlobalValue::DLLImportStorageClass: return 1;
 536   case GlobalValue::DLLExportStorageClass: return 2;
 537   }
 538   llvm_unreachable("Invalid DLL storage class");
 539 }
 540
 541 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
 542   switch (GV.getThreadLocalMode()) {
 543     case GlobalVariable::NotThreadLocal:         return 0;
 544     case GlobalVariable::GeneralDynamicTLSModel: return 1;
 545     case GlobalVariable::LocalDynamicTLSModel:   return 2;
 546     case GlobalVariable::InitialExecTLSModel:    return 3;
 547     case GlobalVariable::LocalExecTLSModel:      return 4;
 548   }
 549   llvm_unreachable("Invalid TLS model");
 550 }
 551
 552 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
 553   switch (C.getSelectionKind()) {
 554   case Comdat::Any:
 555     return bitc::COMDAT_SELECTION_KIND_ANY;
 556   case Comdat::ExactMatch:
 557     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
 558   case Comdat::Largest:
 559     return bitc::COMDAT_SELECTION_KIND_LARGEST;
 560   case Comdat::NoDuplicates:
 561     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
 562   case Comdat::SameSize:
 563     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
 564   }
 565   llvm_unreachable("Invalid selection kind");
 566 }
 567
 568 static void writeComdats(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 569   SmallVector<uint16_t, 64> Vals;
 570   for (const Comdat *C : VE.getComdats()) {
 571     // COMDAT: [selection_kind, name]
 572     Vals.push_back(getEncodedComdatSelectionKind(*C));
 573     size_t Size = C->getName().size();
 574     assert(isUInt<16>(Size));
 575     Vals.push_back(Size);
 576     for (char Chr : C->getName())
 577       Vals.push_back((unsigned char)Chr);
 578     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
 579     Vals.clear();
 580   }
 581 }
 582
 583 /// Write a record that will eventually hold the word offset of the
 584 /// module-level VST. For now the offset is 0, which will be backpatched
 585 /// after the real VST is written. Returns the bit offset to backpatch.
 586 static uint64_t WriteValueSymbolTableForwardDecl(const ValueSymbolTable &VST,
 587                                                  BitstreamWriter &Stream) {
 588   if (VST.empty())
 589     return 0;
 590
 591   // Write a placeholder value in for the offset of the real VST,
 592   // which is written after the function blocks so that it can include
 593   // the offset of each function. The placeholder offset will be
 594   // updated when the real VST is written.
 595   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 596   Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_VSTOFFSET));
 597   // Blocks are 32-bit aligned, so we can use a 32-bit word offset to
 598   // hold the real VST offset. Must use fixed instead of VBR as we don't
 599   // know how many VBR chunks to reserve ahead of time.
 600   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
 601   unsigned VSTOffsetAbbrev = Stream.EmitAbbrev(Abbv);
 602
 603   // Emit the placeholder
 604   uint64_t Vals[] = {bitc::MODULE_CODE_VSTOFFSET, 0};
 605   Stream.EmitRecordWithAbbrev(VSTOffsetAbbrev, Vals);
 606
 607   // Compute and return the bit offset to the placeholder, which will be
 608   // patched when the real VST is written. We can simply subtract the 32-bit
 609   // fixed size from the current bit number to get the location to backpatch.
 610   return Stream.GetCurrentBitNo() - 32;
 611 }
 612
 613 /// Emit top-level description of module, including target triple, inline asm,
 614 /// descriptors for global variables, and function prototype info.
 615 /// Returns the bit offset to backpatch with the location of the real VST.
 616 static uint64_t WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 617                                 BitstreamWriter &Stream) {
 618   // Emit various pieces of data attached to a module.
 619   if (!M->getTargetTriple().empty())
 620     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 621                       0/*TODO*/, Stream);
 622   const std::string &DL = M->getDataLayoutStr();
 623   if (!DL.empty())
 624     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/, Stream);
 625   if (!M->getModuleInlineAsm().empty())
 626     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 627                       0/*TODO*/, Stream);
 628
 629   // Emit information about sections and GC, computing how many there are. Also
 630   // compute the maximum alignment value.
 631   std::map<std::string, unsigned> SectionMap;
 632   std::map<std::string, unsigned> GCMap;
 633   unsigned MaxAlignment = 0;
 634   unsigned MaxGlobalType = 0;
 635   for (const GlobalValue &GV : M->globals()) {
 636     MaxAlignment = std::max(MaxAlignment, GV.getAlignment());
 637     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
 638     if (GV.hasSection()) {
 639       // Give section names unique ID's.
 640       unsigned &Entry = SectionMap[GV.getSection()];
 641       if (!Entry) {
 642         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
 643                           0/*TODO*/, Stream);
 644         Entry = SectionMap.size();
 645       }
 646     }
 647   }
 648   for (const Function &F : *M) {
 649     MaxAlignment = std::max(MaxAlignment, F.getAlignment());
 650     if (F.hasSection()) {
 651       // Give section names unique ID's.
 652       unsigned &Entry = SectionMap[F.getSection()];
 653       if (!Entry) {
 654         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
 655                           0/*TODO*/, Stream);
 656         Entry = SectionMap.size();
 657       }
 658     }
 659     if (F.hasGC()) {
 660       // Same for GC names.
 661       unsigned &Entry = GCMap[F.getGC()];
 662       if (!Entry) {
 663         WriteStringRecord(bitc::MODULE_CODE_GCNAME, F.getGC(),
 664                           0/*TODO*/, Stream);
 665         Entry = GCMap.size();
 666       }
 667     }
 668   }
 669
 670   // Emit abbrev for globals, now that we know # sections and max alignment.
 671   unsigned SimpleGVarAbbrev = 0;
 672   if (!M->global_empty()) {
 673     // Add an abbrev for common globals with no visibility or thread localness.
 674     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 675     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 676     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 677                               Log2_32_Ceil(MaxGlobalType+1)));
 678     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
 679                                                            //| explicitType << 1
 680                                                            //| constant
 681     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
 682     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
 683     if (MaxAlignment == 0)                                 // Alignment.
 684       Abbv->Add(BitCodeAbbrevOp(0));
 685     else {
 686       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 687       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 688                                Log2_32_Ceil(MaxEncAlignment+1)));
 689     }
 690     if (SectionMap.empty())                                    // Section.
 691       Abbv->Add(BitCodeAbbrevOp(0));
 692     else
 693       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 694                                Log2_32_Ceil(SectionMap.size()+1)));
 695     // Don't bother emitting vis + thread local.
 696     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 697   }
 698
 699   // Emit the global variable information.
 700   SmallVector<unsigned, 64> Vals;
 701   for (const GlobalVariable &GV : M->globals()) {
 702     unsigned AbbrevToUse = 0;
 703
 704     // GLOBALVAR: [type, isconst, initid,
 705     //             linkage, alignment, section, visibility, threadlocal,
 706     //             unnamed_addr, externally_initialized, dllstorageclass,
 707     //             comdat]
 708     Vals.push_back(VE.getTypeID(GV.getValueType()));
 709     Vals.push_back(GV.getType()->getAddressSpace() << 2 | 2 | GV.isConstant());
 710     Vals.push_back(GV.isDeclaration() ? 0 :
 711                    (VE.getValueID(GV.getInitializer()) + 1));
 712     Vals.push_back(getEncodedLinkage(GV));
 713     Vals.push_back(Log2_32(GV.getAlignment())+1);
 714     Vals.push_back(GV.hasSection() ? SectionMap[GV.getSection()] : 0);
 715     if (GV.isThreadLocal() ||
 716         GV.getVisibility() != GlobalValue::DefaultVisibility ||
 717         GV.hasUnnamedAddr() || GV.isExternallyInitialized() ||
 718         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
 719         GV.hasComdat()) {
 720       Vals.push_back(getEncodedVisibility(GV));
 721       Vals.push_back(getEncodedThreadLocalMode(GV));
 722       Vals.push_back(GV.hasUnnamedAddr());
 723       Vals.push_back(GV.isExternallyInitialized());
 724       Vals.push_back(getEncodedDLLStorageClass(GV));
 725       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
 726     } else {
 727       AbbrevToUse = SimpleGVarAbbrev;
 728     }
 729
 730     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 731     Vals.clear();
 732   }
 733
 734   // Emit the function proto information.
 735   for (const Function &F : *M) {
 736     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
 737     //             section, visibility, gc, unnamed_addr, prologuedata,
 738     //             dllstorageclass, comdat, prefixdata, personalityfn]
 739     Vals.push_back(VE.getTypeID(F.getFunctionType()));
 740     Vals.push_back(F.getCallingConv());
 741     Vals.push_back(F.isDeclaration());
 742     Vals.push_back(getEncodedLinkage(F));
 743     Vals.push_back(VE.getAttributeID(F.getAttributes()));
 744     Vals.push_back(Log2_32(F.getAlignment())+1);
 745     Vals.push_back(F.hasSection() ? SectionMap[F.getSection()] : 0);
 746     Vals.push_back(getEncodedVisibility(F));
 747     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
 748     Vals.push_back(F.hasUnnamedAddr());
 749     Vals.push_back(F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1)
 750                                        : 0);
 751     Vals.push_back(getEncodedDLLStorageClass(F));
 752     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
 753     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
 754                                      : 0);
 755     Vals.push_back(
 756         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
 757
 758     unsigned AbbrevToUse = 0;
 759     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 760     Vals.clear();
 761   }
 762
 763   // Emit the alias information.
 764   for (const GlobalAlias &A : M->aliases()) {
 765     // ALIAS: [alias type, aliasee val#, linkage, visibility]
 766     Vals.push_back(VE.getTypeID(A.getValueType()));
 767     Vals.push_back(A.getType()->getAddressSpace());
 768     Vals.push_back(VE.getValueID(A.getAliasee()));
 769     Vals.push_back(getEncodedLinkage(A));
 770     Vals.push_back(getEncodedVisibility(A));
 771     Vals.push_back(getEncodedDLLStorageClass(A));
 772     Vals.push_back(getEncodedThreadLocalMode(A));
 773     Vals.push_back(A.hasUnnamedAddr());
 774     unsigned AbbrevToUse = 0;
 775     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 776     Vals.clear();
 777   }
 778
 779   // Write a record indicating the number of module-level metadata IDs
 780   // This is needed because the ids of metadata are assigned implicitly
 781   // based on their ordering in the bitcode, with the function-level
 782   // metadata ids starting after the module-level metadata ids. For
 783   // function importing where we lazy load the metadata as a postpass,
 784   // we want to avoid parsing the module-level metadata before parsing
 785   // the imported functions.
 786   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 787   Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_METADATA_VALUES));
 788   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
 789   unsigned MDValsAbbrev = Stream.EmitAbbrev(Abbv);
 790   Vals.push_back(VE.numMDs());
 791   Stream.EmitRecord(bitc::MODULE_CODE_METADATA_VALUES, Vals, MDValsAbbrev);
 792   Vals.clear();
 793
 794   uint64_t VSTOffsetPlaceholder =
 795       WriteValueSymbolTableForwardDecl(M->getValueSymbolTable(), Stream);
 796   return VSTOffsetPlaceholder;
 797 }
 798
 799 static uint64_t GetOptimizationFlags(const Value *V) {
 800   uint64_t Flags = 0;
 801
 802   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
 803     if (OBO->hasNoSignedWrap())
 804       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
 805     if (OBO->hasNoUnsignedWrap())
 806       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
 807   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
 808     if (PEO->isExact())
 809       Flags |= 1 << bitc::PEO_EXACT;
 810   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
 811     if (FPMO->hasUnsafeAlgebra())
 812       Flags |= FastMathFlags::UnsafeAlgebra;
 813     if (FPMO->hasNoNaNs())
 814       Flags |= FastMathFlags::NoNaNs;
 815     if (FPMO->hasNoInfs())
 816       Flags |= FastMathFlags::NoInfs;
 817     if (FPMO->hasNoSignedZeros())
 818       Flags |= FastMathFlags::NoSignedZeros;
 819     if (FPMO->hasAllowReciprocal())
 820       Flags |= FastMathFlags::AllowReciprocal;
 821   }
 822
 823   return Flags;
 824 }
 825
 826 static void WriteValueAsMetadata(const ValueAsMetadata *MD,
 827                                  const ValueEnumerator &VE,
 828                                  BitstreamWriter &Stream,
 829                                  SmallVectorImpl<uint64_t> &Record) {
 830   // Mimic an MDNode with a value as one operand.
 831   Value *V = MD->getValue();
 832   Record.push_back(VE.getTypeID(V->getType()));
 833   Record.push_back(VE.getValueID(V));
 834   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
 835   Record.clear();
 836 }
 837
 838 static void WriteMDTuple(const MDTuple *N, const ValueEnumerator &VE,
 839                          BitstreamWriter &Stream,
 840                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
 841   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
 842     Metadata *MD = N->getOperand(i);
 843     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
 844            "Unexpected function-local metadata");
 845     Record.push_back(VE.getMetadataOrNullID(MD));
 846   }
 847   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
 848                                     : bitc::METADATA_NODE,
 849                     Record, Abbrev);
 850   Record.clear();
 851 }
 852
 853 static void WriteDILocation(const DILocation *N, const ValueEnumerator &VE,
 854                             BitstreamWriter &Stream,
 855                             SmallVectorImpl<uint64_t> &Record,
 856                             unsigned Abbrev) {
 857   Record.push_back(N->isDistinct());
 858   Record.push_back(N->getLine());
 859   Record.push_back(N->getColumn());
 860   Record.push_back(VE.getMetadataID(N->getScope()));
 861   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
 862
 863   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
 864   Record.clear();
 865 }
 866
 867 static void WriteGenericDINode(const GenericDINode *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(0); // Per-tag version field; unused for now.
 875
 876   for (auto &I : N->operands())
 877     Record.push_back(VE.getMetadataOrNullID(I));
 878
 879   Stream.EmitRecord(bitc::METADATA_GENERIC_DEBUG, Record, Abbrev);
 880   Record.clear();
 881 }
 882
 883 static uint64_t rotateSign(int64_t I) {
 884   uint64_t U = I;
 885   return I < 0 ? ~(U << 1) : U << 1;
 886 }
 887
 888 static void WriteDISubrange(const DISubrange *N, const ValueEnumerator &,
 889                             BitstreamWriter &Stream,
 890                             SmallVectorImpl<uint64_t> &Record,
 891                             unsigned Abbrev) {
 892   Record.push_back(N->isDistinct());
 893   Record.push_back(N->getCount());
 894   Record.push_back(rotateSign(N->getLowerBound()));
 895
 896   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
 897   Record.clear();
 898 }
 899
 900 static void WriteDIEnumerator(const DIEnumerator *N, const ValueEnumerator &VE,
 901                               BitstreamWriter &Stream,
 902                               SmallVectorImpl<uint64_t> &Record,
 903                               unsigned Abbrev) {
 904   Record.push_back(N->isDistinct());
 905   Record.push_back(rotateSign(N->getValue()));
 906   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 907
 908   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
 909   Record.clear();
 910 }
 911
 912 static void WriteDIBasicType(const DIBasicType *N, const ValueEnumerator &VE,
 913                              BitstreamWriter &Stream,
 914                              SmallVectorImpl<uint64_t> &Record,
 915                              unsigned Abbrev) {
 916   Record.push_back(N->isDistinct());
 917   Record.push_back(N->getTag());
 918   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 919   Record.push_back(N->getSizeInBits());
 920   Record.push_back(N->getAlignInBits());
 921   Record.push_back(N->getEncoding());
 922
 923   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
 924   Record.clear();
 925 }
 926
 927 static void WriteDIDerivedType(const DIDerivedType *N,
 928                                const ValueEnumerator &VE,
 929                                BitstreamWriter &Stream,
 930                                SmallVectorImpl<uint64_t> &Record,
 931                                unsigned Abbrev) {
 932   Record.push_back(N->isDistinct());
 933   Record.push_back(N->getTag());
 934   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 935   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 936   Record.push_back(N->getLine());
 937   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 938   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
 939   Record.push_back(N->getSizeInBits());
 940   Record.push_back(N->getAlignInBits());
 941   Record.push_back(N->getOffsetInBits());
 942   Record.push_back(N->getFlags());
 943   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
 944
 945   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
 946   Record.clear();
 947 }
 948
 949 static void WriteDICompositeType(const DICompositeType *N,
 950                                  const ValueEnumerator &VE,
 951                                  BitstreamWriter &Stream,
 952                                  SmallVectorImpl<uint64_t> &Record,
 953                                  unsigned Abbrev) {
 954   Record.push_back(N->isDistinct());
 955   Record.push_back(N->getTag());
 956   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 957   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 958   Record.push_back(N->getLine());
 959   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 960   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
 961   Record.push_back(N->getSizeInBits());
 962   Record.push_back(N->getAlignInBits());
 963   Record.push_back(N->getOffsetInBits());
 964   Record.push_back(N->getFlags());
 965   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
 966   Record.push_back(N->getRuntimeLang());
 967   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
 968   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
 969   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
 970
 971   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
 972   Record.clear();
 973 }
 974
 975 static void WriteDISubroutineType(const DISubroutineType *N,
 976                                   const ValueEnumerator &VE,
 977                                   BitstreamWriter &Stream,
 978                                   SmallVectorImpl<uint64_t> &Record,
 979                                   unsigned Abbrev) {
 980   Record.push_back(N->isDistinct());
 981   Record.push_back(N->getFlags());
 982   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
 983
 984   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
 985   Record.clear();
 986 }
 987
 988 static void WriteDIFile(const DIFile *N, const ValueEnumerator &VE,
 989                         BitstreamWriter &Stream,
 990                         SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
 991   Record.push_back(N->isDistinct());
 992   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
 993   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
 994
 995   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
 996   Record.clear();
 997 }
 998
 999 static void WriteDICompileUnit(const DICompileUnit *N,
1000                                const ValueEnumerator &VE,
1001                                BitstreamWriter &Stream,
1002                                SmallVectorImpl<uint64_t> &Record,
1003                                unsigned Abbrev) {
1004   assert(N->isDistinct() && "Expected distinct compile units");
1005   Record.push_back(/* IsDistinct */ true);
1006   Record.push_back(N->getSourceLanguage());
1007   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1008   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
1009   Record.push_back(N->isOptimized());
1010   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
1011   Record.push_back(N->getRuntimeVersion());
1012   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
1013   Record.push_back(N->getEmissionKind());
1014   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
1015   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
1016   Record.push_back(VE.getMetadataOrNullID(N->getSubprograms().get()));
1017   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
1018   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
1019   Record.push_back(N->getDWOId());
1020
1021   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
1022   Record.clear();
1023 }
1024
1025 static void WriteDISubprogram(const DISubprogram *N, const ValueEnumerator &VE,
1026                               BitstreamWriter &Stream,
1027                               SmallVectorImpl<uint64_t> &Record,
1028                               unsigned Abbrev) {
1029   Record.push_back(N->isDistinct());
1030   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1031   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1032   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1033   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1034   Record.push_back(N->getLine());
1035   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1036   Record.push_back(N->isLocalToUnit());
1037   Record.push_back(N->isDefinition());
1038   Record.push_back(N->getScopeLine());
1039   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
1040   Record.push_back(N->getVirtuality());
1041   Record.push_back(N->getVirtualIndex());
1042   Record.push_back(N->getFlags());
1043   Record.push_back(N->isOptimized());
1044   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1045   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
1046   Record.push_back(VE.getMetadataOrNullID(N->getVariables().get()));
1047
1048   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
1049   Record.clear();
1050 }
1051
1052 static void WriteDILexicalBlock(const DILexicalBlock *N,
1053                                 const ValueEnumerator &VE,
1054                                 BitstreamWriter &Stream,
1055                                 SmallVectorImpl<uint64_t> &Record,
1056                                 unsigned Abbrev) {
1057   Record.push_back(N->isDistinct());
1058   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1059   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1060   Record.push_back(N->getLine());
1061   Record.push_back(N->getColumn());
1062
1063   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
1064   Record.clear();
1065 }
1066
1067 static void WriteDILexicalBlockFile(const DILexicalBlockFile *N,
1068                                     const ValueEnumerator &VE,
1069                                     BitstreamWriter &Stream,
1070                                     SmallVectorImpl<uint64_t> &Record,
1071                                     unsigned Abbrev) {
1072   Record.push_back(N->isDistinct());
1073   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1074   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1075   Record.push_back(N->getDiscriminator());
1076
1077   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
1078   Record.clear();
1079 }
1080
1081 static void WriteDINamespace(const DINamespace *N, const ValueEnumerator &VE,
1082                              BitstreamWriter &Stream,
1083                              SmallVectorImpl<uint64_t> &Record,
1084                              unsigned Abbrev) {
1085   Record.push_back(N->isDistinct());
1086   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1087   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1088   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1089   Record.push_back(N->getLine());
1090
1091   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
1092   Record.clear();
1093 }
1094
1095 static void WriteDIModule(const DIModule *N, const ValueEnumerator &VE,
1096                           BitstreamWriter &Stream,
1097                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
1098   Record.push_back(N->isDistinct());
1099   for (auto &I : N->operands())
1100     Record.push_back(VE.getMetadataOrNullID(I));
1101
1102   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
1103   Record.clear();
1104 }
1105
1106 static void WriteDITemplateTypeParameter(const DITemplateTypeParameter *N,
1107                                          const ValueEnumerator &VE,
1108                                          BitstreamWriter &Stream,
1109                                          SmallVectorImpl<uint64_t> &Record,
1110                                          unsigned Abbrev) {
1111   Record.push_back(N->isDistinct());
1112   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1113   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1114
1115   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
1116   Record.clear();
1117 }
1118
1119 static void WriteDITemplateValueParameter(const DITemplateValueParameter *N,
1120                                           const ValueEnumerator &VE,
1121                                           BitstreamWriter &Stream,
1122                                           SmallVectorImpl<uint64_t> &Record,
1123                                           unsigned Abbrev) {
1124   Record.push_back(N->isDistinct());
1125   Record.push_back(N->getTag());
1126   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1127   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1128   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
1129
1130   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
1131   Record.clear();
1132 }
1133
1134 static void WriteDIGlobalVariable(const DIGlobalVariable *N,
1135                                   const ValueEnumerator &VE,
1136                                   BitstreamWriter &Stream,
1137                                   SmallVectorImpl<uint64_t> &Record,
1138                                   unsigned Abbrev) {
1139   Record.push_back(N->isDistinct());
1140   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1141   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1142   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1143   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1144   Record.push_back(N->getLine());
1145   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1146   Record.push_back(N->isLocalToUnit());
1147   Record.push_back(N->isDefinition());
1148   Record.push_back(VE.getMetadataOrNullID(N->getRawVariable()));
1149   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
1150
1151   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
1152   Record.clear();
1153 }
1154
1155 static void WriteDILocalVariable(const DILocalVariable *N,
1156                                  const ValueEnumerator &VE,
1157                                  BitstreamWriter &Stream,
1158                                  SmallVectorImpl<uint64_t> &Record,
1159                                  unsigned Abbrev) {
1160   Record.push_back(N->isDistinct());
1161   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1162   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1163   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1164   Record.push_back(N->getLine());
1165   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1166   Record.push_back(N->getArg());
1167   Record.push_back(N->getFlags());
1168
1169   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
1170   Record.clear();
1171 }
1172
1173 static void WriteDIExpression(const DIExpression *N, const ValueEnumerator &,
1174                               BitstreamWriter &Stream,
1175                               SmallVectorImpl<uint64_t> &Record,
1176                               unsigned Abbrev) {
1177   Record.reserve(N->getElements().size() + 1);
1178
1179   Record.push_back(N->isDistinct());
1180   Record.append(N->elements_begin(), N->elements_end());
1181
1182   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
1183   Record.clear();
1184 }
1185
1186 static void WriteDIObjCProperty(const DIObjCProperty *N,
1187                                 const ValueEnumerator &VE,
1188                                 BitstreamWriter &Stream,
1189                                 SmallVectorImpl<uint64_t> &Record,
1190                                 unsigned Abbrev) {
1191   Record.push_back(N->isDistinct());
1192   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1193   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1194   Record.push_back(N->getLine());
1195   Record.push_back(VE.getMetadataOrNullID(N->getRawSetterName()));
1196   Record.push_back(VE.getMetadataOrNullID(N->getRawGetterName()));
1197   Record.push_back(N->getAttributes());
1198   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1199
1200   Stream.EmitRecord(bitc::METADATA_OBJC_PROPERTY, Record, Abbrev);
1201   Record.clear();
1202 }
1203
1204 static void WriteDIImportedEntity(const DIImportedEntity *N,
1205                                   const ValueEnumerator &VE,
1206                                   BitstreamWriter &Stream,
1207                                   SmallVectorImpl<uint64_t> &Record,
1208                                   unsigned Abbrev) {
1209   Record.push_back(N->isDistinct());
1210   Record.push_back(N->getTag());
1211   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1212   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
1213   Record.push_back(N->getLine());
1214   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1215
1216   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
1217   Record.clear();
1218 }
1219
1220 static void WriteModuleMetadata(const Module *M,
1221                                 const ValueEnumerator &VE,
1222                                 BitstreamWriter &Stream) {
1223   const auto &MDs = VE.getMDs();
1224   if (MDs.empty() && M->named_metadata_empty())
1225     return;
1226
1227   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1228
1229   unsigned MDSAbbrev = 0;
1230   if (VE.hasMDString()) {
1231     // Abbrev for METADATA_STRING.
1232     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1233     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
1234     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1235     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1236     MDSAbbrev = Stream.EmitAbbrev(Abbv);
1237   }
1238
1239   // Initialize MDNode abbreviations.
1240 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
1241 #include "llvm/IR/Metadata.def"
1242
1243   if (VE.hasDILocation()) {
1244     // Abbrev for METADATA_LOCATION.
1245     //
1246     // Assume the column is usually under 128, and always output the inlined-at
1247     // location (it's never more expensive than building an array size 1).
1248     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1249     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1250     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1251     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1252     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1253     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1254     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1255     DILocationAbbrev = Stream.EmitAbbrev(Abbv);
1256   }
1257
1258   if (VE.hasGenericDINode()) {
1259     // Abbrev for METADATA_GENERIC_DEBUG.
1260     //
1261     // Assume the column is usually under 128, and always output the inlined-at
1262     // location (it's never more expensive than building an array size 1).
1263     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1264     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1265     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1266     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1267     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1268     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1269     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1270     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1271     GenericDINodeAbbrev = Stream.EmitAbbrev(Abbv);
1272   }
1273
1274   unsigned NameAbbrev = 0;
1275   if (!M->named_metadata_empty()) {
1276     // Abbrev for METADATA_NAME.
1277     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1278     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
1279     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1280     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1281     NameAbbrev = Stream.EmitAbbrev(Abbv);
1282   }
1283
1284   SmallVector<uint64_t, 64> Record;
1285   for (const Metadata *MD : MDs) {
1286     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
1287       assert(N->isResolved() && "Expected forward references to be resolved");
1288
1289       switch (N->getMetadataID()) {
1290       default:
1291         llvm_unreachable("Invalid MDNode subclass");
1292 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
1293   case Metadata::CLASS##Kind:                                                  \
1294     Write##CLASS(cast<CLASS>(N), VE, Stream, Record, CLASS##Abbrev);           \
1295     continue;
1296 #include "llvm/IR/Metadata.def"
1297       }
1298     }
1299     if (const auto *MDC = dyn_cast<ConstantAsMetadata>(MD)) {
1300       WriteValueAsMetadata(MDC, VE, Stream, Record);
1301       continue;
1302     }
1303     const MDString *MDS = cast<MDString>(MD);
1304     // Code: [strchar x N]
1305     Record.append(MDS->bytes_begin(), MDS->bytes_end());
1306
1307     // Emit the finished record.
1308     Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
1309     Record.clear();
1310   }
1311
1312   // Write named metadata.
1313   for (const NamedMDNode &NMD : M->named_metadata()) {
1314     // Write name.
1315     StringRef Str = NMD.getName();
1316     Record.append(Str.bytes_begin(), Str.bytes_end());
1317     Stream.EmitRecord(bitc::METADATA_NAME, Record, NameAbbrev);
1318     Record.clear();
1319
1320     // Write named metadata operands.
1321     for (const MDNode *N : NMD.operands())
1322       Record.push_back(VE.getMetadataID(N));
1323     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
1324     Record.clear();
1325   }
1326
1327   Stream.ExitBlock();
1328 }
1329
1330 static void WriteFunctionLocalMetadata(const Function &F,
1331                                        const ValueEnumerator &VE,
1332                                        BitstreamWriter &Stream) {
1333   bool StartedMetadataBlock = false;
1334   SmallVector<uint64_t, 64> Record;
1335   const SmallVectorImpl<const LocalAsMetadata *> &MDs =
1336       VE.getFunctionLocalMDs();
1337   for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1338     assert(MDs[i] && "Expected valid function-local metadata");
1339     if (!StartedMetadataBlock) {
1340       Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1341       StartedMetadataBlock = true;
1342     }
1343     WriteValueAsMetadata(MDs[i], VE, Stream, Record);
1344   }
1345
1346   if (StartedMetadataBlock)
1347     Stream.ExitBlock();
1348 }
1349
1350 static void WriteMetadataAttachment(const Function &F,
1351                                     const ValueEnumerator &VE,
1352                                     BitstreamWriter &Stream) {
1353   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
1354
1355   SmallVector<uint64_t, 64> Record;
1356
1357   // Write metadata attachments
1358   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
1359   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
1360   F.getAllMetadata(MDs);
1361   if (!MDs.empty()) {
1362     for (const auto &I : MDs) {
1363       Record.push_back(I.first);
1364       Record.push_back(VE.getMetadataID(I.second));
1365     }
1366     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1367     Record.clear();
1368   }
1369
1370   for (const BasicBlock &BB : F)
1371     for (const Instruction &I : BB) {
1372       MDs.clear();
1373       I.getAllMetadataOtherThanDebugLoc(MDs);
1374
1375       // If no metadata, ignore instruction.
1376       if (MDs.empty()) continue;
1377
1378       Record.push_back(VE.getInstructionID(&I));
1379
1380       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1381         Record.push_back(MDs[i].first);
1382         Record.push_back(VE.getMetadataID(MDs[i].second));
1383       }
1384       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1385       Record.clear();
1386     }
1387
1388   Stream.ExitBlock();
1389 }
1390
1391 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
1392   SmallVector<uint64_t, 64> Record;
1393
1394   // Write metadata kinds
1395   // METADATA_KIND - [n x [id, name]]
1396   SmallVector<StringRef, 8> Names;
1397   M->getMDKindNames(Names);
1398
1399   if (Names.empty()) return;
1400
1401   Stream.EnterSubblock(bitc::METADATA_KIND_BLOCK_ID, 3);
1402
1403   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
1404     Record.push_back(MDKindID);
1405     StringRef KName = Names[MDKindID];
1406     Record.append(KName.begin(), KName.end());
1407
1408     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
1409     Record.clear();
1410   }
1411
1412   Stream.ExitBlock();
1413 }
1414
1415 static void WriteOperandBundleTags(const Module *M, BitstreamWriter &Stream) {
1416   // Write metadata kinds
1417   //
1418   // OPERAND_BUNDLE_TAGS_BLOCK_ID : N x OPERAND_BUNDLE_TAG
1419   //
1420   // OPERAND_BUNDLE_TAG - [strchr x N]
1421
1422   SmallVector<StringRef, 8> Tags;
1423   M->getOperandBundleTags(Tags);
1424
1425   if (Tags.empty())
1426     return;
1427
1428   Stream.EnterSubblock(bitc::OPERAND_BUNDLE_TAGS_BLOCK_ID, 3);
1429
1430   SmallVector<uint64_t, 64> Record;
1431
1432   for (auto Tag : Tags) {
1433     Record.append(Tag.begin(), Tag.end());
1434
1435     Stream.EmitRecord(bitc::OPERAND_BUNDLE_TAG, Record, 0);
1436     Record.clear();
1437   }
1438
1439   Stream.ExitBlock();
1440 }
1441
1442 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
1443   if ((int64_t)V >= 0)
1444     Vals.push_back(V << 1);
1445   else
1446     Vals.push_back((-V << 1) | 1);
1447 }
1448
1449 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
1450                            const ValueEnumerator &VE,
1451                            BitstreamWriter &Stream, bool isGlobal) {
1452   if (FirstVal == LastVal) return;
1453
1454   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
1455
1456   unsigned AggregateAbbrev = 0;
1457   unsigned String8Abbrev = 0;
1458   unsigned CString7Abbrev = 0;
1459   unsigned CString6Abbrev = 0;
1460   // If this is a constant pool for the module, emit module-specific abbrevs.
1461   if (isGlobal) {
1462     // Abbrev for CST_CODE_AGGREGATE.
1463     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1464     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
1465     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1466     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
1467     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
1468
1469     // Abbrev for CST_CODE_STRING.
1470     Abbv = new BitCodeAbbrev();
1471     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
1472     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1473     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1474     String8Abbrev = Stream.EmitAbbrev(Abbv);
1475     // Abbrev for CST_CODE_CSTRING.
1476     Abbv = new BitCodeAbbrev();
1477     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1478     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1479     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1480     CString7Abbrev = Stream.EmitAbbrev(Abbv);
1481     // Abbrev for CST_CODE_CSTRING.
1482     Abbv = new BitCodeAbbrev();
1483     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1484     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1485     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1486     CString6Abbrev = Stream.EmitAbbrev(Abbv);
1487   }
1488
1489   SmallVector<uint64_t, 64> Record;
1490
1491   const ValueEnumerator::ValueList &Vals = VE.getValues();
1492   Type *LastTy = nullptr;
1493   for (unsigned i = FirstVal; i != LastVal; ++i) {
1494     const Value *V = Vals[i].first;
1495     // If we need to switch types, do so now.
1496     if (V->getType() != LastTy) {
1497       LastTy = V->getType();
1498       Record.push_back(VE.getTypeID(LastTy));
1499       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
1500                         CONSTANTS_SETTYPE_ABBREV);
1501       Record.clear();
1502     }
1503
1504     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
1505       Record.push_back(unsigned(IA->hasSideEffects()) |
1506                        unsigned(IA->isAlignStack()) << 1 |
1507                        unsigned(IA->getDialect()&1) << 2);
1508
1509       // Add the asm string.
1510       const std::string &AsmStr = IA->getAsmString();
1511       Record.push_back(AsmStr.size());
1512       Record.append(AsmStr.begin(), AsmStr.end());
1513
1514       // Add the constraint string.
1515       const std::string &ConstraintStr = IA->getConstraintString();
1516       Record.push_back(ConstraintStr.size());
1517       Record.append(ConstraintStr.begin(), ConstraintStr.end());
1518       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
1519       Record.clear();
1520       continue;
1521     }
1522     const Constant *C = cast<Constant>(V);
1523     unsigned Code = -1U;
1524     unsigned AbbrevToUse = 0;
1525     if (C->isNullValue()) {
1526       Code = bitc::CST_CODE_NULL;
1527     } else if (isa<UndefValue>(C)) {
1528       Code = bitc::CST_CODE_UNDEF;
1529     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
1530       if (IV->getBitWidth() <= 64) {
1531         uint64_t V = IV->getSExtValue();
1532         emitSignedInt64(Record, V);
1533         Code = bitc::CST_CODE_INTEGER;
1534         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
1535       } else {                             // Wide integers, > 64 bits in size.
1536         // We have an arbitrary precision integer value to write whose
1537         // bit width is > 64. However, in canonical unsigned integer
1538         // format it is likely that the high bits are going to be zero.
1539         // So, we only write the number of active words.
1540         unsigned NWords = IV->getValue().getActiveWords();
1541         const uint64_t *RawWords = IV->getValue().getRawData();
1542         for (unsigned i = 0; i != NWords; ++i) {
1543           emitSignedInt64(Record, RawWords[i]);
1544         }
1545         Code = bitc::CST_CODE_WIDE_INTEGER;
1546       }
1547     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
1548       Code = bitc::CST_CODE_FLOAT;
1549       Type *Ty = CFP->getType();
1550       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
1551         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
1552       } else if (Ty->isX86_FP80Ty()) {
1553         // api needed to prevent premature destruction
1554         // bits are not in the same order as a normal i80 APInt, compensate.
1555         APInt api = CFP->getValueAPF().bitcastToAPInt();
1556         const uint64_t *p = api.getRawData();
1557         Record.push_back((p[1] << 48) | (p[0] >> 16));
1558         Record.push_back(p[0] & 0xffffLL);
1559       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
1560         APInt api = CFP->getValueAPF().bitcastToAPInt();
1561         const uint64_t *p = api.getRawData();
1562         Record.push_back(p[0]);
1563         Record.push_back(p[1]);
1564       } else {
1565         assert (0 && "Unknown FP type!");
1566       }
1567     } else if (isa<ConstantDataSequential>(C) &&
1568                cast<ConstantDataSequential>(C)->isString()) {
1569       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
1570       // Emit constant strings specially.
1571       unsigned NumElts = Str->getNumElements();
1572       // If this is a null-terminated string, use the denser CSTRING encoding.
1573       if (Str->isCString()) {
1574         Code = bitc::CST_CODE_CSTRING;
1575         --NumElts;  // Don't encode the null, which isn't allowed by char6.
1576       } else {
1577         Code = bitc::CST_CODE_STRING;
1578         AbbrevToUse = String8Abbrev;
1579       }
1580       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
1581       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
1582       for (unsigned i = 0; i != NumElts; ++i) {
1583         unsigned char V = Str->getElementAsInteger(i);
1584         Record.push_back(V);
1585         isCStr7 &= (V & 128) == 0;
1586         if (isCStrChar6)
1587           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
1588       }
1589
1590       if (isCStrChar6)
1591         AbbrevToUse = CString6Abbrev;
1592       else if (isCStr7)
1593         AbbrevToUse = CString7Abbrev;
1594     } else if (const ConstantDataSequential *CDS =
1595                   dyn_cast<ConstantDataSequential>(C)) {
1596       Code = bitc::CST_CODE_DATA;
1597       Type *EltTy = CDS->getType()->getElementType();
1598       if (isa<IntegerType>(EltTy)) {
1599         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
1600           Record.push_back(CDS->getElementAsInteger(i));
1601       } else if (EltTy->isFloatTy()) {
1602         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1603           union { float F; uint32_t I; };
1604           F = CDS->getElementAsFloat(i);
1605           Record.push_back(I);
1606         }
1607       } else {
1608         assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
1609         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1610           union { double F; uint64_t I; };
1611           F = CDS->getElementAsDouble(i);
1612           Record.push_back(I);
1613         }
1614       }
1615     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
1616                isa<ConstantVector>(C)) {
1617       Code = bitc::CST_CODE_AGGREGATE;
1618       for (const Value *Op : C->operands())
1619         Record.push_back(VE.getValueID(Op));
1620       AbbrevToUse = AggregateAbbrev;
1621     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
1622       switch (CE->getOpcode()) {
1623       default:
1624         if (Instruction::isCast(CE->getOpcode())) {
1625           Code = bitc::CST_CODE_CE_CAST;
1626           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
1627           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1628           Record.push_back(VE.getValueID(C->getOperand(0)));
1629           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
1630         } else {
1631           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
1632           Code = bitc::CST_CODE_CE_BINOP;
1633           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
1634           Record.push_back(VE.getValueID(C->getOperand(0)));
1635           Record.push_back(VE.getValueID(C->getOperand(1)));
1636           uint64_t Flags = GetOptimizationFlags(CE);
1637           if (Flags != 0)
1638             Record.push_back(Flags);
1639         }
1640         break;
1641       case Instruction::GetElementPtr: {
1642         Code = bitc::CST_CODE_CE_GEP;
1643         const auto *GO = cast<GEPOperator>(C);
1644         if (GO->isInBounds())
1645           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
1646         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
1647         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
1648           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
1649           Record.push_back(VE.getValueID(C->getOperand(i)));
1650         }
1651         break;
1652       }
1653       case Instruction::Select:
1654         Code = bitc::CST_CODE_CE_SELECT;
1655         Record.push_back(VE.getValueID(C->getOperand(0)));
1656         Record.push_back(VE.getValueID(C->getOperand(1)));
1657         Record.push_back(VE.getValueID(C->getOperand(2)));
1658         break;
1659       case Instruction::ExtractElement:
1660         Code = bitc::CST_CODE_CE_EXTRACTELT;
1661         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1662         Record.push_back(VE.getValueID(C->getOperand(0)));
1663         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
1664         Record.push_back(VE.getValueID(C->getOperand(1)));
1665         break;
1666       case Instruction::InsertElement:
1667         Code = bitc::CST_CODE_CE_INSERTELT;
1668         Record.push_back(VE.getValueID(C->getOperand(0)));
1669         Record.push_back(VE.getValueID(C->getOperand(1)));
1670         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
1671         Record.push_back(VE.getValueID(C->getOperand(2)));
1672         break;
1673       case Instruction::ShuffleVector:
1674         // If the return type and argument types are the same, this is a
1675         // standard shufflevector instruction.  If the types are different,
1676         // then the shuffle is widening or truncating the input vectors, and
1677         // the argument type must also be encoded.
1678         if (C->getType() == C->getOperand(0)->getType()) {
1679           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
1680         } else {
1681           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
1682           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1683         }
1684         Record.push_back(VE.getValueID(C->getOperand(0)));
1685         Record.push_back(VE.getValueID(C->getOperand(1)));
1686         Record.push_back(VE.getValueID(C->getOperand(2)));
1687         break;
1688       case Instruction::ICmp:
1689       case Instruction::FCmp:
1690         Code = bitc::CST_CODE_CE_CMP;
1691         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1692         Record.push_back(VE.getValueID(C->getOperand(0)));
1693         Record.push_back(VE.getValueID(C->getOperand(1)));
1694         Record.push_back(CE->getPredicate());
1695         break;
1696       }
1697     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
1698       Code = bitc::CST_CODE_BLOCKADDRESS;
1699       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
1700       Record.push_back(VE.getValueID(BA->getFunction()));
1701       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
1702     } else {
1703 #ifndef NDEBUG
1704       C->dump();
1705 #endif
1706       llvm_unreachable("Unknown constant!");
1707     }
1708     Stream.EmitRecord(Code, Record, AbbrevToUse);
1709     Record.clear();
1710   }
1711
1712   Stream.ExitBlock();
1713 }
1714
1715 static void WriteModuleConstants(const ValueEnumerator &VE,
1716                                  BitstreamWriter &Stream) {
1717   const ValueEnumerator::ValueList &Vals = VE.getValues();
1718
1719   // Find the first constant to emit, which is the first non-globalvalue value.
1720   // We know globalvalues have been emitted by WriteModuleInfo.
1721   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1722     if (!isa<GlobalValue>(Vals[i].first)) {
1723       WriteConstants(i, Vals.size(), VE, Stream, true);
1724       return;
1725     }
1726   }
1727 }
1728
1729 /// PushValueAndType - The file has to encode both the value and type id for
1730 /// many values, because we need to know what type to create for forward
1731 /// references.  However, most operands are not forward references, so this type
1732 /// field is not needed.
1733 ///
1734 /// This function adds V's value ID to Vals.  If the value ID is higher than the
1735 /// instruction ID, then it is a forward reference, and it also includes the
1736 /// type ID.  The value ID that is written is encoded relative to the InstID.
1737 static bool PushValueAndType(const Value *V, unsigned InstID,
1738                              SmallVectorImpl<unsigned> &Vals,
1739                              ValueEnumerator &VE) {
1740   unsigned ValID = VE.getValueID(V);
1741   // Make encoding relative to the InstID.
1742   Vals.push_back(InstID - ValID);
1743   if (ValID >= InstID) {
1744     Vals.push_back(VE.getTypeID(V->getType()));
1745     return true;
1746   }
1747   return false;
1748 }
1749
1750 static void WriteOperandBundles(BitstreamWriter &Stream, ImmutableCallSite CS,
1751                                 unsigned InstID, ValueEnumerator &VE) {
1752   SmallVector<unsigned, 64> Record;
1753   LLVMContext &C = CS.getInstruction()->getContext();
1754
1755   for (unsigned i = 0, e = CS.getNumOperandBundles(); i != e; ++i) {
1756     const auto &Bundle = CS.getOperandBundleAt(i);
1757     Record.push_back(C.getOperandBundleTagID(Bundle.getTagName()));
1758
1759     for (auto &Input : Bundle.Inputs)
1760       PushValueAndType(Input, InstID, Record, VE);
1761
1762     Stream.EmitRecord(bitc::FUNC_CODE_OPERAND_BUNDLE, Record);
1763     Record.clear();
1764   }
1765 }
1766
1767 /// pushValue - Like PushValueAndType, but where the type of the value is
1768 /// omitted (perhaps it was already encoded in an earlier operand).
1769 static void pushValue(const Value *V, unsigned InstID,
1770                       SmallVectorImpl<unsigned> &Vals,
1771                       ValueEnumerator &VE) {
1772   unsigned ValID = VE.getValueID(V);
1773   Vals.push_back(InstID - ValID);
1774 }
1775
1776 static void pushValueSigned(const Value *V, unsigned InstID,
1777                             SmallVectorImpl<uint64_t> &Vals,
1778                             ValueEnumerator &VE) {
1779   unsigned ValID = VE.getValueID(V);
1780   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
1781   emitSignedInt64(Vals, diff);
1782 }
1783
1784 /// WriteInstruction - Emit an instruction to the specified stream.
1785 static void WriteInstruction(const Instruction &I, unsigned InstID,
1786                              ValueEnumerator &VE, BitstreamWriter &Stream,
1787                              SmallVectorImpl<unsigned> &Vals) {
1788   unsigned Code = 0;
1789   unsigned AbbrevToUse = 0;
1790   VE.setInstructionID(&I);
1791   switch (I.getOpcode()) {
1792   default:
1793     if (Instruction::isCast(I.getOpcode())) {
1794       Code = bitc::FUNC_CODE_INST_CAST;
1795       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1796         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1797       Vals.push_back(VE.getTypeID(I.getType()));
1798       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1799     } else {
1800       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1801       Code = bitc::FUNC_CODE_INST_BINOP;
1802       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1803         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1804       pushValue(I.getOperand(1), InstID, Vals, VE);
1805       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1806       uint64_t Flags = GetOptimizationFlags(&I);
1807       if (Flags != 0) {
1808         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1809           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1810         Vals.push_back(Flags);
1811       }
1812     }
1813     break;
1814
1815   case Instruction::GetElementPtr: {
1816     Code = bitc::FUNC_CODE_INST_GEP;
1817     AbbrevToUse = FUNCTION_INST_GEP_ABBREV;
1818     auto &GEPInst = cast<GetElementPtrInst>(I);
1819     Vals.push_back(GEPInst.isInBounds());
1820     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
1821     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1822       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1823     break;
1824   }
1825   case Instruction::ExtractValue: {
1826     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1827     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1828     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1829     Vals.append(EVI->idx_begin(), EVI->idx_end());
1830     break;
1831   }
1832   case Instruction::InsertValue: {
1833     Code = bitc::FUNC_CODE_INST_INSERTVAL;
1834     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1835     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1836     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1837     Vals.append(IVI->idx_begin(), IVI->idx_end());
1838     break;
1839   }
1840   case Instruction::Select:
1841     Code = bitc::FUNC_CODE_INST_VSELECT;
1842     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1843     pushValue(I.getOperand(2), InstID, Vals, VE);
1844     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1845     break;
1846   case Instruction::ExtractElement:
1847     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1848     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1849     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1850     break;
1851   case Instruction::InsertElement:
1852     Code = bitc::FUNC_CODE_INST_INSERTELT;
1853     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1854     pushValue(I.getOperand(1), InstID, Vals, VE);
1855     PushValueAndType(I.getOperand(2), InstID, Vals, VE);
1856     break;
1857   case Instruction::ShuffleVector:
1858     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1859     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1860     pushValue(I.getOperand(1), InstID, Vals, VE);
1861     pushValue(I.getOperand(2), InstID, Vals, VE);
1862     break;
1863   case Instruction::ICmp:
1864   case Instruction::FCmp: {
1865     // compare returning Int1Ty or vector of Int1Ty
1866     Code = bitc::FUNC_CODE_INST_CMP2;
1867     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1868     pushValue(I.getOperand(1), InstID, Vals, VE);
1869     Vals.push_back(cast<CmpInst>(I).getPredicate());
1870     uint64_t Flags = GetOptimizationFlags(&I);
1871     if (Flags != 0)
1872       Vals.push_back(Flags);
1873     break;
1874   }
1875
1876   case Instruction::Ret:
1877     {
1878       Code = bitc::FUNC_CODE_INST_RET;
1879       unsigned NumOperands = I.getNumOperands();
1880       if (NumOperands == 0)
1881         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1882       else if (NumOperands == 1) {
1883         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1884           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1885       } else {
1886         for (unsigned i = 0, e = NumOperands; i != e; ++i)
1887           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1888       }
1889     }
1890     break;
1891   case Instruction::Br:
1892     {
1893       Code = bitc::FUNC_CODE_INST_BR;
1894       const BranchInst &II = cast<BranchInst>(I);
1895       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1896       if (II.isConditional()) {
1897         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1898         pushValue(II.getCondition(), InstID, Vals, VE);
1899       }
1900     }
1901     break;
1902   case Instruction::Switch:
1903     {
1904       Code = bitc::FUNC_CODE_INST_SWITCH;
1905       const SwitchInst &SI = cast<SwitchInst>(I);
1906       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
1907       pushValue(SI.getCondition(), InstID, Vals, VE);
1908       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
1909       for (SwitchInst::ConstCaseIt Case : SI.cases()) {
1910         Vals.push_back(VE.getValueID(Case.getCaseValue()));
1911         Vals.push_back(VE.getValueID(Case.getCaseSuccessor()));
1912       }
1913     }
1914     break;
1915   case Instruction::IndirectBr:
1916     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1917     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1918     // Encode the address operand as relative, but not the basic blocks.
1919     pushValue(I.getOperand(0), InstID, Vals, VE);
1920     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
1921       Vals.push_back(VE.getValueID(I.getOperand(i)));
1922     break;
1923
1924   case Instruction::Invoke: {
1925     const InvokeInst *II = cast<InvokeInst>(&I);
1926     const Value *Callee = II->getCalledValue();
1927     FunctionType *FTy = II->getFunctionType();
1928
1929     if (II->hasOperandBundles())
1930       WriteOperandBundles(Stream, II, InstID, VE);
1931
1932     Code = bitc::FUNC_CODE_INST_INVOKE;
1933
1934     Vals.push_back(VE.getAttributeID(II->getAttributes()));
1935     Vals.push_back(II->getCallingConv() | 1 << 13);
1936     Vals.push_back(VE.getValueID(II->getNormalDest()));
1937     Vals.push_back(VE.getValueID(II->getUnwindDest()));
1938     Vals.push_back(VE.getTypeID(FTy));
1939     PushValueAndType(Callee, InstID, Vals, VE);
1940
1941     // Emit value #'s for the fixed parameters.
1942     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1943       pushValue(I.getOperand(i), InstID, Vals, VE);  // fixed param.
1944
1945     // Emit type/value pairs for varargs params.
1946     if (FTy->isVarArg()) {
1947       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1948            i != e; ++i)
1949         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1950     }
1951     break;
1952   }
1953   case Instruction::Resume:
1954     Code = bitc::FUNC_CODE_INST_RESUME;
1955     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1956     break;
1957   case Instruction::CleanupRet: {
1958     Code = bitc::FUNC_CODE_INST_CLEANUPRET;
1959     const auto &CRI = cast<CleanupReturnInst>(I);
1960     pushValue(CRI.getCleanupPad(), InstID, Vals, VE);
1961     if (CRI.hasUnwindDest())
1962       Vals.push_back(VE.getValueID(CRI.getUnwindDest()));
1963     break;
1964   }
1965   case Instruction::CatchRet: {
1966     Code = bitc::FUNC_CODE_INST_CATCHRET;
1967     const auto &CRI = cast<CatchReturnInst>(I);
1968     pushValue(CRI.getCatchPad(), InstID, Vals, VE);
1969     Vals.push_back(VE.getValueID(CRI.getSuccessor()));
1970     break;
1971   }
1972   case Instruction::CatchPad: {
1973     Code = bitc::FUNC_CODE_INST_CATCHPAD;
1974     const auto &CPI = cast<CatchPadInst>(I);
1975     Vals.push_back(VE.getValueID(CPI.getNormalDest()));
1976     Vals.push_back(VE.getValueID(CPI.getUnwindDest()));
1977     unsigned NumArgOperands = CPI.getNumArgOperands();
1978     Vals.push_back(NumArgOperands);
1979     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
1980       PushValueAndType(CPI.getArgOperand(Op), InstID, Vals, VE);
1981     break;
1982   }
1983   case Instruction::TerminatePad: {
1984     Code = bitc::FUNC_CODE_INST_TERMINATEPAD;
1985     const auto &TPI = cast<TerminatePadInst>(I);
1986     Vals.push_back(TPI.hasUnwindDest());
1987     if (TPI.hasUnwindDest())
1988       Vals.push_back(VE.getValueID(TPI.getUnwindDest()));
1989     unsigned NumArgOperands = TPI.getNumArgOperands();
1990     Vals.push_back(NumArgOperands);
1991     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
1992       PushValueAndType(TPI.getArgOperand(Op), InstID, Vals, VE);
1993     break;
1994   }
1995   case Instruction::CleanupPad: {
1996     Code = bitc::FUNC_CODE_INST_CLEANUPPAD;
1997     const auto &CPI = cast<CleanupPadInst>(I);
1998     unsigned NumOperands = CPI.getNumOperands();
1999     Vals.push_back(NumOperands);
2000     for (unsigned Op = 0; Op != NumOperands; ++Op)
2001       PushValueAndType(CPI.getOperand(Op), InstID, Vals, VE);
2002     break;
2003   }
2004   case Instruction::CatchEndPad: {
2005     Code = bitc::FUNC_CODE_INST_CATCHENDPAD;
2006     const auto &CEPI = cast<CatchEndPadInst>(I);
2007     if (CEPI.hasUnwindDest())
2008       Vals.push_back(VE.getValueID(CEPI.getUnwindDest()));
2009     break;
2010   }
2011   case Instruction::CleanupEndPad: {
2012     Code = bitc::FUNC_CODE_INST_CLEANUPENDPAD;
2013     const auto &CEPI = cast<CleanupEndPadInst>(I);
2014     pushValue(CEPI.getCleanupPad(), InstID, Vals, VE);
2015     if (CEPI.hasUnwindDest())
2016       Vals.push_back(VE.getValueID(CEPI.getUnwindDest()));
2017     break;
2018   }
2019   case Instruction::Unreachable:
2020     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
2021     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
2022     break;
2023
2024   case Instruction::PHI: {
2025     const PHINode &PN = cast<PHINode>(I);
2026     Code = bitc::FUNC_CODE_INST_PHI;
2027     // With the newer instruction encoding, forward references could give
2028     // negative valued IDs.  This is most common for PHIs, so we use
2029     // signed VBRs.
2030     SmallVector<uint64_t, 128> Vals64;
2031     Vals64.push_back(VE.getTypeID(PN.getType()));
2032     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
2033       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64, VE);
2034       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
2035     }
2036     // Emit a Vals64 vector and exit.
2037     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
2038     Vals64.clear();
2039     return;
2040   }
2041
2042   case Instruction::LandingPad: {
2043     const LandingPadInst &LP = cast<LandingPadInst>(I);
2044     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
2045     Vals.push_back(VE.getTypeID(LP.getType()));
2046     Vals.push_back(LP.isCleanup());
2047     Vals.push_back(LP.getNumClauses());
2048     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
2049       if (LP.isCatch(I))
2050         Vals.push_back(LandingPadInst::Catch);
2051       else
2052         Vals.push_back(LandingPadInst::Filter);
2053       PushValueAndType(LP.getClause(I), InstID, Vals, VE);
2054     }
2055     break;
2056   }
2057
2058   case Instruction::Alloca: {
2059     Code = bitc::FUNC_CODE_INST_ALLOCA;
2060     const AllocaInst &AI = cast<AllocaInst>(I);
2061     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
2062     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
2063     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
2064     unsigned AlignRecord = Log2_32(AI.getAlignment()) + 1;
2065     assert(Log2_32(Value::MaximumAlignment) + 1 < 1 << 5 &&
2066            "not enough bits for maximum alignment");
2067     assert(AlignRecord < 1 << 5 && "alignment greater than 1 << 64");
2068     AlignRecord |= AI.isUsedWithInAlloca() << 5;
2069     AlignRecord |= 1 << 6;
2070     // Reserve bit 7 for SwiftError flag.
2071     // AlignRecord |= AI.isSwiftError() << 7;
2072     Vals.push_back(AlignRecord);
2073     break;
2074   }
2075
2076   case Instruction::Load:
2077     if (cast<LoadInst>(I).isAtomic()) {
2078       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
2079       PushValueAndType(I.getOperand(0), InstID, Vals, VE);
2080     } else {
2081       Code = bitc::FUNC_CODE_INST_LOAD;
2082       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
2083         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
2084     }
2085     Vals.push_back(VE.getTypeID(I.getType()));
2086     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
2087     Vals.push_back(cast<LoadInst>(I).isVolatile());
2088     if (cast<LoadInst>(I).isAtomic()) {
2089       Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
2090       Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
2091     }
2092     break;
2093   case Instruction::Store:
2094     if (cast<StoreInst>(I).isAtomic())
2095       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
2096     else
2097       Code = bitc::FUNC_CODE_INST_STORE;
2098     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
2099     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // valty + val
2100     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
2101     Vals.push_back(cast<StoreInst>(I).isVolatile());
2102     if (cast<StoreInst>(I).isAtomic()) {
2103       Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
2104       Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
2105     }
2106     break;
2107   case Instruction::AtomicCmpXchg:
2108     Code = bitc::FUNC_CODE_INST_CMPXCHG;
2109     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
2110     PushValueAndType(I.getOperand(1), InstID, Vals, VE);         // cmp.
2111     pushValue(I.getOperand(2), InstID, Vals, VE);         // newval.
2112     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
2113     Vals.push_back(GetEncodedOrdering(
2114                      cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
2115     Vals.push_back(GetEncodedSynchScope(
2116                      cast<AtomicCmpXchgInst>(I).getSynchScope()));
2117     Vals.push_back(GetEncodedOrdering(
2118                      cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
2119     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
2120     break;
2121   case Instruction::AtomicRMW:
2122     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
2123     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
2124     pushValue(I.getOperand(1), InstID, Vals, VE);         // val.
2125     Vals.push_back(GetEncodedRMWOperation(
2126                      cast<AtomicRMWInst>(I).getOperation()));
2127     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
2128     Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
2129     Vals.push_back(GetEncodedSynchScope(
2130                      cast<AtomicRMWInst>(I).getSynchScope()));
2131     break;
2132   case Instruction::Fence:
2133     Code = bitc::FUNC_CODE_INST_FENCE;
2134     Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
2135     Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
2136     break;
2137   case Instruction::Call: {
2138     const CallInst &CI = cast<CallInst>(I);
2139     FunctionType *FTy = CI.getFunctionType();
2140
2141     if (CI.hasOperandBundles())
2142       WriteOperandBundles(Stream, &CI, InstID, VE);
2143
2144     Code = bitc::FUNC_CODE_INST_CALL;
2145
2146     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
2147     Vals.push_back(CI.getCallingConv() << bitc::CALL_CCONV |
2148                    unsigned(CI.isTailCall()) << bitc::CALL_TAIL |
2149                    unsigned(CI.isMustTailCall()) << bitc::CALL_MUSTTAIL |
2150                    1 << bitc::CALL_EXPLICIT_TYPE |
2151                    unsigned(CI.isNoTailCall()) << bitc::CALL_NOTAIL);
2152     Vals.push_back(VE.getTypeID(FTy));
2153     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
2154
2155     // Emit value #'s for the fixed parameters.
2156     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
2157       // Check for labels (can happen with asm labels).
2158       if (FTy->getParamType(i)->isLabelTy())
2159         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
2160       else
2161         pushValue(CI.getArgOperand(i), InstID, Vals, VE);  // fixed param.
2162     }
2163
2164     // Emit type/value pairs for varargs params.
2165     if (FTy->isVarArg()) {
2166       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
2167            i != e; ++i)
2168         PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
2169     }
2170     break;
2171   }
2172   case Instruction::VAArg:
2173     Code = bitc::FUNC_CODE_INST_VAARG;
2174     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
2175     pushValue(I.getOperand(0), InstID, Vals, VE); // valist.
2176     Vals.push_back(VE.getTypeID(I.getType())); // restype.
2177     break;
2178   }
2179
2180   Stream.EmitRecord(Code, Vals, AbbrevToUse);
2181   Vals.clear();
2182 }
2183
2184 enum StringEncoding { SE_Char6, SE_Fixed7, SE_Fixed8 };
2185
2186 /// Determine the encoding to use for the given string name and length.
2187 static StringEncoding getStringEncoding(const char *Str, unsigned StrLen) {
2188   bool isChar6 = true;
2189   for (const char *C = Str, *E = C + StrLen; C != E; ++C) {
2190     if (isChar6)
2191       isChar6 = BitCodeAbbrevOp::isChar6(*C);
2192     if ((unsigned char)*C & 128)
2193       // don't bother scanning the rest.
2194       return SE_Fixed8;
2195   }
2196   if (isChar6)
2197     return SE_Char6;
2198   else
2199     return SE_Fixed7;
2200 }
2201
2202 /// Emit names for globals/functions etc. The VSTOffsetPlaceholder,
2203 /// BitcodeStartBit and FunctionIndex are only passed for the module-level
2204 /// VST, where we are including a function bitcode index and need to
2205 /// backpatch the VST forward declaration record.
2206 static void WriteValueSymbolTable(
2207     const ValueSymbolTable &VST, const ValueEnumerator &VE,
2208     BitstreamWriter &Stream, uint64_t VSTOffsetPlaceholder = 0,
2209     uint64_t BitcodeStartBit = 0,
2210     DenseMap<const Function *, std::unique_ptr<FunctionInfo>> *FunctionIndex =
2211         nullptr) {
2212   if (VST.empty()) {
2213     // WriteValueSymbolTableForwardDecl should have returned early as
2214     // well. Ensure this handling remains in sync by asserting that
2215     // the placeholder offset is not set.
2216     assert(VSTOffsetPlaceholder == 0);
2217     return;
2218   }
2219
2220   if (VSTOffsetPlaceholder > 0) {
2221     // Get the offset of the VST we are writing, and backpatch it into
2222     // the VST forward declaration record.
2223     uint64_t VSTOffset = Stream.GetCurrentBitNo();
2224     // The BitcodeStartBit was the stream offset of the actual bitcode
2225     // (e.g. excluding any initial darwin header).
2226     VSTOffset -= BitcodeStartBit;
2227     assert((VSTOffset & 31) == 0 && "VST block not 32-bit aligned");
2228     Stream.BackpatchWord(VSTOffsetPlaceholder, VSTOffset / 32);
2229   }
2230
2231   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
2232
2233   // For the module-level VST, add abbrev Ids for the VST_CODE_FNENTRY
2234   // records, which are not used in the per-function VSTs.
2235   unsigned FnEntry8BitAbbrev;
2236   unsigned FnEntry7BitAbbrev;
2237   unsigned FnEntry6BitAbbrev;
2238   if (VSTOffsetPlaceholder > 0) {
2239     // 8-bit fixed-width VST_FNENTRY function strings.
2240     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2241     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
2242     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
2243     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
2244     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2245     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2246     FnEntry8BitAbbrev = Stream.EmitAbbrev(Abbv);
2247
2248     // 7-bit fixed width VST_FNENTRY function strings.
2249     Abbv = new BitCodeAbbrev();
2250     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
2251     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
2252     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
2253     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2254     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2255     FnEntry7BitAbbrev = Stream.EmitAbbrev(Abbv);
2256
2257     // 6-bit char6 VST_FNENTRY function strings.
2258     Abbv = new BitCodeAbbrev();
2259     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
2260     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // value id
2261     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
2262     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2263     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2264     FnEntry6BitAbbrev = Stream.EmitAbbrev(Abbv);
2265   }
2266
2267   // FIXME: Set up the abbrev, we know how many values there are!
2268   // FIXME: We know if the type names can use 7-bit ascii.
2269   SmallVector<unsigned, 64> NameVals;
2270
2271   for (const ValueName &Name : VST) {
2272     // Figure out the encoding to use for the name.
2273     StringEncoding Bits =
2274         getStringEncoding(Name.getKeyData(), Name.getKeyLength());
2275
2276     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
2277     NameVals.push_back(VE.getValueID(Name.getValue()));
2278
2279     Function *F = dyn_cast<Function>(Name.getValue());
2280     if (!F) {
2281       // If value is an alias, need to get the aliased base object to
2282       // see if it is a function.
2283       auto *GA = dyn_cast<GlobalAlias>(Name.getValue());
2284       if (GA && GA->getBaseObject())
2285         F = dyn_cast<Function>(GA->getBaseObject());
2286     }
2287
2288     // VST_ENTRY:   [valueid, namechar x N]
2289     // VST_FNENTRY: [valueid, funcoffset, namechar x N]
2290     // VST_BBENTRY: [bbid, namechar x N]
2291     unsigned Code;
2292     if (isa<BasicBlock>(Name.getValue())) {
2293       Code = bitc::VST_CODE_BBENTRY;
2294       if (Bits == SE_Char6)
2295         AbbrevToUse = VST_BBENTRY_6_ABBREV;
2296     } else if (F && !F->isDeclaration()) {
2297       // Must be the module-level VST, where we pass in the Index and
2298       // have a VSTOffsetPlaceholder. The function-level VST should not
2299       // contain any Function symbols.
2300       assert(FunctionIndex);
2301       assert(VSTOffsetPlaceholder > 0);
2302
2303       // Save the word offset of the function (from the start of the
2304       // actual bitcode written to the stream).
2305       assert(FunctionIndex->count(F) == 1);
2306       uint64_t BitcodeIndex =
2307           (*FunctionIndex)[F]->bitcodeIndex() - BitcodeStartBit;
2308       assert((BitcodeIndex & 31) == 0 && "function block not 32-bit aligned");
2309       NameVals.push_back(BitcodeIndex / 32);
2310
2311       Code = bitc::VST_CODE_FNENTRY;
2312       AbbrevToUse = FnEntry8BitAbbrev;
2313       if (Bits == SE_Char6)
2314         AbbrevToUse = FnEntry6BitAbbrev;
2315       else if (Bits == SE_Fixed7)
2316         AbbrevToUse = FnEntry7BitAbbrev;
2317     } else {
2318       Code = bitc::VST_CODE_ENTRY;
2319       if (Bits == SE_Char6)
2320         AbbrevToUse = VST_ENTRY_6_ABBREV;
2321       else if (Bits == SE_Fixed7)
2322         AbbrevToUse = VST_ENTRY_7_ABBREV;
2323     }
2324
2325     for (const auto P : Name.getKey())
2326       NameVals.push_back((unsigned char)P);
2327
2328     // Emit the finished record.
2329     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
2330     NameVals.clear();
2331   }
2332   Stream.ExitBlock();
2333 }
2334
2335 /// Emit function names and summary offsets for the combined index
2336 /// used by ThinLTO.
2337 static void WriteCombinedValueSymbolTable(const FunctionInfoIndex &Index,
2338                                           BitstreamWriter &Stream) {
2339   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
2340
2341   // 8-bit fixed-width VST_COMBINED_FNENTRY function strings.
2342   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2343   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_COMBINED_FNENTRY));
2344   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
2345   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2346   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2347   unsigned FnEntry8BitAbbrev = Stream.EmitAbbrev(Abbv);
2348
2349   // 7-bit fixed width VST_COMBINED_FNENTRY function strings.
2350   Abbv = new BitCodeAbbrev();
2351   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_COMBINED_FNENTRY));
2352   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
2353   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2354   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2355   unsigned FnEntry7BitAbbrev = Stream.EmitAbbrev(Abbv);
2356
2357   // 6-bit char6 VST_COMBINED_FNENTRY function strings.
2358   Abbv = new BitCodeAbbrev();
2359   Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_COMBINED_FNENTRY));
2360   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // funcoffset
2361   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2362   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2363   unsigned FnEntry6BitAbbrev = Stream.EmitAbbrev(Abbv);
2364
2365   // FIXME: We know if the type names can use 7-bit ascii.
2366   SmallVector<unsigned, 64> NameVals;
2367
2368   for (const auto &FII : Index) {
2369     for (const auto &FI : FII.getValue()) {
2370       NameVals.push_back(FI->bitcodeIndex());
2371
2372       StringRef FuncName = FII.first();
2373
2374       // Figure out the encoding to use for the name.
2375       StringEncoding Bits = getStringEncoding(FuncName.data(), FuncName.size());
2376
2377       // VST_COMBINED_FNENTRY: [funcsumoffset, namechar x N]
2378       unsigned AbbrevToUse = FnEntry8BitAbbrev;
2379       if (Bits == SE_Char6)
2380         AbbrevToUse = FnEntry6BitAbbrev;
2381       else if (Bits == SE_Fixed7)
2382         AbbrevToUse = FnEntry7BitAbbrev;
2383
2384       for (const auto P : FuncName)
2385         NameVals.push_back((unsigned char)P);
2386
2387       // Emit the finished record.
2388       Stream.EmitRecord(bitc::VST_CODE_COMBINED_FNENTRY, NameVals, AbbrevToUse);
2389       NameVals.clear();
2390     }
2391   }
2392   Stream.ExitBlock();
2393 }
2394
2395 static void WriteUseList(ValueEnumerator &VE, UseListOrder &&Order,
2396                          BitstreamWriter &Stream) {
2397   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
2398   unsigned Code;
2399   if (isa<BasicBlock>(Order.V))
2400     Code = bitc::USELIST_CODE_BB;
2401   else
2402     Code = bitc::USELIST_CODE_DEFAULT;
2403
2404   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
2405   Record.push_back(VE.getValueID(Order.V));
2406   Stream.EmitRecord(Code, Record);
2407 }
2408
2409 static void WriteUseListBlock(const Function *F, ValueEnumerator &VE,
2410                               BitstreamWriter &Stream) {
2411   assert(VE.shouldPreserveUseListOrder() &&
2412          "Expected to be preserving use-list order");
2413
2414   auto hasMore = [&]() {
2415     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
2416   };
2417   if (!hasMore())
2418     // Nothing to do.
2419     return;
2420
2421   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
2422   while (hasMore()) {
2423     WriteUseList(VE, std::move(VE.UseListOrders.back()), Stream);
2424     VE.UseListOrders.pop_back();
2425   }
2426   Stream.ExitBlock();
2427 }
2428
2429 /// \brief Save information for the given function into the function index.
2430 ///
2431 /// At a minimum this saves the bitcode index of the function record that
2432 /// was just written. However, if we are emitting function summary information,
2433 /// for example for ThinLTO, then a \a FunctionSummary object is created
2434 /// to hold the provided summary information.
2435 static void SaveFunctionInfo(
2436     const Function &F,
2437     DenseMap<const Function *, std::unique_ptr<FunctionInfo>> &FunctionIndex,
2438     unsigned NumInsts, uint64_t BitcodeIndex, bool EmitFunctionSummary) {
2439   std::unique_ptr<FunctionSummary> FuncSummary;
2440   if (EmitFunctionSummary) {
2441     FuncSummary = llvm::make_unique<FunctionSummary>(NumInsts);
2442     FuncSummary->setLocalFunction(F.hasLocalLinkage());
2443   }
2444   FunctionIndex[&F] =
2445       llvm::make_unique<FunctionInfo>(BitcodeIndex, std::move(FuncSummary));
2446 }
2447
2448 /// Emit a function body to the module stream.
2449 static void WriteFunction(
2450     const Function &F, ValueEnumerator &VE, BitstreamWriter &Stream,
2451     DenseMap<const Function *, std::unique_ptr<FunctionInfo>> &FunctionIndex,
2452     bool EmitFunctionSummary) {
2453   // Save the bitcode index of the start of this function block for recording
2454   // in the VST.
2455   uint64_t BitcodeIndex = Stream.GetCurrentBitNo();
2456
2457   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
2458   VE.incorporateFunction(F);
2459
2460   SmallVector<unsigned, 64> Vals;
2461
2462   // Emit the number of basic blocks, so the reader can create them ahead of
2463   // time.
2464   Vals.push_back(VE.getBasicBlocks().size());
2465   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
2466   Vals.clear();
2467
2468   // If there are function-local constants, emit them now.
2469   unsigned CstStart, CstEnd;
2470   VE.getFunctionConstantRange(CstStart, CstEnd);
2471   WriteConstants(CstStart, CstEnd, VE, Stream, false);
2472
2473   // If there is function-local metadata, emit it now.
2474   WriteFunctionLocalMetadata(F, VE, Stream);
2475
2476   // Keep a running idea of what the instruction ID is.
2477   unsigned InstID = CstEnd;
2478
2479   bool NeedsMetadataAttachment = F.hasMetadata();
2480
2481   DILocation *LastDL = nullptr;
2482   unsigned NumInsts = 0;
2483
2484   // Finally, emit all the instructions, in order.
2485   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
2486     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
2487          I != E; ++I) {
2488       WriteInstruction(*I, InstID, VE, Stream, Vals);
2489
2490       if (!isa<DbgInfoIntrinsic>(I))
2491         ++NumInsts;
2492
2493       if (!I->getType()->isVoidTy())
2494         ++InstID;
2495
2496       // If the instruction has metadata, write a metadata attachment later.
2497       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
2498
2499       // If the instruction has a debug location, emit it.
2500       DILocation *DL = I->getDebugLoc();
2501       if (!DL)
2502         continue;
2503
2504       if (DL == LastDL) {
2505         // Just repeat the same debug loc as last time.
2506         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
2507         continue;
2508       }
2509
2510       Vals.push_back(DL->getLine());
2511       Vals.push_back(DL->getColumn());
2512       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
2513       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
2514       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
2515       Vals.clear();
2516
2517       LastDL = DL;
2518     }
2519
2520   // Emit names for all the instructions etc.
2521   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
2522
2523   if (NeedsMetadataAttachment)
2524     WriteMetadataAttachment(F, VE, Stream);
2525   if (VE.shouldPreserveUseListOrder())
2526     WriteUseListBlock(&F, VE, Stream);
2527   VE.purgeFunction();
2528   Stream.ExitBlock();
2529
2530   SaveFunctionInfo(F, FunctionIndex, NumInsts, BitcodeIndex,
2531                    EmitFunctionSummary);
2532 }
2533
2534 // Emit blockinfo, which defines the standard abbreviations etc.
2535 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
2536   // We only want to emit block info records for blocks that have multiple
2537   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
2538   // Other blocks can define their abbrevs inline.
2539   Stream.EnterBlockInfoBlock(2);
2540
2541   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
2542     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2543     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
2544     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2545     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2546     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2547     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2548                                    Abbv) != VST_ENTRY_8_ABBREV)
2549       llvm_unreachable("Unexpected abbrev ordering!");
2550   }
2551
2552   { // 7-bit fixed width VST_ENTRY strings.
2553     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2554     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2555     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2556     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2557     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2558     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2559                                    Abbv) != VST_ENTRY_7_ABBREV)
2560       llvm_unreachable("Unexpected abbrev ordering!");
2561   }
2562   { // 6-bit char6 VST_ENTRY strings.
2563     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2564     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2565     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2566     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2567     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2568     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2569                                    Abbv) != VST_ENTRY_6_ABBREV)
2570       llvm_unreachable("Unexpected abbrev ordering!");
2571   }
2572   { // 6-bit char6 VST_BBENTRY strings.
2573     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2574     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
2575     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2576     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2577     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2578     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2579                                    Abbv) != VST_BBENTRY_6_ABBREV)
2580       llvm_unreachable("Unexpected abbrev ordering!");
2581   }
2582
2583
2584
2585   { // SETTYPE abbrev for CONSTANTS_BLOCK.
2586     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2587     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
2588     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2589                               VE.computeBitsRequiredForTypeIndicies()));
2590     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2591                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
2592       llvm_unreachable("Unexpected abbrev ordering!");
2593   }
2594
2595   { // INTEGER abbrev for CONSTANTS_BLOCK.
2596     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2597     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
2598     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2599     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2600                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
2601       llvm_unreachable("Unexpected abbrev ordering!");
2602   }
2603
2604   { // CE_CAST abbrev for CONSTANTS_BLOCK.
2605     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2606     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
2607     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
2608     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
2609                               VE.computeBitsRequiredForTypeIndicies()));
2610     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
2611
2612     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2613                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
2614       llvm_unreachable("Unexpected abbrev ordering!");
2615   }
2616   { // NULL abbrev for CONSTANTS_BLOCK.
2617     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2618     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
2619     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2620                                    Abbv) != CONSTANTS_NULL_Abbrev)
2621       llvm_unreachable("Unexpected abbrev ordering!");
2622   }
2623
2624   // FIXME: This should only use space for first class types!
2625
2626   { // INST_LOAD abbrev for FUNCTION_BLOCK.
2627     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2628     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
2629     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
2630     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2631                               VE.computeBitsRequiredForTypeIndicies()));
2632     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
2633     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
2634     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2635                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
2636       llvm_unreachable("Unexpected abbrev ordering!");
2637   }
2638   { // INST_BINOP abbrev for FUNCTION_BLOCK.
2639     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2640     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2641     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2642     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2643     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2644     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2645                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
2646       llvm_unreachable("Unexpected abbrev ordering!");
2647   }
2648   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
2649     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2650     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2651     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2652     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2653     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2654     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
2655     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2656                                    Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
2657       llvm_unreachable("Unexpected abbrev ordering!");
2658   }
2659   { // INST_CAST abbrev for FUNCTION_BLOCK.
2660     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2661     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
2662     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
2663     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
2664                               VE.computeBitsRequiredForTypeIndicies()));
2665     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
2666     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2667                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
2668       llvm_unreachable("Unexpected abbrev ordering!");
2669   }
2670
2671   { // INST_RET abbrev for FUNCTION_BLOCK.
2672     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2673     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2674     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2675                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
2676       llvm_unreachable("Unexpected abbrev ordering!");
2677   }
2678   { // INST_RET abbrev for FUNCTION_BLOCK.
2679     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2680     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2681     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
2682     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2683                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
2684       llvm_unreachable("Unexpected abbrev ordering!");
2685   }
2686   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
2687     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2688     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
2689     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2690                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
2691       llvm_unreachable("Unexpected abbrev ordering!");
2692   }
2693   {
2694     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2695     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
2696     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2697     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
2698                               Log2_32_Ceil(VE.getTypes().size() + 1)));
2699     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2700     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2701     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2702         FUNCTION_INST_GEP_ABBREV)
2703       llvm_unreachable("Unexpected abbrev ordering!");
2704   }
2705
2706   Stream.ExitBlock();
2707 }
2708
2709 /// Write the module path strings, currently only used when generating
2710 /// a combined index file.
2711 static void WriteModStrings(const FunctionInfoIndex &I,
2712                             BitstreamWriter &Stream) {
2713   Stream.EnterSubblock(bitc::MODULE_STRTAB_BLOCK_ID, 3);
2714
2715   // TODO: See which abbrev sizes we actually need to emit
2716
2717   // 8-bit fixed-width MST_ENTRY strings.
2718   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2719   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
2720   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2721   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2722   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2723   unsigned Abbrev8Bit = Stream.EmitAbbrev(Abbv);
2724
2725   // 7-bit fixed width MST_ENTRY strings.
2726   Abbv = new BitCodeAbbrev();
2727   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
2728   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2729   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2730   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2731   unsigned Abbrev7Bit = Stream.EmitAbbrev(Abbv);
2732
2733   // 6-bit char6 MST_ENTRY strings.
2734   Abbv = new BitCodeAbbrev();
2735   Abbv->Add(BitCodeAbbrevOp(bitc::MST_CODE_ENTRY));
2736   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2737   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2738   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2739   unsigned Abbrev6Bit = Stream.EmitAbbrev(Abbv);
2740
2741   SmallVector<unsigned, 64> NameVals;
2742   for (const StringMapEntry<uint64_t> &MPSE : I.modPathStringEntries()) {
2743     StringEncoding Bits =
2744         getStringEncoding(MPSE.getKey().data(), MPSE.getKey().size());
2745     unsigned AbbrevToUse = Abbrev8Bit;
2746     if (Bits == SE_Char6)
2747       AbbrevToUse = Abbrev6Bit;
2748     else if (Bits == SE_Fixed7)
2749       AbbrevToUse = Abbrev7Bit;
2750
2751     NameVals.push_back(MPSE.getValue());
2752
2753     for (const auto P : MPSE.getKey())
2754       NameVals.push_back((unsigned char)P);
2755
2756     // Emit the finished record.
2757     Stream.EmitRecord(bitc::MST_CODE_ENTRY, NameVals, AbbrevToUse);
2758     NameVals.clear();
2759   }
2760   Stream.ExitBlock();
2761 }
2762
2763 // Helper to emit a single function summary record.
2764 static void WritePerModuleFunctionSummaryRecord(
2765     SmallVector<unsigned, 64> &NameVals, FunctionSummary *FS, unsigned ValueID,
2766     unsigned FSAbbrev, BitstreamWriter &Stream) {
2767   assert(FS);
2768   NameVals.push_back(ValueID);
2769   NameVals.push_back(FS->isLocalFunction());
2770   NameVals.push_back(FS->instCount());
2771
2772   // Emit the finished record.
2773   Stream.EmitRecord(bitc::FS_CODE_PERMODULE_ENTRY, NameVals, FSAbbrev);
2774   NameVals.clear();
2775 }
2776
2777 /// Emit the per-module function summary section alongside the rest of
2778 /// the module's bitcode.
2779 static void WritePerModuleFunctionSummary(
2780     DenseMap<const Function *, std::unique_ptr<FunctionInfo>> &FunctionIndex,
2781     const Module *M, const ValueEnumerator &VE, BitstreamWriter &Stream) {
2782   Stream.EnterSubblock(bitc::FUNCTION_SUMMARY_BLOCK_ID, 3);
2783
2784   // Abbrev for FS_CODE_PERMODULE_ENTRY.
2785   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2786   Abbv->Add(BitCodeAbbrevOp(bitc::FS_CODE_PERMODULE_ENTRY));
2787   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // valueid
2788   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // islocal
2789   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // instcount
2790   unsigned FSAbbrev = Stream.EmitAbbrev(Abbv);
2791
2792   SmallVector<unsigned, 64> NameVals;
2793   for (auto &I : FunctionIndex) {
2794     // Skip anonymous functions. We will emit a function summary for
2795     // any aliases below.
2796     if (!I.first->hasName())
2797       continue;
2798
2799     WritePerModuleFunctionSummaryRecord(
2800         NameVals, I.second->functionSummary(),
2801         VE.getValueID(M->getValueSymbolTable().lookup(I.first->getName())),
2802         FSAbbrev, Stream);
2803   }
2804
2805   for (const GlobalAlias &A : M->aliases()) {
2806     if (!A.getBaseObject())
2807       continue;
2808     const Function *F = dyn_cast<Function>(A.getBaseObject());
2809     if (!F || F->isDeclaration())
2810       continue;
2811
2812     assert(FunctionIndex.count(F) == 1);
2813     WritePerModuleFunctionSummaryRecord(
2814         NameVals, FunctionIndex[F]->functionSummary(),
2815         VE.getValueID(M->getValueSymbolTable().lookup(A.getName())), FSAbbrev,
2816         Stream);
2817   }
2818
2819   Stream.ExitBlock();
2820 }
2821
2822 /// Emit the combined function summary section into the combined index
2823 /// file.
2824 static void WriteCombinedFunctionSummary(const FunctionInfoIndex &I,
2825                                          BitstreamWriter &Stream) {
2826   Stream.EnterSubblock(bitc::FUNCTION_SUMMARY_BLOCK_ID, 3);
2827
2828   // Abbrev for FS_CODE_COMBINED_ENTRY.
2829   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2830   Abbv->Add(BitCodeAbbrevOp(bitc::FS_CODE_COMBINED_ENTRY));
2831   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // modid
2832   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8)); // instcount
2833   unsigned FSAbbrev = Stream.EmitAbbrev(Abbv);
2834
2835   SmallVector<unsigned, 64> NameVals;
2836   for (const auto &FII : I) {
2837     for (auto &FI : FII.getValue()) {
2838       FunctionSummary *FS = FI->functionSummary();
2839       assert(FS);
2840
2841       NameVals.push_back(I.getModuleId(FS->modulePath()));
2842       NameVals.push_back(FS->instCount());
2843
2844       // Record the starting offset of this summary entry for use
2845       // in the VST entry. Add the current code size since the
2846       // reader will invoke readRecord after the abbrev id read.
2847       FI->setBitcodeIndex(Stream.GetCurrentBitNo() + Stream.GetAbbrevIDWidth());
2848
2849       // Emit the finished record.
2850       Stream.EmitRecord(bitc::FS_CODE_COMBINED_ENTRY, NameVals, FSAbbrev);
2851       NameVals.clear();
2852     }
2853   }
2854
2855   Stream.ExitBlock();
2856 }
2857
2858 // Create the "IDENTIFICATION_BLOCK_ID" containing a single string with the
2859 // current llvm version, and a record for the epoch number.
2860 static void WriteIdentificationBlock(const Module *M, BitstreamWriter &Stream) {
2861   Stream.EnterSubblock(bitc::IDENTIFICATION_BLOCK_ID, 5);
2862
2863   // Write the "user readable" string identifying the bitcode producer
2864   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2865   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_STRING));
2866   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2867   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2868   auto StringAbbrev = Stream.EmitAbbrev(Abbv);
2869   WriteStringRecord(bitc::IDENTIFICATION_CODE_STRING,
2870                     "LLVM" LLVM_VERSION_STRING, StringAbbrev, Stream);
2871
2872   // Write the epoch version
2873   Abbv = new BitCodeAbbrev();
2874   Abbv->Add(BitCodeAbbrevOp(bitc::IDENTIFICATION_CODE_EPOCH));
2875   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2876   auto EpochAbbrev = Stream.EmitAbbrev(Abbv);
2877   SmallVector<unsigned, 1> Vals = {bitc::BITCODE_CURRENT_EPOCH};
2878   Stream.EmitRecord(bitc::IDENTIFICATION_CODE_EPOCH, Vals, EpochAbbrev);
2879   Stream.ExitBlock();
2880 }
2881
2882 /// WriteModule - Emit the specified module to the bitstream.
2883 static void WriteModule(const Module *M, BitstreamWriter &Stream,
2884                         bool ShouldPreserveUseListOrder,
2885                         uint64_t BitcodeStartBit, bool EmitFunctionSummary) {
2886   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
2887
2888   SmallVector<unsigned, 1> Vals;
2889   unsigned CurVersion = 1;
2890   Vals.push_back(CurVersion);
2891   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
2892
2893   // Analyze the module, enumerating globals, functions, etc.
2894   ValueEnumerator VE(*M, ShouldPreserveUseListOrder);
2895
2896   // Emit blockinfo, which defines the standard abbreviations etc.
2897   WriteBlockInfo(VE, Stream);
2898
2899   // Emit information about attribute groups.
2900   WriteAttributeGroupTable(VE, Stream);
2901
2902   // Emit information about parameter attributes.
2903   WriteAttributeTable(VE, Stream);
2904
2905   // Emit information describing all of the types in the module.
2906   WriteTypeTable(VE, Stream);
2907
2908   writeComdats(VE, Stream);
2909
2910   // Emit top-level description of module, including target triple, inline asm,
2911   // descriptors for global variables, and function prototype info.
2912   uint64_t VSTOffsetPlaceholder = WriteModuleInfo(M, VE, Stream);
2913
2914   // Emit constants.
2915   WriteModuleConstants(VE, Stream);
2916
2917   // Emit metadata.
2918   WriteModuleMetadata(M, VE, Stream);
2919
2920   // Emit metadata.
2921   WriteModuleMetadataStore(M, Stream);
2922
2923   // Emit module-level use-lists.
2924   if (VE.shouldPreserveUseListOrder())
2925     WriteUseListBlock(nullptr, VE, Stream);
2926
2927   WriteOperandBundleTags(M, Stream);
2928
2929   // Emit function bodies.
2930   DenseMap<const Function *, std::unique_ptr<FunctionInfo>> FunctionIndex;
2931   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
2932     if (!F->isDeclaration())
2933       WriteFunction(*F, VE, Stream, FunctionIndex, EmitFunctionSummary);
2934
2935   // Need to write after the above call to WriteFunction which populates
2936   // the summary information in the index.
2937   if (EmitFunctionSummary)
2938     WritePerModuleFunctionSummary(FunctionIndex, M, VE, Stream);
2939
2940   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream,
2941                         VSTOffsetPlaceholder, BitcodeStartBit, &FunctionIndex);
2942
2943   Stream.ExitBlock();
2944 }
2945
2946 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
2947 /// header and trailer to make it compatible with the system archiver.  To do
2948 /// this we emit the following header, and then emit a trailer that pads the
2949 /// file out to be a multiple of 16 bytes.
2950 ///
2951 /// struct bc_header {
2952 ///   uint32_t Magic;         // 0x0B17C0DE
2953 ///   uint32_t Version;       // Version, currently always 0.
2954 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
2955 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
2956 ///   uint32_t CPUType;       // CPU specifier.
2957 ///   ... potentially more later ...
2958 /// };
2959 enum {
2960   DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
2961   DarwinBCHeaderSize = 5*4
2962 };
2963
2964 static void WriteInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
2965                                uint32_t &Position) {
2966   support::endian::write32le(&Buffer[Position], Value);
2967   Position += 4;
2968 }
2969
2970 static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
2971                                          const Triple &TT) {
2972   unsigned CPUType = ~0U;
2973
2974   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
2975   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
2976   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
2977   // specific constants here because they are implicitly part of the Darwin ABI.
2978   enum {
2979     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
2980     DARWIN_CPU_TYPE_X86        = 7,
2981     DARWIN_CPU_TYPE_ARM        = 12,
2982     DARWIN_CPU_TYPE_POWERPC    = 18
2983   };
2984
2985   Triple::ArchType Arch = TT.getArch();
2986   if (Arch == Triple::x86_64)
2987     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
2988   else if (Arch == Triple::x86)
2989     CPUType = DARWIN_CPU_TYPE_X86;
2990   else if (Arch == Triple::ppc)
2991     CPUType = DARWIN_CPU_TYPE_POWERPC;
2992   else if (Arch == Triple::ppc64)
2993     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
2994   else if (Arch == Triple::arm || Arch == Triple::thumb)
2995     CPUType = DARWIN_CPU_TYPE_ARM;
2996
2997   // Traditional Bitcode starts after header.
2998   assert(Buffer.size() >= DarwinBCHeaderSize &&
2999          "Expected header size to be reserved");
3000   unsigned BCOffset = DarwinBCHeaderSize;
3001   unsigned BCSize = Buffer.size()-DarwinBCHeaderSize;
3002
3003   // Write the magic and version.
3004   unsigned Position = 0;
3005   WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position);
3006   WriteInt32ToBuffer(0          , Buffer, Position); // Version.
3007   WriteInt32ToBuffer(BCOffset   , Buffer, Position);
3008   WriteInt32ToBuffer(BCSize     , Buffer, Position);
3009   WriteInt32ToBuffer(CPUType    , Buffer, Position);
3010
3011   // If the file is not a multiple of 16 bytes, insert dummy padding.
3012   while (Buffer.size() & 15)
3013     Buffer.push_back(0);
3014 }
3015
3016 /// Helper to write the header common to all bitcode files.
3017 static void WriteBitcodeHeader(BitstreamWriter &Stream) {
3018   // Emit the file header.
3019   Stream.Emit((unsigned)'B', 8);
3020   Stream.Emit((unsigned)'C', 8);
3021   Stream.Emit(0x0, 4);
3022   Stream.Emit(0xC, 4);
3023   Stream.Emit(0xE, 4);
3024   Stream.Emit(0xD, 4);
3025 }
3026
3027 /// WriteBitcodeToFile - Write the specified module to the specified output
3028 /// stream.
3029 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out,
3030                               bool ShouldPreserveUseListOrder,
3031                               bool EmitFunctionSummary) {
3032   SmallVector<char, 0> Buffer;
3033   Buffer.reserve(256*1024);
3034
3035   // If this is darwin or another generic macho target, reserve space for the
3036   // header.
3037   Triple TT(M->getTargetTriple());
3038   if (TT.isOSDarwin())
3039     Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0);
3040
3041   // Emit the module into the buffer.
3042   {
3043     BitstreamWriter Stream(Buffer);
3044     // Save the start bit of the actual bitcode, in case there is space
3045     // saved at the start for the darwin header above. The reader stream
3046     // will start at the bitcode, and we need the offset of the VST
3047     // to line up.
3048     uint64_t BitcodeStartBit = Stream.GetCurrentBitNo();
3049
3050     // Emit the file header.
3051     WriteBitcodeHeader(Stream);
3052
3053     WriteIdentificationBlock(M, Stream);
3054
3055     // Emit the module.
3056     WriteModule(M, Stream, ShouldPreserveUseListOrder, BitcodeStartBit,
3057                 EmitFunctionSummary);
3058   }
3059
3060   if (TT.isOSDarwin())
3061     EmitDarwinBCHeaderAndTrailer(Buffer, TT);
3062
3063   // Write the generated bitstream to "Out".
3064   Out.write((char*)&Buffer.front(), Buffer.size());
3065 }
3066
3067 // Write the specified function summary index to the given raw output stream,
3068 // where it will be written in a new bitcode block. This is used when
3069 // writing the combined index file for ThinLTO.
3070 void llvm::WriteFunctionSummaryToFile(const FunctionInfoIndex &Index,
3071                                       raw_ostream &Out) {
3072   SmallVector<char, 0> Buffer;
3073   Buffer.reserve(256 * 1024);
3074
3075   BitstreamWriter Stream(Buffer);
3076
3077   // Emit the bitcode header.
3078   WriteBitcodeHeader(Stream);
3079
3080   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
3081
3082   SmallVector<unsigned, 1> Vals;
3083   unsigned CurVersion = 1;
3084   Vals.push_back(CurVersion);
3085   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
3086
3087   // Write the module paths in the combined index.
3088   WriteModStrings(Index, Stream);
3089
3090   // Write the function summary combined index records.
3091   WriteCombinedFunctionSummary(Index, Stream);
3092
3093   // Need a special VST writer for the combined index (we don't have a
3094   // real VST and real values when this is invoked).
3095   WriteCombinedValueSymbolTable(Index, Stream);
3096
3097   Stream.ExitBlock();
3098
3099   Out.write((char *)&Buffer.front(), Buffer.size());
3100 }