lib/Bitcode/Writer/BitcodeWriter.cpp

   1 //===--- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ----------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Bitcode writer implementation.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Bitcode/ReaderWriter.h"
  15 #include "ValueEnumerator.h"
  16 #include "llvm/ADT/Triple.h"
  17 #include "llvm/Bitcode/BitstreamWriter.h"
  18 #include "llvm/Bitcode/LLVMBitCodes.h"
  19 #include "llvm/IR/Constants.h"
  20 #include "llvm/IR/DebugInfoMetadata.h"
  21 #include "llvm/IR/DerivedTypes.h"
  22 #include "llvm/IR/InlineAsm.h"
  23 #include "llvm/IR/Instructions.h"
  24 #include "llvm/IR/Module.h"
  25 #include "llvm/IR/Operator.h"
  26 #include "llvm/IR/UseListOrder.h"
  27 #include "llvm/IR/ValueSymbolTable.h"
  28 #include "llvm/Support/CommandLine.h"
  29 #include "llvm/Support/ErrorHandling.h"
  30 #include "llvm/Support/MathExtras.h"
  31 #include "llvm/Support/Program.h"
  32 #include "llvm/Support/raw_ostream.h"
  33 #include <cctype>
  34 #include <map>
  35 using namespace llvm;
  36
  37 /// These are manifest constants used by the bitcode writer. They do not need to
  38 /// be kept in sync with the reader, but need to be consistent within this file.
  39 enum {
  40   // VALUE_SYMTAB_BLOCK abbrev id's.
  41   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  42   VST_ENTRY_7_ABBREV,
  43   VST_ENTRY_6_ABBREV,
  44   VST_BBENTRY_6_ABBREV,
  45
  46   // CONSTANTS_BLOCK abbrev id's.
  47   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  48   CONSTANTS_INTEGER_ABBREV,
  49   CONSTANTS_CE_CAST_Abbrev,
  50   CONSTANTS_NULL_Abbrev,
  51
  52   // FUNCTION_BLOCK abbrev id's.
  53   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  54   FUNCTION_INST_BINOP_ABBREV,
  55   FUNCTION_INST_BINOP_FLAGS_ABBREV,
  56   FUNCTION_INST_CAST_ABBREV,
  57   FUNCTION_INST_RET_VOID_ABBREV,
  58   FUNCTION_INST_RET_VAL_ABBREV,
  59   FUNCTION_INST_UNREACHABLE_ABBREV,
  60   FUNCTION_INST_GEP_ABBREV,
  61 };
  62
  63 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
  64   switch (Opcode) {
  65   default: llvm_unreachable("Unknown cast instruction!");
  66   case Instruction::Trunc   : return bitc::CAST_TRUNC;
  67   case Instruction::ZExt    : return bitc::CAST_ZEXT;
  68   case Instruction::SExt    : return bitc::CAST_SEXT;
  69   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
  70   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
  71   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
  72   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
  73   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
  74   case Instruction::FPExt   : return bitc::CAST_FPEXT;
  75   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
  76   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
  77   case Instruction::BitCast : return bitc::CAST_BITCAST;
  78   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
  79   }
  80 }
  81
  82 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
  83   switch (Opcode) {
  84   default: llvm_unreachable("Unknown binary instruction!");
  85   case Instruction::Add:
  86   case Instruction::FAdd: return bitc::BINOP_ADD;
  87   case Instruction::Sub:
  88   case Instruction::FSub: return bitc::BINOP_SUB;
  89   case Instruction::Mul:
  90   case Instruction::FMul: return bitc::BINOP_MUL;
  91   case Instruction::UDiv: return bitc::BINOP_UDIV;
  92   case Instruction::FDiv:
  93   case Instruction::SDiv: return bitc::BINOP_SDIV;
  94   case Instruction::URem: return bitc::BINOP_UREM;
  95   case Instruction::FRem:
  96   case Instruction::SRem: return bitc::BINOP_SREM;
  97   case Instruction::Shl:  return bitc::BINOP_SHL;
  98   case Instruction::LShr: return bitc::BINOP_LSHR;
  99   case Instruction::AShr: return bitc::BINOP_ASHR;
 100   case Instruction::And:  return bitc::BINOP_AND;
 101   case Instruction::Or:   return bitc::BINOP_OR;
 102   case Instruction::Xor:  return bitc::BINOP_XOR;
 103   }
 104 }
 105
 106 static unsigned GetEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
 107   switch (Op) {
 108   default: llvm_unreachable("Unknown RMW operation!");
 109   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
 110   case AtomicRMWInst::Add: return bitc::RMW_ADD;
 111   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
 112   case AtomicRMWInst::And: return bitc::RMW_AND;
 113   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
 114   case AtomicRMWInst::Or: return bitc::RMW_OR;
 115   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
 116   case AtomicRMWInst::Max: return bitc::RMW_MAX;
 117   case AtomicRMWInst::Min: return bitc::RMW_MIN;
 118   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
 119   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
 120   }
 121 }
 122
 123 static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
 124   switch (Ordering) {
 125   case NotAtomic: return bitc::ORDERING_NOTATOMIC;
 126   case Unordered: return bitc::ORDERING_UNORDERED;
 127   case Monotonic: return bitc::ORDERING_MONOTONIC;
 128   case Acquire: return bitc::ORDERING_ACQUIRE;
 129   case Release: return bitc::ORDERING_RELEASE;
 130   case AcquireRelease: return bitc::ORDERING_ACQREL;
 131   case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
 132   }
 133   llvm_unreachable("Invalid ordering");
 134 }
 135
 136 static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
 137   switch (SynchScope) {
 138   case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
 139   case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
 140   }
 141   llvm_unreachable("Invalid synch scope");
 142 }
 143
 144 static void WriteStringRecord(unsigned Code, StringRef Str,
 145                               unsigned AbbrevToUse, BitstreamWriter &Stream) {
 146   SmallVector<unsigned, 64> Vals;
 147
 148   // Code: [strchar x N]
 149   for (unsigned i = 0, e = Str.size(); i != e; ++i) {
 150     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
 151       AbbrevToUse = 0;
 152     Vals.push_back(Str[i]);
 153   }
 154
 155   // Emit the finished record.
 156   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 157 }
 158
 159 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
 160   switch (Kind) {
 161   case Attribute::Alignment:
 162     return bitc::ATTR_KIND_ALIGNMENT;
 163   case Attribute::AlwaysInline:
 164     return bitc::ATTR_KIND_ALWAYS_INLINE;
 165   case Attribute::Builtin:
 166     return bitc::ATTR_KIND_BUILTIN;
 167   case Attribute::ByVal:
 168     return bitc::ATTR_KIND_BY_VAL;
 169   case Attribute::Convergent:
 170     return bitc::ATTR_KIND_CONVERGENT;
 171   case Attribute::InAlloca:
 172     return bitc::ATTR_KIND_IN_ALLOCA;
 173   case Attribute::Cold:
 174     return bitc::ATTR_KIND_COLD;
 175   case Attribute::InlineHint:
 176     return bitc::ATTR_KIND_INLINE_HINT;
 177   case Attribute::InReg:
 178     return bitc::ATTR_KIND_IN_REG;
 179   case Attribute::JumpTable:
 180     return bitc::ATTR_KIND_JUMP_TABLE;
 181   case Attribute::MinSize:
 182     return bitc::ATTR_KIND_MIN_SIZE;
 183   case Attribute::Naked:
 184     return bitc::ATTR_KIND_NAKED;
 185   case Attribute::Nest:
 186     return bitc::ATTR_KIND_NEST;
 187   case Attribute::NoAlias:
 188     return bitc::ATTR_KIND_NO_ALIAS;
 189   case Attribute::NoBuiltin:
 190     return bitc::ATTR_KIND_NO_BUILTIN;
 191   case Attribute::NoCapture:
 192     return bitc::ATTR_KIND_NO_CAPTURE;
 193   case Attribute::NoDuplicate:
 194     return bitc::ATTR_KIND_NO_DUPLICATE;
 195   case Attribute::NoImplicitFloat:
 196     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
 197   case Attribute::NoInline:
 198     return bitc::ATTR_KIND_NO_INLINE;
 199   case Attribute::NonLazyBind:
 200     return bitc::ATTR_KIND_NON_LAZY_BIND;
 201   case Attribute::NonNull:
 202     return bitc::ATTR_KIND_NON_NULL;
 203   case Attribute::Dereferenceable:
 204     return bitc::ATTR_KIND_DEREFERENCEABLE;
 205   case Attribute::DereferenceableOrNull:
 206     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
 207   case Attribute::NoRedZone:
 208     return bitc::ATTR_KIND_NO_RED_ZONE;
 209   case Attribute::NoReturn:
 210     return bitc::ATTR_KIND_NO_RETURN;
 211   case Attribute::NoUnwind:
 212     return bitc::ATTR_KIND_NO_UNWIND;
 213   case Attribute::OptimizeForSize:
 214     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
 215   case Attribute::OptimizeNone:
 216     return bitc::ATTR_KIND_OPTIMIZE_NONE;
 217   case Attribute::ReadNone:
 218     return bitc::ATTR_KIND_READ_NONE;
 219   case Attribute::ReadOnly:
 220     return bitc::ATTR_KIND_READ_ONLY;
 221   case Attribute::Returned:
 222     return bitc::ATTR_KIND_RETURNED;
 223   case Attribute::ReturnsTwice:
 224     return bitc::ATTR_KIND_RETURNS_TWICE;
 225   case Attribute::SExt:
 226     return bitc::ATTR_KIND_S_EXT;
 227   case Attribute::StackAlignment:
 228     return bitc::ATTR_KIND_STACK_ALIGNMENT;
 229   case Attribute::StackProtect:
 230     return bitc::ATTR_KIND_STACK_PROTECT;
 231   case Attribute::StackProtectReq:
 232     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
 233   case Attribute::StackProtectStrong:
 234     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
 235   case Attribute::SafeStack:
 236     return bitc::ATTR_KIND_SAFESTACK;
 237   case Attribute::StructRet:
 238     return bitc::ATTR_KIND_STRUCT_RET;
 239   case Attribute::SanitizeAddress:
 240     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
 241   case Attribute::SanitizeThread:
 242     return bitc::ATTR_KIND_SANITIZE_THREAD;
 243   case Attribute::SanitizeMemory:
 244     return bitc::ATTR_KIND_SANITIZE_MEMORY;
 245   case Attribute::UWTable:
 246     return bitc::ATTR_KIND_UW_TABLE;
 247   case Attribute::ZExt:
 248     return bitc::ATTR_KIND_Z_EXT;
 249   case Attribute::EndAttrKinds:
 250     llvm_unreachable("Can not encode end-attribute kinds marker.");
 251   case Attribute::None:
 252     llvm_unreachable("Can not encode none-attribute.");
 253   }
 254
 255   llvm_unreachable("Trying to encode unknown attribute");
 256 }
 257
 258 static void WriteAttributeGroupTable(const ValueEnumerator &VE,
 259                                      BitstreamWriter &Stream) {
 260   const std::vector<AttributeSet> &AttrGrps = VE.getAttributeGroups();
 261   if (AttrGrps.empty()) return;
 262
 263   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
 264
 265   SmallVector<uint64_t, 64> Record;
 266   for (unsigned i = 0, e = AttrGrps.size(); i != e; ++i) {
 267     AttributeSet AS = AttrGrps[i];
 268     for (unsigned i = 0, e = AS.getNumSlots(); i != e; ++i) {
 269       AttributeSet A = AS.getSlotAttributes(i);
 270
 271       Record.push_back(VE.getAttributeGroupID(A));
 272       Record.push_back(AS.getSlotIndex(i));
 273
 274       for (AttributeSet::iterator I = AS.begin(0), E = AS.end(0);
 275            I != E; ++I) {
 276         Attribute Attr = *I;
 277         if (Attr.isEnumAttribute()) {
 278           Record.push_back(0);
 279           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 280         } else if (Attr.isIntAttribute()) {
 281           Record.push_back(1);
 282           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 283           Record.push_back(Attr.getValueAsInt());
 284         } else {
 285           StringRef Kind = Attr.getKindAsString();
 286           StringRef Val = Attr.getValueAsString();
 287
 288           Record.push_back(Val.empty() ? 3 : 4);
 289           Record.append(Kind.begin(), Kind.end());
 290           Record.push_back(0);
 291           if (!Val.empty()) {
 292             Record.append(Val.begin(), Val.end());
 293             Record.push_back(0);
 294           }
 295         }
 296       }
 297
 298       Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
 299       Record.clear();
 300     }
 301   }
 302
 303   Stream.ExitBlock();
 304 }
 305
 306 static void WriteAttributeTable(const ValueEnumerator &VE,
 307                                 BitstreamWriter &Stream) {
 308   const std::vector<AttributeSet> &Attrs = VE.getAttributes();
 309   if (Attrs.empty()) return;
 310
 311   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 312
 313   SmallVector<uint64_t, 64> Record;
 314   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
 315     const AttributeSet &A = Attrs[i];
 316     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
 317       Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
 318
 319     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 320     Record.clear();
 321   }
 322
 323   Stream.ExitBlock();
 324 }
 325
 326 /// WriteTypeTable - Write out the type table for a module.
 327 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 328   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 329
 330   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
 331   SmallVector<uint64_t, 64> TypeVals;
 332
 333   uint64_t NumBits = VE.computeBitsRequiredForTypeIndicies();
 334
 335   // Abbrev for TYPE_CODE_POINTER.
 336   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 337   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
 338   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 339   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
 340   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
 341
 342   // Abbrev for TYPE_CODE_FUNCTION.
 343   Abbv = new BitCodeAbbrev();
 344   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
 345   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
 346   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 347   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 348
 349   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 350
 351   // Abbrev for TYPE_CODE_STRUCT_ANON.
 352   Abbv = new BitCodeAbbrev();
 353   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
 354   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 355   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 356   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 357
 358   unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
 359
 360   // Abbrev for TYPE_CODE_STRUCT_NAME.
 361   Abbv = new BitCodeAbbrev();
 362   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
 363   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 364   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 365   unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
 366
 367   // Abbrev for TYPE_CODE_STRUCT_NAMED.
 368   Abbv = new BitCodeAbbrev();
 369   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
 370   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 371   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 372   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 373
 374   unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
 375
 376   // Abbrev for TYPE_CODE_ARRAY.
 377   Abbv = new BitCodeAbbrev();
 378   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 379   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 380   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 381
 382   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 383
 384   // Emit an entry count so the reader can reserve space.
 385   TypeVals.push_back(TypeList.size());
 386   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 387   TypeVals.clear();
 388
 389   // Loop over all of the types, emitting each in turn.
 390   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 391     Type *T = TypeList[i];
 392     int AbbrevToUse = 0;
 393     unsigned Code = 0;
 394
 395     switch (T->getTypeID()) {
 396     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
 397     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
 398     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
 399     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
 400     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
 401     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
 402     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 403     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
 404     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
 405     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
 406     case Type::IntegerTyID:
 407       // INTEGER: [width]
 408       Code = bitc::TYPE_CODE_INTEGER;
 409       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 410       break;
 411     case Type::PointerTyID: {
 412       PointerType *PTy = cast<PointerType>(T);
 413       // POINTER: [pointee type, address space]
 414       Code = bitc::TYPE_CODE_POINTER;
 415       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
 416       unsigned AddressSpace = PTy->getAddressSpace();
 417       TypeVals.push_back(AddressSpace);
 418       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
 419       break;
 420     }
 421     case Type::FunctionTyID: {
 422       FunctionType *FT = cast<FunctionType>(T);
 423       // FUNCTION: [isvararg, retty, paramty x N]
 424       Code = bitc::TYPE_CODE_FUNCTION;
 425       TypeVals.push_back(FT->isVarArg());
 426       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 427       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 428         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 429       AbbrevToUse = FunctionAbbrev;
 430       break;
 431     }
 432     case Type::StructTyID: {
 433       StructType *ST = cast<StructType>(T);
 434       // STRUCT: [ispacked, eltty x N]
 435       TypeVals.push_back(ST->isPacked());
 436       // Output all of the element types.
 437       for (StructType::element_iterator I = ST->element_begin(),
 438            E = ST->element_end(); I != E; ++I)
 439         TypeVals.push_back(VE.getTypeID(*I));
 440
 441       if (ST->isLiteral()) {
 442         Code = bitc::TYPE_CODE_STRUCT_ANON;
 443         AbbrevToUse = StructAnonAbbrev;
 444       } else {
 445         if (ST->isOpaque()) {
 446           Code = bitc::TYPE_CODE_OPAQUE;
 447         } else {
 448           Code = bitc::TYPE_CODE_STRUCT_NAMED;
 449           AbbrevToUse = StructNamedAbbrev;
 450         }
 451
 452         // Emit the name if it is present.
 453         if (!ST->getName().empty())
 454           WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
 455                             StructNameAbbrev, Stream);
 456       }
 457       break;
 458     }
 459     case Type::ArrayTyID: {
 460       ArrayType *AT = cast<ArrayType>(T);
 461       // ARRAY: [numelts, eltty]
 462       Code = bitc::TYPE_CODE_ARRAY;
 463       TypeVals.push_back(AT->getNumElements());
 464       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 465       AbbrevToUse = ArrayAbbrev;
 466       break;
 467     }
 468     case Type::VectorTyID: {
 469       VectorType *VT = cast<VectorType>(T);
 470       // VECTOR [numelts, eltty]
 471       Code = bitc::TYPE_CODE_VECTOR;
 472       TypeVals.push_back(VT->getNumElements());
 473       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 474       break;
 475     }
 476     }
 477
 478     // Emit the finished record.
 479     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 480     TypeVals.clear();
 481   }
 482
 483   Stream.ExitBlock();
 484 }
 485
 486 static unsigned getEncodedLinkage(const GlobalValue &GV) {
 487   switch (GV.getLinkage()) {
 488   case GlobalValue::ExternalLinkage:
 489     return 0;
 490   case GlobalValue::WeakAnyLinkage:
 491     return 16;
 492   case GlobalValue::AppendingLinkage:
 493     return 2;
 494   case GlobalValue::InternalLinkage:
 495     return 3;
 496   case GlobalValue::LinkOnceAnyLinkage:
 497     return 18;
 498   case GlobalValue::ExternalWeakLinkage:
 499     return 7;
 500   case GlobalValue::CommonLinkage:
 501     return 8;
 502   case GlobalValue::PrivateLinkage:
 503     return 9;
 504   case GlobalValue::WeakODRLinkage:
 505     return 17;
 506   case GlobalValue::LinkOnceODRLinkage:
 507     return 19;
 508   case GlobalValue::AvailableExternallyLinkage:
 509     return 12;
 510   }
 511   llvm_unreachable("Invalid linkage");
 512 }
 513
 514 static unsigned getEncodedVisibility(const GlobalValue &GV) {
 515   switch (GV.getVisibility()) {
 516   case GlobalValue::DefaultVisibility:   return 0;
 517   case GlobalValue::HiddenVisibility:    return 1;
 518   case GlobalValue::ProtectedVisibility: return 2;
 519   }
 520   llvm_unreachable("Invalid visibility");
 521 }
 522
 523 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
 524   switch (GV.getDLLStorageClass()) {
 525   case GlobalValue::DefaultStorageClass:   return 0;
 526   case GlobalValue::DLLImportStorageClass: return 1;
 527   case GlobalValue::DLLExportStorageClass: return 2;
 528   }
 529   llvm_unreachable("Invalid DLL storage class");
 530 }
 531
 532 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
 533   switch (GV.getThreadLocalMode()) {
 534     case GlobalVariable::NotThreadLocal:         return 0;
 535     case GlobalVariable::GeneralDynamicTLSModel: return 1;
 536     case GlobalVariable::LocalDynamicTLSModel:   return 2;
 537     case GlobalVariable::InitialExecTLSModel:    return 3;
 538     case GlobalVariable::LocalExecTLSModel:      return 4;
 539   }
 540   llvm_unreachable("Invalid TLS model");
 541 }
 542
 543 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
 544   switch (C.getSelectionKind()) {
 545   case Comdat::Any:
 546     return bitc::COMDAT_SELECTION_KIND_ANY;
 547   case Comdat::ExactMatch:
 548     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
 549   case Comdat::Largest:
 550     return bitc::COMDAT_SELECTION_KIND_LARGEST;
 551   case Comdat::NoDuplicates:
 552     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
 553   case Comdat::SameSize:
 554     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
 555   }
 556   llvm_unreachable("Invalid selection kind");
 557 }
 558
 559 static void writeComdats(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 560   SmallVector<uint16_t, 64> Vals;
 561   for (const Comdat *C : VE.getComdats()) {
 562     // COMDAT: [selection_kind, name]
 563     Vals.push_back(getEncodedComdatSelectionKind(*C));
 564     size_t Size = C->getName().size();
 565     assert(isUInt<16>(Size));
 566     Vals.push_back(Size);
 567     for (char Chr : C->getName())
 568       Vals.push_back((unsigned char)Chr);
 569     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
 570     Vals.clear();
 571   }
 572 }
 573
 574 // Emit top-level description of module, including target triple, inline asm,
 575 // descriptors for global variables, and function prototype info.
 576 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 577                             BitstreamWriter &Stream) {
 578   // Emit various pieces of data attached to a module.
 579   if (!M->getTargetTriple().empty())
 580     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 581                       0/*TODO*/, Stream);
 582   const std::string &DL = M->getDataLayoutStr();
 583   if (!DL.empty())
 584     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/, Stream);
 585   if (!M->getModuleInlineAsm().empty())
 586     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 587                       0/*TODO*/, Stream);
 588
 589   // Emit information about sections and GC, computing how many there are. Also
 590   // compute the maximum alignment value.
 591   std::map<std::string, unsigned> SectionMap;
 592   std::map<std::string, unsigned> GCMap;
 593   unsigned MaxAlignment = 0;
 594   unsigned MaxGlobalType = 0;
 595   for (const GlobalValue &GV : M->globals()) {
 596     MaxAlignment = std::max(MaxAlignment, GV.getAlignment());
 597     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
 598     if (GV.hasSection()) {
 599       // Give section names unique ID's.
 600       unsigned &Entry = SectionMap[GV.getSection()];
 601       if (!Entry) {
 602         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
 603                           0/*TODO*/, Stream);
 604         Entry = SectionMap.size();
 605       }
 606     }
 607   }
 608   for (const Function &F : *M) {
 609     MaxAlignment = std::max(MaxAlignment, F.getAlignment());
 610     if (F.hasSection()) {
 611       // Give section names unique ID's.
 612       unsigned &Entry = SectionMap[F.getSection()];
 613       if (!Entry) {
 614         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
 615                           0/*TODO*/, Stream);
 616         Entry = SectionMap.size();
 617       }
 618     }
 619     if (F.hasGC()) {
 620       // Same for GC names.
 621       unsigned &Entry = GCMap[F.getGC()];
 622       if (!Entry) {
 623         WriteStringRecord(bitc::MODULE_CODE_GCNAME, F.getGC(),
 624                           0/*TODO*/, Stream);
 625         Entry = GCMap.size();
 626       }
 627     }
 628   }
 629
 630   // Emit abbrev for globals, now that we know # sections and max alignment.
 631   unsigned SimpleGVarAbbrev = 0;
 632   if (!M->global_empty()) {
 633     // Add an abbrev for common globals with no visibility or thread localness.
 634     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 635     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 636     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 637                               Log2_32_Ceil(MaxGlobalType+1)));
 638     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
 639                                                            //| explicitType << 1
 640                                                            //| constant
 641     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
 642     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
 643     if (MaxAlignment == 0)                                 // Alignment.
 644       Abbv->Add(BitCodeAbbrevOp(0));
 645     else {
 646       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 647       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 648                                Log2_32_Ceil(MaxEncAlignment+1)));
 649     }
 650     if (SectionMap.empty())                                    // Section.
 651       Abbv->Add(BitCodeAbbrevOp(0));
 652     else
 653       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 654                                Log2_32_Ceil(SectionMap.size()+1)));
 655     // Don't bother emitting vis + thread local.
 656     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 657   }
 658
 659   // Emit the global variable information.
 660   SmallVector<unsigned, 64> Vals;
 661   for (const GlobalVariable &GV : M->globals()) {
 662     unsigned AbbrevToUse = 0;
 663
 664     // GLOBALVAR: [type, isconst, initid,
 665     //             linkage, alignment, section, visibility, threadlocal,
 666     //             unnamed_addr, externally_initialized, dllstorageclass,
 667     //             comdat]
 668     Vals.push_back(VE.getTypeID(GV.getValueType()));
 669     Vals.push_back(GV.getType()->getAddressSpace() << 2 | 2 | GV.isConstant());
 670     Vals.push_back(GV.isDeclaration() ? 0 :
 671                    (VE.getValueID(GV.getInitializer()) + 1));
 672     Vals.push_back(getEncodedLinkage(GV));
 673     Vals.push_back(Log2_32(GV.getAlignment())+1);
 674     Vals.push_back(GV.hasSection() ? SectionMap[GV.getSection()] : 0);
 675     if (GV.isThreadLocal() ||
 676         GV.getVisibility() != GlobalValue::DefaultVisibility ||
 677         GV.hasUnnamedAddr() || GV.isExternallyInitialized() ||
 678         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
 679         GV.hasComdat()) {
 680       Vals.push_back(getEncodedVisibility(GV));
 681       Vals.push_back(getEncodedThreadLocalMode(GV));
 682       Vals.push_back(GV.hasUnnamedAddr());
 683       Vals.push_back(GV.isExternallyInitialized());
 684       Vals.push_back(getEncodedDLLStorageClass(GV));
 685       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
 686     } else {
 687       AbbrevToUse = SimpleGVarAbbrev;
 688     }
 689
 690     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 691     Vals.clear();
 692   }
 693
 694   // Emit the function proto information.
 695   for (const Function &F : *M) {
 696     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
 697     //             section, visibility, gc, unnamed_addr, prologuedata,
 698     //             dllstorageclass, comdat, prefixdata]
 699     Vals.push_back(VE.getTypeID(F.getFunctionType()));
 700     Vals.push_back(F.getCallingConv());
 701     Vals.push_back(F.isDeclaration());
 702     Vals.push_back(getEncodedLinkage(F));
 703     Vals.push_back(VE.getAttributeID(F.getAttributes()));
 704     Vals.push_back(Log2_32(F.getAlignment())+1);
 705     Vals.push_back(F.hasSection() ? SectionMap[F.getSection()] : 0);
 706     Vals.push_back(getEncodedVisibility(F));
 707     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
 708     Vals.push_back(F.hasUnnamedAddr());
 709     Vals.push_back(F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1)
 710                                        : 0);
 711     Vals.push_back(getEncodedDLLStorageClass(F));
 712     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
 713     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
 714                                      : 0);
 715
 716     unsigned AbbrevToUse = 0;
 717     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 718     Vals.clear();
 719   }
 720
 721   // Emit the alias information.
 722   for (const GlobalAlias &A : M->aliases()) {
 723     // ALIAS: [alias type, aliasee val#, linkage, visibility]
 724     Vals.push_back(VE.getTypeID(A.getType()));
 725     Vals.push_back(VE.getValueID(A.getAliasee()));
 726     Vals.push_back(getEncodedLinkage(A));
 727     Vals.push_back(getEncodedVisibility(A));
 728     Vals.push_back(getEncodedDLLStorageClass(A));
 729     Vals.push_back(getEncodedThreadLocalMode(A));
 730     Vals.push_back(A.hasUnnamedAddr());
 731     unsigned AbbrevToUse = 0;
 732     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 733     Vals.clear();
 734   }
 735 }
 736
 737 static uint64_t GetOptimizationFlags(const Value *V) {
 738   uint64_t Flags = 0;
 739
 740   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
 741     if (OBO->hasNoSignedWrap())
 742       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
 743     if (OBO->hasNoUnsignedWrap())
 744       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
 745   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
 746     if (PEO->isExact())
 747       Flags |= 1 << bitc::PEO_EXACT;
 748   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
 749     if (FPMO->hasUnsafeAlgebra())
 750       Flags |= FastMathFlags::UnsafeAlgebra;
 751     if (FPMO->hasNoNaNs())
 752       Flags |= FastMathFlags::NoNaNs;
 753     if (FPMO->hasNoInfs())
 754       Flags |= FastMathFlags::NoInfs;
 755     if (FPMO->hasNoSignedZeros())
 756       Flags |= FastMathFlags::NoSignedZeros;
 757     if (FPMO->hasAllowReciprocal())
 758       Flags |= FastMathFlags::AllowReciprocal;
 759   }
 760
 761   return Flags;
 762 }
 763
 764 static void WriteValueAsMetadata(const ValueAsMetadata *MD,
 765                                  const ValueEnumerator &VE,
 766                                  BitstreamWriter &Stream,
 767                                  SmallVectorImpl<uint64_t> &Record) {
 768   // Mimic an MDNode with a value as one operand.
 769   Value *V = MD->getValue();
 770   Record.push_back(VE.getTypeID(V->getType()));
 771   Record.push_back(VE.getValueID(V));
 772   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
 773   Record.clear();
 774 }
 775
 776 static void WriteMDTuple(const MDTuple *N, const ValueEnumerator &VE,
 777                          BitstreamWriter &Stream,
 778                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
 779   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
 780     Metadata *MD = N->getOperand(i);
 781     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
 782            "Unexpected function-local metadata");
 783     Record.push_back(VE.getMetadataOrNullID(MD));
 784   }
 785   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
 786                                     : bitc::METADATA_NODE,
 787                     Record, Abbrev);
 788   Record.clear();
 789 }
 790
 791 static void WriteDILocation(const DILocation *N, const ValueEnumerator &VE,
 792                             BitstreamWriter &Stream,
 793                             SmallVectorImpl<uint64_t> &Record,
 794                             unsigned Abbrev) {
 795   Record.push_back(N->isDistinct());
 796   Record.push_back(N->getLine());
 797   Record.push_back(N->getColumn());
 798   Record.push_back(VE.getMetadataID(N->getScope()));
 799   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
 800
 801   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
 802   Record.clear();
 803 }
 804
 805 static void WriteGenericDINode(const GenericDINode *N,
 806                                const ValueEnumerator &VE,
 807                                BitstreamWriter &Stream,
 808                                SmallVectorImpl<uint64_t> &Record,
 809                                unsigned Abbrev) {
 810   Record.push_back(N->isDistinct());
 811   Record.push_back(N->getTag());
 812   Record.push_back(0); // Per-tag version field; unused for now.
 813
 814   for (auto &I : N->operands())
 815     Record.push_back(VE.getMetadataOrNullID(I));
 816
 817   Stream.EmitRecord(bitc::METADATA_GENERIC_DEBUG, Record, Abbrev);
 818   Record.clear();
 819 }
 820
 821 static uint64_t rotateSign(int64_t I) {
 822   uint64_t U = I;
 823   return I < 0 ? ~(U << 1) : U << 1;
 824 }
 825
 826 static void WriteDISubrange(const DISubrange *N, const ValueEnumerator &,
 827                             BitstreamWriter &Stream,
 828                             SmallVectorImpl<uint64_t> &Record,
 829                             unsigned Abbrev) {
 830   Record.push_back(N->isDistinct());
 831   Record.push_back(N->getCount());
 832   Record.push_back(rotateSign(N->getLowerBound()));
 833
 834   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
 835   Record.clear();
 836 }
 837
 838 static void WriteDIEnumerator(const DIEnumerator *N, const ValueEnumerator &VE,
 839                               BitstreamWriter &Stream,
 840                               SmallVectorImpl<uint64_t> &Record,
 841                               unsigned Abbrev) {
 842   Record.push_back(N->isDistinct());
 843   Record.push_back(rotateSign(N->getValue()));
 844   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 845
 846   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
 847   Record.clear();
 848 }
 849
 850 static void WriteDIBasicType(const DIBasicType *N, const ValueEnumerator &VE,
 851                              BitstreamWriter &Stream,
 852                              SmallVectorImpl<uint64_t> &Record,
 853                              unsigned Abbrev) {
 854   Record.push_back(N->isDistinct());
 855   Record.push_back(N->getTag());
 856   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 857   Record.push_back(N->getSizeInBits());
 858   Record.push_back(N->getAlignInBits());
 859   Record.push_back(N->getEncoding());
 860
 861   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
 862   Record.clear();
 863 }
 864
 865 static void WriteDIDerivedType(const DIDerivedType *N,
 866                                const ValueEnumerator &VE,
 867                                BitstreamWriter &Stream,
 868                                SmallVectorImpl<uint64_t> &Record,
 869                                unsigned Abbrev) {
 870   Record.push_back(N->isDistinct());
 871   Record.push_back(N->getTag());
 872   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 873   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 874   Record.push_back(N->getLine());
 875   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 876   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
 877   Record.push_back(N->getSizeInBits());
 878   Record.push_back(N->getAlignInBits());
 879   Record.push_back(N->getOffsetInBits());
 880   Record.push_back(N->getFlags());
 881   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
 882
 883   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
 884   Record.clear();
 885 }
 886
 887 static void WriteDICompositeType(const DICompositeType *N,
 888                                  const ValueEnumerator &VE,
 889                                  BitstreamWriter &Stream,
 890                                  SmallVectorImpl<uint64_t> &Record,
 891                                  unsigned Abbrev) {
 892   Record.push_back(N->isDistinct());
 893   Record.push_back(N->getTag());
 894   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 895   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 896   Record.push_back(N->getLine());
 897   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 898   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
 899   Record.push_back(N->getSizeInBits());
 900   Record.push_back(N->getAlignInBits());
 901   Record.push_back(N->getOffsetInBits());
 902   Record.push_back(N->getFlags());
 903   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
 904   Record.push_back(N->getRuntimeLang());
 905   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
 906   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
 907   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
 908
 909   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
 910   Record.clear();
 911 }
 912
 913 static void WriteDISubroutineType(const DISubroutineType *N,
 914                                   const ValueEnumerator &VE,
 915                                   BitstreamWriter &Stream,
 916                                   SmallVectorImpl<uint64_t> &Record,
 917                                   unsigned Abbrev) {
 918   Record.push_back(N->isDistinct());
 919   Record.push_back(N->getFlags());
 920   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
 921
 922   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
 923   Record.clear();
 924 }
 925
 926 static void WriteDIFile(const DIFile *N, const ValueEnumerator &VE,
 927                         BitstreamWriter &Stream,
 928                         SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
 929   Record.push_back(N->isDistinct());
 930   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
 931   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
 932
 933   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
 934   Record.clear();
 935 }
 936
 937 static void WriteDICompileUnit(const DICompileUnit *N,
 938                                const ValueEnumerator &VE,
 939                                BitstreamWriter &Stream,
 940                                SmallVectorImpl<uint64_t> &Record,
 941                                unsigned Abbrev) {
 942   Record.push_back(N->isDistinct());
 943   Record.push_back(N->getSourceLanguage());
 944   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 945   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
 946   Record.push_back(N->isOptimized());
 947   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
 948   Record.push_back(N->getRuntimeVersion());
 949   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
 950   Record.push_back(N->getEmissionKind());
 951   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
 952   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
 953   Record.push_back(VE.getMetadataOrNullID(N->getSubprograms().get()));
 954   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
 955   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
 956   Record.push_back(N->getDWOId());
 957
 958   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
 959   Record.clear();
 960 }
 961
 962 static void WriteDISubprogram(const DISubprogram *N, const ValueEnumerator &VE,
 963                               BitstreamWriter &Stream,
 964                               SmallVectorImpl<uint64_t> &Record,
 965                               unsigned Abbrev) {
 966   Record.push_back(N->isDistinct());
 967   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 968   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 969   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
 970   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 971   Record.push_back(N->getLine());
 972   Record.push_back(VE.getMetadataOrNullID(N->getType()));
 973   Record.push_back(N->isLocalToUnit());
 974   Record.push_back(N->isDefinition());
 975   Record.push_back(N->getScopeLine());
 976   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
 977   Record.push_back(N->getVirtuality());
 978   Record.push_back(N->getVirtualIndex());
 979   Record.push_back(N->getFlags());
 980   Record.push_back(N->isOptimized());
 981   Record.push_back(VE.getMetadataOrNullID(N->getRawFunction()));
 982   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
 983   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
 984   Record.push_back(VE.getMetadataOrNullID(N->getVariables().get()));
 985
 986   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
 987   Record.clear();
 988 }
 989
 990 static void WriteDILexicalBlock(const DILexicalBlock *N,
 991                                 const ValueEnumerator &VE,
 992                                 BitstreamWriter &Stream,
 993                                 SmallVectorImpl<uint64_t> &Record,
 994                                 unsigned Abbrev) {
 995   Record.push_back(N->isDistinct());
 996   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 997   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 998   Record.push_back(N->getLine());
 999   Record.push_back(N->getColumn());
1000
1001   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
1002   Record.clear();
1003 }
1004
1005 static void WriteDILexicalBlockFile(const DILexicalBlockFile *N,
1006                                     const ValueEnumerator &VE,
1007                                     BitstreamWriter &Stream,
1008                                     SmallVectorImpl<uint64_t> &Record,
1009                                     unsigned Abbrev) {
1010   Record.push_back(N->isDistinct());
1011   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1012   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1013   Record.push_back(N->getDiscriminator());
1014
1015   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
1016   Record.clear();
1017 }
1018
1019 static void WriteDINamespace(const DINamespace *N, const ValueEnumerator &VE,
1020                              BitstreamWriter &Stream,
1021                              SmallVectorImpl<uint64_t> &Record,
1022                              unsigned Abbrev) {
1023   Record.push_back(N->isDistinct());
1024   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1025   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1026   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1027   Record.push_back(N->getLine());
1028
1029   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
1030   Record.clear();
1031 }
1032
1033 static void WriteDITemplateTypeParameter(const DITemplateTypeParameter *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->getRawName()));
1040   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1041
1042   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
1043   Record.clear();
1044 }
1045
1046 static void WriteDITemplateValueParameter(const DITemplateValueParameter *N,
1047                                           const ValueEnumerator &VE,
1048                                           BitstreamWriter &Stream,
1049                                           SmallVectorImpl<uint64_t> &Record,
1050                                           unsigned Abbrev) {
1051   Record.push_back(N->isDistinct());
1052   Record.push_back(N->getTag());
1053   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1054   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1055   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
1056
1057   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
1058   Record.clear();
1059 }
1060
1061 static void WriteDIGlobalVariable(const DIGlobalVariable *N,
1062                                   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->getRawName()));
1069   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1070   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1071   Record.push_back(N->getLine());
1072   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1073   Record.push_back(N->isLocalToUnit());
1074   Record.push_back(N->isDefinition());
1075   Record.push_back(VE.getMetadataOrNullID(N->getRawVariable()));
1076   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
1077
1078   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
1079   Record.clear();
1080 }
1081
1082 static void WriteDILocalVariable(const DILocalVariable *N,
1083                                  const ValueEnumerator &VE,
1084                                  BitstreamWriter &Stream,
1085                                  SmallVectorImpl<uint64_t> &Record,
1086                                  unsigned Abbrev) {
1087   Record.push_back(N->isDistinct());
1088   Record.push_back(N->getTag());
1089   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1090   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1091   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1092   Record.push_back(N->getLine());
1093   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1094   Record.push_back(N->getArg());
1095   Record.push_back(N->getFlags());
1096
1097   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
1098   Record.clear();
1099 }
1100
1101 static void WriteDIExpression(const DIExpression *N, const ValueEnumerator &,
1102                               BitstreamWriter &Stream,
1103                               SmallVectorImpl<uint64_t> &Record,
1104                               unsigned Abbrev) {
1105   Record.reserve(N->getElements().size() + 1);
1106
1107   Record.push_back(N->isDistinct());
1108   Record.append(N->elements_begin(), N->elements_end());
1109
1110   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
1111   Record.clear();
1112 }
1113
1114 static void WriteDIObjCProperty(const DIObjCProperty *N,
1115                                 const ValueEnumerator &VE,
1116                                 BitstreamWriter &Stream,
1117                                 SmallVectorImpl<uint64_t> &Record,
1118                                 unsigned Abbrev) {
1119   Record.push_back(N->isDistinct());
1120   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1121   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1122   Record.push_back(N->getLine());
1123   Record.push_back(VE.getMetadataOrNullID(N->getRawSetterName()));
1124   Record.push_back(VE.getMetadataOrNullID(N->getRawGetterName()));
1125   Record.push_back(N->getAttributes());
1126   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1127
1128   Stream.EmitRecord(bitc::METADATA_OBJC_PROPERTY, Record, Abbrev);
1129   Record.clear();
1130 }
1131
1132 static void WriteDIImportedEntity(const DIImportedEntity *N,
1133                                   const ValueEnumerator &VE,
1134                                   BitstreamWriter &Stream,
1135                                   SmallVectorImpl<uint64_t> &Record,
1136                                   unsigned Abbrev) {
1137   Record.push_back(N->isDistinct());
1138   Record.push_back(N->getTag());
1139   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1140   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
1141   Record.push_back(N->getLine());
1142   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1143
1144   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
1145   Record.clear();
1146 }
1147
1148 static void WriteModuleMetadata(const Module *M,
1149                                 const ValueEnumerator &VE,
1150                                 BitstreamWriter &Stream) {
1151   const auto &MDs = VE.getMDs();
1152   if (MDs.empty() && M->named_metadata_empty())
1153     return;
1154
1155   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1156
1157   unsigned MDSAbbrev = 0;
1158   if (VE.hasMDString()) {
1159     // Abbrev for METADATA_STRING.
1160     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1161     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
1162     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1163     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1164     MDSAbbrev = Stream.EmitAbbrev(Abbv);
1165   }
1166
1167   // Initialize MDNode abbreviations.
1168 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
1169 #include "llvm/IR/Metadata.def"
1170
1171   if (VE.hasDILocation()) {
1172     // Abbrev for METADATA_LOCATION.
1173     //
1174     // Assume the column is usually under 128, and always output the inlined-at
1175     // location (it's never more expensive than building an array size 1).
1176     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1177     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1178     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1179     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1180     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1181     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1182     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1183     DILocationAbbrev = Stream.EmitAbbrev(Abbv);
1184   }
1185
1186   if (VE.hasGenericDINode()) {
1187     // Abbrev for METADATA_GENERIC_DEBUG.
1188     //
1189     // Assume the column is usually under 128, and always output the inlined-at
1190     // location (it's never more expensive than building an array size 1).
1191     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1192     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1193     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1194     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1195     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1196     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1197     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1198     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1199     GenericDINodeAbbrev = Stream.EmitAbbrev(Abbv);
1200   }
1201
1202   unsigned NameAbbrev = 0;
1203   if (!M->named_metadata_empty()) {
1204     // Abbrev for METADATA_NAME.
1205     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1206     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
1207     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1208     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1209     NameAbbrev = Stream.EmitAbbrev(Abbv);
1210   }
1211
1212   SmallVector<uint64_t, 64> Record;
1213   for (const Metadata *MD : MDs) {
1214     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
1215       assert(N->isResolved() && "Expected forward references to be resolved");
1216
1217       switch (N->getMetadataID()) {
1218       default:
1219         llvm_unreachable("Invalid MDNode subclass");
1220 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
1221   case Metadata::CLASS##Kind:                                                  \
1222     Write##CLASS(cast<CLASS>(N), VE, Stream, Record, CLASS##Abbrev);           \
1223     continue;
1224 #include "llvm/IR/Metadata.def"
1225       }
1226     }
1227     if (const auto *MDC = dyn_cast<ConstantAsMetadata>(MD)) {
1228       WriteValueAsMetadata(MDC, VE, Stream, Record);
1229       continue;
1230     }
1231     const MDString *MDS = cast<MDString>(MD);
1232     // Code: [strchar x N]
1233     Record.append(MDS->bytes_begin(), MDS->bytes_end());
1234
1235     // Emit the finished record.
1236     Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
1237     Record.clear();
1238   }
1239
1240   // Write named metadata.
1241   for (const NamedMDNode &NMD : M->named_metadata()) {
1242     // Write name.
1243     StringRef Str = NMD.getName();
1244     Record.append(Str.bytes_begin(), Str.bytes_end());
1245     Stream.EmitRecord(bitc::METADATA_NAME, Record, NameAbbrev);
1246     Record.clear();
1247
1248     // Write named metadata operands.
1249     for (const MDNode *N : NMD.operands())
1250       Record.push_back(VE.getMetadataID(N));
1251     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
1252     Record.clear();
1253   }
1254
1255   Stream.ExitBlock();
1256 }
1257
1258 static void WriteFunctionLocalMetadata(const Function &F,
1259                                        const ValueEnumerator &VE,
1260                                        BitstreamWriter &Stream) {
1261   bool StartedMetadataBlock = false;
1262   SmallVector<uint64_t, 64> Record;
1263   const SmallVectorImpl<const LocalAsMetadata *> &MDs =
1264       VE.getFunctionLocalMDs();
1265   for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1266     assert(MDs[i] && "Expected valid function-local metadata");
1267     if (!StartedMetadataBlock) {
1268       Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1269       StartedMetadataBlock = true;
1270     }
1271     WriteValueAsMetadata(MDs[i], VE, Stream, Record);
1272   }
1273
1274   if (StartedMetadataBlock)
1275     Stream.ExitBlock();
1276 }
1277
1278 static void WriteMetadataAttachment(const Function &F,
1279                                     const ValueEnumerator &VE,
1280                                     BitstreamWriter &Stream) {
1281   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
1282
1283   SmallVector<uint64_t, 64> Record;
1284
1285   // Write metadata attachments
1286   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
1287   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
1288   F.getAllMetadata(MDs);
1289   if (!MDs.empty()) {
1290     for (const auto &I : MDs) {
1291       Record.push_back(I.first);
1292       Record.push_back(VE.getMetadataID(I.second));
1293     }
1294     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1295     Record.clear();
1296   }
1297
1298   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1299     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1300          I != E; ++I) {
1301       MDs.clear();
1302       I->getAllMetadataOtherThanDebugLoc(MDs);
1303
1304       // If no metadata, ignore instruction.
1305       if (MDs.empty()) continue;
1306
1307       Record.push_back(VE.getInstructionID(I));
1308
1309       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1310         Record.push_back(MDs[i].first);
1311         Record.push_back(VE.getMetadataID(MDs[i].second));
1312       }
1313       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1314       Record.clear();
1315     }
1316
1317   Stream.ExitBlock();
1318 }
1319
1320 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
1321   SmallVector<uint64_t, 64> Record;
1322
1323   // Write metadata kinds
1324   // METADATA_KIND - [n x [id, name]]
1325   SmallVector<StringRef, 8> Names;
1326   M->getMDKindNames(Names);
1327
1328   if (Names.empty()) return;
1329
1330   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1331
1332   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
1333     Record.push_back(MDKindID);
1334     StringRef KName = Names[MDKindID];
1335     Record.append(KName.begin(), KName.end());
1336
1337     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
1338     Record.clear();
1339   }
1340
1341   Stream.ExitBlock();
1342 }
1343
1344 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
1345   if ((int64_t)V >= 0)
1346     Vals.push_back(V << 1);
1347   else
1348     Vals.push_back((-V << 1) | 1);
1349 }
1350
1351 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
1352                            const ValueEnumerator &VE,
1353                            BitstreamWriter &Stream, bool isGlobal) {
1354   if (FirstVal == LastVal) return;
1355
1356   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
1357
1358   unsigned AggregateAbbrev = 0;
1359   unsigned String8Abbrev = 0;
1360   unsigned CString7Abbrev = 0;
1361   unsigned CString6Abbrev = 0;
1362   // If this is a constant pool for the module, emit module-specific abbrevs.
1363   if (isGlobal) {
1364     // Abbrev for CST_CODE_AGGREGATE.
1365     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1366     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
1367     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1368     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
1369     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
1370
1371     // Abbrev for CST_CODE_STRING.
1372     Abbv = new BitCodeAbbrev();
1373     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
1374     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1375     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1376     String8Abbrev = Stream.EmitAbbrev(Abbv);
1377     // Abbrev for CST_CODE_CSTRING.
1378     Abbv = new BitCodeAbbrev();
1379     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1380     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1381     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1382     CString7Abbrev = Stream.EmitAbbrev(Abbv);
1383     // Abbrev for CST_CODE_CSTRING.
1384     Abbv = new BitCodeAbbrev();
1385     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1386     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1387     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1388     CString6Abbrev = Stream.EmitAbbrev(Abbv);
1389   }
1390
1391   SmallVector<uint64_t, 64> Record;
1392
1393   const ValueEnumerator::ValueList &Vals = VE.getValues();
1394   Type *LastTy = nullptr;
1395   for (unsigned i = FirstVal; i != LastVal; ++i) {
1396     const Value *V = Vals[i].first;
1397     // If we need to switch types, do so now.
1398     if (V->getType() != LastTy) {
1399       LastTy = V->getType();
1400       Record.push_back(VE.getTypeID(LastTy));
1401       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
1402                         CONSTANTS_SETTYPE_ABBREV);
1403       Record.clear();
1404     }
1405
1406     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
1407       Record.push_back(unsigned(IA->hasSideEffects()) |
1408                        unsigned(IA->isAlignStack()) << 1 |
1409                        unsigned(IA->getDialect()&1) << 2);
1410
1411       // Add the asm string.
1412       const std::string &AsmStr = IA->getAsmString();
1413       Record.push_back(AsmStr.size());
1414       Record.append(AsmStr.begin(), AsmStr.end());
1415
1416       // Add the constraint string.
1417       const std::string &ConstraintStr = IA->getConstraintString();
1418       Record.push_back(ConstraintStr.size());
1419       Record.append(ConstraintStr.begin(), ConstraintStr.end());
1420       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
1421       Record.clear();
1422       continue;
1423     }
1424     const Constant *C = cast<Constant>(V);
1425     unsigned Code = -1U;
1426     unsigned AbbrevToUse = 0;
1427     if (C->isNullValue()) {
1428       Code = bitc::CST_CODE_NULL;
1429     } else if (isa<UndefValue>(C)) {
1430       Code = bitc::CST_CODE_UNDEF;
1431     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
1432       if (IV->getBitWidth() <= 64) {
1433         uint64_t V = IV->getSExtValue();
1434         emitSignedInt64(Record, V);
1435         Code = bitc::CST_CODE_INTEGER;
1436         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
1437       } else {                             // Wide integers, > 64 bits in size.
1438         // We have an arbitrary precision integer value to write whose
1439         // bit width is > 64. However, in canonical unsigned integer
1440         // format it is likely that the high bits are going to be zero.
1441         // So, we only write the number of active words.
1442         unsigned NWords = IV->getValue().getActiveWords();
1443         const uint64_t *RawWords = IV->getValue().getRawData();
1444         for (unsigned i = 0; i != NWords; ++i) {
1445           emitSignedInt64(Record, RawWords[i]);
1446         }
1447         Code = bitc::CST_CODE_WIDE_INTEGER;
1448       }
1449     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
1450       Code = bitc::CST_CODE_FLOAT;
1451       Type *Ty = CFP->getType();
1452       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
1453         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
1454       } else if (Ty->isX86_FP80Ty()) {
1455         // api needed to prevent premature destruction
1456         // bits are not in the same order as a normal i80 APInt, compensate.
1457         APInt api = CFP->getValueAPF().bitcastToAPInt();
1458         const uint64_t *p = api.getRawData();
1459         Record.push_back((p[1] << 48) | (p[0] >> 16));
1460         Record.push_back(p[0] & 0xffffLL);
1461       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
1462         APInt api = CFP->getValueAPF().bitcastToAPInt();
1463         const uint64_t *p = api.getRawData();
1464         Record.push_back(p[0]);
1465         Record.push_back(p[1]);
1466       } else {
1467         assert (0 && "Unknown FP type!");
1468       }
1469     } else if (isa<ConstantDataSequential>(C) &&
1470                cast<ConstantDataSequential>(C)->isString()) {
1471       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
1472       // Emit constant strings specially.
1473       unsigned NumElts = Str->getNumElements();
1474       // If this is a null-terminated string, use the denser CSTRING encoding.
1475       if (Str->isCString()) {
1476         Code = bitc::CST_CODE_CSTRING;
1477         --NumElts;  // Don't encode the null, which isn't allowed by char6.
1478       } else {
1479         Code = bitc::CST_CODE_STRING;
1480         AbbrevToUse = String8Abbrev;
1481       }
1482       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
1483       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
1484       for (unsigned i = 0; i != NumElts; ++i) {
1485         unsigned char V = Str->getElementAsInteger(i);
1486         Record.push_back(V);
1487         isCStr7 &= (V & 128) == 0;
1488         if (isCStrChar6)
1489           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
1490       }
1491
1492       if (isCStrChar6)
1493         AbbrevToUse = CString6Abbrev;
1494       else if (isCStr7)
1495         AbbrevToUse = CString7Abbrev;
1496     } else if (const ConstantDataSequential *CDS =
1497                   dyn_cast<ConstantDataSequential>(C)) {
1498       Code = bitc::CST_CODE_DATA;
1499       Type *EltTy = CDS->getType()->getElementType();
1500       if (isa<IntegerType>(EltTy)) {
1501         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
1502           Record.push_back(CDS->getElementAsInteger(i));
1503       } else if (EltTy->isFloatTy()) {
1504         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1505           union { float F; uint32_t I; };
1506           F = CDS->getElementAsFloat(i);
1507           Record.push_back(I);
1508         }
1509       } else {
1510         assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
1511         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1512           union { double F; uint64_t I; };
1513           F = CDS->getElementAsDouble(i);
1514           Record.push_back(I);
1515         }
1516       }
1517     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
1518                isa<ConstantVector>(C)) {
1519       Code = bitc::CST_CODE_AGGREGATE;
1520       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
1521         Record.push_back(VE.getValueID(C->getOperand(i)));
1522       AbbrevToUse = AggregateAbbrev;
1523     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
1524       switch (CE->getOpcode()) {
1525       default:
1526         if (Instruction::isCast(CE->getOpcode())) {
1527           Code = bitc::CST_CODE_CE_CAST;
1528           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
1529           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1530           Record.push_back(VE.getValueID(C->getOperand(0)));
1531           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
1532         } else {
1533           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
1534           Code = bitc::CST_CODE_CE_BINOP;
1535           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
1536           Record.push_back(VE.getValueID(C->getOperand(0)));
1537           Record.push_back(VE.getValueID(C->getOperand(1)));
1538           uint64_t Flags = GetOptimizationFlags(CE);
1539           if (Flags != 0)
1540             Record.push_back(Flags);
1541         }
1542         break;
1543       case Instruction::GetElementPtr: {
1544         Code = bitc::CST_CODE_CE_GEP;
1545         const auto *GO = cast<GEPOperator>(C);
1546         if (GO->isInBounds())
1547           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
1548         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
1549         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
1550           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
1551           Record.push_back(VE.getValueID(C->getOperand(i)));
1552         }
1553         break;
1554       }
1555       case Instruction::Select:
1556         Code = bitc::CST_CODE_CE_SELECT;
1557         Record.push_back(VE.getValueID(C->getOperand(0)));
1558         Record.push_back(VE.getValueID(C->getOperand(1)));
1559         Record.push_back(VE.getValueID(C->getOperand(2)));
1560         break;
1561       case Instruction::ExtractElement:
1562         Code = bitc::CST_CODE_CE_EXTRACTELT;
1563         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1564         Record.push_back(VE.getValueID(C->getOperand(0)));
1565         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
1566         Record.push_back(VE.getValueID(C->getOperand(1)));
1567         break;
1568       case Instruction::InsertElement:
1569         Code = bitc::CST_CODE_CE_INSERTELT;
1570         Record.push_back(VE.getValueID(C->getOperand(0)));
1571         Record.push_back(VE.getValueID(C->getOperand(1)));
1572         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
1573         Record.push_back(VE.getValueID(C->getOperand(2)));
1574         break;
1575       case Instruction::ShuffleVector:
1576         // If the return type and argument types are the same, this is a
1577         // standard shufflevector instruction.  If the types are different,
1578         // then the shuffle is widening or truncating the input vectors, and
1579         // the argument type must also be encoded.
1580         if (C->getType() == C->getOperand(0)->getType()) {
1581           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
1582         } else {
1583           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
1584           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1585         }
1586         Record.push_back(VE.getValueID(C->getOperand(0)));
1587         Record.push_back(VE.getValueID(C->getOperand(1)));
1588         Record.push_back(VE.getValueID(C->getOperand(2)));
1589         break;
1590       case Instruction::ICmp:
1591       case Instruction::FCmp:
1592         Code = bitc::CST_CODE_CE_CMP;
1593         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1594         Record.push_back(VE.getValueID(C->getOperand(0)));
1595         Record.push_back(VE.getValueID(C->getOperand(1)));
1596         Record.push_back(CE->getPredicate());
1597         break;
1598       }
1599     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
1600       Code = bitc::CST_CODE_BLOCKADDRESS;
1601       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
1602       Record.push_back(VE.getValueID(BA->getFunction()));
1603       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
1604     } else {
1605 #ifndef NDEBUG
1606       C->dump();
1607 #endif
1608       llvm_unreachable("Unknown constant!");
1609     }
1610     Stream.EmitRecord(Code, Record, AbbrevToUse);
1611     Record.clear();
1612   }
1613
1614   Stream.ExitBlock();
1615 }
1616
1617 static void WriteModuleConstants(const ValueEnumerator &VE,
1618                                  BitstreamWriter &Stream) {
1619   const ValueEnumerator::ValueList &Vals = VE.getValues();
1620
1621   // Find the first constant to emit, which is the first non-globalvalue value.
1622   // We know globalvalues have been emitted by WriteModuleInfo.
1623   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1624     if (!isa<GlobalValue>(Vals[i].first)) {
1625       WriteConstants(i, Vals.size(), VE, Stream, true);
1626       return;
1627     }
1628   }
1629 }
1630
1631 /// PushValueAndType - The file has to encode both the value and type id for
1632 /// many values, because we need to know what type to create for forward
1633 /// references.  However, most operands are not forward references, so this type
1634 /// field is not needed.
1635 ///
1636 /// This function adds V's value ID to Vals.  If the value ID is higher than the
1637 /// instruction ID, then it is a forward reference, and it also includes the
1638 /// type ID.  The value ID that is written is encoded relative to the InstID.
1639 static bool PushValueAndType(const Value *V, unsigned InstID,
1640                              SmallVectorImpl<unsigned> &Vals,
1641                              ValueEnumerator &VE) {
1642   unsigned ValID = VE.getValueID(V);
1643   // Make encoding relative to the InstID.
1644   Vals.push_back(InstID - ValID);
1645   if (ValID >= InstID) {
1646     Vals.push_back(VE.getTypeID(V->getType()));
1647     return true;
1648   }
1649   return false;
1650 }
1651
1652 /// pushValue - Like PushValueAndType, but where the type of the value is
1653 /// omitted (perhaps it was already encoded in an earlier operand).
1654 static void pushValue(const Value *V, unsigned InstID,
1655                       SmallVectorImpl<unsigned> &Vals,
1656                       ValueEnumerator &VE) {
1657   unsigned ValID = VE.getValueID(V);
1658   Vals.push_back(InstID - ValID);
1659 }
1660
1661 static void pushValueSigned(const Value *V, unsigned InstID,
1662                             SmallVectorImpl<uint64_t> &Vals,
1663                             ValueEnumerator &VE) {
1664   unsigned ValID = VE.getValueID(V);
1665   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
1666   emitSignedInt64(Vals, diff);
1667 }
1668
1669 /// WriteInstruction - Emit an instruction to the specified stream.
1670 static void WriteInstruction(const Instruction &I, unsigned InstID,
1671                              ValueEnumerator &VE, BitstreamWriter &Stream,
1672                              SmallVectorImpl<unsigned> &Vals) {
1673   unsigned Code = 0;
1674   unsigned AbbrevToUse = 0;
1675   VE.setInstructionID(&I);
1676   switch (I.getOpcode()) {
1677   default:
1678     if (Instruction::isCast(I.getOpcode())) {
1679       Code = bitc::FUNC_CODE_INST_CAST;
1680       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1681         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1682       Vals.push_back(VE.getTypeID(I.getType()));
1683       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1684     } else {
1685       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1686       Code = bitc::FUNC_CODE_INST_BINOP;
1687       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1688         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1689       pushValue(I.getOperand(1), InstID, Vals, VE);
1690       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1691       uint64_t Flags = GetOptimizationFlags(&I);
1692       if (Flags != 0) {
1693         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1694           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1695         Vals.push_back(Flags);
1696       }
1697     }
1698     break;
1699
1700   case Instruction::GetElementPtr: {
1701     Code = bitc::FUNC_CODE_INST_GEP;
1702     AbbrevToUse = FUNCTION_INST_GEP_ABBREV;
1703     auto &GEPInst = cast<GetElementPtrInst>(I);
1704     Vals.push_back(GEPInst.isInBounds());
1705     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
1706     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1707       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1708     break;
1709   }
1710   case Instruction::ExtractValue: {
1711     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1712     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1713     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1714     Vals.append(EVI->idx_begin(), EVI->idx_end());
1715     break;
1716   }
1717   case Instruction::InsertValue: {
1718     Code = bitc::FUNC_CODE_INST_INSERTVAL;
1719     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1720     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1721     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1722     Vals.append(IVI->idx_begin(), IVI->idx_end());
1723     break;
1724   }
1725   case Instruction::Select:
1726     Code = bitc::FUNC_CODE_INST_VSELECT;
1727     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1728     pushValue(I.getOperand(2), InstID, Vals, VE);
1729     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1730     break;
1731   case Instruction::ExtractElement:
1732     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1733     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1734     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1735     break;
1736   case Instruction::InsertElement:
1737     Code = bitc::FUNC_CODE_INST_INSERTELT;
1738     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1739     pushValue(I.getOperand(1), InstID, Vals, VE);
1740     PushValueAndType(I.getOperand(2), InstID, Vals, VE);
1741     break;
1742   case Instruction::ShuffleVector:
1743     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1744     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1745     pushValue(I.getOperand(1), InstID, Vals, VE);
1746     pushValue(I.getOperand(2), InstID, Vals, VE);
1747     break;
1748   case Instruction::ICmp:
1749   case Instruction::FCmp:
1750     // compare returning Int1Ty or vector of Int1Ty
1751     Code = bitc::FUNC_CODE_INST_CMP2;
1752     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1753     pushValue(I.getOperand(1), InstID, Vals, VE);
1754     Vals.push_back(cast<CmpInst>(I).getPredicate());
1755     break;
1756
1757   case Instruction::Ret:
1758     {
1759       Code = bitc::FUNC_CODE_INST_RET;
1760       unsigned NumOperands = I.getNumOperands();
1761       if (NumOperands == 0)
1762         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1763       else if (NumOperands == 1) {
1764         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1765           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1766       } else {
1767         for (unsigned i = 0, e = NumOperands; i != e; ++i)
1768           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1769       }
1770     }
1771     break;
1772   case Instruction::Br:
1773     {
1774       Code = bitc::FUNC_CODE_INST_BR;
1775       const BranchInst &II = cast<BranchInst>(I);
1776       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1777       if (II.isConditional()) {
1778         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1779         pushValue(II.getCondition(), InstID, Vals, VE);
1780       }
1781     }
1782     break;
1783   case Instruction::Switch:
1784     {
1785       Code = bitc::FUNC_CODE_INST_SWITCH;
1786       const SwitchInst &SI = cast<SwitchInst>(I);
1787       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
1788       pushValue(SI.getCondition(), InstID, Vals, VE);
1789       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
1790       for (SwitchInst::ConstCaseIt i = SI.case_begin(), e = SI.case_end();
1791            i != e; ++i) {
1792         Vals.push_back(VE.getValueID(i.getCaseValue()));
1793         Vals.push_back(VE.getValueID(i.getCaseSuccessor()));
1794       }
1795     }
1796     break;
1797   case Instruction::IndirectBr:
1798     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1799     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1800     // Encode the address operand as relative, but not the basic blocks.
1801     pushValue(I.getOperand(0), InstID, Vals, VE);
1802     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
1803       Vals.push_back(VE.getValueID(I.getOperand(i)));
1804     break;
1805
1806   case Instruction::Invoke: {
1807     const InvokeInst *II = cast<InvokeInst>(&I);
1808     const Value *Callee = II->getCalledValue();
1809     FunctionType *FTy = II->getFunctionType();
1810     Code = bitc::FUNC_CODE_INST_INVOKE;
1811
1812     Vals.push_back(VE.getAttributeID(II->getAttributes()));
1813     Vals.push_back(II->getCallingConv() | 1 << 13);
1814     Vals.push_back(VE.getValueID(II->getNormalDest()));
1815     Vals.push_back(VE.getValueID(II->getUnwindDest()));
1816     Vals.push_back(VE.getTypeID(FTy));
1817     PushValueAndType(Callee, InstID, Vals, VE);
1818
1819     // Emit value #'s for the fixed parameters.
1820     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1821       pushValue(I.getOperand(i), InstID, Vals, VE);  // fixed param.
1822
1823     // Emit type/value pairs for varargs params.
1824     if (FTy->isVarArg()) {
1825       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1826            i != e; ++i)
1827         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1828     }
1829     break;
1830   }
1831   case Instruction::Resume:
1832     Code = bitc::FUNC_CODE_INST_RESUME;
1833     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1834     break;
1835   case Instruction::Unreachable:
1836     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1837     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1838     break;
1839
1840   case Instruction::PHI: {
1841     const PHINode &PN = cast<PHINode>(I);
1842     Code = bitc::FUNC_CODE_INST_PHI;
1843     // With the newer instruction encoding, forward references could give
1844     // negative valued IDs.  This is most common for PHIs, so we use
1845     // signed VBRs.
1846     SmallVector<uint64_t, 128> Vals64;
1847     Vals64.push_back(VE.getTypeID(PN.getType()));
1848     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1849       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64, VE);
1850       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1851     }
1852     // Emit a Vals64 vector and exit.
1853     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
1854     Vals64.clear();
1855     return;
1856   }
1857
1858   case Instruction::LandingPad: {
1859     const LandingPadInst &LP = cast<LandingPadInst>(I);
1860     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
1861     Vals.push_back(VE.getTypeID(LP.getType()));
1862     PushValueAndType(LP.getPersonalityFn(), InstID, Vals, VE);
1863     Vals.push_back(LP.isCleanup());
1864     Vals.push_back(LP.getNumClauses());
1865     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1866       if (LP.isCatch(I))
1867         Vals.push_back(LandingPadInst::Catch);
1868       else
1869         Vals.push_back(LandingPadInst::Filter);
1870       PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1871     }
1872     break;
1873   }
1874
1875   case Instruction::Alloca: {
1876     Code = bitc::FUNC_CODE_INST_ALLOCA;
1877     const AllocaInst &AI = cast<AllocaInst>(I);
1878     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
1879     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1880     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1881     unsigned AlignRecord = Log2_32(AI.getAlignment()) + 1;
1882     assert(Log2_32(Value::MaximumAlignment) + 1 < 1 << 5 &&
1883            "not enough bits for maximum alignment");
1884     assert(AlignRecord < 1 << 5 && "alignment greater than 1 << 64");
1885     AlignRecord |= AI.isUsedWithInAlloca() << 5;
1886     AlignRecord |= 1 << 6;
1887     Vals.push_back(AlignRecord);
1888     break;
1889   }
1890
1891   case Instruction::Load:
1892     if (cast<LoadInst>(I).isAtomic()) {
1893       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1894       PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1895     } else {
1896       Code = bitc::FUNC_CODE_INST_LOAD;
1897       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1898         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1899     }
1900     Vals.push_back(VE.getTypeID(I.getType()));
1901     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1902     Vals.push_back(cast<LoadInst>(I).isVolatile());
1903     if (cast<LoadInst>(I).isAtomic()) {
1904       Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1905       Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1906     }
1907     break;
1908   case Instruction::Store:
1909     if (cast<StoreInst>(I).isAtomic())
1910       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1911     else
1912       Code = bitc::FUNC_CODE_INST_STORE;
1913     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1914     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // valty + val
1915     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1916     Vals.push_back(cast<StoreInst>(I).isVolatile());
1917     if (cast<StoreInst>(I).isAtomic()) {
1918       Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1919       Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1920     }
1921     break;
1922   case Instruction::AtomicCmpXchg:
1923     Code = bitc::FUNC_CODE_INST_CMPXCHG;
1924     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1925     PushValueAndType(I.getOperand(1), InstID, Vals, VE);         // cmp.
1926     pushValue(I.getOperand(2), InstID, Vals, VE);         // newval.
1927     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1928     Vals.push_back(GetEncodedOrdering(
1929                      cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
1930     Vals.push_back(GetEncodedSynchScope(
1931                      cast<AtomicCmpXchgInst>(I).getSynchScope()));
1932     Vals.push_back(GetEncodedOrdering(
1933                      cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
1934     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
1935     break;
1936   case Instruction::AtomicRMW:
1937     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
1938     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1939     pushValue(I.getOperand(1), InstID, Vals, VE);         // val.
1940     Vals.push_back(GetEncodedRMWOperation(
1941                      cast<AtomicRMWInst>(I).getOperation()));
1942     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
1943     Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
1944     Vals.push_back(GetEncodedSynchScope(
1945                      cast<AtomicRMWInst>(I).getSynchScope()));
1946     break;
1947   case Instruction::Fence:
1948     Code = bitc::FUNC_CODE_INST_FENCE;
1949     Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
1950     Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
1951     break;
1952   case Instruction::Call: {
1953     const CallInst &CI = cast<CallInst>(I);
1954     FunctionType *FTy = CI.getFunctionType();
1955
1956     Code = bitc::FUNC_CODE_INST_CALL;
1957
1958     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1959     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()) |
1960                    unsigned(CI.isMustTailCall()) << 14 | 1 << 15);
1961     Vals.push_back(VE.getTypeID(FTy));
1962     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1963
1964     // Emit value #'s for the fixed parameters.
1965     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1966       // Check for labels (can happen with asm labels).
1967       if (FTy->getParamType(i)->isLabelTy())
1968         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
1969       else
1970         pushValue(CI.getArgOperand(i), InstID, Vals, VE);  // fixed param.
1971     }
1972
1973     // Emit type/value pairs for varargs params.
1974     if (FTy->isVarArg()) {
1975       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1976            i != e; ++i)
1977         PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1978     }
1979     break;
1980   }
1981   case Instruction::VAArg:
1982     Code = bitc::FUNC_CODE_INST_VAARG;
1983     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1984     pushValue(I.getOperand(0), InstID, Vals, VE); // valist.
1985     Vals.push_back(VE.getTypeID(I.getType())); // restype.
1986     break;
1987   }
1988
1989   Stream.EmitRecord(Code, Vals, AbbrevToUse);
1990   Vals.clear();
1991 }
1992
1993 // Emit names for globals/functions etc.
1994 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1995                                   const ValueEnumerator &VE,
1996                                   BitstreamWriter &Stream) {
1997   if (VST.empty()) return;
1998   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1999
2000   // FIXME: Set up the abbrev, we know how many values there are!
2001   // FIXME: We know if the type names can use 7-bit ascii.
2002   SmallVector<unsigned, 64> NameVals;
2003
2004   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
2005        SI != SE; ++SI) {
2006
2007     const ValueName &Name = *SI;
2008
2009     // Figure out the encoding to use for the name.
2010     bool is7Bit = true;
2011     bool isChar6 = true;
2012     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
2013          C != E; ++C) {
2014       if (isChar6)
2015         isChar6 = BitCodeAbbrevOp::isChar6(*C);
2016       if ((unsigned char)*C & 128) {
2017         is7Bit = false;
2018         break;  // don't bother scanning the rest.
2019       }
2020     }
2021
2022     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
2023
2024     // VST_ENTRY:   [valueid, namechar x N]
2025     // VST_BBENTRY: [bbid, namechar x N]
2026     unsigned Code;
2027     if (isa<BasicBlock>(SI->getValue())) {
2028       Code = bitc::VST_CODE_BBENTRY;
2029       if (isChar6)
2030         AbbrevToUse = VST_BBENTRY_6_ABBREV;
2031     } else {
2032       Code = bitc::VST_CODE_ENTRY;
2033       if (isChar6)
2034         AbbrevToUse = VST_ENTRY_6_ABBREV;
2035       else if (is7Bit)
2036         AbbrevToUse = VST_ENTRY_7_ABBREV;
2037     }
2038
2039     NameVals.push_back(VE.getValueID(SI->getValue()));
2040     for (const char *P = Name.getKeyData(),
2041          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
2042       NameVals.push_back((unsigned char)*P);
2043
2044     // Emit the finished record.
2045     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
2046     NameVals.clear();
2047   }
2048   Stream.ExitBlock();
2049 }
2050
2051 static void WriteUseList(ValueEnumerator &VE, UseListOrder &&Order,
2052                          BitstreamWriter &Stream) {
2053   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
2054   unsigned Code;
2055   if (isa<BasicBlock>(Order.V))
2056     Code = bitc::USELIST_CODE_BB;
2057   else
2058     Code = bitc::USELIST_CODE_DEFAULT;
2059
2060   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
2061   Record.push_back(VE.getValueID(Order.V));
2062   Stream.EmitRecord(Code, Record);
2063 }
2064
2065 static void WriteUseListBlock(const Function *F, ValueEnumerator &VE,
2066                               BitstreamWriter &Stream) {
2067   assert(VE.shouldPreserveUseListOrder() &&
2068          "Expected to be preserving use-list order");
2069
2070   auto hasMore = [&]() {
2071     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
2072   };
2073   if (!hasMore())
2074     // Nothing to do.
2075     return;
2076
2077   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
2078   while (hasMore()) {
2079     WriteUseList(VE, std::move(VE.UseListOrders.back()), Stream);
2080     VE.UseListOrders.pop_back();
2081   }
2082   Stream.ExitBlock();
2083 }
2084
2085 /// WriteFunction - Emit a function body to the module stream.
2086 static void WriteFunction(const Function &F, ValueEnumerator &VE,
2087                           BitstreamWriter &Stream) {
2088   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
2089   VE.incorporateFunction(F);
2090
2091   SmallVector<unsigned, 64> Vals;
2092
2093   // Emit the number of basic blocks, so the reader can create them ahead of
2094   // time.
2095   Vals.push_back(VE.getBasicBlocks().size());
2096   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
2097   Vals.clear();
2098
2099   // If there are function-local constants, emit them now.
2100   unsigned CstStart, CstEnd;
2101   VE.getFunctionConstantRange(CstStart, CstEnd);
2102   WriteConstants(CstStart, CstEnd, VE, Stream, false);
2103
2104   // If there is function-local metadata, emit it now.
2105   WriteFunctionLocalMetadata(F, VE, Stream);
2106
2107   // Keep a running idea of what the instruction ID is.
2108   unsigned InstID = CstEnd;
2109
2110   bool NeedsMetadataAttachment = F.hasMetadata();
2111
2112   DILocation *LastDL = nullptr;
2113
2114   // Finally, emit all the instructions, in order.
2115   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
2116     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
2117          I != E; ++I) {
2118       WriteInstruction(*I, InstID, VE, Stream, Vals);
2119
2120       if (!I->getType()->isVoidTy())
2121         ++InstID;
2122
2123       // If the instruction has metadata, write a metadata attachment later.
2124       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
2125
2126       // If the instruction has a debug location, emit it.
2127       DILocation *DL = I->getDebugLoc();
2128       if (!DL)
2129         continue;
2130
2131       if (DL == LastDL) {
2132         // Just repeat the same debug loc as last time.
2133         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
2134         continue;
2135       }
2136
2137       Vals.push_back(DL->getLine());
2138       Vals.push_back(DL->getColumn());
2139       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
2140       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
2141       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
2142       Vals.clear();
2143
2144       LastDL = DL;
2145     }
2146
2147   // Emit names for all the instructions etc.
2148   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
2149
2150   if (NeedsMetadataAttachment)
2151     WriteMetadataAttachment(F, VE, Stream);
2152   if (VE.shouldPreserveUseListOrder())
2153     WriteUseListBlock(&F, VE, Stream);
2154   VE.purgeFunction();
2155   Stream.ExitBlock();
2156 }
2157
2158 // Emit blockinfo, which defines the standard abbreviations etc.
2159 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
2160   // We only want to emit block info records for blocks that have multiple
2161   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
2162   // Other blocks can define their abbrevs inline.
2163   Stream.EnterBlockInfoBlock(2);
2164
2165   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
2166     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2167     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
2168     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2169     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2170     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2171     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2172                                    Abbv) != VST_ENTRY_8_ABBREV)
2173       llvm_unreachable("Unexpected abbrev ordering!");
2174   }
2175
2176   { // 7-bit fixed width VST_ENTRY strings.
2177     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2178     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2179     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2180     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2181     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2182     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2183                                    Abbv) != VST_ENTRY_7_ABBREV)
2184       llvm_unreachable("Unexpected abbrev ordering!");
2185   }
2186   { // 6-bit char6 VST_ENTRY strings.
2187     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2188     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2189     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2190     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2191     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2192     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2193                                    Abbv) != VST_ENTRY_6_ABBREV)
2194       llvm_unreachable("Unexpected abbrev ordering!");
2195   }
2196   { // 6-bit char6 VST_BBENTRY strings.
2197     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2198     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
2199     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2200     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2201     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2202     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2203                                    Abbv) != VST_BBENTRY_6_ABBREV)
2204       llvm_unreachable("Unexpected abbrev ordering!");
2205   }
2206
2207
2208
2209   { // SETTYPE abbrev for CONSTANTS_BLOCK.
2210     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2211     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
2212     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2213                               VE.computeBitsRequiredForTypeIndicies()));
2214     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2215                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
2216       llvm_unreachable("Unexpected abbrev ordering!");
2217   }
2218
2219   { // INTEGER abbrev for CONSTANTS_BLOCK.
2220     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2221     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
2222     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2223     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2224                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
2225       llvm_unreachable("Unexpected abbrev ordering!");
2226   }
2227
2228   { // CE_CAST abbrev for CONSTANTS_BLOCK.
2229     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2230     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
2231     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
2232     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
2233                               VE.computeBitsRequiredForTypeIndicies()));
2234     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
2235
2236     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2237                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
2238       llvm_unreachable("Unexpected abbrev ordering!");
2239   }
2240   { // NULL abbrev for CONSTANTS_BLOCK.
2241     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2242     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
2243     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2244                                    Abbv) != CONSTANTS_NULL_Abbrev)
2245       llvm_unreachable("Unexpected abbrev ordering!");
2246   }
2247
2248   // FIXME: This should only use space for first class types!
2249
2250   { // INST_LOAD abbrev for FUNCTION_BLOCK.
2251     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2252     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
2253     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
2254     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2255                               VE.computeBitsRequiredForTypeIndicies()));
2256     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
2257     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
2258     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2259                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
2260       llvm_unreachable("Unexpected abbrev ordering!");
2261   }
2262   { // INST_BINOP abbrev for FUNCTION_BLOCK.
2263     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2264     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2265     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2266     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2267     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2268     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2269                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
2270       llvm_unreachable("Unexpected abbrev ordering!");
2271   }
2272   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
2273     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2274     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2275     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2276     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2277     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2278     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
2279     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2280                                    Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
2281       llvm_unreachable("Unexpected abbrev ordering!");
2282   }
2283   { // INST_CAST abbrev for FUNCTION_BLOCK.
2284     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2285     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
2286     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
2287     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
2288                               VE.computeBitsRequiredForTypeIndicies()));
2289     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
2290     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2291                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
2292       llvm_unreachable("Unexpected abbrev ordering!");
2293   }
2294
2295   { // INST_RET abbrev for FUNCTION_BLOCK.
2296     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2297     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2298     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2299                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
2300       llvm_unreachable("Unexpected abbrev ordering!");
2301   }
2302   { // INST_RET abbrev for FUNCTION_BLOCK.
2303     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2304     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2305     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
2306     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2307                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
2308       llvm_unreachable("Unexpected abbrev ordering!");
2309   }
2310   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
2311     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2312     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
2313     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2314                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
2315       llvm_unreachable("Unexpected abbrev ordering!");
2316   }
2317   {
2318     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2319     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
2320     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2321     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
2322                               Log2_32_Ceil(VE.getTypes().size() + 1)));
2323     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2324     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2325     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2326         FUNCTION_INST_GEP_ABBREV)
2327       llvm_unreachable("Unexpected abbrev ordering!");
2328   }
2329
2330   Stream.ExitBlock();
2331 }
2332
2333 /// WriteModule - Emit the specified module to the bitstream.
2334 static void WriteModule(const Module *M, BitstreamWriter &Stream,
2335                         bool ShouldPreserveUseListOrder) {
2336   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
2337
2338   SmallVector<unsigned, 1> Vals;
2339   unsigned CurVersion = 1;
2340   Vals.push_back(CurVersion);
2341   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
2342
2343   // Analyze the module, enumerating globals, functions, etc.
2344   ValueEnumerator VE(*M, ShouldPreserveUseListOrder);
2345
2346   // Emit blockinfo, which defines the standard abbreviations etc.
2347   WriteBlockInfo(VE, Stream);
2348
2349   // Emit information about attribute groups.
2350   WriteAttributeGroupTable(VE, Stream);
2351
2352   // Emit information about parameter attributes.
2353   WriteAttributeTable(VE, Stream);
2354
2355   // Emit information describing all of the types in the module.
2356   WriteTypeTable(VE, Stream);
2357
2358   writeComdats(VE, Stream);
2359
2360   // Emit top-level description of module, including target triple, inline asm,
2361   // descriptors for global variables, and function prototype info.
2362   WriteModuleInfo(M, VE, Stream);
2363
2364   // Emit constants.
2365   WriteModuleConstants(VE, Stream);
2366
2367   // Emit metadata.
2368   WriteModuleMetadata(M, VE, Stream);
2369
2370   // Emit metadata.
2371   WriteModuleMetadataStore(M, Stream);
2372
2373   // Emit names for globals/functions etc.
2374   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
2375
2376   // Emit module-level use-lists.
2377   if (VE.shouldPreserveUseListOrder())
2378     WriteUseListBlock(nullptr, VE, Stream);
2379
2380   // Emit function bodies.
2381   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
2382     if (!F->isDeclaration())
2383       WriteFunction(*F, VE, Stream);
2384
2385   Stream.ExitBlock();
2386 }
2387
2388 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
2389 /// header and trailer to make it compatible with the system archiver.  To do
2390 /// this we emit the following header, and then emit a trailer that pads the
2391 /// file out to be a multiple of 16 bytes.
2392 ///
2393 /// struct bc_header {
2394 ///   uint32_t Magic;         // 0x0B17C0DE
2395 ///   uint32_t Version;       // Version, currently always 0.
2396 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
2397 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
2398 ///   uint32_t CPUType;       // CPU specifier.
2399 ///   ... potentially more later ...
2400 /// };
2401 enum {
2402   DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
2403   DarwinBCHeaderSize = 5*4
2404 };
2405
2406 static void WriteInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
2407                                uint32_t &Position) {
2408   Buffer[Position + 0] = (unsigned char) (Value >>  0);
2409   Buffer[Position + 1] = (unsigned char) (Value >>  8);
2410   Buffer[Position + 2] = (unsigned char) (Value >> 16);
2411   Buffer[Position + 3] = (unsigned char) (Value >> 24);
2412   Position += 4;
2413 }
2414
2415 static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
2416                                          const Triple &TT) {
2417   unsigned CPUType = ~0U;
2418
2419   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
2420   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
2421   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
2422   // specific constants here because they are implicitly part of the Darwin ABI.
2423   enum {
2424     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
2425     DARWIN_CPU_TYPE_X86        = 7,
2426     DARWIN_CPU_TYPE_ARM        = 12,
2427     DARWIN_CPU_TYPE_POWERPC    = 18
2428   };
2429
2430   Triple::ArchType Arch = TT.getArch();
2431   if (Arch == Triple::x86_64)
2432     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
2433   else if (Arch == Triple::x86)
2434     CPUType = DARWIN_CPU_TYPE_X86;
2435   else if (Arch == Triple::ppc)
2436     CPUType = DARWIN_CPU_TYPE_POWERPC;
2437   else if (Arch == Triple::ppc64)
2438     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
2439   else if (Arch == Triple::arm || Arch == Triple::thumb)
2440     CPUType = DARWIN_CPU_TYPE_ARM;
2441
2442   // Traditional Bitcode starts after header.
2443   assert(Buffer.size() >= DarwinBCHeaderSize &&
2444          "Expected header size to be reserved");
2445   unsigned BCOffset = DarwinBCHeaderSize;
2446   unsigned BCSize = Buffer.size()-DarwinBCHeaderSize;
2447
2448   // Write the magic and version.
2449   unsigned Position = 0;
2450   WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position);
2451   WriteInt32ToBuffer(0          , Buffer, Position); // Version.
2452   WriteInt32ToBuffer(BCOffset   , Buffer, Position);
2453   WriteInt32ToBuffer(BCSize     , Buffer, Position);
2454   WriteInt32ToBuffer(CPUType    , Buffer, Position);
2455
2456   // If the file is not a multiple of 16 bytes, insert dummy padding.
2457   while (Buffer.size() & 15)
2458     Buffer.push_back(0);
2459 }
2460
2461 /// WriteBitcodeToFile - Write the specified module to the specified output
2462 /// stream.
2463 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out,
2464                               bool ShouldPreserveUseListOrder) {
2465   SmallVector<char, 0> Buffer;
2466   Buffer.reserve(256*1024);
2467
2468   // If this is darwin or another generic macho target, reserve space for the
2469   // header.
2470   Triple TT(M->getTargetTriple());
2471   if (TT.isOSDarwin())
2472     Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0);
2473
2474   // Emit the module into the buffer.
2475   {
2476     BitstreamWriter Stream(Buffer);
2477
2478     // Emit the file header.
2479     Stream.Emit((unsigned)'B', 8);
2480     Stream.Emit((unsigned)'C', 8);
2481     Stream.Emit(0x0, 4);
2482     Stream.Emit(0xC, 4);
2483     Stream.Emit(0xE, 4);
2484     Stream.Emit(0xD, 4);
2485
2486     // Emit the module.
2487     WriteModule(M, Stream, ShouldPreserveUseListOrder);
2488   }
2489
2490   if (TT.isOSDarwin())
2491     EmitDarwinBCHeaderAndTrailer(Buffer, TT);
2492
2493   // Write the generated bitstream to "Out".
2494   Out.write((char*)&Buffer.front(), Buffer.size());
2495 }