lib/Bitcode/Writer/BitcodeWriter.cpp

   1 //===--- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ----------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Bitcode writer implementation.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Bitcode/ReaderWriter.h"
  15 #include "ValueEnumerator.h"
  16 #include "llvm/ADT/Triple.h"
  17 #include "llvm/Bitcode/BitstreamWriter.h"
  18 #include "llvm/Bitcode/LLVMBitCodes.h"
  19 #include "llvm/IR/CallSite.h"
  20 #include "llvm/IR/Constants.h"
  21 #include "llvm/IR/DebugInfoMetadata.h"
  22 #include "llvm/IR/DerivedTypes.h"
  23 #include "llvm/IR/InlineAsm.h"
  24 #include "llvm/IR/Instructions.h"
  25 #include "llvm/IR/LLVMContext.h"
  26 #include "llvm/IR/Module.h"
  27 #include "llvm/IR/Operator.h"
  28 #include "llvm/IR/UseListOrder.h"
  29 #include "llvm/IR/ValueSymbolTable.h"
  30 #include "llvm/Support/CommandLine.h"
  31 #include "llvm/Support/ErrorHandling.h"
  32 #include "llvm/Support/MathExtras.h"
  33 #include "llvm/Support/Program.h"
  34 #include "llvm/Support/raw_ostream.h"
  35 #include <cctype>
  36 #include <map>
  37 using namespace llvm;
  38
  39 /// These are manifest constants used by the bitcode writer. They do not need to
  40 /// be kept in sync with the reader, but need to be consistent within this file.
  41 enum {
  42   // VALUE_SYMTAB_BLOCK abbrev id's.
  43   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  44   VST_ENTRY_7_ABBREV,
  45   VST_ENTRY_6_ABBREV,
  46   VST_BBENTRY_6_ABBREV,
  47
  48   // CONSTANTS_BLOCK abbrev id's.
  49   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  50   CONSTANTS_INTEGER_ABBREV,
  51   CONSTANTS_CE_CAST_Abbrev,
  52   CONSTANTS_NULL_Abbrev,
  53
  54   // FUNCTION_BLOCK abbrev id's.
  55   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  56   FUNCTION_INST_BINOP_ABBREV,
  57   FUNCTION_INST_BINOP_FLAGS_ABBREV,
  58   FUNCTION_INST_CAST_ABBREV,
  59   FUNCTION_INST_RET_VOID_ABBREV,
  60   FUNCTION_INST_RET_VAL_ABBREV,
  61   FUNCTION_INST_UNREACHABLE_ABBREV,
  62   FUNCTION_INST_GEP_ABBREV,
  63 };
  64
  65 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
  66   switch (Opcode) {
  67   default: llvm_unreachable("Unknown cast instruction!");
  68   case Instruction::Trunc   : return bitc::CAST_TRUNC;
  69   case Instruction::ZExt    : return bitc::CAST_ZEXT;
  70   case Instruction::SExt    : return bitc::CAST_SEXT;
  71   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
  72   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
  73   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
  74   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
  75   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
  76   case Instruction::FPExt   : return bitc::CAST_FPEXT;
  77   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
  78   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
  79   case Instruction::BitCast : return bitc::CAST_BITCAST;
  80   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
  81   }
  82 }
  83
  84 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
  85   switch (Opcode) {
  86   default: llvm_unreachable("Unknown binary instruction!");
  87   case Instruction::Add:
  88   case Instruction::FAdd: return bitc::BINOP_ADD;
  89   case Instruction::Sub:
  90   case Instruction::FSub: return bitc::BINOP_SUB;
  91   case Instruction::Mul:
  92   case Instruction::FMul: return bitc::BINOP_MUL;
  93   case Instruction::UDiv: return bitc::BINOP_UDIV;
  94   case Instruction::FDiv:
  95   case Instruction::SDiv: return bitc::BINOP_SDIV;
  96   case Instruction::URem: return bitc::BINOP_UREM;
  97   case Instruction::FRem:
  98   case Instruction::SRem: return bitc::BINOP_SREM;
  99   case Instruction::Shl:  return bitc::BINOP_SHL;
 100   case Instruction::LShr: return bitc::BINOP_LSHR;
 101   case Instruction::AShr: return bitc::BINOP_ASHR;
 102   case Instruction::And:  return bitc::BINOP_AND;
 103   case Instruction::Or:   return bitc::BINOP_OR;
 104   case Instruction::Xor:  return bitc::BINOP_XOR;
 105   }
 106 }
 107
 108 static unsigned GetEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
 109   switch (Op) {
 110   default: llvm_unreachable("Unknown RMW operation!");
 111   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
 112   case AtomicRMWInst::Add: return bitc::RMW_ADD;
 113   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
 114   case AtomicRMWInst::And: return bitc::RMW_AND;
 115   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
 116   case AtomicRMWInst::Or: return bitc::RMW_OR;
 117   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
 118   case AtomicRMWInst::Max: return bitc::RMW_MAX;
 119   case AtomicRMWInst::Min: return bitc::RMW_MIN;
 120   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
 121   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
 122   }
 123 }
 124
 125 static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
 126   switch (Ordering) {
 127   case NotAtomic: return bitc::ORDERING_NOTATOMIC;
 128   case Unordered: return bitc::ORDERING_UNORDERED;
 129   case Monotonic: return bitc::ORDERING_MONOTONIC;
 130   case Acquire: return bitc::ORDERING_ACQUIRE;
 131   case Release: return bitc::ORDERING_RELEASE;
 132   case AcquireRelease: return bitc::ORDERING_ACQREL;
 133   case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
 134   }
 135   llvm_unreachable("Invalid ordering");
 136 }
 137
 138 static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
 139   switch (SynchScope) {
 140   case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
 141   case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
 142   }
 143   llvm_unreachable("Invalid synch scope");
 144 }
 145
 146 static void WriteStringRecord(unsigned Code, StringRef Str,
 147                               unsigned AbbrevToUse, BitstreamWriter &Stream) {
 148   SmallVector<unsigned, 64> Vals;
 149
 150   // Code: [strchar x N]
 151   for (unsigned i = 0, e = Str.size(); i != e; ++i) {
 152     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
 153       AbbrevToUse = 0;
 154     Vals.push_back(Str[i]);
 155   }
 156
 157   // Emit the finished record.
 158   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 159 }
 160
 161 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
 162   switch (Kind) {
 163   case Attribute::Alignment:
 164     return bitc::ATTR_KIND_ALIGNMENT;
 165   case Attribute::AlwaysInline:
 166     return bitc::ATTR_KIND_ALWAYS_INLINE;
 167   case Attribute::ArgMemOnly:
 168     return bitc::ATTR_KIND_ARGMEMONLY;
 169   case Attribute::Builtin:
 170     return bitc::ATTR_KIND_BUILTIN;
 171   case Attribute::ByVal:
 172     return bitc::ATTR_KIND_BY_VAL;
 173   case Attribute::Convergent:
 174     return bitc::ATTR_KIND_CONVERGENT;
 175   case Attribute::InAlloca:
 176     return bitc::ATTR_KIND_IN_ALLOCA;
 177   case Attribute::Cold:
 178     return bitc::ATTR_KIND_COLD;
 179   case Attribute::InlineHint:
 180     return bitc::ATTR_KIND_INLINE_HINT;
 181   case Attribute::InReg:
 182     return bitc::ATTR_KIND_IN_REG;
 183   case Attribute::JumpTable:
 184     return bitc::ATTR_KIND_JUMP_TABLE;
 185   case Attribute::MinSize:
 186     return bitc::ATTR_KIND_MIN_SIZE;
 187   case Attribute::Naked:
 188     return bitc::ATTR_KIND_NAKED;
 189   case Attribute::Nest:
 190     return bitc::ATTR_KIND_NEST;
 191   case Attribute::NoAlias:
 192     return bitc::ATTR_KIND_NO_ALIAS;
 193   case Attribute::NoBuiltin:
 194     return bitc::ATTR_KIND_NO_BUILTIN;
 195   case Attribute::NoCapture:
 196     return bitc::ATTR_KIND_NO_CAPTURE;
 197   case Attribute::NoDuplicate:
 198     return bitc::ATTR_KIND_NO_DUPLICATE;
 199   case Attribute::NoImplicitFloat:
 200     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
 201   case Attribute::NoInline:
 202     return bitc::ATTR_KIND_NO_INLINE;
 203   case Attribute::NonLazyBind:
 204     return bitc::ATTR_KIND_NON_LAZY_BIND;
 205   case Attribute::NonNull:
 206     return bitc::ATTR_KIND_NON_NULL;
 207   case Attribute::Dereferenceable:
 208     return bitc::ATTR_KIND_DEREFERENCEABLE;
 209   case Attribute::DereferenceableOrNull:
 210     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
 211   case Attribute::NoRedZone:
 212     return bitc::ATTR_KIND_NO_RED_ZONE;
 213   case Attribute::NoReturn:
 214     return bitc::ATTR_KIND_NO_RETURN;
 215   case Attribute::NoUnwind:
 216     return bitc::ATTR_KIND_NO_UNWIND;
 217   case Attribute::OptimizeForSize:
 218     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
 219   case Attribute::OptimizeNone:
 220     return bitc::ATTR_KIND_OPTIMIZE_NONE;
 221   case Attribute::ReadNone:
 222     return bitc::ATTR_KIND_READ_NONE;
 223   case Attribute::ReadOnly:
 224     return bitc::ATTR_KIND_READ_ONLY;
 225   case Attribute::Returned:
 226     return bitc::ATTR_KIND_RETURNED;
 227   case Attribute::ReturnsTwice:
 228     return bitc::ATTR_KIND_RETURNS_TWICE;
 229   case Attribute::SExt:
 230     return bitc::ATTR_KIND_S_EXT;
 231   case Attribute::StackAlignment:
 232     return bitc::ATTR_KIND_STACK_ALIGNMENT;
 233   case Attribute::StackProtect:
 234     return bitc::ATTR_KIND_STACK_PROTECT;
 235   case Attribute::StackProtectReq:
 236     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
 237   case Attribute::StackProtectStrong:
 238     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
 239   case Attribute::SafeStack:
 240     return bitc::ATTR_KIND_SAFESTACK;
 241   case Attribute::StructRet:
 242     return bitc::ATTR_KIND_STRUCT_RET;
 243   case Attribute::SanitizeAddress:
 244     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
 245   case Attribute::SanitizeThread:
 246     return bitc::ATTR_KIND_SANITIZE_THREAD;
 247   case Attribute::SanitizeMemory:
 248     return bitc::ATTR_KIND_SANITIZE_MEMORY;
 249   case Attribute::UWTable:
 250     return bitc::ATTR_KIND_UW_TABLE;
 251   case Attribute::ZExt:
 252     return bitc::ATTR_KIND_Z_EXT;
 253   case Attribute::EndAttrKinds:
 254     llvm_unreachable("Can not encode end-attribute kinds marker.");
 255   case Attribute::None:
 256     llvm_unreachable("Can not encode none-attribute.");
 257   }
 258
 259   llvm_unreachable("Trying to encode unknown attribute");
 260 }
 261
 262 static void WriteAttributeGroupTable(const ValueEnumerator &VE,
 263                                      BitstreamWriter &Stream) {
 264   const std::vector<AttributeSet> &AttrGrps = VE.getAttributeGroups();
 265   if (AttrGrps.empty()) return;
 266
 267   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
 268
 269   SmallVector<uint64_t, 64> Record;
 270   for (unsigned i = 0, e = AttrGrps.size(); i != e; ++i) {
 271     AttributeSet AS = AttrGrps[i];
 272     for (unsigned i = 0, e = AS.getNumSlots(); i != e; ++i) {
 273       AttributeSet A = AS.getSlotAttributes(i);
 274
 275       Record.push_back(VE.getAttributeGroupID(A));
 276       Record.push_back(AS.getSlotIndex(i));
 277
 278       for (AttributeSet::iterator I = AS.begin(0), E = AS.end(0);
 279            I != E; ++I) {
 280         Attribute Attr = *I;
 281         if (Attr.isEnumAttribute()) {
 282           Record.push_back(0);
 283           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 284         } else if (Attr.isIntAttribute()) {
 285           Record.push_back(1);
 286           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 287           Record.push_back(Attr.getValueAsInt());
 288         } else {
 289           StringRef Kind = Attr.getKindAsString();
 290           StringRef Val = Attr.getValueAsString();
 291
 292           Record.push_back(Val.empty() ? 3 : 4);
 293           Record.append(Kind.begin(), Kind.end());
 294           Record.push_back(0);
 295           if (!Val.empty()) {
 296             Record.append(Val.begin(), Val.end());
 297             Record.push_back(0);
 298           }
 299         }
 300       }
 301
 302       Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
 303       Record.clear();
 304     }
 305   }
 306
 307   Stream.ExitBlock();
 308 }
 309
 310 static void WriteAttributeTable(const ValueEnumerator &VE,
 311                                 BitstreamWriter &Stream) {
 312   const std::vector<AttributeSet> &Attrs = VE.getAttributes();
 313   if (Attrs.empty()) return;
 314
 315   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 316
 317   SmallVector<uint64_t, 64> Record;
 318   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
 319     const AttributeSet &A = Attrs[i];
 320     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
 321       Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
 322
 323     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 324     Record.clear();
 325   }
 326
 327   Stream.ExitBlock();
 328 }
 329
 330 /// WriteTypeTable - Write out the type table for a module.
 331 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 332   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 333
 334   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
 335   SmallVector<uint64_t, 64> TypeVals;
 336
 337   uint64_t NumBits = VE.computeBitsRequiredForTypeIndicies();
 338
 339   // Abbrev for TYPE_CODE_POINTER.
 340   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 341   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
 342   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 343   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
 344   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
 345
 346   // Abbrev for TYPE_CODE_FUNCTION.
 347   Abbv = new BitCodeAbbrev();
 348   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
 349   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
 350   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 351   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 352
 353   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 354
 355   // Abbrev for TYPE_CODE_STRUCT_ANON.
 356   Abbv = new BitCodeAbbrev();
 357   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
 358   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 359   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 360   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 361
 362   unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
 363
 364   // Abbrev for TYPE_CODE_STRUCT_NAME.
 365   Abbv = new BitCodeAbbrev();
 366   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
 367   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 368   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 369   unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
 370
 371   // Abbrev for TYPE_CODE_STRUCT_NAMED.
 372   Abbv = new BitCodeAbbrev();
 373   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
 374   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 375   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 376   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 377
 378   unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
 379
 380   // Abbrev for TYPE_CODE_ARRAY.
 381   Abbv = new BitCodeAbbrev();
 382   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 383   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 384   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 385
 386   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 387
 388   // Emit an entry count so the reader can reserve space.
 389   TypeVals.push_back(TypeList.size());
 390   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 391   TypeVals.clear();
 392
 393   // Loop over all of the types, emitting each in turn.
 394   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 395     Type *T = TypeList[i];
 396     int AbbrevToUse = 0;
 397     unsigned Code = 0;
 398
 399     switch (T->getTypeID()) {
 400     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
 401     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
 402     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
 403     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
 404     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
 405     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
 406     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 407     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
 408     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
 409     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
 410     case Type::TokenTyID:     Code = bitc::TYPE_CODE_TOKEN;     break;
 411     case Type::IntegerTyID:
 412       // INTEGER: [width]
 413       Code = bitc::TYPE_CODE_INTEGER;
 414       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 415       break;
 416     case Type::PointerTyID: {
 417       PointerType *PTy = cast<PointerType>(T);
 418       // POINTER: [pointee type, address space]
 419       Code = bitc::TYPE_CODE_POINTER;
 420       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
 421       unsigned AddressSpace = PTy->getAddressSpace();
 422       TypeVals.push_back(AddressSpace);
 423       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
 424       break;
 425     }
 426     case Type::FunctionTyID: {
 427       FunctionType *FT = cast<FunctionType>(T);
 428       // FUNCTION: [isvararg, retty, paramty x N]
 429       Code = bitc::TYPE_CODE_FUNCTION;
 430       TypeVals.push_back(FT->isVarArg());
 431       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 432       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 433         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 434       AbbrevToUse = FunctionAbbrev;
 435       break;
 436     }
 437     case Type::StructTyID: {
 438       StructType *ST = cast<StructType>(T);
 439       // STRUCT: [ispacked, eltty x N]
 440       TypeVals.push_back(ST->isPacked());
 441       // Output all of the element types.
 442       for (StructType::element_iterator I = ST->element_begin(),
 443            E = ST->element_end(); I != E; ++I)
 444         TypeVals.push_back(VE.getTypeID(*I));
 445
 446       if (ST->isLiteral()) {
 447         Code = bitc::TYPE_CODE_STRUCT_ANON;
 448         AbbrevToUse = StructAnonAbbrev;
 449       } else {
 450         if (ST->isOpaque()) {
 451           Code = bitc::TYPE_CODE_OPAQUE;
 452         } else {
 453           Code = bitc::TYPE_CODE_STRUCT_NAMED;
 454           AbbrevToUse = StructNamedAbbrev;
 455         }
 456
 457         // Emit the name if it is present.
 458         if (!ST->getName().empty())
 459           WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
 460                             StructNameAbbrev, Stream);
 461       }
 462       break;
 463     }
 464     case Type::ArrayTyID: {
 465       ArrayType *AT = cast<ArrayType>(T);
 466       // ARRAY: [numelts, eltty]
 467       Code = bitc::TYPE_CODE_ARRAY;
 468       TypeVals.push_back(AT->getNumElements());
 469       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 470       AbbrevToUse = ArrayAbbrev;
 471       break;
 472     }
 473     case Type::VectorTyID: {
 474       VectorType *VT = cast<VectorType>(T);
 475       // VECTOR [numelts, eltty]
 476       Code = bitc::TYPE_CODE_VECTOR;
 477       TypeVals.push_back(VT->getNumElements());
 478       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 479       break;
 480     }
 481     }
 482
 483     // Emit the finished record.
 484     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 485     TypeVals.clear();
 486   }
 487
 488   Stream.ExitBlock();
 489 }
 490
 491 static unsigned getEncodedLinkage(const GlobalValue &GV) {
 492   switch (GV.getLinkage()) {
 493   case GlobalValue::ExternalLinkage:
 494     return 0;
 495   case GlobalValue::WeakAnyLinkage:
 496     return 16;
 497   case GlobalValue::AppendingLinkage:
 498     return 2;
 499   case GlobalValue::InternalLinkage:
 500     return 3;
 501   case GlobalValue::LinkOnceAnyLinkage:
 502     return 18;
 503   case GlobalValue::ExternalWeakLinkage:
 504     return 7;
 505   case GlobalValue::CommonLinkage:
 506     return 8;
 507   case GlobalValue::PrivateLinkage:
 508     return 9;
 509   case GlobalValue::WeakODRLinkage:
 510     return 17;
 511   case GlobalValue::LinkOnceODRLinkage:
 512     return 19;
 513   case GlobalValue::AvailableExternallyLinkage:
 514     return 12;
 515   }
 516   llvm_unreachable("Invalid linkage");
 517 }
 518
 519 static unsigned getEncodedVisibility(const GlobalValue &GV) {
 520   switch (GV.getVisibility()) {
 521   case GlobalValue::DefaultVisibility:   return 0;
 522   case GlobalValue::HiddenVisibility:    return 1;
 523   case GlobalValue::ProtectedVisibility: return 2;
 524   }
 525   llvm_unreachable("Invalid visibility");
 526 }
 527
 528 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
 529   switch (GV.getDLLStorageClass()) {
 530   case GlobalValue::DefaultStorageClass:   return 0;
 531   case GlobalValue::DLLImportStorageClass: return 1;
 532   case GlobalValue::DLLExportStorageClass: return 2;
 533   }
 534   llvm_unreachable("Invalid DLL storage class");
 535 }
 536
 537 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
 538   switch (GV.getThreadLocalMode()) {
 539     case GlobalVariable::NotThreadLocal:         return 0;
 540     case GlobalVariable::GeneralDynamicTLSModel: return 1;
 541     case GlobalVariable::LocalDynamicTLSModel:   return 2;
 542     case GlobalVariable::InitialExecTLSModel:    return 3;
 543     case GlobalVariable::LocalExecTLSModel:      return 4;
 544   }
 545   llvm_unreachable("Invalid TLS model");
 546 }
 547
 548 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
 549   switch (C.getSelectionKind()) {
 550   case Comdat::Any:
 551     return bitc::COMDAT_SELECTION_KIND_ANY;
 552   case Comdat::ExactMatch:
 553     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
 554   case Comdat::Largest:
 555     return bitc::COMDAT_SELECTION_KIND_LARGEST;
 556   case Comdat::NoDuplicates:
 557     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
 558   case Comdat::SameSize:
 559     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
 560   }
 561   llvm_unreachable("Invalid selection kind");
 562 }
 563
 564 static void writeComdats(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 565   SmallVector<uint16_t, 64> Vals;
 566   for (const Comdat *C : VE.getComdats()) {
 567     // COMDAT: [selection_kind, name]
 568     Vals.push_back(getEncodedComdatSelectionKind(*C));
 569     size_t Size = C->getName().size();
 570     assert(isUInt<16>(Size));
 571     Vals.push_back(Size);
 572     for (char Chr : C->getName())
 573       Vals.push_back((unsigned char)Chr);
 574     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
 575     Vals.clear();
 576   }
 577 }
 578
 579 /// Write a record that will eventually hold the word offset of the
 580 /// module-level VST. For now the offset is 0, which will be backpatched
 581 /// after the real VST is written. Returns the bit offset to backpatch.
 582 static uint64_t WriteValueSymbolTableForwardDecl(const ValueSymbolTable &VST,
 583                                                  BitstreamWriter &Stream) {
 584   if (VST.empty()) return 0;
 585
 586   // Write a placeholder value in for the offset of the real VST,
 587   // which is written after the function blocks so that it can include
 588   // the offset of each function. The placeholder offset will be
 589   // updated when the real VST is written.
 590   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 591   Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_VSTOFFSET));
 592   // Blocks are 32-bit aligned, so we can use a 32-bit word offset to
 593   // hold the real VST offset. Must use fixed instead of VBR as we don't
 594   // know how many VBR chunks to reserve ahead of time.
 595   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 32));
 596   unsigned VSTOffsetAbbrev = Stream.EmitAbbrev(Abbv);
 597
 598   // Emit the placeholder
 599   uint64_t Vals[] = {bitc::MODULE_CODE_VSTOFFSET, 0};
 600   Stream.EmitRecordWithAbbrev(VSTOffsetAbbrev, Vals);
 601
 602   // Compute and return the bit offset to the placeholder, which will be
 603   // patched when the real VST is written. We can simply subtract the 32-bit
 604   // fixed size from the current bit number to get the location to backpatch.
 605   return Stream.GetCurrentBitNo() - 32;
 606 }
 607
 608 /// Emit top-level description of module, including target triple, inline asm,
 609 /// descriptors for global variables, and function prototype info.
 610 /// Returns the bit offset to backpatch with the location of the real VST.
 611 static uint64_t WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 612                                 BitstreamWriter &Stream) {
 613   // Emit various pieces of data attached to a module.
 614   if (!M->getTargetTriple().empty())
 615     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 616                       0/*TODO*/, Stream);
 617   const std::string &DL = M->getDataLayoutStr();
 618   if (!DL.empty())
 619     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/, Stream);
 620   if (!M->getModuleInlineAsm().empty())
 621     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 622                       0/*TODO*/, Stream);
 623
 624   // Emit information about sections and GC, computing how many there are. Also
 625   // compute the maximum alignment value.
 626   std::map<std::string, unsigned> SectionMap;
 627   std::map<std::string, unsigned> GCMap;
 628   unsigned MaxAlignment = 0;
 629   unsigned MaxGlobalType = 0;
 630   for (const GlobalValue &GV : M->globals()) {
 631     MaxAlignment = std::max(MaxAlignment, GV.getAlignment());
 632     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
 633     if (GV.hasSection()) {
 634       // Give section names unique ID's.
 635       unsigned &Entry = SectionMap[GV.getSection()];
 636       if (!Entry) {
 637         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
 638                           0/*TODO*/, Stream);
 639         Entry = SectionMap.size();
 640       }
 641     }
 642   }
 643   for (const Function &F : *M) {
 644     MaxAlignment = std::max(MaxAlignment, F.getAlignment());
 645     if (F.hasSection()) {
 646       // Give section names unique ID's.
 647       unsigned &Entry = SectionMap[F.getSection()];
 648       if (!Entry) {
 649         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
 650                           0/*TODO*/, Stream);
 651         Entry = SectionMap.size();
 652       }
 653     }
 654     if (F.hasGC()) {
 655       // Same for GC names.
 656       unsigned &Entry = GCMap[F.getGC()];
 657       if (!Entry) {
 658         WriteStringRecord(bitc::MODULE_CODE_GCNAME, F.getGC(),
 659                           0/*TODO*/, Stream);
 660         Entry = GCMap.size();
 661       }
 662     }
 663   }
 664
 665   // Emit abbrev for globals, now that we know # sections and max alignment.
 666   unsigned SimpleGVarAbbrev = 0;
 667   if (!M->global_empty()) {
 668     // Add an abbrev for common globals with no visibility or thread localness.
 669     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 670     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 671     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 672                               Log2_32_Ceil(MaxGlobalType+1)));
 673     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
 674                                                            //| explicitType << 1
 675                                                            //| constant
 676     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
 677     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
 678     if (MaxAlignment == 0)                                 // Alignment.
 679       Abbv->Add(BitCodeAbbrevOp(0));
 680     else {
 681       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 682       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 683                                Log2_32_Ceil(MaxEncAlignment+1)));
 684     }
 685     if (SectionMap.empty())                                    // Section.
 686       Abbv->Add(BitCodeAbbrevOp(0));
 687     else
 688       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 689                                Log2_32_Ceil(SectionMap.size()+1)));
 690     // Don't bother emitting vis + thread local.
 691     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 692   }
 693
 694   // Emit the global variable information.
 695   SmallVector<unsigned, 64> Vals;
 696   for (const GlobalVariable &GV : M->globals()) {
 697     unsigned AbbrevToUse = 0;
 698
 699     // GLOBALVAR: [type, isconst, initid,
 700     //             linkage, alignment, section, visibility, threadlocal,
 701     //             unnamed_addr, externally_initialized, dllstorageclass,
 702     //             comdat]
 703     Vals.push_back(VE.getTypeID(GV.getValueType()));
 704     Vals.push_back(GV.getType()->getAddressSpace() << 2 | 2 | GV.isConstant());
 705     Vals.push_back(GV.isDeclaration() ? 0 :
 706                    (VE.getValueID(GV.getInitializer()) + 1));
 707     Vals.push_back(getEncodedLinkage(GV));
 708     Vals.push_back(Log2_32(GV.getAlignment())+1);
 709     Vals.push_back(GV.hasSection() ? SectionMap[GV.getSection()] : 0);
 710     if (GV.isThreadLocal() ||
 711         GV.getVisibility() != GlobalValue::DefaultVisibility ||
 712         GV.hasUnnamedAddr() || GV.isExternallyInitialized() ||
 713         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
 714         GV.hasComdat()) {
 715       Vals.push_back(getEncodedVisibility(GV));
 716       Vals.push_back(getEncodedThreadLocalMode(GV));
 717       Vals.push_back(GV.hasUnnamedAddr());
 718       Vals.push_back(GV.isExternallyInitialized());
 719       Vals.push_back(getEncodedDLLStorageClass(GV));
 720       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
 721     } else {
 722       AbbrevToUse = SimpleGVarAbbrev;
 723     }
 724
 725     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 726     Vals.clear();
 727   }
 728
 729   // Emit the function proto information.
 730   for (const Function &F : *M) {
 731     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
 732     //             section, visibility, gc, unnamed_addr, prologuedata,
 733     //             dllstorageclass, comdat, prefixdata, personalityfn]
 734     Vals.push_back(VE.getTypeID(F.getFunctionType()));
 735     Vals.push_back(F.getCallingConv());
 736     Vals.push_back(F.isDeclaration());
 737     Vals.push_back(getEncodedLinkage(F));
 738     Vals.push_back(VE.getAttributeID(F.getAttributes()));
 739     Vals.push_back(Log2_32(F.getAlignment())+1);
 740     Vals.push_back(F.hasSection() ? SectionMap[F.getSection()] : 0);
 741     Vals.push_back(getEncodedVisibility(F));
 742     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
 743     Vals.push_back(F.hasUnnamedAddr());
 744     Vals.push_back(F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1)
 745                                        : 0);
 746     Vals.push_back(getEncodedDLLStorageClass(F));
 747     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
 748     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
 749                                      : 0);
 750     Vals.push_back(
 751         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
 752
 753     unsigned AbbrevToUse = 0;
 754     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 755     Vals.clear();
 756   }
 757
 758   // Emit the alias information.
 759   for (const GlobalAlias &A : M->aliases()) {
 760     // ALIAS: [alias type, aliasee val#, linkage, visibility]
 761     Vals.push_back(VE.getTypeID(A.getValueType()));
 762     Vals.push_back(A.getType()->getAddressSpace());
 763     Vals.push_back(VE.getValueID(A.getAliasee()));
 764     Vals.push_back(getEncodedLinkage(A));
 765     Vals.push_back(getEncodedVisibility(A));
 766     Vals.push_back(getEncodedDLLStorageClass(A));
 767     Vals.push_back(getEncodedThreadLocalMode(A));
 768     Vals.push_back(A.hasUnnamedAddr());
 769     unsigned AbbrevToUse = 0;
 770     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 771     Vals.clear();
 772   }
 773
 774   uint64_t VSTOffsetPlaceholder =
 775       WriteValueSymbolTableForwardDecl(M->getValueSymbolTable(), Stream);
 776   return VSTOffsetPlaceholder;
 777 }
 778
 779 static uint64_t GetOptimizationFlags(const Value *V) {
 780   uint64_t Flags = 0;
 781
 782   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
 783     if (OBO->hasNoSignedWrap())
 784       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
 785     if (OBO->hasNoUnsignedWrap())
 786       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
 787   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
 788     if (PEO->isExact())
 789       Flags |= 1 << bitc::PEO_EXACT;
 790   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
 791     if (FPMO->hasUnsafeAlgebra())
 792       Flags |= FastMathFlags::UnsafeAlgebra;
 793     if (FPMO->hasNoNaNs())
 794       Flags |= FastMathFlags::NoNaNs;
 795     if (FPMO->hasNoInfs())
 796       Flags |= FastMathFlags::NoInfs;
 797     if (FPMO->hasNoSignedZeros())
 798       Flags |= FastMathFlags::NoSignedZeros;
 799     if (FPMO->hasAllowReciprocal())
 800       Flags |= FastMathFlags::AllowReciprocal;
 801   }
 802
 803   return Flags;
 804 }
 805
 806 static void WriteValueAsMetadata(const ValueAsMetadata *MD,
 807                                  const ValueEnumerator &VE,
 808                                  BitstreamWriter &Stream,
 809                                  SmallVectorImpl<uint64_t> &Record) {
 810   // Mimic an MDNode with a value as one operand.
 811   Value *V = MD->getValue();
 812   Record.push_back(VE.getTypeID(V->getType()));
 813   Record.push_back(VE.getValueID(V));
 814   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
 815   Record.clear();
 816 }
 817
 818 static void WriteMDTuple(const MDTuple *N, const ValueEnumerator &VE,
 819                          BitstreamWriter &Stream,
 820                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
 821   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
 822     Metadata *MD = N->getOperand(i);
 823     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
 824            "Unexpected function-local metadata");
 825     Record.push_back(VE.getMetadataOrNullID(MD));
 826   }
 827   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
 828                                     : bitc::METADATA_NODE,
 829                     Record, Abbrev);
 830   Record.clear();
 831 }
 832
 833 static void WriteDILocation(const DILocation *N, const ValueEnumerator &VE,
 834                             BitstreamWriter &Stream,
 835                             SmallVectorImpl<uint64_t> &Record,
 836                             unsigned Abbrev) {
 837   Record.push_back(N->isDistinct());
 838   Record.push_back(N->getLine());
 839   Record.push_back(N->getColumn());
 840   Record.push_back(VE.getMetadataID(N->getScope()));
 841   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
 842
 843   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
 844   Record.clear();
 845 }
 846
 847 static void WriteGenericDINode(const GenericDINode *N,
 848                                const ValueEnumerator &VE,
 849                                BitstreamWriter &Stream,
 850                                SmallVectorImpl<uint64_t> &Record,
 851                                unsigned Abbrev) {
 852   Record.push_back(N->isDistinct());
 853   Record.push_back(N->getTag());
 854   Record.push_back(0); // Per-tag version field; unused for now.
 855
 856   for (auto &I : N->operands())
 857     Record.push_back(VE.getMetadataOrNullID(I));
 858
 859   Stream.EmitRecord(bitc::METADATA_GENERIC_DEBUG, Record, Abbrev);
 860   Record.clear();
 861 }
 862
 863 static uint64_t rotateSign(int64_t I) {
 864   uint64_t U = I;
 865   return I < 0 ? ~(U << 1) : U << 1;
 866 }
 867
 868 static void WriteDISubrange(const DISubrange *N, const ValueEnumerator &,
 869                             BitstreamWriter &Stream,
 870                             SmallVectorImpl<uint64_t> &Record,
 871                             unsigned Abbrev) {
 872   Record.push_back(N->isDistinct());
 873   Record.push_back(N->getCount());
 874   Record.push_back(rotateSign(N->getLowerBound()));
 875
 876   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
 877   Record.clear();
 878 }
 879
 880 static void WriteDIEnumerator(const DIEnumerator *N, const ValueEnumerator &VE,
 881                               BitstreamWriter &Stream,
 882                               SmallVectorImpl<uint64_t> &Record,
 883                               unsigned Abbrev) {
 884   Record.push_back(N->isDistinct());
 885   Record.push_back(rotateSign(N->getValue()));
 886   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 887
 888   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
 889   Record.clear();
 890 }
 891
 892 static void WriteDIBasicType(const DIBasicType *N, const ValueEnumerator &VE,
 893                              BitstreamWriter &Stream,
 894                              SmallVectorImpl<uint64_t> &Record,
 895                              unsigned Abbrev) {
 896   Record.push_back(N->isDistinct());
 897   Record.push_back(N->getTag());
 898   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 899   Record.push_back(N->getSizeInBits());
 900   Record.push_back(N->getAlignInBits());
 901   Record.push_back(N->getEncoding());
 902
 903   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
 904   Record.clear();
 905 }
 906
 907 static void WriteDIDerivedType(const DIDerivedType *N,
 908                                const ValueEnumerator &VE,
 909                                BitstreamWriter &Stream,
 910                                SmallVectorImpl<uint64_t> &Record,
 911                                unsigned Abbrev) {
 912   Record.push_back(N->isDistinct());
 913   Record.push_back(N->getTag());
 914   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 915   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 916   Record.push_back(N->getLine());
 917   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 918   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
 919   Record.push_back(N->getSizeInBits());
 920   Record.push_back(N->getAlignInBits());
 921   Record.push_back(N->getOffsetInBits());
 922   Record.push_back(N->getFlags());
 923   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
 924
 925   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
 926   Record.clear();
 927 }
 928
 929 static void WriteDICompositeType(const DICompositeType *N,
 930                                  const ValueEnumerator &VE,
 931                                  BitstreamWriter &Stream,
 932                                  SmallVectorImpl<uint64_t> &Record,
 933                                  unsigned Abbrev) {
 934   Record.push_back(N->isDistinct());
 935   Record.push_back(N->getTag());
 936   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 937   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 938   Record.push_back(N->getLine());
 939   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 940   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
 941   Record.push_back(N->getSizeInBits());
 942   Record.push_back(N->getAlignInBits());
 943   Record.push_back(N->getOffsetInBits());
 944   Record.push_back(N->getFlags());
 945   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
 946   Record.push_back(N->getRuntimeLang());
 947   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
 948   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
 949   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
 950
 951   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
 952   Record.clear();
 953 }
 954
 955 static void WriteDISubroutineType(const DISubroutineType *N,
 956                                   const ValueEnumerator &VE,
 957                                   BitstreamWriter &Stream,
 958                                   SmallVectorImpl<uint64_t> &Record,
 959                                   unsigned Abbrev) {
 960   Record.push_back(N->isDistinct());
 961   Record.push_back(N->getFlags());
 962   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
 963
 964   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
 965   Record.clear();
 966 }
 967
 968 static void WriteDIFile(const DIFile *N, const ValueEnumerator &VE,
 969                         BitstreamWriter &Stream,
 970                         SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
 971   Record.push_back(N->isDistinct());
 972   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
 973   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
 974
 975   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
 976   Record.clear();
 977 }
 978
 979 static void WriteDICompileUnit(const DICompileUnit *N,
 980                                const ValueEnumerator &VE,
 981                                BitstreamWriter &Stream,
 982                                SmallVectorImpl<uint64_t> &Record,
 983                                unsigned Abbrev) {
 984   assert(N->isDistinct() && "Expected distinct compile units");
 985   Record.push_back(/* IsDistinct */ true);
 986   Record.push_back(N->getSourceLanguage());
 987   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 988   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
 989   Record.push_back(N->isOptimized());
 990   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
 991   Record.push_back(N->getRuntimeVersion());
 992   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
 993   Record.push_back(N->getEmissionKind());
 994   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
 995   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
 996   Record.push_back(VE.getMetadataOrNullID(N->getSubprograms().get()));
 997   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
 998   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
 999   Record.push_back(N->getDWOId());
1000
1001   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
1002   Record.clear();
1003 }
1004
1005 static void WriteDISubprogram(const DISubprogram *N, const ValueEnumerator &VE,
1006                               BitstreamWriter &Stream,
1007                               SmallVectorImpl<uint64_t> &Record,
1008                               unsigned Abbrev) {
1009   Record.push_back(N->isDistinct());
1010   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1011   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1012   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1013   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1014   Record.push_back(N->getLine());
1015   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1016   Record.push_back(N->isLocalToUnit());
1017   Record.push_back(N->isDefinition());
1018   Record.push_back(N->getScopeLine());
1019   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
1020   Record.push_back(N->getVirtuality());
1021   Record.push_back(N->getVirtualIndex());
1022   Record.push_back(N->getFlags());
1023   Record.push_back(N->isOptimized());
1024   Record.push_back(VE.getMetadataOrNullID(N->getRawFunction()));
1025   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
1026   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
1027   Record.push_back(VE.getMetadataOrNullID(N->getVariables().get()));
1028
1029   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
1030   Record.clear();
1031 }
1032
1033 static void WriteDILexicalBlock(const DILexicalBlock *N,
1034                                 const ValueEnumerator &VE,
1035                                 BitstreamWriter &Stream,
1036                                 SmallVectorImpl<uint64_t> &Record,
1037                                 unsigned Abbrev) {
1038   Record.push_back(N->isDistinct());
1039   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1040   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1041   Record.push_back(N->getLine());
1042   Record.push_back(N->getColumn());
1043
1044   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
1045   Record.clear();
1046 }
1047
1048 static void WriteDILexicalBlockFile(const DILexicalBlockFile *N,
1049                                     const ValueEnumerator &VE,
1050                                     BitstreamWriter &Stream,
1051                                     SmallVectorImpl<uint64_t> &Record,
1052                                     unsigned Abbrev) {
1053   Record.push_back(N->isDistinct());
1054   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1055   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1056   Record.push_back(N->getDiscriminator());
1057
1058   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
1059   Record.clear();
1060 }
1061
1062 static void WriteDINamespace(const DINamespace *N, const ValueEnumerator &VE,
1063                              BitstreamWriter &Stream,
1064                              SmallVectorImpl<uint64_t> &Record,
1065                              unsigned Abbrev) {
1066   Record.push_back(N->isDistinct());
1067   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1068   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1069   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1070   Record.push_back(N->getLine());
1071
1072   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
1073   Record.clear();
1074 }
1075
1076 static void WriteDIModule(const DIModule *N, const ValueEnumerator &VE,
1077                           BitstreamWriter &Stream,
1078                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
1079   Record.push_back(N->isDistinct());
1080   for (auto &I : N->operands())
1081     Record.push_back(VE.getMetadataOrNullID(I));
1082
1083   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
1084   Record.clear();
1085 }
1086
1087 static void WriteDITemplateTypeParameter(const DITemplateTypeParameter *N,
1088                                          const ValueEnumerator &VE,
1089                                          BitstreamWriter &Stream,
1090                                          SmallVectorImpl<uint64_t> &Record,
1091                                          unsigned Abbrev) {
1092   Record.push_back(N->isDistinct());
1093   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1094   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1095
1096   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
1097   Record.clear();
1098 }
1099
1100 static void WriteDITemplateValueParameter(const DITemplateValueParameter *N,
1101                                           const ValueEnumerator &VE,
1102                                           BitstreamWriter &Stream,
1103                                           SmallVectorImpl<uint64_t> &Record,
1104                                           unsigned Abbrev) {
1105   Record.push_back(N->isDistinct());
1106   Record.push_back(N->getTag());
1107   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1108   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1109   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
1110
1111   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
1112   Record.clear();
1113 }
1114
1115 static void WriteDIGlobalVariable(const DIGlobalVariable *N,
1116                                   const ValueEnumerator &VE,
1117                                   BitstreamWriter &Stream,
1118                                   SmallVectorImpl<uint64_t> &Record,
1119                                   unsigned Abbrev) {
1120   Record.push_back(N->isDistinct());
1121   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1122   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1123   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1124   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1125   Record.push_back(N->getLine());
1126   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1127   Record.push_back(N->isLocalToUnit());
1128   Record.push_back(N->isDefinition());
1129   Record.push_back(VE.getMetadataOrNullID(N->getRawVariable()));
1130   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
1131
1132   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
1133   Record.clear();
1134 }
1135
1136 static void WriteDILocalVariable(const DILocalVariable *N,
1137                                  const ValueEnumerator &VE,
1138                                  BitstreamWriter &Stream,
1139                                  SmallVectorImpl<uint64_t> &Record,
1140                                  unsigned Abbrev) {
1141   Record.push_back(N->isDistinct());
1142   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1143   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1144   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1145   Record.push_back(N->getLine());
1146   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1147   Record.push_back(N->getArg());
1148   Record.push_back(N->getFlags());
1149
1150   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
1151   Record.clear();
1152 }
1153
1154 static void WriteDIExpression(const DIExpression *N, const ValueEnumerator &,
1155                               BitstreamWriter &Stream,
1156                               SmallVectorImpl<uint64_t> &Record,
1157                               unsigned Abbrev) {
1158   Record.reserve(N->getElements().size() + 1);
1159
1160   Record.push_back(N->isDistinct());
1161   Record.append(N->elements_begin(), N->elements_end());
1162
1163   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
1164   Record.clear();
1165 }
1166
1167 static void WriteDIObjCProperty(const DIObjCProperty *N,
1168                                 const ValueEnumerator &VE,
1169                                 BitstreamWriter &Stream,
1170                                 SmallVectorImpl<uint64_t> &Record,
1171                                 unsigned Abbrev) {
1172   Record.push_back(N->isDistinct());
1173   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1174   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1175   Record.push_back(N->getLine());
1176   Record.push_back(VE.getMetadataOrNullID(N->getRawSetterName()));
1177   Record.push_back(VE.getMetadataOrNullID(N->getRawGetterName()));
1178   Record.push_back(N->getAttributes());
1179   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1180
1181   Stream.EmitRecord(bitc::METADATA_OBJC_PROPERTY, Record, Abbrev);
1182   Record.clear();
1183 }
1184
1185 static void WriteDIImportedEntity(const DIImportedEntity *N,
1186                                   const ValueEnumerator &VE,
1187                                   BitstreamWriter &Stream,
1188                                   SmallVectorImpl<uint64_t> &Record,
1189                                   unsigned Abbrev) {
1190   Record.push_back(N->isDistinct());
1191   Record.push_back(N->getTag());
1192   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1193   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
1194   Record.push_back(N->getLine());
1195   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1196
1197   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
1198   Record.clear();
1199 }
1200
1201 static void WriteModuleMetadata(const Module *M,
1202                                 const ValueEnumerator &VE,
1203                                 BitstreamWriter &Stream) {
1204   const auto &MDs = VE.getMDs();
1205   if (MDs.empty() && M->named_metadata_empty())
1206     return;
1207
1208   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1209
1210   unsigned MDSAbbrev = 0;
1211   if (VE.hasMDString()) {
1212     // Abbrev for METADATA_STRING.
1213     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1214     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
1215     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1216     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1217     MDSAbbrev = Stream.EmitAbbrev(Abbv);
1218   }
1219
1220   // Initialize MDNode abbreviations.
1221 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
1222 #include "llvm/IR/Metadata.def"
1223
1224   if (VE.hasDILocation()) {
1225     // Abbrev for METADATA_LOCATION.
1226     //
1227     // Assume the column is usually under 128, and always output the inlined-at
1228     // location (it's never more expensive than building an array size 1).
1229     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1230     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1231     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1232     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1233     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1234     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1235     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1236     DILocationAbbrev = Stream.EmitAbbrev(Abbv);
1237   }
1238
1239   if (VE.hasGenericDINode()) {
1240     // Abbrev for METADATA_GENERIC_DEBUG.
1241     //
1242     // Assume the column is usually under 128, and always output the inlined-at
1243     // location (it's never more expensive than building an array size 1).
1244     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1245     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1246     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1247     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1248     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1249     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1250     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1251     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1252     GenericDINodeAbbrev = Stream.EmitAbbrev(Abbv);
1253   }
1254
1255   unsigned NameAbbrev = 0;
1256   if (!M->named_metadata_empty()) {
1257     // Abbrev for METADATA_NAME.
1258     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1259     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
1260     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1261     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1262     NameAbbrev = Stream.EmitAbbrev(Abbv);
1263   }
1264
1265   SmallVector<uint64_t, 64> Record;
1266   for (const Metadata *MD : MDs) {
1267     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
1268       assert(N->isResolved() && "Expected forward references to be resolved");
1269
1270       switch (N->getMetadataID()) {
1271       default:
1272         llvm_unreachable("Invalid MDNode subclass");
1273 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
1274   case Metadata::CLASS##Kind:                                                  \
1275     Write##CLASS(cast<CLASS>(N), VE, Stream, Record, CLASS##Abbrev);           \
1276     continue;
1277 #include "llvm/IR/Metadata.def"
1278       }
1279     }
1280     if (const auto *MDC = dyn_cast<ConstantAsMetadata>(MD)) {
1281       WriteValueAsMetadata(MDC, VE, Stream, Record);
1282       continue;
1283     }
1284     const MDString *MDS = cast<MDString>(MD);
1285     // Code: [strchar x N]
1286     Record.append(MDS->bytes_begin(), MDS->bytes_end());
1287
1288     // Emit the finished record.
1289     Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
1290     Record.clear();
1291   }
1292
1293   // Write named metadata.
1294   for (const NamedMDNode &NMD : M->named_metadata()) {
1295     // Write name.
1296     StringRef Str = NMD.getName();
1297     Record.append(Str.bytes_begin(), Str.bytes_end());
1298     Stream.EmitRecord(bitc::METADATA_NAME, Record, NameAbbrev);
1299     Record.clear();
1300
1301     // Write named metadata operands.
1302     for (const MDNode *N : NMD.operands())
1303       Record.push_back(VE.getMetadataID(N));
1304     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
1305     Record.clear();
1306   }
1307
1308   Stream.ExitBlock();
1309 }
1310
1311 static void WriteFunctionLocalMetadata(const Function &F,
1312                                        const ValueEnumerator &VE,
1313                                        BitstreamWriter &Stream) {
1314   bool StartedMetadataBlock = false;
1315   SmallVector<uint64_t, 64> Record;
1316   const SmallVectorImpl<const LocalAsMetadata *> &MDs =
1317       VE.getFunctionLocalMDs();
1318   for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1319     assert(MDs[i] && "Expected valid function-local metadata");
1320     if (!StartedMetadataBlock) {
1321       Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1322       StartedMetadataBlock = true;
1323     }
1324     WriteValueAsMetadata(MDs[i], VE, Stream, Record);
1325   }
1326
1327   if (StartedMetadataBlock)
1328     Stream.ExitBlock();
1329 }
1330
1331 static void WriteMetadataAttachment(const Function &F,
1332                                     const ValueEnumerator &VE,
1333                                     BitstreamWriter &Stream) {
1334   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
1335
1336   SmallVector<uint64_t, 64> Record;
1337
1338   // Write metadata attachments
1339   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
1340   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
1341   F.getAllMetadata(MDs);
1342   if (!MDs.empty()) {
1343     for (const auto &I : MDs) {
1344       Record.push_back(I.first);
1345       Record.push_back(VE.getMetadataID(I.second));
1346     }
1347     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1348     Record.clear();
1349   }
1350
1351   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1352     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1353          I != E; ++I) {
1354       MDs.clear();
1355       I->getAllMetadataOtherThanDebugLoc(MDs);
1356
1357       // If no metadata, ignore instruction.
1358       if (MDs.empty()) continue;
1359
1360       Record.push_back(VE.getInstructionID(I));
1361
1362       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1363         Record.push_back(MDs[i].first);
1364         Record.push_back(VE.getMetadataID(MDs[i].second));
1365       }
1366       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1367       Record.clear();
1368     }
1369
1370   Stream.ExitBlock();
1371 }
1372
1373 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
1374   SmallVector<uint64_t, 64> Record;
1375
1376   // Write metadata kinds
1377   // METADATA_KIND - [n x [id, name]]
1378   SmallVector<StringRef, 8> Names;
1379   M->getMDKindNames(Names);
1380
1381   if (Names.empty()) return;
1382
1383   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1384
1385   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
1386     Record.push_back(MDKindID);
1387     StringRef KName = Names[MDKindID];
1388     Record.append(KName.begin(), KName.end());
1389
1390     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
1391     Record.clear();
1392   }
1393
1394   Stream.ExitBlock();
1395 }
1396
1397 static void WriteOperandBundleTags(const Module *M, BitstreamWriter &Stream) {
1398   // Write metadata kinds
1399   //
1400   // OPERAND_BUNDLE_TAGS_BLOCK_ID : N x OPERAND_BUNDLE_TAG
1401   //
1402   // OPERAND_BUNDLE_TAG - [strchr x N]
1403
1404   SmallVector<StringRef, 8> Tags;
1405   M->getOperandBundleTags(Tags);
1406
1407   if (Tags.empty())
1408     return;
1409
1410   Stream.EnterSubblock(bitc::OPERAND_BUNDLE_TAGS_BLOCK_ID, 3);
1411
1412   SmallVector<uint64_t, 64> Record;
1413
1414   for (auto Tag : Tags) {
1415     Record.append(Tag.begin(), Tag.end());
1416
1417     Stream.EmitRecord(bitc::OPERAND_BUNDLE_TAG, Record, 0);
1418     Record.clear();
1419   }
1420
1421   Stream.ExitBlock();
1422 }
1423
1424 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
1425   if ((int64_t)V >= 0)
1426     Vals.push_back(V << 1);
1427   else
1428     Vals.push_back((-V << 1) | 1);
1429 }
1430
1431 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
1432                            const ValueEnumerator &VE,
1433                            BitstreamWriter &Stream, bool isGlobal) {
1434   if (FirstVal == LastVal) return;
1435
1436   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
1437
1438   unsigned AggregateAbbrev = 0;
1439   unsigned String8Abbrev = 0;
1440   unsigned CString7Abbrev = 0;
1441   unsigned CString6Abbrev = 0;
1442   // If this is a constant pool for the module, emit module-specific abbrevs.
1443   if (isGlobal) {
1444     // Abbrev for CST_CODE_AGGREGATE.
1445     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1446     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
1447     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1448     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
1449     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
1450
1451     // Abbrev for CST_CODE_STRING.
1452     Abbv = new BitCodeAbbrev();
1453     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
1454     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1455     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1456     String8Abbrev = Stream.EmitAbbrev(Abbv);
1457     // Abbrev for CST_CODE_CSTRING.
1458     Abbv = new BitCodeAbbrev();
1459     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1460     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1461     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1462     CString7Abbrev = Stream.EmitAbbrev(Abbv);
1463     // Abbrev for CST_CODE_CSTRING.
1464     Abbv = new BitCodeAbbrev();
1465     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1466     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1467     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1468     CString6Abbrev = Stream.EmitAbbrev(Abbv);
1469   }
1470
1471   SmallVector<uint64_t, 64> Record;
1472
1473   const ValueEnumerator::ValueList &Vals = VE.getValues();
1474   Type *LastTy = nullptr;
1475   for (unsigned i = FirstVal; i != LastVal; ++i) {
1476     const Value *V = Vals[i].first;
1477     // If we need to switch types, do so now.
1478     if (V->getType() != LastTy) {
1479       LastTy = V->getType();
1480       Record.push_back(VE.getTypeID(LastTy));
1481       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
1482                         CONSTANTS_SETTYPE_ABBREV);
1483       Record.clear();
1484     }
1485
1486     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
1487       Record.push_back(unsigned(IA->hasSideEffects()) |
1488                        unsigned(IA->isAlignStack()) << 1 |
1489                        unsigned(IA->getDialect()&1) << 2);
1490
1491       // Add the asm string.
1492       const std::string &AsmStr = IA->getAsmString();
1493       Record.push_back(AsmStr.size());
1494       Record.append(AsmStr.begin(), AsmStr.end());
1495
1496       // Add the constraint string.
1497       const std::string &ConstraintStr = IA->getConstraintString();
1498       Record.push_back(ConstraintStr.size());
1499       Record.append(ConstraintStr.begin(), ConstraintStr.end());
1500       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
1501       Record.clear();
1502       continue;
1503     }
1504     const Constant *C = cast<Constant>(V);
1505     unsigned Code = -1U;
1506     unsigned AbbrevToUse = 0;
1507     if (C->isNullValue()) {
1508       Code = bitc::CST_CODE_NULL;
1509     } else if (isa<UndefValue>(C)) {
1510       Code = bitc::CST_CODE_UNDEF;
1511     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
1512       if (IV->getBitWidth() <= 64) {
1513         uint64_t V = IV->getSExtValue();
1514         emitSignedInt64(Record, V);
1515         Code = bitc::CST_CODE_INTEGER;
1516         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
1517       } else {                             // Wide integers, > 64 bits in size.
1518         // We have an arbitrary precision integer value to write whose
1519         // bit width is > 64. However, in canonical unsigned integer
1520         // format it is likely that the high bits are going to be zero.
1521         // So, we only write the number of active words.
1522         unsigned NWords = IV->getValue().getActiveWords();
1523         const uint64_t *RawWords = IV->getValue().getRawData();
1524         for (unsigned i = 0; i != NWords; ++i) {
1525           emitSignedInt64(Record, RawWords[i]);
1526         }
1527         Code = bitc::CST_CODE_WIDE_INTEGER;
1528       }
1529     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
1530       Code = bitc::CST_CODE_FLOAT;
1531       Type *Ty = CFP->getType();
1532       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
1533         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
1534       } else if (Ty->isX86_FP80Ty()) {
1535         // api needed to prevent premature destruction
1536         // bits are not in the same order as a normal i80 APInt, compensate.
1537         APInt api = CFP->getValueAPF().bitcastToAPInt();
1538         const uint64_t *p = api.getRawData();
1539         Record.push_back((p[1] << 48) | (p[0] >> 16));
1540         Record.push_back(p[0] & 0xffffLL);
1541       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
1542         APInt api = CFP->getValueAPF().bitcastToAPInt();
1543         const uint64_t *p = api.getRawData();
1544         Record.push_back(p[0]);
1545         Record.push_back(p[1]);
1546       } else {
1547         assert (0 && "Unknown FP type!");
1548       }
1549     } else if (isa<ConstantDataSequential>(C) &&
1550                cast<ConstantDataSequential>(C)->isString()) {
1551       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
1552       // Emit constant strings specially.
1553       unsigned NumElts = Str->getNumElements();
1554       // If this is a null-terminated string, use the denser CSTRING encoding.
1555       if (Str->isCString()) {
1556         Code = bitc::CST_CODE_CSTRING;
1557         --NumElts;  // Don't encode the null, which isn't allowed by char6.
1558       } else {
1559         Code = bitc::CST_CODE_STRING;
1560         AbbrevToUse = String8Abbrev;
1561       }
1562       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
1563       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
1564       for (unsigned i = 0; i != NumElts; ++i) {
1565         unsigned char V = Str->getElementAsInteger(i);
1566         Record.push_back(V);
1567         isCStr7 &= (V & 128) == 0;
1568         if (isCStrChar6)
1569           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
1570       }
1571
1572       if (isCStrChar6)
1573         AbbrevToUse = CString6Abbrev;
1574       else if (isCStr7)
1575         AbbrevToUse = CString7Abbrev;
1576     } else if (const ConstantDataSequential *CDS =
1577                   dyn_cast<ConstantDataSequential>(C)) {
1578       Code = bitc::CST_CODE_DATA;
1579       Type *EltTy = CDS->getType()->getElementType();
1580       if (isa<IntegerType>(EltTy)) {
1581         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
1582           Record.push_back(CDS->getElementAsInteger(i));
1583       } else if (EltTy->isFloatTy()) {
1584         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1585           union { float F; uint32_t I; };
1586           F = CDS->getElementAsFloat(i);
1587           Record.push_back(I);
1588         }
1589       } else {
1590         assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
1591         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1592           union { double F; uint64_t I; };
1593           F = CDS->getElementAsDouble(i);
1594           Record.push_back(I);
1595         }
1596       }
1597     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
1598                isa<ConstantVector>(C)) {
1599       Code = bitc::CST_CODE_AGGREGATE;
1600       for (const Value *Op : C->operands())
1601         Record.push_back(VE.getValueID(Op));
1602       AbbrevToUse = AggregateAbbrev;
1603     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
1604       switch (CE->getOpcode()) {
1605       default:
1606         if (Instruction::isCast(CE->getOpcode())) {
1607           Code = bitc::CST_CODE_CE_CAST;
1608           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
1609           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1610           Record.push_back(VE.getValueID(C->getOperand(0)));
1611           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
1612         } else {
1613           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
1614           Code = bitc::CST_CODE_CE_BINOP;
1615           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
1616           Record.push_back(VE.getValueID(C->getOperand(0)));
1617           Record.push_back(VE.getValueID(C->getOperand(1)));
1618           uint64_t Flags = GetOptimizationFlags(CE);
1619           if (Flags != 0)
1620             Record.push_back(Flags);
1621         }
1622         break;
1623       case Instruction::GetElementPtr: {
1624         Code = bitc::CST_CODE_CE_GEP;
1625         const auto *GO = cast<GEPOperator>(C);
1626         if (GO->isInBounds())
1627           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
1628         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
1629         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
1630           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
1631           Record.push_back(VE.getValueID(C->getOperand(i)));
1632         }
1633         break;
1634       }
1635       case Instruction::Select:
1636         Code = bitc::CST_CODE_CE_SELECT;
1637         Record.push_back(VE.getValueID(C->getOperand(0)));
1638         Record.push_back(VE.getValueID(C->getOperand(1)));
1639         Record.push_back(VE.getValueID(C->getOperand(2)));
1640         break;
1641       case Instruction::ExtractElement:
1642         Code = bitc::CST_CODE_CE_EXTRACTELT;
1643         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1644         Record.push_back(VE.getValueID(C->getOperand(0)));
1645         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
1646         Record.push_back(VE.getValueID(C->getOperand(1)));
1647         break;
1648       case Instruction::InsertElement:
1649         Code = bitc::CST_CODE_CE_INSERTELT;
1650         Record.push_back(VE.getValueID(C->getOperand(0)));
1651         Record.push_back(VE.getValueID(C->getOperand(1)));
1652         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
1653         Record.push_back(VE.getValueID(C->getOperand(2)));
1654         break;
1655       case Instruction::ShuffleVector:
1656         // If the return type and argument types are the same, this is a
1657         // standard shufflevector instruction.  If the types are different,
1658         // then the shuffle is widening or truncating the input vectors, and
1659         // the argument type must also be encoded.
1660         if (C->getType() == C->getOperand(0)->getType()) {
1661           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
1662         } else {
1663           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
1664           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1665         }
1666         Record.push_back(VE.getValueID(C->getOperand(0)));
1667         Record.push_back(VE.getValueID(C->getOperand(1)));
1668         Record.push_back(VE.getValueID(C->getOperand(2)));
1669         break;
1670       case Instruction::ICmp:
1671       case Instruction::FCmp:
1672         Code = bitc::CST_CODE_CE_CMP;
1673         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1674         Record.push_back(VE.getValueID(C->getOperand(0)));
1675         Record.push_back(VE.getValueID(C->getOperand(1)));
1676         Record.push_back(CE->getPredicate());
1677         break;
1678       }
1679     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
1680       Code = bitc::CST_CODE_BLOCKADDRESS;
1681       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
1682       Record.push_back(VE.getValueID(BA->getFunction()));
1683       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
1684     } else {
1685 #ifndef NDEBUG
1686       C->dump();
1687 #endif
1688       llvm_unreachable("Unknown constant!");
1689     }
1690     Stream.EmitRecord(Code, Record, AbbrevToUse);
1691     Record.clear();
1692   }
1693
1694   Stream.ExitBlock();
1695 }
1696
1697 static void WriteModuleConstants(const ValueEnumerator &VE,
1698                                  BitstreamWriter &Stream) {
1699   const ValueEnumerator::ValueList &Vals = VE.getValues();
1700
1701   // Find the first constant to emit, which is the first non-globalvalue value.
1702   // We know globalvalues have been emitted by WriteModuleInfo.
1703   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1704     if (!isa<GlobalValue>(Vals[i].first)) {
1705       WriteConstants(i, Vals.size(), VE, Stream, true);
1706       return;
1707     }
1708   }
1709 }
1710
1711 /// PushValueAndType - The file has to encode both the value and type id for
1712 /// many values, because we need to know what type to create for forward
1713 /// references.  However, most operands are not forward references, so this type
1714 /// field is not needed.
1715 ///
1716 /// This function adds V's value ID to Vals.  If the value ID is higher than the
1717 /// instruction ID, then it is a forward reference, and it also includes the
1718 /// type ID.  The value ID that is written is encoded relative to the InstID.
1719 static bool PushValueAndType(const Value *V, unsigned InstID,
1720                              SmallVectorImpl<unsigned> &Vals,
1721                              ValueEnumerator &VE) {
1722   unsigned ValID = VE.getValueID(V);
1723   // Make encoding relative to the InstID.
1724   Vals.push_back(InstID - ValID);
1725   if (ValID >= InstID) {
1726     Vals.push_back(VE.getTypeID(V->getType()));
1727     return true;
1728   }
1729   return false;
1730 }
1731
1732 static void WriteOperandBundles(BitstreamWriter &Stream, ImmutableCallSite CS,
1733                                 unsigned InstID, ValueEnumerator &VE) {
1734   SmallVector<unsigned, 64> Record;
1735   LLVMContext &C = CS.getInstruction()->getContext();
1736
1737   for (unsigned i = 0, e = CS.getNumOperandBundles(); i != e; ++i) {
1738     const auto &Bundle = CS.getOperandBundle(i);
1739     Record.push_back(C.getOperandBundleTagID(Bundle.Tag));
1740
1741     for (auto &Input : Bundle.Inputs)
1742       PushValueAndType(Input, InstID, Record, VE);
1743
1744     Stream.EmitRecord(bitc::FUNC_CODE_OPERAND_BUNDLE, Record);
1745     Record.clear();
1746   }
1747 }
1748
1749 /// pushValue - Like PushValueAndType, but where the type of the value is
1750 /// omitted (perhaps it was already encoded in an earlier operand).
1751 static void pushValue(const Value *V, unsigned InstID,
1752                       SmallVectorImpl<unsigned> &Vals,
1753                       ValueEnumerator &VE) {
1754   unsigned ValID = VE.getValueID(V);
1755   Vals.push_back(InstID - ValID);
1756 }
1757
1758 static void pushValueSigned(const Value *V, unsigned InstID,
1759                             SmallVectorImpl<uint64_t> &Vals,
1760                             ValueEnumerator &VE) {
1761   unsigned ValID = VE.getValueID(V);
1762   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
1763   emitSignedInt64(Vals, diff);
1764 }
1765
1766 /// WriteInstruction - Emit an instruction to the specified stream.
1767 static void WriteInstruction(const Instruction &I, unsigned InstID,
1768                              ValueEnumerator &VE, BitstreamWriter &Stream,
1769                              SmallVectorImpl<unsigned> &Vals) {
1770   unsigned Code = 0;
1771   unsigned AbbrevToUse = 0;
1772   VE.setInstructionID(&I);
1773   switch (I.getOpcode()) {
1774   default:
1775     if (Instruction::isCast(I.getOpcode())) {
1776       Code = bitc::FUNC_CODE_INST_CAST;
1777       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1778         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1779       Vals.push_back(VE.getTypeID(I.getType()));
1780       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1781     } else {
1782       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1783       Code = bitc::FUNC_CODE_INST_BINOP;
1784       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1785         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1786       pushValue(I.getOperand(1), InstID, Vals, VE);
1787       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1788       uint64_t Flags = GetOptimizationFlags(&I);
1789       if (Flags != 0) {
1790         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1791           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1792         Vals.push_back(Flags);
1793       }
1794     }
1795     break;
1796
1797   case Instruction::GetElementPtr: {
1798     Code = bitc::FUNC_CODE_INST_GEP;
1799     AbbrevToUse = FUNCTION_INST_GEP_ABBREV;
1800     auto &GEPInst = cast<GetElementPtrInst>(I);
1801     Vals.push_back(GEPInst.isInBounds());
1802     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
1803     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1804       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1805     break;
1806   }
1807   case Instruction::ExtractValue: {
1808     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1809     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1810     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1811     Vals.append(EVI->idx_begin(), EVI->idx_end());
1812     break;
1813   }
1814   case Instruction::InsertValue: {
1815     Code = bitc::FUNC_CODE_INST_INSERTVAL;
1816     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1817     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1818     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1819     Vals.append(IVI->idx_begin(), IVI->idx_end());
1820     break;
1821   }
1822   case Instruction::Select:
1823     Code = bitc::FUNC_CODE_INST_VSELECT;
1824     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1825     pushValue(I.getOperand(2), InstID, Vals, VE);
1826     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1827     break;
1828   case Instruction::ExtractElement:
1829     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1830     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1831     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1832     break;
1833   case Instruction::InsertElement:
1834     Code = bitc::FUNC_CODE_INST_INSERTELT;
1835     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1836     pushValue(I.getOperand(1), InstID, Vals, VE);
1837     PushValueAndType(I.getOperand(2), InstID, Vals, VE);
1838     break;
1839   case Instruction::ShuffleVector:
1840     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1841     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1842     pushValue(I.getOperand(1), InstID, Vals, VE);
1843     pushValue(I.getOperand(2), InstID, Vals, VE);
1844     break;
1845   case Instruction::ICmp:
1846   case Instruction::FCmp: {
1847     // compare returning Int1Ty or vector of Int1Ty
1848     Code = bitc::FUNC_CODE_INST_CMP2;
1849     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1850     pushValue(I.getOperand(1), InstID, Vals, VE);
1851     Vals.push_back(cast<CmpInst>(I).getPredicate());
1852     uint64_t Flags = GetOptimizationFlags(&I);
1853     if (Flags != 0)
1854       Vals.push_back(Flags);
1855     break;
1856   }
1857
1858   case Instruction::Ret:
1859     {
1860       Code = bitc::FUNC_CODE_INST_RET;
1861       unsigned NumOperands = I.getNumOperands();
1862       if (NumOperands == 0)
1863         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1864       else if (NumOperands == 1) {
1865         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1866           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1867       } else {
1868         for (unsigned i = 0, e = NumOperands; i != e; ++i)
1869           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1870       }
1871     }
1872     break;
1873   case Instruction::Br:
1874     {
1875       Code = bitc::FUNC_CODE_INST_BR;
1876       const BranchInst &II = cast<BranchInst>(I);
1877       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1878       if (II.isConditional()) {
1879         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1880         pushValue(II.getCondition(), InstID, Vals, VE);
1881       }
1882     }
1883     break;
1884   case Instruction::Switch:
1885     {
1886       Code = bitc::FUNC_CODE_INST_SWITCH;
1887       const SwitchInst &SI = cast<SwitchInst>(I);
1888       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
1889       pushValue(SI.getCondition(), InstID, Vals, VE);
1890       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
1891       for (SwitchInst::ConstCaseIt i = SI.case_begin(), e = SI.case_end();
1892            i != e; ++i) {
1893         Vals.push_back(VE.getValueID(i.getCaseValue()));
1894         Vals.push_back(VE.getValueID(i.getCaseSuccessor()));
1895       }
1896     }
1897     break;
1898   case Instruction::IndirectBr:
1899     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1900     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1901     // Encode the address operand as relative, but not the basic blocks.
1902     pushValue(I.getOperand(0), InstID, Vals, VE);
1903     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
1904       Vals.push_back(VE.getValueID(I.getOperand(i)));
1905     break;
1906
1907   case Instruction::Invoke: {
1908     const InvokeInst *II = cast<InvokeInst>(&I);
1909     const Value *Callee = II->getCalledValue();
1910     FunctionType *FTy = II->getFunctionType();
1911
1912     if (II->hasOperandBundles())
1913       WriteOperandBundles(Stream, II, InstID, VE);
1914
1915     Code = bitc::FUNC_CODE_INST_INVOKE;
1916
1917     Vals.push_back(VE.getAttributeID(II->getAttributes()));
1918     Vals.push_back(II->getCallingConv() | 1 << 13);
1919     Vals.push_back(VE.getValueID(II->getNormalDest()));
1920     Vals.push_back(VE.getValueID(II->getUnwindDest()));
1921     Vals.push_back(VE.getTypeID(FTy));
1922     PushValueAndType(Callee, InstID, Vals, VE);
1923
1924     // Emit value #'s for the fixed parameters.
1925     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1926       pushValue(I.getOperand(i), InstID, Vals, VE);  // fixed param.
1927
1928     // Emit type/value pairs for varargs params.
1929     if (FTy->isVarArg()) {
1930       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1931            i != e; ++i)
1932         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1933     }
1934     break;
1935   }
1936   case Instruction::Resume:
1937     Code = bitc::FUNC_CODE_INST_RESUME;
1938     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1939     break;
1940   case Instruction::CleanupRet: {
1941     Code = bitc::FUNC_CODE_INST_CLEANUPRET;
1942     const auto &CRI = cast<CleanupReturnInst>(I);
1943     pushValue(CRI.getCleanupPad(), InstID, Vals, VE);
1944     if (CRI.hasUnwindDest())
1945       Vals.push_back(VE.getValueID(CRI.getUnwindDest()));
1946     break;
1947   }
1948   case Instruction::CatchRet: {
1949     Code = bitc::FUNC_CODE_INST_CATCHRET;
1950     const auto &CRI = cast<CatchReturnInst>(I);
1951     pushValue(CRI.getCatchPad(), InstID, Vals, VE);
1952     Vals.push_back(VE.getValueID(CRI.getSuccessor()));
1953     break;
1954   }
1955   case Instruction::CatchPad: {
1956     Code = bitc::FUNC_CODE_INST_CATCHPAD;
1957     const auto &CPI = cast<CatchPadInst>(I);
1958     Vals.push_back(VE.getValueID(CPI.getNormalDest()));
1959     Vals.push_back(VE.getValueID(CPI.getUnwindDest()));
1960     unsigned NumArgOperands = CPI.getNumArgOperands();
1961     Vals.push_back(NumArgOperands);
1962     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
1963       PushValueAndType(CPI.getArgOperand(Op), InstID, Vals, VE);
1964     break;
1965   }
1966   case Instruction::TerminatePad: {
1967     Code = bitc::FUNC_CODE_INST_TERMINATEPAD;
1968     const auto &TPI = cast<TerminatePadInst>(I);
1969     Vals.push_back(TPI.hasUnwindDest());
1970     if (TPI.hasUnwindDest())
1971       Vals.push_back(VE.getValueID(TPI.getUnwindDest()));
1972     unsigned NumArgOperands = TPI.getNumArgOperands();
1973     Vals.push_back(NumArgOperands);
1974     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
1975       PushValueAndType(TPI.getArgOperand(Op), InstID, Vals, VE);
1976     break;
1977   }
1978   case Instruction::CleanupPad: {
1979     Code = bitc::FUNC_CODE_INST_CLEANUPPAD;
1980     const auto &CPI = cast<CleanupPadInst>(I);
1981     unsigned NumOperands = CPI.getNumOperands();
1982     Vals.push_back(NumOperands);
1983     for (unsigned Op = 0; Op != NumOperands; ++Op)
1984       PushValueAndType(CPI.getOperand(Op), InstID, Vals, VE);
1985     break;
1986   }
1987   case Instruction::CatchEndPad: {
1988     Code = bitc::FUNC_CODE_INST_CATCHENDPAD;
1989     const auto &CEPI = cast<CatchEndPadInst>(I);
1990     if (CEPI.hasUnwindDest())
1991       Vals.push_back(VE.getValueID(CEPI.getUnwindDest()));
1992     break;
1993   }
1994   case Instruction::CleanupEndPad: {
1995     Code = bitc::FUNC_CODE_INST_CLEANUPENDPAD;
1996     const auto &CEPI = cast<CleanupEndPadInst>(I);
1997     pushValue(CEPI.getCleanupPad(), InstID, Vals, VE);
1998     if (CEPI.hasUnwindDest())
1999       Vals.push_back(VE.getValueID(CEPI.getUnwindDest()));
2000     break;
2001   }
2002   case Instruction::Unreachable:
2003     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
2004     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
2005     break;
2006
2007   case Instruction::PHI: {
2008     const PHINode &PN = cast<PHINode>(I);
2009     Code = bitc::FUNC_CODE_INST_PHI;
2010     // With the newer instruction encoding, forward references could give
2011     // negative valued IDs.  This is most common for PHIs, so we use
2012     // signed VBRs.
2013     SmallVector<uint64_t, 128> Vals64;
2014     Vals64.push_back(VE.getTypeID(PN.getType()));
2015     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
2016       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64, VE);
2017       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
2018     }
2019     // Emit a Vals64 vector and exit.
2020     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
2021     Vals64.clear();
2022     return;
2023   }
2024
2025   case Instruction::LandingPad: {
2026     const LandingPadInst &LP = cast<LandingPadInst>(I);
2027     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
2028     Vals.push_back(VE.getTypeID(LP.getType()));
2029     Vals.push_back(LP.isCleanup());
2030     Vals.push_back(LP.getNumClauses());
2031     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
2032       if (LP.isCatch(I))
2033         Vals.push_back(LandingPadInst::Catch);
2034       else
2035         Vals.push_back(LandingPadInst::Filter);
2036       PushValueAndType(LP.getClause(I), InstID, Vals, VE);
2037     }
2038     break;
2039   }
2040
2041   case Instruction::Alloca: {
2042     Code = bitc::FUNC_CODE_INST_ALLOCA;
2043     const AllocaInst &AI = cast<AllocaInst>(I);
2044     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
2045     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
2046     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
2047     unsigned AlignRecord = Log2_32(AI.getAlignment()) + 1;
2048     assert(Log2_32(Value::MaximumAlignment) + 1 < 1 << 5 &&
2049            "not enough bits for maximum alignment");
2050     assert(AlignRecord < 1 << 5 && "alignment greater than 1 << 64");
2051     AlignRecord |= AI.isUsedWithInAlloca() << 5;
2052     AlignRecord |= 1 << 6;
2053     // Reserve bit 7 for SwiftError flag.
2054     // AlignRecord |= AI.isSwiftError() << 7;
2055     Vals.push_back(AlignRecord);
2056     break;
2057   }
2058
2059   case Instruction::Load:
2060     if (cast<LoadInst>(I).isAtomic()) {
2061       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
2062       PushValueAndType(I.getOperand(0), InstID, Vals, VE);
2063     } else {
2064       Code = bitc::FUNC_CODE_INST_LOAD;
2065       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
2066         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
2067     }
2068     Vals.push_back(VE.getTypeID(I.getType()));
2069     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
2070     Vals.push_back(cast<LoadInst>(I).isVolatile());
2071     if (cast<LoadInst>(I).isAtomic()) {
2072       Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
2073       Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
2074     }
2075     break;
2076   case Instruction::Store:
2077     if (cast<StoreInst>(I).isAtomic())
2078       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
2079     else
2080       Code = bitc::FUNC_CODE_INST_STORE;
2081     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
2082     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // valty + val
2083     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
2084     Vals.push_back(cast<StoreInst>(I).isVolatile());
2085     if (cast<StoreInst>(I).isAtomic()) {
2086       Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
2087       Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
2088     }
2089     break;
2090   case Instruction::AtomicCmpXchg:
2091     Code = bitc::FUNC_CODE_INST_CMPXCHG;
2092     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
2093     PushValueAndType(I.getOperand(1), InstID, Vals, VE);         // cmp.
2094     pushValue(I.getOperand(2), InstID, Vals, VE);         // newval.
2095     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
2096     Vals.push_back(GetEncodedOrdering(
2097                      cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
2098     Vals.push_back(GetEncodedSynchScope(
2099                      cast<AtomicCmpXchgInst>(I).getSynchScope()));
2100     Vals.push_back(GetEncodedOrdering(
2101                      cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
2102     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
2103     break;
2104   case Instruction::AtomicRMW:
2105     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
2106     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
2107     pushValue(I.getOperand(1), InstID, Vals, VE);         // val.
2108     Vals.push_back(GetEncodedRMWOperation(
2109                      cast<AtomicRMWInst>(I).getOperation()));
2110     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
2111     Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
2112     Vals.push_back(GetEncodedSynchScope(
2113                      cast<AtomicRMWInst>(I).getSynchScope()));
2114     break;
2115   case Instruction::Fence:
2116     Code = bitc::FUNC_CODE_INST_FENCE;
2117     Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
2118     Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
2119     break;
2120   case Instruction::Call: {
2121     const CallInst &CI = cast<CallInst>(I);
2122     FunctionType *FTy = CI.getFunctionType();
2123
2124     if (CI.hasOperandBundles())
2125       WriteOperandBundles(Stream, &CI, InstID, VE);
2126
2127     Code = bitc::FUNC_CODE_INST_CALL;
2128
2129     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
2130     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()) |
2131                    unsigned(CI.isMustTailCall()) << 14 | 1 << 15);
2132     Vals.push_back(VE.getTypeID(FTy));
2133     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
2134
2135     // Emit value #'s for the fixed parameters.
2136     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
2137       // Check for labels (can happen with asm labels).
2138       if (FTy->getParamType(i)->isLabelTy())
2139         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
2140       else
2141         pushValue(CI.getArgOperand(i), InstID, Vals, VE);  // fixed param.
2142     }
2143
2144     // Emit type/value pairs for varargs params.
2145     if (FTy->isVarArg()) {
2146       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
2147            i != e; ++i)
2148         PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
2149     }
2150     break;
2151   }
2152   case Instruction::VAArg:
2153     Code = bitc::FUNC_CODE_INST_VAARG;
2154     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
2155     pushValue(I.getOperand(0), InstID, Vals, VE); // valist.
2156     Vals.push_back(VE.getTypeID(I.getType())); // restype.
2157     break;
2158   }
2159
2160   Stream.EmitRecord(Code, Vals, AbbrevToUse);
2161   Vals.clear();
2162 }
2163
2164 enum StringEncoding { SE_Char6, SE_Fixed7, SE_Fixed8 };
2165
2166 /// Determine the encoding to use for the given string name and length.
2167 static StringEncoding getStringEncoding(const char *Str, unsigned StrLen) {
2168   bool isChar6 = true;
2169   for (const char *C = Str, *E = C + StrLen; C != E; ++C) {
2170     if (isChar6)
2171       isChar6 = BitCodeAbbrevOp::isChar6(*C);
2172     if ((unsigned char)*C & 128)
2173       // don't bother scanning the rest.
2174       return SE_Fixed8;
2175   }
2176   if (isChar6)
2177     return SE_Char6;
2178   else
2179     return SE_Fixed7;
2180 }
2181
2182 /// Emit names for globals/functions etc. The VSTOffsetPlaceholder,
2183 /// BitcodeStartBit and FunctionIndex are only passed for the module-level
2184 /// VST, where we are including a function bitcode index and need to
2185 /// backpatch the VST forward declaration record.
2186 static void WriteValueSymbolTable(
2187     const ValueSymbolTable &VST, const ValueEnumerator &VE,
2188     BitstreamWriter &Stream, uint64_t VSTOffsetPlaceholder = 0,
2189     uint64_t BitcodeStartBit = 0,
2190     DenseMap<const Function *, uint64_t> *FunctionIndex = nullptr) {
2191   if (VST.empty()) {
2192     // WriteValueSymbolTableForwardDecl should have returned early as
2193     // well. Ensure this handling remains in sync by asserting that
2194     // the placeholder offset is not set.
2195     assert(VSTOffsetPlaceholder == 0);
2196     return;
2197   }
2198
2199   if (VSTOffsetPlaceholder > 0) {
2200     // Get the offset of the VST we are writing, and backpatch it into
2201     // the VST forward declaration record.
2202     uint64_t VSTOffset = Stream.GetCurrentBitNo();
2203     // The BitcodeStartBit was the stream offset of the actual bitcode
2204     // (e.g. excluding any initial darwin header).
2205     VSTOffset -= BitcodeStartBit;
2206     assert((VSTOffset & 31) == 0 && "VST block not 32-bit aligned");
2207     Stream.BackpatchWord(VSTOffsetPlaceholder, VSTOffset / 32);
2208   }
2209
2210   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
2211
2212   // For the module-level VST, add abbrev Ids for the VST_CODE_FNENTRY
2213   // records, which are not used in the per-function VSTs.
2214   unsigned FnEntry8BitAbbrev;
2215   unsigned FnEntry7BitAbbrev;
2216   unsigned FnEntry6BitAbbrev;
2217   if (VSTOffsetPlaceholder > 0) {
2218     // 8-bit fixed-width VST_FNENTRY function strings.
2219     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2220     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
2221     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));  // value id
2222     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));  // funcoffset
2223     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2224     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2225     FnEntry8BitAbbrev = Stream.EmitAbbrev(Abbv);
2226
2227     // 7-bit fixed width VST_FNENTRY function strings.
2228     Abbv = new BitCodeAbbrev();
2229     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
2230     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));  // value id
2231     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));  // funcoffset
2232     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2233     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2234     FnEntry7BitAbbrev = Stream.EmitAbbrev(Abbv);
2235
2236     // 6-bit char6 VST_FNENTRY function strings.
2237     Abbv = new BitCodeAbbrev();
2238     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_FNENTRY));
2239     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));  // value id
2240     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));  // funcoffset
2241     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2242     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2243     FnEntry6BitAbbrev = Stream.EmitAbbrev(Abbv);
2244   }
2245
2246   // FIXME: Set up the abbrev, we know how many values there are!
2247   // FIXME: We know if the type names can use 7-bit ascii.
2248   SmallVector<unsigned, 64> NameVals;
2249
2250   for (const ValueName &Name : VST) {
2251     // Figure out the encoding to use for the name.
2252     StringEncoding Bits =
2253         getStringEncoding(Name.getKeyData(), Name.getKeyLength());
2254
2255     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
2256     NameVals.push_back(VE.getValueID(Name.getValue()));
2257
2258     Function *F = dyn_cast<Function>(Name.getValue());
2259     if (!F) {
2260       // If value is an alias, need to get the aliased base object to
2261       // see if it is a function.
2262       auto *GA = dyn_cast<GlobalAlias>(Name.getValue());
2263       if (GA && GA->getBaseObject())
2264         F = dyn_cast<Function>(GA->getBaseObject());
2265     }
2266
2267     // VST_ENTRY:   [valueid, namechar x N]
2268     // VST_FNENTRY: [valueid, funcoffset, namechar x N]
2269     // VST_BBENTRY: [bbid, namechar x N]
2270     unsigned Code;
2271     if (isa<BasicBlock>(Name.getValue())) {
2272       Code = bitc::VST_CODE_BBENTRY;
2273       if (Bits == SE_Char6)
2274         AbbrevToUse = VST_BBENTRY_6_ABBREV;
2275     } else if (F && !F->isDeclaration()) {
2276       // Must be the module-level VST, where we pass in the Index and
2277       // have a VSTOffsetPlaceholder. The function-level VST should not
2278       // contain any Function symbols.
2279       assert(FunctionIndex);
2280       assert(VSTOffsetPlaceholder > 0);
2281
2282       // Save the word offset of the function (from the start of the
2283       // actual bitcode written to the stream).
2284       assert(FunctionIndex->count(F) == 1);
2285       uint64_t BitcodeIndex = (*FunctionIndex)[F] - BitcodeStartBit;
2286       assert((BitcodeIndex & 31) == 0 && "function block not 32-bit aligned");
2287       NameVals.push_back(BitcodeIndex / 32);
2288
2289       Code = bitc::VST_CODE_FNENTRY;
2290       AbbrevToUse = FnEntry8BitAbbrev;
2291       if (Bits == SE_Char6)
2292         AbbrevToUse = FnEntry6BitAbbrev;
2293       else if (Bits == SE_Fixed7)
2294         AbbrevToUse = FnEntry7BitAbbrev;
2295     } else {
2296       Code = bitc::VST_CODE_ENTRY;
2297       if (Bits == SE_Char6)
2298         AbbrevToUse = VST_ENTRY_6_ABBREV;
2299       else if (Bits == SE_Fixed7)
2300         AbbrevToUse = VST_ENTRY_7_ABBREV;
2301     }
2302
2303     for (const char *P = Name.getKeyData(),
2304          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
2305       NameVals.push_back((unsigned char)*P);
2306
2307     // Emit the finished record.
2308     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
2309     NameVals.clear();
2310   }
2311   Stream.ExitBlock();
2312 }
2313
2314 static void WriteUseList(ValueEnumerator &VE, UseListOrder &&Order,
2315                          BitstreamWriter &Stream) {
2316   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
2317   unsigned Code;
2318   if (isa<BasicBlock>(Order.V))
2319     Code = bitc::USELIST_CODE_BB;
2320   else
2321     Code = bitc::USELIST_CODE_DEFAULT;
2322
2323   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
2324   Record.push_back(VE.getValueID(Order.V));
2325   Stream.EmitRecord(Code, Record);
2326 }
2327
2328 static void WriteUseListBlock(const Function *F, ValueEnumerator &VE,
2329                               BitstreamWriter &Stream) {
2330   assert(VE.shouldPreserveUseListOrder() &&
2331          "Expected to be preserving use-list order");
2332
2333   auto hasMore = [&]() {
2334     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
2335   };
2336   if (!hasMore())
2337     // Nothing to do.
2338     return;
2339
2340   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
2341   while (hasMore()) {
2342     WriteUseList(VE, std::move(VE.UseListOrders.back()), Stream);
2343     VE.UseListOrders.pop_back();
2344   }
2345   Stream.ExitBlock();
2346 }
2347
2348 /// WriteFunction - Emit a function body to the module stream.
2349 static void WriteFunction(const Function &F, ValueEnumerator &VE,
2350                           BitstreamWriter &Stream,
2351                           DenseMap<const Function *, uint64_t> &FunctionIndex) {
2352   // Save the bitcode index of the start of this function block for recording
2353   // in the VST.
2354   uint64_t BitcodeIndex = Stream.GetCurrentBitNo();
2355   FunctionIndex[&F] = BitcodeIndex;
2356
2357   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
2358   VE.incorporateFunction(F);
2359
2360   SmallVector<unsigned, 64> Vals;
2361
2362   // Emit the number of basic blocks, so the reader can create them ahead of
2363   // time.
2364   Vals.push_back(VE.getBasicBlocks().size());
2365   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
2366   Vals.clear();
2367
2368   // If there are function-local constants, emit them now.
2369   unsigned CstStart, CstEnd;
2370   VE.getFunctionConstantRange(CstStart, CstEnd);
2371   WriteConstants(CstStart, CstEnd, VE, Stream, false);
2372
2373   // If there is function-local metadata, emit it now.
2374   WriteFunctionLocalMetadata(F, VE, Stream);
2375
2376   // Keep a running idea of what the instruction ID is.
2377   unsigned InstID = CstEnd;
2378
2379   bool NeedsMetadataAttachment = F.hasMetadata();
2380
2381   DILocation *LastDL = nullptr;
2382
2383   // Finally, emit all the instructions, in order.
2384   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
2385     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
2386          I != E; ++I) {
2387       WriteInstruction(*I, InstID, VE, Stream, Vals);
2388
2389       if (!I->getType()->isVoidTy())
2390         ++InstID;
2391
2392       // If the instruction has metadata, write a metadata attachment later.
2393       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
2394
2395       // If the instruction has a debug location, emit it.
2396       DILocation *DL = I->getDebugLoc();
2397       if (!DL)
2398         continue;
2399
2400       if (DL == LastDL) {
2401         // Just repeat the same debug loc as last time.
2402         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
2403         continue;
2404       }
2405
2406       Vals.push_back(DL->getLine());
2407       Vals.push_back(DL->getColumn());
2408       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
2409       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
2410       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
2411       Vals.clear();
2412
2413       LastDL = DL;
2414     }
2415
2416   // Emit names for all the instructions etc.
2417   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
2418
2419   if (NeedsMetadataAttachment)
2420     WriteMetadataAttachment(F, VE, Stream);
2421   if (VE.shouldPreserveUseListOrder())
2422     WriteUseListBlock(&F, VE, Stream);
2423   VE.purgeFunction();
2424   Stream.ExitBlock();
2425 }
2426
2427 // Emit blockinfo, which defines the standard abbreviations etc.
2428 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
2429   // We only want to emit block info records for blocks that have multiple
2430   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
2431   // Other blocks can define their abbrevs inline.
2432   Stream.EnterBlockInfoBlock(2);
2433
2434   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
2435     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2436     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
2437     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2438     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2439     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2440     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2441                                    Abbv) != VST_ENTRY_8_ABBREV)
2442       llvm_unreachable("Unexpected abbrev ordering!");
2443   }
2444
2445   { // 7-bit fixed width VST_ENTRY strings.
2446     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2447     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2448     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2449     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2450     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2451     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2452                                    Abbv) != VST_ENTRY_7_ABBREV)
2453       llvm_unreachable("Unexpected abbrev ordering!");
2454   }
2455   { // 6-bit char6 VST_ENTRY strings.
2456     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2457     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2458     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2459     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2460     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2461     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2462                                    Abbv) != VST_ENTRY_6_ABBREV)
2463       llvm_unreachable("Unexpected abbrev ordering!");
2464   }
2465   { // 6-bit char6 VST_BBENTRY strings.
2466     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2467     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
2468     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2469     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2470     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2471     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2472                                    Abbv) != VST_BBENTRY_6_ABBREV)
2473       llvm_unreachable("Unexpected abbrev ordering!");
2474   }
2475
2476
2477
2478   { // SETTYPE abbrev for CONSTANTS_BLOCK.
2479     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2480     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
2481     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2482                               VE.computeBitsRequiredForTypeIndicies()));
2483     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2484                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
2485       llvm_unreachable("Unexpected abbrev ordering!");
2486   }
2487
2488   { // INTEGER abbrev for CONSTANTS_BLOCK.
2489     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2490     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
2491     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2492     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2493                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
2494       llvm_unreachable("Unexpected abbrev ordering!");
2495   }
2496
2497   { // CE_CAST abbrev for CONSTANTS_BLOCK.
2498     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2499     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
2500     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
2501     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
2502                               VE.computeBitsRequiredForTypeIndicies()));
2503     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
2504
2505     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2506                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
2507       llvm_unreachable("Unexpected abbrev ordering!");
2508   }
2509   { // NULL abbrev for CONSTANTS_BLOCK.
2510     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2511     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
2512     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2513                                    Abbv) != CONSTANTS_NULL_Abbrev)
2514       llvm_unreachable("Unexpected abbrev ordering!");
2515   }
2516
2517   // FIXME: This should only use space for first class types!
2518
2519   { // INST_LOAD abbrev for FUNCTION_BLOCK.
2520     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2521     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
2522     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
2523     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2524                               VE.computeBitsRequiredForTypeIndicies()));
2525     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
2526     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
2527     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2528                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
2529       llvm_unreachable("Unexpected abbrev ordering!");
2530   }
2531   { // INST_BINOP abbrev for FUNCTION_BLOCK.
2532     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2533     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2534     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2535     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2536     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2537     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2538                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
2539       llvm_unreachable("Unexpected abbrev ordering!");
2540   }
2541   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
2542     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2543     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2544     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2545     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2546     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2547     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
2548     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2549                                    Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
2550       llvm_unreachable("Unexpected abbrev ordering!");
2551   }
2552   { // INST_CAST abbrev for FUNCTION_BLOCK.
2553     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2554     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
2555     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
2556     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
2557                               VE.computeBitsRequiredForTypeIndicies()));
2558     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
2559     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2560                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
2561       llvm_unreachable("Unexpected abbrev ordering!");
2562   }
2563
2564   { // INST_RET abbrev for FUNCTION_BLOCK.
2565     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2566     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2567     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2568                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
2569       llvm_unreachable("Unexpected abbrev ordering!");
2570   }
2571   { // INST_RET abbrev for FUNCTION_BLOCK.
2572     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2573     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2574     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
2575     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2576                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
2577       llvm_unreachable("Unexpected abbrev ordering!");
2578   }
2579   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
2580     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2581     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
2582     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2583                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
2584       llvm_unreachable("Unexpected abbrev ordering!");
2585   }
2586   {
2587     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2588     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
2589     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2590     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
2591                               Log2_32_Ceil(VE.getTypes().size() + 1)));
2592     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2593     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2594     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2595         FUNCTION_INST_GEP_ABBREV)
2596       llvm_unreachable("Unexpected abbrev ordering!");
2597   }
2598
2599   Stream.ExitBlock();
2600 }
2601
2602 /// WriteModule - Emit the specified module to the bitstream.
2603 static void WriteModule(const Module *M, BitstreamWriter &Stream,
2604                         bool ShouldPreserveUseListOrder,
2605                         uint64_t BitcodeStartBit) {
2606   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
2607
2608   SmallVector<unsigned, 1> Vals;
2609   unsigned CurVersion = 1;
2610   Vals.push_back(CurVersion);
2611   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
2612
2613   // Analyze the module, enumerating globals, functions, etc.
2614   ValueEnumerator VE(*M, ShouldPreserveUseListOrder);
2615
2616   // Emit blockinfo, which defines the standard abbreviations etc.
2617   WriteBlockInfo(VE, Stream);
2618
2619   // Emit information about attribute groups.
2620   WriteAttributeGroupTable(VE, Stream);
2621
2622   // Emit information about parameter attributes.
2623   WriteAttributeTable(VE, Stream);
2624
2625   // Emit information describing all of the types in the module.
2626   WriteTypeTable(VE, Stream);
2627
2628   writeComdats(VE, Stream);
2629
2630   // Emit top-level description of module, including target triple, inline asm,
2631   // descriptors for global variables, and function prototype info.
2632   uint64_t VSTOffsetPlaceholder = WriteModuleInfo(M, VE, Stream);
2633
2634   // Emit constants.
2635   WriteModuleConstants(VE, Stream);
2636
2637   // Emit metadata.
2638   WriteModuleMetadata(M, VE, Stream);
2639
2640   // Emit metadata.
2641   WriteModuleMetadataStore(M, Stream);
2642
2643   // Emit module-level use-lists.
2644   if (VE.shouldPreserveUseListOrder())
2645     WriteUseListBlock(nullptr, VE, Stream);
2646
2647   WriteOperandBundleTags(M, Stream);
2648
2649   // Emit function bodies.
2650   DenseMap<const Function *, uint64_t> FunctionIndex;
2651   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
2652     if (!F->isDeclaration())
2653       WriteFunction(*F, VE, Stream, FunctionIndex);
2654
2655   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream,
2656                         VSTOffsetPlaceholder, BitcodeStartBit, &FunctionIndex);
2657
2658   Stream.ExitBlock();
2659 }
2660
2661 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
2662 /// header and trailer to make it compatible with the system archiver.  To do
2663 /// this we emit the following header, and then emit a trailer that pads the
2664 /// file out to be a multiple of 16 bytes.
2665 ///
2666 /// struct bc_header {
2667 ///   uint32_t Magic;         // 0x0B17C0DE
2668 ///   uint32_t Version;       // Version, currently always 0.
2669 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
2670 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
2671 ///   uint32_t CPUType;       // CPU specifier.
2672 ///   ... potentially more later ...
2673 /// };
2674 enum {
2675   DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
2676   DarwinBCHeaderSize = 5*4
2677 };
2678
2679 static void WriteInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
2680                                uint32_t &Position) {
2681   support::endian::write32le(&Buffer[Position], Value);
2682   Position += 4;
2683 }
2684
2685 static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
2686                                          const Triple &TT) {
2687   unsigned CPUType = ~0U;
2688
2689   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
2690   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
2691   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
2692   // specific constants here because they are implicitly part of the Darwin ABI.
2693   enum {
2694     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
2695     DARWIN_CPU_TYPE_X86        = 7,
2696     DARWIN_CPU_TYPE_ARM        = 12,
2697     DARWIN_CPU_TYPE_POWERPC    = 18
2698   };
2699
2700   Triple::ArchType Arch = TT.getArch();
2701   if (Arch == Triple::x86_64)
2702     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
2703   else if (Arch == Triple::x86)
2704     CPUType = DARWIN_CPU_TYPE_X86;
2705   else if (Arch == Triple::ppc)
2706     CPUType = DARWIN_CPU_TYPE_POWERPC;
2707   else if (Arch == Triple::ppc64)
2708     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
2709   else if (Arch == Triple::arm || Arch == Triple::thumb)
2710     CPUType = DARWIN_CPU_TYPE_ARM;
2711
2712   // Traditional Bitcode starts after header.
2713   assert(Buffer.size() >= DarwinBCHeaderSize &&
2714          "Expected header size to be reserved");
2715   unsigned BCOffset = DarwinBCHeaderSize;
2716   unsigned BCSize = Buffer.size()-DarwinBCHeaderSize;
2717
2718   // Write the magic and version.
2719   unsigned Position = 0;
2720   WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position);
2721   WriteInt32ToBuffer(0          , Buffer, Position); // Version.
2722   WriteInt32ToBuffer(BCOffset   , Buffer, Position);
2723   WriteInt32ToBuffer(BCSize     , Buffer, Position);
2724   WriteInt32ToBuffer(CPUType    , Buffer, Position);
2725
2726   // If the file is not a multiple of 16 bytes, insert dummy padding.
2727   while (Buffer.size() & 15)
2728     Buffer.push_back(0);
2729 }
2730
2731 /// WriteBitcodeToFile - Write the specified module to the specified output
2732 /// stream.
2733 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out,
2734                               bool ShouldPreserveUseListOrder) {
2735   SmallVector<char, 0> Buffer;
2736   Buffer.reserve(256*1024);
2737
2738   // If this is darwin or another generic macho target, reserve space for the
2739   // header.
2740   Triple TT(M->getTargetTriple());
2741   if (TT.isOSDarwin())
2742     Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0);
2743
2744   // Emit the module into the buffer.
2745   {
2746     BitstreamWriter Stream(Buffer);
2747     // Save the start bit of the actual bitcode, in case there is space
2748     // saved at the start for the darwin header above. The reader stream
2749     // will start at the bitcode, and we need the offset of the VST
2750     // to line up.
2751     uint64_t BitcodeStartBit = Stream.GetCurrentBitNo();
2752
2753     // Emit the file header.
2754     Stream.Emit((unsigned)'B', 8);
2755     Stream.Emit((unsigned)'C', 8);
2756     Stream.Emit(0x0, 4);
2757     Stream.Emit(0xC, 4);
2758     Stream.Emit(0xE, 4);
2759     Stream.Emit(0xD, 4);
2760
2761     // Emit the module.
2762     WriteModule(M, Stream, ShouldPreserveUseListOrder, BitcodeStartBit);
2763   }
2764
2765   if (TT.isOSDarwin())
2766     EmitDarwinBCHeaderAndTrailer(Buffer, TT);
2767
2768   // Write the generated bitstream to "Out".
2769   Out.write((char*)&Buffer.front(), Buffer.size());
2770 }