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::ArgMemOnly:
 166     return bitc::ATTR_KIND_ARGMEMONLY;
 167   case Attribute::Builtin:
 168     return bitc::ATTR_KIND_BUILTIN;
 169   case Attribute::ByVal:
 170     return bitc::ATTR_KIND_BY_VAL;
 171   case Attribute::Convergent:
 172     return bitc::ATTR_KIND_CONVERGENT;
 173   case Attribute::InAlloca:
 174     return bitc::ATTR_KIND_IN_ALLOCA;
 175   case Attribute::Cold:
 176     return bitc::ATTR_KIND_COLD;
 177   case Attribute::InlineHint:
 178     return bitc::ATTR_KIND_INLINE_HINT;
 179   case Attribute::InReg:
 180     return bitc::ATTR_KIND_IN_REG;
 181   case Attribute::JumpTable:
 182     return bitc::ATTR_KIND_JUMP_TABLE;
 183   case Attribute::MinSize:
 184     return bitc::ATTR_KIND_MIN_SIZE;
 185   case Attribute::Naked:
 186     return bitc::ATTR_KIND_NAKED;
 187   case Attribute::Nest:
 188     return bitc::ATTR_KIND_NEST;
 189   case Attribute::NoAlias:
 190     return bitc::ATTR_KIND_NO_ALIAS;
 191   case Attribute::NoBuiltin:
 192     return bitc::ATTR_KIND_NO_BUILTIN;
 193   case Attribute::NoCapture:
 194     return bitc::ATTR_KIND_NO_CAPTURE;
 195   case Attribute::NoDuplicate:
 196     return bitc::ATTR_KIND_NO_DUPLICATE;
 197   case Attribute::NoImplicitFloat:
 198     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
 199   case Attribute::NoInline:
 200     return bitc::ATTR_KIND_NO_INLINE;
 201   case Attribute::NonLazyBind:
 202     return bitc::ATTR_KIND_NON_LAZY_BIND;
 203   case Attribute::NonNull:
 204     return bitc::ATTR_KIND_NON_NULL;
 205   case Attribute::Dereferenceable:
 206     return bitc::ATTR_KIND_DEREFERENCEABLE;
 207   case Attribute::DereferenceableOrNull:
 208     return bitc::ATTR_KIND_DEREFERENCEABLE_OR_NULL;
 209   case Attribute::NoRedZone:
 210     return bitc::ATTR_KIND_NO_RED_ZONE;
 211   case Attribute::NoReturn:
 212     return bitc::ATTR_KIND_NO_RETURN;
 213   case Attribute::NoUnwind:
 214     return bitc::ATTR_KIND_NO_UNWIND;
 215   case Attribute::OptimizeForSize:
 216     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
 217   case Attribute::OptimizeNone:
 218     return bitc::ATTR_KIND_OPTIMIZE_NONE;
 219   case Attribute::ReadNone:
 220     return bitc::ATTR_KIND_READ_NONE;
 221   case Attribute::ReadOnly:
 222     return bitc::ATTR_KIND_READ_ONLY;
 223   case Attribute::Returned:
 224     return bitc::ATTR_KIND_RETURNED;
 225   case Attribute::ReturnsTwice:
 226     return bitc::ATTR_KIND_RETURNS_TWICE;
 227   case Attribute::SExt:
 228     return bitc::ATTR_KIND_S_EXT;
 229   case Attribute::StackAlignment:
 230     return bitc::ATTR_KIND_STACK_ALIGNMENT;
 231   case Attribute::StackProtect:
 232     return bitc::ATTR_KIND_STACK_PROTECT;
 233   case Attribute::StackProtectReq:
 234     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
 235   case Attribute::StackProtectStrong:
 236     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
 237   case Attribute::SafeStack:
 238     return bitc::ATTR_KIND_SAFESTACK;
 239   case Attribute::StructRet:
 240     return bitc::ATTR_KIND_STRUCT_RET;
 241   case Attribute::SanitizeAddress:
 242     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
 243   case Attribute::SanitizeThread:
 244     return bitc::ATTR_KIND_SANITIZE_THREAD;
 245   case Attribute::SanitizeMemory:
 246     return bitc::ATTR_KIND_SANITIZE_MEMORY;
 247   case Attribute::UWTable:
 248     return bitc::ATTR_KIND_UW_TABLE;
 249   case Attribute::ZExt:
 250     return bitc::ATTR_KIND_Z_EXT;
 251   case Attribute::EndAttrKinds:
 252     llvm_unreachable("Can not encode end-attribute kinds marker.");
 253   case Attribute::None:
 254     llvm_unreachable("Can not encode none-attribute.");
 255   }
 256
 257   llvm_unreachable("Trying to encode unknown attribute");
 258 }
 259
 260 static void WriteAttributeGroupTable(const ValueEnumerator &VE,
 261                                      BitstreamWriter &Stream) {
 262   const std::vector<AttributeSet> &AttrGrps = VE.getAttributeGroups();
 263   if (AttrGrps.empty()) return;
 264
 265   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
 266
 267   SmallVector<uint64_t, 64> Record;
 268   for (unsigned i = 0, e = AttrGrps.size(); i != e; ++i) {
 269     AttributeSet AS = AttrGrps[i];
 270     for (unsigned i = 0, e = AS.getNumSlots(); i != e; ++i) {
 271       AttributeSet A = AS.getSlotAttributes(i);
 272
 273       Record.push_back(VE.getAttributeGroupID(A));
 274       Record.push_back(AS.getSlotIndex(i));
 275
 276       for (AttributeSet::iterator I = AS.begin(0), E = AS.end(0);
 277            I != E; ++I) {
 278         Attribute Attr = *I;
 279         if (Attr.isEnumAttribute()) {
 280           Record.push_back(0);
 281           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 282         } else if (Attr.isIntAttribute()) {
 283           Record.push_back(1);
 284           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 285           Record.push_back(Attr.getValueAsInt());
 286         } else {
 287           StringRef Kind = Attr.getKindAsString();
 288           StringRef Val = Attr.getValueAsString();
 289
 290           Record.push_back(Val.empty() ? 3 : 4);
 291           Record.append(Kind.begin(), Kind.end());
 292           Record.push_back(0);
 293           if (!Val.empty()) {
 294             Record.append(Val.begin(), Val.end());
 295             Record.push_back(0);
 296           }
 297         }
 298       }
 299
 300       Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
 301       Record.clear();
 302     }
 303   }
 304
 305   Stream.ExitBlock();
 306 }
 307
 308 static void WriteAttributeTable(const ValueEnumerator &VE,
 309                                 BitstreamWriter &Stream) {
 310   const std::vector<AttributeSet> &Attrs = VE.getAttributes();
 311   if (Attrs.empty()) return;
 312
 313   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 314
 315   SmallVector<uint64_t, 64> Record;
 316   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
 317     const AttributeSet &A = Attrs[i];
 318     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
 319       Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
 320
 321     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 322     Record.clear();
 323   }
 324
 325   Stream.ExitBlock();
 326 }
 327
 328 /// WriteTypeTable - Write out the type table for a module.
 329 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 330   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 331
 332   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
 333   SmallVector<uint64_t, 64> TypeVals;
 334
 335   uint64_t NumBits = VE.computeBitsRequiredForTypeIndicies();
 336
 337   // Abbrev for TYPE_CODE_POINTER.
 338   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 339   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
 340   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 341   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
 342   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
 343
 344   // Abbrev for TYPE_CODE_FUNCTION.
 345   Abbv = new BitCodeAbbrev();
 346   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
 347   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
 348   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 349   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 350
 351   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 352
 353   // Abbrev for TYPE_CODE_STRUCT_ANON.
 354   Abbv = new BitCodeAbbrev();
 355   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
 356   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 357   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 358   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 359
 360   unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
 361
 362   // Abbrev for TYPE_CODE_STRUCT_NAME.
 363   Abbv = new BitCodeAbbrev();
 364   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
 365   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 366   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 367   unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
 368
 369   // Abbrev for TYPE_CODE_STRUCT_NAMED.
 370   Abbv = new BitCodeAbbrev();
 371   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
 372   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 373   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 374   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 375
 376   unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
 377
 378   // Abbrev for TYPE_CODE_ARRAY.
 379   Abbv = new BitCodeAbbrev();
 380   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 381   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 382   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 383
 384   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 385
 386   // Emit an entry count so the reader can reserve space.
 387   TypeVals.push_back(TypeList.size());
 388   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 389   TypeVals.clear();
 390
 391   // Loop over all of the types, emitting each in turn.
 392   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 393     Type *T = TypeList[i];
 394     int AbbrevToUse = 0;
 395     unsigned Code = 0;
 396
 397     switch (T->getTypeID()) {
 398     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
 399     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
 400     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
 401     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
 402     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
 403     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
 404     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 405     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
 406     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
 407     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
 408     case Type::IntegerTyID:
 409       // INTEGER: [width]
 410       Code = bitc::TYPE_CODE_INTEGER;
 411       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 412       break;
 413     case Type::PointerTyID: {
 414       PointerType *PTy = cast<PointerType>(T);
 415       // POINTER: [pointee type, address space]
 416       Code = bitc::TYPE_CODE_POINTER;
 417       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
 418       unsigned AddressSpace = PTy->getAddressSpace();
 419       TypeVals.push_back(AddressSpace);
 420       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
 421       break;
 422     }
 423     case Type::FunctionTyID: {
 424       FunctionType *FT = cast<FunctionType>(T);
 425       // FUNCTION: [isvararg, retty, paramty x N]
 426       Code = bitc::TYPE_CODE_FUNCTION;
 427       TypeVals.push_back(FT->isVarArg());
 428       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 429       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 430         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 431       AbbrevToUse = FunctionAbbrev;
 432       break;
 433     }
 434     case Type::StructTyID: {
 435       StructType *ST = cast<StructType>(T);
 436       // STRUCT: [ispacked, eltty x N]
 437       TypeVals.push_back(ST->isPacked());
 438       // Output all of the element types.
 439       for (StructType::element_iterator I = ST->element_begin(),
 440            E = ST->element_end(); I != E; ++I)
 441         TypeVals.push_back(VE.getTypeID(*I));
 442
 443       if (ST->isLiteral()) {
 444         Code = bitc::TYPE_CODE_STRUCT_ANON;
 445         AbbrevToUse = StructAnonAbbrev;
 446       } else {
 447         if (ST->isOpaque()) {
 448           Code = bitc::TYPE_CODE_OPAQUE;
 449         } else {
 450           Code = bitc::TYPE_CODE_STRUCT_NAMED;
 451           AbbrevToUse = StructNamedAbbrev;
 452         }
 453
 454         // Emit the name if it is present.
 455         if (!ST->getName().empty())
 456           WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
 457                             StructNameAbbrev, Stream);
 458       }
 459       break;
 460     }
 461     case Type::ArrayTyID: {
 462       ArrayType *AT = cast<ArrayType>(T);
 463       // ARRAY: [numelts, eltty]
 464       Code = bitc::TYPE_CODE_ARRAY;
 465       TypeVals.push_back(AT->getNumElements());
 466       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 467       AbbrevToUse = ArrayAbbrev;
 468       break;
 469     }
 470     case Type::VectorTyID: {
 471       VectorType *VT = cast<VectorType>(T);
 472       // VECTOR [numelts, eltty]
 473       Code = bitc::TYPE_CODE_VECTOR;
 474       TypeVals.push_back(VT->getNumElements());
 475       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 476       break;
 477     }
 478     }
 479
 480     // Emit the finished record.
 481     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 482     TypeVals.clear();
 483   }
 484
 485   Stream.ExitBlock();
 486 }
 487
 488 static unsigned getEncodedLinkage(const GlobalValue &GV) {
 489   switch (GV.getLinkage()) {
 490   case GlobalValue::ExternalLinkage:
 491     return 0;
 492   case GlobalValue::WeakAnyLinkage:
 493     return 16;
 494   case GlobalValue::AppendingLinkage:
 495     return 2;
 496   case GlobalValue::InternalLinkage:
 497     return 3;
 498   case GlobalValue::LinkOnceAnyLinkage:
 499     return 18;
 500   case GlobalValue::ExternalWeakLinkage:
 501     return 7;
 502   case GlobalValue::CommonLinkage:
 503     return 8;
 504   case GlobalValue::PrivateLinkage:
 505     return 9;
 506   case GlobalValue::WeakODRLinkage:
 507     return 17;
 508   case GlobalValue::LinkOnceODRLinkage:
 509     return 19;
 510   case GlobalValue::AvailableExternallyLinkage:
 511     return 12;
 512   }
 513   llvm_unreachable("Invalid linkage");
 514 }
 515
 516 static unsigned getEncodedVisibility(const GlobalValue &GV) {
 517   switch (GV.getVisibility()) {
 518   case GlobalValue::DefaultVisibility:   return 0;
 519   case GlobalValue::HiddenVisibility:    return 1;
 520   case GlobalValue::ProtectedVisibility: return 2;
 521   }
 522   llvm_unreachable("Invalid visibility");
 523 }
 524
 525 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
 526   switch (GV.getDLLStorageClass()) {
 527   case GlobalValue::DefaultStorageClass:   return 0;
 528   case GlobalValue::DLLImportStorageClass: return 1;
 529   case GlobalValue::DLLExportStorageClass: return 2;
 530   }
 531   llvm_unreachable("Invalid DLL storage class");
 532 }
 533
 534 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
 535   switch (GV.getThreadLocalMode()) {
 536     case GlobalVariable::NotThreadLocal:         return 0;
 537     case GlobalVariable::GeneralDynamicTLSModel: return 1;
 538     case GlobalVariable::LocalDynamicTLSModel:   return 2;
 539     case GlobalVariable::InitialExecTLSModel:    return 3;
 540     case GlobalVariable::LocalExecTLSModel:      return 4;
 541   }
 542   llvm_unreachable("Invalid TLS model");
 543 }
 544
 545 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
 546   switch (C.getSelectionKind()) {
 547   case Comdat::Any:
 548     return bitc::COMDAT_SELECTION_KIND_ANY;
 549   case Comdat::ExactMatch:
 550     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
 551   case Comdat::Largest:
 552     return bitc::COMDAT_SELECTION_KIND_LARGEST;
 553   case Comdat::NoDuplicates:
 554     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
 555   case Comdat::SameSize:
 556     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
 557   }
 558   llvm_unreachable("Invalid selection kind");
 559 }
 560
 561 static void writeComdats(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 562   SmallVector<uint16_t, 64> Vals;
 563   for (const Comdat *C : VE.getComdats()) {
 564     // COMDAT: [selection_kind, name]
 565     Vals.push_back(getEncodedComdatSelectionKind(*C));
 566     size_t Size = C->getName().size();
 567     assert(isUInt<16>(Size));
 568     Vals.push_back(Size);
 569     for (char Chr : C->getName())
 570       Vals.push_back((unsigned char)Chr);
 571     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
 572     Vals.clear();
 573   }
 574 }
 575
 576 // Emit top-level description of module, including target triple, inline asm,
 577 // descriptors for global variables, and function prototype info.
 578 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 579                             BitstreamWriter &Stream) {
 580   // Emit various pieces of data attached to a module.
 581   if (!M->getTargetTriple().empty())
 582     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 583                       0/*TODO*/, Stream);
 584   const std::string &DL = M->getDataLayoutStr();
 585   if (!DL.empty())
 586     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/, Stream);
 587   if (!M->getModuleInlineAsm().empty())
 588     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 589                       0/*TODO*/, Stream);
 590
 591   // Emit information about sections and GC, computing how many there are. Also
 592   // compute the maximum alignment value.
 593   std::map<std::string, unsigned> SectionMap;
 594   std::map<std::string, unsigned> GCMap;
 595   unsigned MaxAlignment = 0;
 596   unsigned MaxGlobalType = 0;
 597   for (const GlobalValue &GV : M->globals()) {
 598     MaxAlignment = std::max(MaxAlignment, GV.getAlignment());
 599     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getValueType()));
 600     if (GV.hasSection()) {
 601       // Give section names unique ID's.
 602       unsigned &Entry = SectionMap[GV.getSection()];
 603       if (!Entry) {
 604         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
 605                           0/*TODO*/, Stream);
 606         Entry = SectionMap.size();
 607       }
 608     }
 609   }
 610   for (const Function &F : *M) {
 611     MaxAlignment = std::max(MaxAlignment, F.getAlignment());
 612     if (F.hasSection()) {
 613       // Give section names unique ID's.
 614       unsigned &Entry = SectionMap[F.getSection()];
 615       if (!Entry) {
 616         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
 617                           0/*TODO*/, Stream);
 618         Entry = SectionMap.size();
 619       }
 620     }
 621     if (F.hasGC()) {
 622       // Same for GC names.
 623       unsigned &Entry = GCMap[F.getGC()];
 624       if (!Entry) {
 625         WriteStringRecord(bitc::MODULE_CODE_GCNAME, F.getGC(),
 626                           0/*TODO*/, Stream);
 627         Entry = GCMap.size();
 628       }
 629     }
 630   }
 631
 632   // Emit abbrev for globals, now that we know # sections and max alignment.
 633   unsigned SimpleGVarAbbrev = 0;
 634   if (!M->global_empty()) {
 635     // Add an abbrev for common globals with no visibility or thread localness.
 636     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 637     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 638     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 639                               Log2_32_Ceil(MaxGlobalType+1)));
 640     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // AddrSpace << 2
 641                                                            //| explicitType << 1
 642                                                            //| constant
 643     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));   // Initializer.
 644     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5)); // Linkage.
 645     if (MaxAlignment == 0)                                 // Alignment.
 646       Abbv->Add(BitCodeAbbrevOp(0));
 647     else {
 648       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 649       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 650                                Log2_32_Ceil(MaxEncAlignment+1)));
 651     }
 652     if (SectionMap.empty())                                    // Section.
 653       Abbv->Add(BitCodeAbbrevOp(0));
 654     else
 655       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 656                                Log2_32_Ceil(SectionMap.size()+1)));
 657     // Don't bother emitting vis + thread local.
 658     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 659   }
 660
 661   // Emit the global variable information.
 662   SmallVector<unsigned, 64> Vals;
 663   for (const GlobalVariable &GV : M->globals()) {
 664     unsigned AbbrevToUse = 0;
 665
 666     // GLOBALVAR: [type, isconst, initid,
 667     //             linkage, alignment, section, visibility, threadlocal,
 668     //             unnamed_addr, externally_initialized, dllstorageclass,
 669     //             comdat]
 670     Vals.push_back(VE.getTypeID(GV.getValueType()));
 671     Vals.push_back(GV.getType()->getAddressSpace() << 2 | 2 | GV.isConstant());
 672     Vals.push_back(GV.isDeclaration() ? 0 :
 673                    (VE.getValueID(GV.getInitializer()) + 1));
 674     Vals.push_back(getEncodedLinkage(GV));
 675     Vals.push_back(Log2_32(GV.getAlignment())+1);
 676     Vals.push_back(GV.hasSection() ? SectionMap[GV.getSection()] : 0);
 677     if (GV.isThreadLocal() ||
 678         GV.getVisibility() != GlobalValue::DefaultVisibility ||
 679         GV.hasUnnamedAddr() || GV.isExternallyInitialized() ||
 680         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
 681         GV.hasComdat()) {
 682       Vals.push_back(getEncodedVisibility(GV));
 683       Vals.push_back(getEncodedThreadLocalMode(GV));
 684       Vals.push_back(GV.hasUnnamedAddr());
 685       Vals.push_back(GV.isExternallyInitialized());
 686       Vals.push_back(getEncodedDLLStorageClass(GV));
 687       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
 688     } else {
 689       AbbrevToUse = SimpleGVarAbbrev;
 690     }
 691
 692     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 693     Vals.clear();
 694   }
 695
 696   // Emit the function proto information.
 697   for (const Function &F : *M) {
 698     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
 699     //             section, visibility, gc, unnamed_addr, prologuedata,
 700     //             dllstorageclass, comdat, prefixdata, personalityfn]
 701     Vals.push_back(VE.getTypeID(F.getFunctionType()));
 702     Vals.push_back(F.getCallingConv());
 703     Vals.push_back(F.isDeclaration());
 704     Vals.push_back(getEncodedLinkage(F));
 705     Vals.push_back(VE.getAttributeID(F.getAttributes()));
 706     Vals.push_back(Log2_32(F.getAlignment())+1);
 707     Vals.push_back(F.hasSection() ? SectionMap[F.getSection()] : 0);
 708     Vals.push_back(getEncodedVisibility(F));
 709     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
 710     Vals.push_back(F.hasUnnamedAddr());
 711     Vals.push_back(F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1)
 712                                        : 0);
 713     Vals.push_back(getEncodedDLLStorageClass(F));
 714     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
 715     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
 716                                      : 0);
 717     Vals.push_back(
 718         F.hasPersonalityFn() ? (VE.getValueID(F.getPersonalityFn()) + 1) : 0);
 719
 720     unsigned AbbrevToUse = 0;
 721     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 722     Vals.clear();
 723   }
 724
 725   // Emit the alias information.
 726   for (const GlobalAlias &A : M->aliases()) {
 727     // ALIAS: [alias type, aliasee val#, linkage, visibility]
 728     Vals.push_back(VE.getTypeID(A.getType()));
 729     Vals.push_back(VE.getValueID(A.getAliasee()));
 730     Vals.push_back(getEncodedLinkage(A));
 731     Vals.push_back(getEncodedVisibility(A));
 732     Vals.push_back(getEncodedDLLStorageClass(A));
 733     Vals.push_back(getEncodedThreadLocalMode(A));
 734     Vals.push_back(A.hasUnnamedAddr());
 735     unsigned AbbrevToUse = 0;
 736     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 737     Vals.clear();
 738   }
 739 }
 740
 741 static uint64_t GetOptimizationFlags(const Value *V) {
 742   uint64_t Flags = 0;
 743
 744   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
 745     if (OBO->hasNoSignedWrap())
 746       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
 747     if (OBO->hasNoUnsignedWrap())
 748       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
 749   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
 750     if (PEO->isExact())
 751       Flags |= 1 << bitc::PEO_EXACT;
 752   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
 753     if (FPMO->hasUnsafeAlgebra())
 754       Flags |= FastMathFlags::UnsafeAlgebra;
 755     if (FPMO->hasNoNaNs())
 756       Flags |= FastMathFlags::NoNaNs;
 757     if (FPMO->hasNoInfs())
 758       Flags |= FastMathFlags::NoInfs;
 759     if (FPMO->hasNoSignedZeros())
 760       Flags |= FastMathFlags::NoSignedZeros;
 761     if (FPMO->hasAllowReciprocal())
 762       Flags |= FastMathFlags::AllowReciprocal;
 763   }
 764
 765   return Flags;
 766 }
 767
 768 static void WriteValueAsMetadata(const ValueAsMetadata *MD,
 769                                  const ValueEnumerator &VE,
 770                                  BitstreamWriter &Stream,
 771                                  SmallVectorImpl<uint64_t> &Record) {
 772   // Mimic an MDNode with a value as one operand.
 773   Value *V = MD->getValue();
 774   Record.push_back(VE.getTypeID(V->getType()));
 775   Record.push_back(VE.getValueID(V));
 776   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
 777   Record.clear();
 778 }
 779
 780 static void WriteMDTuple(const MDTuple *N, const ValueEnumerator &VE,
 781                          BitstreamWriter &Stream,
 782                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
 783   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
 784     Metadata *MD = N->getOperand(i);
 785     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
 786            "Unexpected function-local metadata");
 787     Record.push_back(VE.getMetadataOrNullID(MD));
 788   }
 789   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
 790                                     : bitc::METADATA_NODE,
 791                     Record, Abbrev);
 792   Record.clear();
 793 }
 794
 795 static void WriteDILocation(const DILocation *N, const ValueEnumerator &VE,
 796                             BitstreamWriter &Stream,
 797                             SmallVectorImpl<uint64_t> &Record,
 798                             unsigned Abbrev) {
 799   Record.push_back(N->isDistinct());
 800   Record.push_back(N->getLine());
 801   Record.push_back(N->getColumn());
 802   Record.push_back(VE.getMetadataID(N->getScope()));
 803   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
 804
 805   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
 806   Record.clear();
 807 }
 808
 809 static void WriteGenericDINode(const GenericDINode *N,
 810                                const ValueEnumerator &VE,
 811                                BitstreamWriter &Stream,
 812                                SmallVectorImpl<uint64_t> &Record,
 813                                unsigned Abbrev) {
 814   Record.push_back(N->isDistinct());
 815   Record.push_back(N->getTag());
 816   Record.push_back(0); // Per-tag version field; unused for now.
 817
 818   for (auto &I : N->operands())
 819     Record.push_back(VE.getMetadataOrNullID(I));
 820
 821   Stream.EmitRecord(bitc::METADATA_GENERIC_DEBUG, Record, Abbrev);
 822   Record.clear();
 823 }
 824
 825 static uint64_t rotateSign(int64_t I) {
 826   uint64_t U = I;
 827   return I < 0 ? ~(U << 1) : U << 1;
 828 }
 829
 830 static void WriteDISubrange(const DISubrange *N, const ValueEnumerator &,
 831                             BitstreamWriter &Stream,
 832                             SmallVectorImpl<uint64_t> &Record,
 833                             unsigned Abbrev) {
 834   Record.push_back(N->isDistinct());
 835   Record.push_back(N->getCount());
 836   Record.push_back(rotateSign(N->getLowerBound()));
 837
 838   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
 839   Record.clear();
 840 }
 841
 842 static void WriteDIEnumerator(const DIEnumerator *N, const ValueEnumerator &VE,
 843                               BitstreamWriter &Stream,
 844                               SmallVectorImpl<uint64_t> &Record,
 845                               unsigned Abbrev) {
 846   Record.push_back(N->isDistinct());
 847   Record.push_back(rotateSign(N->getValue()));
 848   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 849
 850   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
 851   Record.clear();
 852 }
 853
 854 static void WriteDIBasicType(const DIBasicType *N, const ValueEnumerator &VE,
 855                              BitstreamWriter &Stream,
 856                              SmallVectorImpl<uint64_t> &Record,
 857                              unsigned Abbrev) {
 858   Record.push_back(N->isDistinct());
 859   Record.push_back(N->getTag());
 860   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 861   Record.push_back(N->getSizeInBits());
 862   Record.push_back(N->getAlignInBits());
 863   Record.push_back(N->getEncoding());
 864
 865   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
 866   Record.clear();
 867 }
 868
 869 static void WriteDIDerivedType(const DIDerivedType *N,
 870                                const ValueEnumerator &VE,
 871                                BitstreamWriter &Stream,
 872                                SmallVectorImpl<uint64_t> &Record,
 873                                unsigned Abbrev) {
 874   Record.push_back(N->isDistinct());
 875   Record.push_back(N->getTag());
 876   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 877   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 878   Record.push_back(N->getLine());
 879   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 880   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
 881   Record.push_back(N->getSizeInBits());
 882   Record.push_back(N->getAlignInBits());
 883   Record.push_back(N->getOffsetInBits());
 884   Record.push_back(N->getFlags());
 885   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
 886
 887   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
 888   Record.clear();
 889 }
 890
 891 static void WriteDICompositeType(const DICompositeType *N,
 892                                  const ValueEnumerator &VE,
 893                                  BitstreamWriter &Stream,
 894                                  SmallVectorImpl<uint64_t> &Record,
 895                                  unsigned Abbrev) {
 896   Record.push_back(N->isDistinct());
 897   Record.push_back(N->getTag());
 898   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 899   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 900   Record.push_back(N->getLine());
 901   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 902   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
 903   Record.push_back(N->getSizeInBits());
 904   Record.push_back(N->getAlignInBits());
 905   Record.push_back(N->getOffsetInBits());
 906   Record.push_back(N->getFlags());
 907   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
 908   Record.push_back(N->getRuntimeLang());
 909   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
 910   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
 911   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
 912
 913   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
 914   Record.clear();
 915 }
 916
 917 static void WriteDISubroutineType(const DISubroutineType *N,
 918                                   const ValueEnumerator &VE,
 919                                   BitstreamWriter &Stream,
 920                                   SmallVectorImpl<uint64_t> &Record,
 921                                   unsigned Abbrev) {
 922   Record.push_back(N->isDistinct());
 923   Record.push_back(N->getFlags());
 924   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
 925
 926   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
 927   Record.clear();
 928 }
 929
 930 static void WriteDIFile(const DIFile *N, const ValueEnumerator &VE,
 931                         BitstreamWriter &Stream,
 932                         SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
 933   Record.push_back(N->isDistinct());
 934   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
 935   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
 936
 937   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
 938   Record.clear();
 939 }
 940
 941 static void WriteDICompileUnit(const DICompileUnit *N,
 942                                const ValueEnumerator &VE,
 943                                BitstreamWriter &Stream,
 944                                SmallVectorImpl<uint64_t> &Record,
 945                                unsigned Abbrev) {
 946   Record.push_back(N->isDistinct());
 947   Record.push_back(N->getSourceLanguage());
 948   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 949   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
 950   Record.push_back(N->isOptimized());
 951   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
 952   Record.push_back(N->getRuntimeVersion());
 953   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
 954   Record.push_back(N->getEmissionKind());
 955   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
 956   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
 957   Record.push_back(VE.getMetadataOrNullID(N->getSubprograms().get()));
 958   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
 959   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
 960   Record.push_back(N->getDWOId());
 961
 962   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
 963   Record.clear();
 964 }
 965
 966 static void WriteDISubprogram(const DISubprogram *N, const ValueEnumerator &VE,
 967                               BitstreamWriter &Stream,
 968                               SmallVectorImpl<uint64_t> &Record,
 969                               unsigned Abbrev) {
 970   Record.push_back(N->isDistinct());
 971   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 972   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 973   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
 974   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 975   Record.push_back(N->getLine());
 976   Record.push_back(VE.getMetadataOrNullID(N->getType()));
 977   Record.push_back(N->isLocalToUnit());
 978   Record.push_back(N->isDefinition());
 979   Record.push_back(N->getScopeLine());
 980   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
 981   Record.push_back(N->getVirtuality());
 982   Record.push_back(N->getVirtualIndex());
 983   Record.push_back(N->getFlags());
 984   Record.push_back(N->isOptimized());
 985   Record.push_back(VE.getMetadataOrNullID(N->getRawFunction()));
 986   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
 987   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
 988   Record.push_back(VE.getMetadataOrNullID(N->getVariables().get()));
 989
 990   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
 991   Record.clear();
 992 }
 993
 994 static void WriteDILexicalBlock(const DILexicalBlock *N,
 995                                 const ValueEnumerator &VE,
 996                                 BitstreamWriter &Stream,
 997                                 SmallVectorImpl<uint64_t> &Record,
 998                                 unsigned Abbrev) {
 999   Record.push_back(N->isDistinct());
1000   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1001   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1002   Record.push_back(N->getLine());
1003   Record.push_back(N->getColumn());
1004
1005   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
1006   Record.clear();
1007 }
1008
1009 static void WriteDILexicalBlockFile(const DILexicalBlockFile *N,
1010                                     const ValueEnumerator &VE,
1011                                     BitstreamWriter &Stream,
1012                                     SmallVectorImpl<uint64_t> &Record,
1013                                     unsigned Abbrev) {
1014   Record.push_back(N->isDistinct());
1015   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1016   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1017   Record.push_back(N->getDiscriminator());
1018
1019   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
1020   Record.clear();
1021 }
1022
1023 static void WriteDINamespace(const DINamespace *N, const ValueEnumerator &VE,
1024                              BitstreamWriter &Stream,
1025                              SmallVectorImpl<uint64_t> &Record,
1026                              unsigned Abbrev) {
1027   Record.push_back(N->isDistinct());
1028   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1029   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1030   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1031   Record.push_back(N->getLine());
1032
1033   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
1034   Record.clear();
1035 }
1036
1037 static void WriteDIModule(const DIModule *N, const ValueEnumerator &VE,
1038                           BitstreamWriter &Stream,
1039                           SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
1040   Record.push_back(N->isDistinct());
1041   for (auto &I : N->operands())
1042     Record.push_back(VE.getMetadataOrNullID(I));
1043
1044   Stream.EmitRecord(bitc::METADATA_MODULE, Record, Abbrev);
1045   Record.clear();
1046 }
1047
1048 static void WriteDITemplateTypeParameter(const DITemplateTypeParameter *N,
1049                                          const ValueEnumerator &VE,
1050                                          BitstreamWriter &Stream,
1051                                          SmallVectorImpl<uint64_t> &Record,
1052                                          unsigned Abbrev) {
1053   Record.push_back(N->isDistinct());
1054   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1055   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1056
1057   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
1058   Record.clear();
1059 }
1060
1061 static void WriteDITemplateValueParameter(const DITemplateValueParameter *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(N->getTag());
1068   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1069   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1070   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
1071
1072   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
1073   Record.clear();
1074 }
1075
1076 static void WriteDIGlobalVariable(const DIGlobalVariable *N,
1077                                   const ValueEnumerator &VE,
1078                                   BitstreamWriter &Stream,
1079                                   SmallVectorImpl<uint64_t> &Record,
1080                                   unsigned Abbrev) {
1081   Record.push_back(N->isDistinct());
1082   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1083   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1084   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1085   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1086   Record.push_back(N->getLine());
1087   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1088   Record.push_back(N->isLocalToUnit());
1089   Record.push_back(N->isDefinition());
1090   Record.push_back(VE.getMetadataOrNullID(N->getRawVariable()));
1091   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
1092
1093   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
1094   Record.clear();
1095 }
1096
1097 static void WriteDILocalVariable(const DILocalVariable *N,
1098                                  const ValueEnumerator &VE,
1099                                  BitstreamWriter &Stream,
1100                                  SmallVectorImpl<uint64_t> &Record,
1101                                  unsigned Abbrev) {
1102   Record.push_back(N->isDistinct());
1103   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1104   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1105   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1106   Record.push_back(N->getLine());
1107   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1108   Record.push_back(N->getArg());
1109   Record.push_back(N->getFlags());
1110
1111   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
1112   Record.clear();
1113 }
1114
1115 static void WriteDIExpression(const DIExpression *N, const ValueEnumerator &,
1116                               BitstreamWriter &Stream,
1117                               SmallVectorImpl<uint64_t> &Record,
1118                               unsigned Abbrev) {
1119   Record.reserve(N->getElements().size() + 1);
1120
1121   Record.push_back(N->isDistinct());
1122   Record.append(N->elements_begin(), N->elements_end());
1123
1124   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
1125   Record.clear();
1126 }
1127
1128 static void WriteDIObjCProperty(const DIObjCProperty *N,
1129                                 const ValueEnumerator &VE,
1130                                 BitstreamWriter &Stream,
1131                                 SmallVectorImpl<uint64_t> &Record,
1132                                 unsigned Abbrev) {
1133   Record.push_back(N->isDistinct());
1134   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1135   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1136   Record.push_back(N->getLine());
1137   Record.push_back(VE.getMetadataOrNullID(N->getRawSetterName()));
1138   Record.push_back(VE.getMetadataOrNullID(N->getRawGetterName()));
1139   Record.push_back(N->getAttributes());
1140   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1141
1142   Stream.EmitRecord(bitc::METADATA_OBJC_PROPERTY, Record, Abbrev);
1143   Record.clear();
1144 }
1145
1146 static void WriteDIImportedEntity(const DIImportedEntity *N,
1147                                   const ValueEnumerator &VE,
1148                                   BitstreamWriter &Stream,
1149                                   SmallVectorImpl<uint64_t> &Record,
1150                                   unsigned Abbrev) {
1151   Record.push_back(N->isDistinct());
1152   Record.push_back(N->getTag());
1153   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1154   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
1155   Record.push_back(N->getLine());
1156   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1157
1158   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
1159   Record.clear();
1160 }
1161
1162 static void WriteModuleMetadata(const Module *M,
1163                                 const ValueEnumerator &VE,
1164                                 BitstreamWriter &Stream) {
1165   const auto &MDs = VE.getMDs();
1166   if (MDs.empty() && M->named_metadata_empty())
1167     return;
1168
1169   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1170
1171   unsigned MDSAbbrev = 0;
1172   if (VE.hasMDString()) {
1173     // Abbrev for METADATA_STRING.
1174     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1175     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
1176     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1177     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1178     MDSAbbrev = Stream.EmitAbbrev(Abbv);
1179   }
1180
1181   // Initialize MDNode abbreviations.
1182 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
1183 #include "llvm/IR/Metadata.def"
1184
1185   if (VE.hasDILocation()) {
1186     // Abbrev for METADATA_LOCATION.
1187     //
1188     // Assume the column is usually under 128, and always output the inlined-at
1189     // location (it's never more expensive than building an array size 1).
1190     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1191     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1192     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1193     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1194     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1195     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1196     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1197     DILocationAbbrev = Stream.EmitAbbrev(Abbv);
1198   }
1199
1200   if (VE.hasGenericDINode()) {
1201     // Abbrev for METADATA_GENERIC_DEBUG.
1202     //
1203     // Assume the column is usually under 128, and always output the inlined-at
1204     // location (it's never more expensive than building an array size 1).
1205     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1206     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1207     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1208     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1209     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1210     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1211     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1212     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1213     GenericDINodeAbbrev = Stream.EmitAbbrev(Abbv);
1214   }
1215
1216   unsigned NameAbbrev = 0;
1217   if (!M->named_metadata_empty()) {
1218     // Abbrev for METADATA_NAME.
1219     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1220     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
1221     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1222     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1223     NameAbbrev = Stream.EmitAbbrev(Abbv);
1224   }
1225
1226   SmallVector<uint64_t, 64> Record;
1227   for (const Metadata *MD : MDs) {
1228     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
1229       assert(N->isResolved() && "Expected forward references to be resolved");
1230
1231       switch (N->getMetadataID()) {
1232       default:
1233         llvm_unreachable("Invalid MDNode subclass");
1234 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
1235   case Metadata::CLASS##Kind:                                                  \
1236     Write##CLASS(cast<CLASS>(N), VE, Stream, Record, CLASS##Abbrev);           \
1237     continue;
1238 #include "llvm/IR/Metadata.def"
1239       }
1240     }
1241     if (const auto *MDC = dyn_cast<ConstantAsMetadata>(MD)) {
1242       WriteValueAsMetadata(MDC, VE, Stream, Record);
1243       continue;
1244     }
1245     const MDString *MDS = cast<MDString>(MD);
1246     // Code: [strchar x N]
1247     Record.append(MDS->bytes_begin(), MDS->bytes_end());
1248
1249     // Emit the finished record.
1250     Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
1251     Record.clear();
1252   }
1253
1254   // Write named metadata.
1255   for (const NamedMDNode &NMD : M->named_metadata()) {
1256     // Write name.
1257     StringRef Str = NMD.getName();
1258     Record.append(Str.bytes_begin(), Str.bytes_end());
1259     Stream.EmitRecord(bitc::METADATA_NAME, Record, NameAbbrev);
1260     Record.clear();
1261
1262     // Write named metadata operands.
1263     for (const MDNode *N : NMD.operands())
1264       Record.push_back(VE.getMetadataID(N));
1265     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
1266     Record.clear();
1267   }
1268
1269   Stream.ExitBlock();
1270 }
1271
1272 static void WriteFunctionLocalMetadata(const Function &F,
1273                                        const ValueEnumerator &VE,
1274                                        BitstreamWriter &Stream) {
1275   bool StartedMetadataBlock = false;
1276   SmallVector<uint64_t, 64> Record;
1277   const SmallVectorImpl<const LocalAsMetadata *> &MDs =
1278       VE.getFunctionLocalMDs();
1279   for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1280     assert(MDs[i] && "Expected valid function-local metadata");
1281     if (!StartedMetadataBlock) {
1282       Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1283       StartedMetadataBlock = true;
1284     }
1285     WriteValueAsMetadata(MDs[i], VE, Stream, Record);
1286   }
1287
1288   if (StartedMetadataBlock)
1289     Stream.ExitBlock();
1290 }
1291
1292 static void WriteMetadataAttachment(const Function &F,
1293                                     const ValueEnumerator &VE,
1294                                     BitstreamWriter &Stream) {
1295   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
1296
1297   SmallVector<uint64_t, 64> Record;
1298
1299   // Write metadata attachments
1300   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
1301   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
1302   F.getAllMetadata(MDs);
1303   if (!MDs.empty()) {
1304     for (const auto &I : MDs) {
1305       Record.push_back(I.first);
1306       Record.push_back(VE.getMetadataID(I.second));
1307     }
1308     Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1309     Record.clear();
1310   }
1311
1312   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1313     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1314          I != E; ++I) {
1315       MDs.clear();
1316       I->getAllMetadataOtherThanDebugLoc(MDs);
1317
1318       // If no metadata, ignore instruction.
1319       if (MDs.empty()) continue;
1320
1321       Record.push_back(VE.getInstructionID(I));
1322
1323       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1324         Record.push_back(MDs[i].first);
1325         Record.push_back(VE.getMetadataID(MDs[i].second));
1326       }
1327       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1328       Record.clear();
1329     }
1330
1331   Stream.ExitBlock();
1332 }
1333
1334 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
1335   SmallVector<uint64_t, 64> Record;
1336
1337   // Write metadata kinds
1338   // METADATA_KIND - [n x [id, name]]
1339   SmallVector<StringRef, 8> Names;
1340   M->getMDKindNames(Names);
1341
1342   if (Names.empty()) return;
1343
1344   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1345
1346   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
1347     Record.push_back(MDKindID);
1348     StringRef KName = Names[MDKindID];
1349     Record.append(KName.begin(), KName.end());
1350
1351     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
1352     Record.clear();
1353   }
1354
1355   Stream.ExitBlock();
1356 }
1357
1358 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
1359   if ((int64_t)V >= 0)
1360     Vals.push_back(V << 1);
1361   else
1362     Vals.push_back((-V << 1) | 1);
1363 }
1364
1365 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
1366                            const ValueEnumerator &VE,
1367                            BitstreamWriter &Stream, bool isGlobal) {
1368   if (FirstVal == LastVal) return;
1369
1370   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
1371
1372   unsigned AggregateAbbrev = 0;
1373   unsigned String8Abbrev = 0;
1374   unsigned CString7Abbrev = 0;
1375   unsigned CString6Abbrev = 0;
1376   // If this is a constant pool for the module, emit module-specific abbrevs.
1377   if (isGlobal) {
1378     // Abbrev for CST_CODE_AGGREGATE.
1379     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1380     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
1381     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1382     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
1383     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
1384
1385     // Abbrev for CST_CODE_STRING.
1386     Abbv = new BitCodeAbbrev();
1387     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
1388     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1389     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1390     String8Abbrev = Stream.EmitAbbrev(Abbv);
1391     // Abbrev for CST_CODE_CSTRING.
1392     Abbv = new BitCodeAbbrev();
1393     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1394     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1395     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1396     CString7Abbrev = Stream.EmitAbbrev(Abbv);
1397     // Abbrev for CST_CODE_CSTRING.
1398     Abbv = new BitCodeAbbrev();
1399     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1400     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1401     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1402     CString6Abbrev = Stream.EmitAbbrev(Abbv);
1403   }
1404
1405   SmallVector<uint64_t, 64> Record;
1406
1407   const ValueEnumerator::ValueList &Vals = VE.getValues();
1408   Type *LastTy = nullptr;
1409   for (unsigned i = FirstVal; i != LastVal; ++i) {
1410     const Value *V = Vals[i].first;
1411     // If we need to switch types, do so now.
1412     if (V->getType() != LastTy) {
1413       LastTy = V->getType();
1414       Record.push_back(VE.getTypeID(LastTy));
1415       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
1416                         CONSTANTS_SETTYPE_ABBREV);
1417       Record.clear();
1418     }
1419
1420     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
1421       Record.push_back(unsigned(IA->hasSideEffects()) |
1422                        unsigned(IA->isAlignStack()) << 1 |
1423                        unsigned(IA->getDialect()&1) << 2);
1424
1425       // Add the asm string.
1426       const std::string &AsmStr = IA->getAsmString();
1427       Record.push_back(AsmStr.size());
1428       Record.append(AsmStr.begin(), AsmStr.end());
1429
1430       // Add the constraint string.
1431       const std::string &ConstraintStr = IA->getConstraintString();
1432       Record.push_back(ConstraintStr.size());
1433       Record.append(ConstraintStr.begin(), ConstraintStr.end());
1434       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
1435       Record.clear();
1436       continue;
1437     }
1438     const Constant *C = cast<Constant>(V);
1439     unsigned Code = -1U;
1440     unsigned AbbrevToUse = 0;
1441     if (C->isNullValue()) {
1442       Code = bitc::CST_CODE_NULL;
1443     } else if (isa<UndefValue>(C)) {
1444       Code = bitc::CST_CODE_UNDEF;
1445     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
1446       if (IV->getBitWidth() <= 64) {
1447         uint64_t V = IV->getSExtValue();
1448         emitSignedInt64(Record, V);
1449         Code = bitc::CST_CODE_INTEGER;
1450         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
1451       } else {                             // Wide integers, > 64 bits in size.
1452         // We have an arbitrary precision integer value to write whose
1453         // bit width is > 64. However, in canonical unsigned integer
1454         // format it is likely that the high bits are going to be zero.
1455         // So, we only write the number of active words.
1456         unsigned NWords = IV->getValue().getActiveWords();
1457         const uint64_t *RawWords = IV->getValue().getRawData();
1458         for (unsigned i = 0; i != NWords; ++i) {
1459           emitSignedInt64(Record, RawWords[i]);
1460         }
1461         Code = bitc::CST_CODE_WIDE_INTEGER;
1462       }
1463     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
1464       Code = bitc::CST_CODE_FLOAT;
1465       Type *Ty = CFP->getType();
1466       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
1467         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
1468       } else if (Ty->isX86_FP80Ty()) {
1469         // api needed to prevent premature destruction
1470         // bits are not in the same order as a normal i80 APInt, compensate.
1471         APInt api = CFP->getValueAPF().bitcastToAPInt();
1472         const uint64_t *p = api.getRawData();
1473         Record.push_back((p[1] << 48) | (p[0] >> 16));
1474         Record.push_back(p[0] & 0xffffLL);
1475       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
1476         APInt api = CFP->getValueAPF().bitcastToAPInt();
1477         const uint64_t *p = api.getRawData();
1478         Record.push_back(p[0]);
1479         Record.push_back(p[1]);
1480       } else {
1481         assert (0 && "Unknown FP type!");
1482       }
1483     } else if (isa<ConstantDataSequential>(C) &&
1484                cast<ConstantDataSequential>(C)->isString()) {
1485       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
1486       // Emit constant strings specially.
1487       unsigned NumElts = Str->getNumElements();
1488       // If this is a null-terminated string, use the denser CSTRING encoding.
1489       if (Str->isCString()) {
1490         Code = bitc::CST_CODE_CSTRING;
1491         --NumElts;  // Don't encode the null, which isn't allowed by char6.
1492       } else {
1493         Code = bitc::CST_CODE_STRING;
1494         AbbrevToUse = String8Abbrev;
1495       }
1496       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
1497       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
1498       for (unsigned i = 0; i != NumElts; ++i) {
1499         unsigned char V = Str->getElementAsInteger(i);
1500         Record.push_back(V);
1501         isCStr7 &= (V & 128) == 0;
1502         if (isCStrChar6)
1503           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
1504       }
1505
1506       if (isCStrChar6)
1507         AbbrevToUse = CString6Abbrev;
1508       else if (isCStr7)
1509         AbbrevToUse = CString7Abbrev;
1510     } else if (const ConstantDataSequential *CDS =
1511                   dyn_cast<ConstantDataSequential>(C)) {
1512       Code = bitc::CST_CODE_DATA;
1513       Type *EltTy = CDS->getType()->getElementType();
1514       if (isa<IntegerType>(EltTy)) {
1515         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
1516           Record.push_back(CDS->getElementAsInteger(i));
1517       } else if (EltTy->isFloatTy()) {
1518         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1519           union { float F; uint32_t I; };
1520           F = CDS->getElementAsFloat(i);
1521           Record.push_back(I);
1522         }
1523       } else {
1524         assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
1525         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1526           union { double F; uint64_t I; };
1527           F = CDS->getElementAsDouble(i);
1528           Record.push_back(I);
1529         }
1530       }
1531     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
1532                isa<ConstantVector>(C)) {
1533       Code = bitc::CST_CODE_AGGREGATE;
1534       for (const Value *Op : C->operands())
1535         Record.push_back(VE.getValueID(Op));
1536       AbbrevToUse = AggregateAbbrev;
1537     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
1538       switch (CE->getOpcode()) {
1539       default:
1540         if (Instruction::isCast(CE->getOpcode())) {
1541           Code = bitc::CST_CODE_CE_CAST;
1542           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
1543           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1544           Record.push_back(VE.getValueID(C->getOperand(0)));
1545           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
1546         } else {
1547           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
1548           Code = bitc::CST_CODE_CE_BINOP;
1549           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
1550           Record.push_back(VE.getValueID(C->getOperand(0)));
1551           Record.push_back(VE.getValueID(C->getOperand(1)));
1552           uint64_t Flags = GetOptimizationFlags(CE);
1553           if (Flags != 0)
1554             Record.push_back(Flags);
1555         }
1556         break;
1557       case Instruction::GetElementPtr: {
1558         Code = bitc::CST_CODE_CE_GEP;
1559         const auto *GO = cast<GEPOperator>(C);
1560         if (GO->isInBounds())
1561           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
1562         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
1563         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
1564           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
1565           Record.push_back(VE.getValueID(C->getOperand(i)));
1566         }
1567         break;
1568       }
1569       case Instruction::Select:
1570         Code = bitc::CST_CODE_CE_SELECT;
1571         Record.push_back(VE.getValueID(C->getOperand(0)));
1572         Record.push_back(VE.getValueID(C->getOperand(1)));
1573         Record.push_back(VE.getValueID(C->getOperand(2)));
1574         break;
1575       case Instruction::ExtractElement:
1576         Code = bitc::CST_CODE_CE_EXTRACTELT;
1577         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1578         Record.push_back(VE.getValueID(C->getOperand(0)));
1579         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
1580         Record.push_back(VE.getValueID(C->getOperand(1)));
1581         break;
1582       case Instruction::InsertElement:
1583         Code = bitc::CST_CODE_CE_INSERTELT;
1584         Record.push_back(VE.getValueID(C->getOperand(0)));
1585         Record.push_back(VE.getValueID(C->getOperand(1)));
1586         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
1587         Record.push_back(VE.getValueID(C->getOperand(2)));
1588         break;
1589       case Instruction::ShuffleVector:
1590         // If the return type and argument types are the same, this is a
1591         // standard shufflevector instruction.  If the types are different,
1592         // then the shuffle is widening or truncating the input vectors, and
1593         // the argument type must also be encoded.
1594         if (C->getType() == C->getOperand(0)->getType()) {
1595           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
1596         } else {
1597           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
1598           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1599         }
1600         Record.push_back(VE.getValueID(C->getOperand(0)));
1601         Record.push_back(VE.getValueID(C->getOperand(1)));
1602         Record.push_back(VE.getValueID(C->getOperand(2)));
1603         break;
1604       case Instruction::ICmp:
1605       case Instruction::FCmp:
1606         Code = bitc::CST_CODE_CE_CMP;
1607         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1608         Record.push_back(VE.getValueID(C->getOperand(0)));
1609         Record.push_back(VE.getValueID(C->getOperand(1)));
1610         Record.push_back(CE->getPredicate());
1611         break;
1612       }
1613     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
1614       Code = bitc::CST_CODE_BLOCKADDRESS;
1615       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
1616       Record.push_back(VE.getValueID(BA->getFunction()));
1617       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
1618     } else {
1619 #ifndef NDEBUG
1620       C->dump();
1621 #endif
1622       llvm_unreachable("Unknown constant!");
1623     }
1624     Stream.EmitRecord(Code, Record, AbbrevToUse);
1625     Record.clear();
1626   }
1627
1628   Stream.ExitBlock();
1629 }
1630
1631 static void WriteModuleConstants(const ValueEnumerator &VE,
1632                                  BitstreamWriter &Stream) {
1633   const ValueEnumerator::ValueList &Vals = VE.getValues();
1634
1635   // Find the first constant to emit, which is the first non-globalvalue value.
1636   // We know globalvalues have been emitted by WriteModuleInfo.
1637   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1638     if (!isa<GlobalValue>(Vals[i].first)) {
1639       WriteConstants(i, Vals.size(), VE, Stream, true);
1640       return;
1641     }
1642   }
1643 }
1644
1645 /// PushValueAndType - The file has to encode both the value and type id for
1646 /// many values, because we need to know what type to create for forward
1647 /// references.  However, most operands are not forward references, so this type
1648 /// field is not needed.
1649 ///
1650 /// This function adds V's value ID to Vals.  If the value ID is higher than the
1651 /// instruction ID, then it is a forward reference, and it also includes the
1652 /// type ID.  The value ID that is written is encoded relative to the InstID.
1653 static bool PushValueAndType(const Value *V, unsigned InstID,
1654                              SmallVectorImpl<unsigned> &Vals,
1655                              ValueEnumerator &VE) {
1656   unsigned ValID = VE.getValueID(V);
1657   // Make encoding relative to the InstID.
1658   Vals.push_back(InstID - ValID);
1659   if (ValID >= InstID) {
1660     Vals.push_back(VE.getTypeID(V->getType()));
1661     return true;
1662   }
1663   return false;
1664 }
1665
1666 /// pushValue - Like PushValueAndType, but where the type of the value is
1667 /// omitted (perhaps it was already encoded in an earlier operand).
1668 static void pushValue(const Value *V, unsigned InstID,
1669                       SmallVectorImpl<unsigned> &Vals,
1670                       ValueEnumerator &VE) {
1671   unsigned ValID = VE.getValueID(V);
1672   Vals.push_back(InstID - ValID);
1673 }
1674
1675 static void pushValueSigned(const Value *V, unsigned InstID,
1676                             SmallVectorImpl<uint64_t> &Vals,
1677                             ValueEnumerator &VE) {
1678   unsigned ValID = VE.getValueID(V);
1679   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
1680   emitSignedInt64(Vals, diff);
1681 }
1682
1683 /// WriteInstruction - Emit an instruction to the specified stream.
1684 static void WriteInstruction(const Instruction &I, unsigned InstID,
1685                              ValueEnumerator &VE, BitstreamWriter &Stream,
1686                              SmallVectorImpl<unsigned> &Vals) {
1687   unsigned Code = 0;
1688   unsigned AbbrevToUse = 0;
1689   VE.setInstructionID(&I);
1690   switch (I.getOpcode()) {
1691   default:
1692     if (Instruction::isCast(I.getOpcode())) {
1693       Code = bitc::FUNC_CODE_INST_CAST;
1694       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1695         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1696       Vals.push_back(VE.getTypeID(I.getType()));
1697       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1698     } else {
1699       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1700       Code = bitc::FUNC_CODE_INST_BINOP;
1701       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1702         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1703       pushValue(I.getOperand(1), InstID, Vals, VE);
1704       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1705       uint64_t Flags = GetOptimizationFlags(&I);
1706       if (Flags != 0) {
1707         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1708           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1709         Vals.push_back(Flags);
1710       }
1711     }
1712     break;
1713
1714   case Instruction::GetElementPtr: {
1715     Code = bitc::FUNC_CODE_INST_GEP;
1716     AbbrevToUse = FUNCTION_INST_GEP_ABBREV;
1717     auto &GEPInst = cast<GetElementPtrInst>(I);
1718     Vals.push_back(GEPInst.isInBounds());
1719     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
1720     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1721       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1722     break;
1723   }
1724   case Instruction::ExtractValue: {
1725     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1726     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1727     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1728     Vals.append(EVI->idx_begin(), EVI->idx_end());
1729     break;
1730   }
1731   case Instruction::InsertValue: {
1732     Code = bitc::FUNC_CODE_INST_INSERTVAL;
1733     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1734     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1735     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1736     Vals.append(IVI->idx_begin(), IVI->idx_end());
1737     break;
1738   }
1739   case Instruction::Select:
1740     Code = bitc::FUNC_CODE_INST_VSELECT;
1741     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1742     pushValue(I.getOperand(2), InstID, Vals, VE);
1743     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1744     break;
1745   case Instruction::ExtractElement:
1746     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1747     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1748     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1749     break;
1750   case Instruction::InsertElement:
1751     Code = bitc::FUNC_CODE_INST_INSERTELT;
1752     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1753     pushValue(I.getOperand(1), InstID, Vals, VE);
1754     PushValueAndType(I.getOperand(2), InstID, Vals, VE);
1755     break;
1756   case Instruction::ShuffleVector:
1757     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1758     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1759     pushValue(I.getOperand(1), InstID, Vals, VE);
1760     pushValue(I.getOperand(2), InstID, Vals, VE);
1761     break;
1762   case Instruction::ICmp:
1763   case Instruction::FCmp: {
1764     // compare returning Int1Ty or vector of Int1Ty
1765     Code = bitc::FUNC_CODE_INST_CMP2;
1766     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1767     pushValue(I.getOperand(1), InstID, Vals, VE);
1768     Vals.push_back(cast<CmpInst>(I).getPredicate());
1769     uint64_t Flags = GetOptimizationFlags(&I);
1770     if (Flags != 0)
1771       Vals.push_back(Flags);
1772     break;
1773   }
1774
1775   case Instruction::Ret:
1776     {
1777       Code = bitc::FUNC_CODE_INST_RET;
1778       unsigned NumOperands = I.getNumOperands();
1779       if (NumOperands == 0)
1780         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1781       else if (NumOperands == 1) {
1782         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1783           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1784       } else {
1785         for (unsigned i = 0, e = NumOperands; i != e; ++i)
1786           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1787       }
1788     }
1789     break;
1790   case Instruction::Br:
1791     {
1792       Code = bitc::FUNC_CODE_INST_BR;
1793       const BranchInst &II = cast<BranchInst>(I);
1794       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1795       if (II.isConditional()) {
1796         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1797         pushValue(II.getCondition(), InstID, Vals, VE);
1798       }
1799     }
1800     break;
1801   case Instruction::Switch:
1802     {
1803       Code = bitc::FUNC_CODE_INST_SWITCH;
1804       const SwitchInst &SI = cast<SwitchInst>(I);
1805       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
1806       pushValue(SI.getCondition(), InstID, Vals, VE);
1807       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
1808       for (SwitchInst::ConstCaseIt i = SI.case_begin(), e = SI.case_end();
1809            i != e; ++i) {
1810         Vals.push_back(VE.getValueID(i.getCaseValue()));
1811         Vals.push_back(VE.getValueID(i.getCaseSuccessor()));
1812       }
1813     }
1814     break;
1815   case Instruction::IndirectBr:
1816     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1817     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1818     // Encode the address operand as relative, but not the basic blocks.
1819     pushValue(I.getOperand(0), InstID, Vals, VE);
1820     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
1821       Vals.push_back(VE.getValueID(I.getOperand(i)));
1822     break;
1823
1824   case Instruction::Invoke: {
1825     const InvokeInst *II = cast<InvokeInst>(&I);
1826     const Value *Callee = II->getCalledValue();
1827     FunctionType *FTy = II->getFunctionType();
1828     Code = bitc::FUNC_CODE_INST_INVOKE;
1829
1830     Vals.push_back(VE.getAttributeID(II->getAttributes()));
1831     Vals.push_back(II->getCallingConv() | 1 << 13);
1832     Vals.push_back(VE.getValueID(II->getNormalDest()));
1833     Vals.push_back(VE.getValueID(II->getUnwindDest()));
1834     Vals.push_back(VE.getTypeID(FTy));
1835     PushValueAndType(Callee, InstID, Vals, VE);
1836
1837     // Emit value #'s for the fixed parameters.
1838     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1839       pushValue(I.getOperand(i), InstID, Vals, VE);  // fixed param.
1840
1841     // Emit type/value pairs for varargs params.
1842     if (FTy->isVarArg()) {
1843       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1844            i != e; ++i)
1845         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1846     }
1847     break;
1848   }
1849   case Instruction::Resume:
1850     Code = bitc::FUNC_CODE_INST_RESUME;
1851     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1852     break;
1853   case Instruction::CleanupRet: {
1854     Code = bitc::FUNC_CODE_INST_CLEANUPRET;
1855     const auto &CRI = cast<CleanupReturnInst>(I);
1856     Vals.push_back(CRI.hasReturnValue());
1857     Vals.push_back(CRI.hasUnwindDest());
1858     if (CRI.hasReturnValue())
1859       PushValueAndType(CRI.getReturnValue(), InstID, Vals, VE);
1860     if (CRI.hasUnwindDest())
1861       Vals.push_back(VE.getValueID(CRI.getUnwindDest()));
1862     break;
1863   }
1864   case Instruction::CatchRet: {
1865     Code = bitc::FUNC_CODE_INST_CATCHRET;
1866     const auto &CRI = cast<CatchReturnInst>(I);
1867     Vals.push_back(VE.getValueID(CRI.getSuccessor()));
1868     break;
1869   }
1870   case Instruction::CatchPad: {
1871     Code = bitc::FUNC_CODE_INST_CATCHPAD;
1872     const auto &CPI = cast<CatchPadInst>(I);
1873     Vals.push_back(VE.getTypeID(CPI.getType()));
1874     Vals.push_back(VE.getValueID(CPI.getNormalDest()));
1875     Vals.push_back(VE.getValueID(CPI.getUnwindDest()));
1876     unsigned NumArgOperands = CPI.getNumArgOperands();
1877     Vals.push_back(NumArgOperands);
1878     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
1879       PushValueAndType(CPI.getArgOperand(Op), InstID, Vals, VE);
1880     break;
1881   }
1882   case Instruction::TerminatePad: {
1883     Code = bitc::FUNC_CODE_INST_TERMINATEPAD;
1884     const auto &TPI = cast<TerminatePadInst>(I);
1885     Vals.push_back(TPI.hasUnwindDest());
1886     if (TPI.hasUnwindDest())
1887       Vals.push_back(VE.getValueID(TPI.getUnwindDest()));
1888     unsigned NumArgOperands = TPI.getNumArgOperands();
1889     Vals.push_back(NumArgOperands);
1890     for (unsigned Op = 0; Op != NumArgOperands; ++Op)
1891       PushValueAndType(TPI.getArgOperand(Op), InstID, Vals, VE);
1892     break;
1893   }
1894   case Instruction::CleanupPad: {
1895     Code = bitc::FUNC_CODE_INST_CLEANUPPAD;
1896     const auto &CPI = cast<CleanupPadInst>(I);
1897     Vals.push_back(VE.getTypeID(CPI.getType()));
1898     unsigned NumOperands = CPI.getNumOperands();
1899     Vals.push_back(NumOperands);
1900     for (unsigned Op = 0; Op != NumOperands; ++Op)
1901       PushValueAndType(CPI.getOperand(Op), InstID, Vals, VE);
1902     break;
1903   }
1904   case Instruction::CatchEndPad: {
1905     Code = bitc::FUNC_CODE_INST_CATCHENDPAD;
1906     const auto &CEPI = cast<CatchEndPadInst>(I);
1907     if (CEPI.hasUnwindDest())
1908       Vals.push_back(VE.getValueID(CEPI.getUnwindDest()));
1909     break;
1910   }
1911   case Instruction::Unreachable:
1912     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1913     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1914     break;
1915
1916   case Instruction::PHI: {
1917     const PHINode &PN = cast<PHINode>(I);
1918     Code = bitc::FUNC_CODE_INST_PHI;
1919     // With the newer instruction encoding, forward references could give
1920     // negative valued IDs.  This is most common for PHIs, so we use
1921     // signed VBRs.
1922     SmallVector<uint64_t, 128> Vals64;
1923     Vals64.push_back(VE.getTypeID(PN.getType()));
1924     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1925       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64, VE);
1926       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1927     }
1928     // Emit a Vals64 vector and exit.
1929     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
1930     Vals64.clear();
1931     return;
1932   }
1933
1934   case Instruction::LandingPad: {
1935     const LandingPadInst &LP = cast<LandingPadInst>(I);
1936     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
1937     Vals.push_back(VE.getTypeID(LP.getType()));
1938     Vals.push_back(LP.isCleanup());
1939     Vals.push_back(LP.getNumClauses());
1940     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1941       if (LP.isCatch(I))
1942         Vals.push_back(LandingPadInst::Catch);
1943       else
1944         Vals.push_back(LandingPadInst::Filter);
1945       PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1946     }
1947     break;
1948   }
1949
1950   case Instruction::Alloca: {
1951     Code = bitc::FUNC_CODE_INST_ALLOCA;
1952     const AllocaInst &AI = cast<AllocaInst>(I);
1953     Vals.push_back(VE.getTypeID(AI.getAllocatedType()));
1954     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1955     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1956     unsigned AlignRecord = Log2_32(AI.getAlignment()) + 1;
1957     assert(Log2_32(Value::MaximumAlignment) + 1 < 1 << 5 &&
1958            "not enough bits for maximum alignment");
1959     assert(AlignRecord < 1 << 5 && "alignment greater than 1 << 64");
1960     AlignRecord |= AI.isUsedWithInAlloca() << 5;
1961     AlignRecord |= 1 << 6;
1962     // Reserve bit 7 for SwiftError flag.
1963     // AlignRecord |= AI.isSwiftError() << 7;
1964     Vals.push_back(AlignRecord);
1965     break;
1966   }
1967
1968   case Instruction::Load:
1969     if (cast<LoadInst>(I).isAtomic()) {
1970       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1971       PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1972     } else {
1973       Code = bitc::FUNC_CODE_INST_LOAD;
1974       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1975         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1976     }
1977     Vals.push_back(VE.getTypeID(I.getType()));
1978     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1979     Vals.push_back(cast<LoadInst>(I).isVolatile());
1980     if (cast<LoadInst>(I).isAtomic()) {
1981       Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1982       Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1983     }
1984     break;
1985   case Instruction::Store:
1986     if (cast<StoreInst>(I).isAtomic())
1987       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1988     else
1989       Code = bitc::FUNC_CODE_INST_STORE;
1990     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1991     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // valty + val
1992     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1993     Vals.push_back(cast<StoreInst>(I).isVolatile());
1994     if (cast<StoreInst>(I).isAtomic()) {
1995       Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1996       Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1997     }
1998     break;
1999   case Instruction::AtomicCmpXchg:
2000     Code = bitc::FUNC_CODE_INST_CMPXCHG;
2001     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
2002     PushValueAndType(I.getOperand(1), InstID, Vals, VE);         // cmp.
2003     pushValue(I.getOperand(2), InstID, Vals, VE);         // newval.
2004     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
2005     Vals.push_back(GetEncodedOrdering(
2006                      cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
2007     Vals.push_back(GetEncodedSynchScope(
2008                      cast<AtomicCmpXchgInst>(I).getSynchScope()));
2009     Vals.push_back(GetEncodedOrdering(
2010                      cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
2011     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
2012     break;
2013   case Instruction::AtomicRMW:
2014     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
2015     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
2016     pushValue(I.getOperand(1), InstID, Vals, VE);         // val.
2017     Vals.push_back(GetEncodedRMWOperation(
2018                      cast<AtomicRMWInst>(I).getOperation()));
2019     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
2020     Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
2021     Vals.push_back(GetEncodedSynchScope(
2022                      cast<AtomicRMWInst>(I).getSynchScope()));
2023     break;
2024   case Instruction::Fence:
2025     Code = bitc::FUNC_CODE_INST_FENCE;
2026     Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
2027     Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
2028     break;
2029   case Instruction::Call: {
2030     const CallInst &CI = cast<CallInst>(I);
2031     FunctionType *FTy = CI.getFunctionType();
2032
2033     Code = bitc::FUNC_CODE_INST_CALL;
2034
2035     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
2036     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()) |
2037                    unsigned(CI.isMustTailCall()) << 14 | 1 << 15);
2038     Vals.push_back(VE.getTypeID(FTy));
2039     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
2040
2041     // Emit value #'s for the fixed parameters.
2042     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
2043       // Check for labels (can happen with asm labels).
2044       if (FTy->getParamType(i)->isLabelTy())
2045         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
2046       else
2047         pushValue(CI.getArgOperand(i), InstID, Vals, VE);  // fixed param.
2048     }
2049
2050     // Emit type/value pairs for varargs params.
2051     if (FTy->isVarArg()) {
2052       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
2053            i != e; ++i)
2054         PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
2055     }
2056     break;
2057   }
2058   case Instruction::VAArg:
2059     Code = bitc::FUNC_CODE_INST_VAARG;
2060     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
2061     pushValue(I.getOperand(0), InstID, Vals, VE); // valist.
2062     Vals.push_back(VE.getTypeID(I.getType())); // restype.
2063     break;
2064   }
2065
2066   Stream.EmitRecord(Code, Vals, AbbrevToUse);
2067   Vals.clear();
2068 }
2069
2070 // Emit names for globals/functions etc.
2071 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
2072                                   const ValueEnumerator &VE,
2073                                   BitstreamWriter &Stream) {
2074   if (VST.empty()) return;
2075   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
2076
2077   // FIXME: Set up the abbrev, we know how many values there are!
2078   // FIXME: We know if the type names can use 7-bit ascii.
2079   SmallVector<unsigned, 64> NameVals;
2080
2081   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
2082        SI != SE; ++SI) {
2083
2084     const ValueName &Name = *SI;
2085
2086     // Figure out the encoding to use for the name.
2087     bool is7Bit = true;
2088     bool isChar6 = true;
2089     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
2090          C != E; ++C) {
2091       if (isChar6)
2092         isChar6 = BitCodeAbbrevOp::isChar6(*C);
2093       if ((unsigned char)*C & 128) {
2094         is7Bit = false;
2095         break;  // don't bother scanning the rest.
2096       }
2097     }
2098
2099     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
2100
2101     // VST_ENTRY:   [valueid, namechar x N]
2102     // VST_BBENTRY: [bbid, namechar x N]
2103     unsigned Code;
2104     if (isa<BasicBlock>(SI->getValue())) {
2105       Code = bitc::VST_CODE_BBENTRY;
2106       if (isChar6)
2107         AbbrevToUse = VST_BBENTRY_6_ABBREV;
2108     } else {
2109       Code = bitc::VST_CODE_ENTRY;
2110       if (isChar6)
2111         AbbrevToUse = VST_ENTRY_6_ABBREV;
2112       else if (is7Bit)
2113         AbbrevToUse = VST_ENTRY_7_ABBREV;
2114     }
2115
2116     NameVals.push_back(VE.getValueID(SI->getValue()));
2117     for (const char *P = Name.getKeyData(),
2118          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
2119       NameVals.push_back((unsigned char)*P);
2120
2121     // Emit the finished record.
2122     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
2123     NameVals.clear();
2124   }
2125   Stream.ExitBlock();
2126 }
2127
2128 static void WriteUseList(ValueEnumerator &VE, UseListOrder &&Order,
2129                          BitstreamWriter &Stream) {
2130   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
2131   unsigned Code;
2132   if (isa<BasicBlock>(Order.V))
2133     Code = bitc::USELIST_CODE_BB;
2134   else
2135     Code = bitc::USELIST_CODE_DEFAULT;
2136
2137   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
2138   Record.push_back(VE.getValueID(Order.V));
2139   Stream.EmitRecord(Code, Record);
2140 }
2141
2142 static void WriteUseListBlock(const Function *F, ValueEnumerator &VE,
2143                               BitstreamWriter &Stream) {
2144   assert(VE.shouldPreserveUseListOrder() &&
2145          "Expected to be preserving use-list order");
2146
2147   auto hasMore = [&]() {
2148     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
2149   };
2150   if (!hasMore())
2151     // Nothing to do.
2152     return;
2153
2154   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
2155   while (hasMore()) {
2156     WriteUseList(VE, std::move(VE.UseListOrders.back()), Stream);
2157     VE.UseListOrders.pop_back();
2158   }
2159   Stream.ExitBlock();
2160 }
2161
2162 /// WriteFunction - Emit a function body to the module stream.
2163 static void WriteFunction(const Function &F, ValueEnumerator &VE,
2164                           BitstreamWriter &Stream) {
2165   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
2166   VE.incorporateFunction(F);
2167
2168   SmallVector<unsigned, 64> Vals;
2169
2170   // Emit the number of basic blocks, so the reader can create them ahead of
2171   // time.
2172   Vals.push_back(VE.getBasicBlocks().size());
2173   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
2174   Vals.clear();
2175
2176   // If there are function-local constants, emit them now.
2177   unsigned CstStart, CstEnd;
2178   VE.getFunctionConstantRange(CstStart, CstEnd);
2179   WriteConstants(CstStart, CstEnd, VE, Stream, false);
2180
2181   // If there is function-local metadata, emit it now.
2182   WriteFunctionLocalMetadata(F, VE, Stream);
2183
2184   // Keep a running idea of what the instruction ID is.
2185   unsigned InstID = CstEnd;
2186
2187   bool NeedsMetadataAttachment = F.hasMetadata();
2188
2189   DILocation *LastDL = nullptr;
2190
2191   // Finally, emit all the instructions, in order.
2192   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
2193     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
2194          I != E; ++I) {
2195       WriteInstruction(*I, InstID, VE, Stream, Vals);
2196
2197       if (!I->getType()->isVoidTy())
2198         ++InstID;
2199
2200       // If the instruction has metadata, write a metadata attachment later.
2201       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
2202
2203       // If the instruction has a debug location, emit it.
2204       DILocation *DL = I->getDebugLoc();
2205       if (!DL)
2206         continue;
2207
2208       if (DL == LastDL) {
2209         // Just repeat the same debug loc as last time.
2210         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
2211         continue;
2212       }
2213
2214       Vals.push_back(DL->getLine());
2215       Vals.push_back(DL->getColumn());
2216       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
2217       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
2218       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
2219       Vals.clear();
2220
2221       LastDL = DL;
2222     }
2223
2224   // Emit names for all the instructions etc.
2225   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
2226
2227   if (NeedsMetadataAttachment)
2228     WriteMetadataAttachment(F, VE, Stream);
2229   if (VE.shouldPreserveUseListOrder())
2230     WriteUseListBlock(&F, VE, Stream);
2231   VE.purgeFunction();
2232   Stream.ExitBlock();
2233 }
2234
2235 // Emit blockinfo, which defines the standard abbreviations etc.
2236 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
2237   // We only want to emit block info records for blocks that have multiple
2238   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
2239   // Other blocks can define their abbrevs inline.
2240   Stream.EnterBlockInfoBlock(2);
2241
2242   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
2243     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2244     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
2245     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2246     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2247     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2248     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2249                                    Abbv) != VST_ENTRY_8_ABBREV)
2250       llvm_unreachable("Unexpected abbrev ordering!");
2251   }
2252
2253   { // 7-bit fixed width VST_ENTRY strings.
2254     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2255     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2256     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2257     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2258     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2259     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2260                                    Abbv) != VST_ENTRY_7_ABBREV)
2261       llvm_unreachable("Unexpected abbrev ordering!");
2262   }
2263   { // 6-bit char6 VST_ENTRY strings.
2264     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2265     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2266     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2267     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2268     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2269     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2270                                    Abbv) != VST_ENTRY_6_ABBREV)
2271       llvm_unreachable("Unexpected abbrev ordering!");
2272   }
2273   { // 6-bit char6 VST_BBENTRY strings.
2274     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2275     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
2276     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2277     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2278     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2279     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2280                                    Abbv) != VST_BBENTRY_6_ABBREV)
2281       llvm_unreachable("Unexpected abbrev ordering!");
2282   }
2283
2284
2285
2286   { // SETTYPE abbrev for CONSTANTS_BLOCK.
2287     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2288     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
2289     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2290                               VE.computeBitsRequiredForTypeIndicies()));
2291     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2292                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
2293       llvm_unreachable("Unexpected abbrev ordering!");
2294   }
2295
2296   { // INTEGER abbrev for CONSTANTS_BLOCK.
2297     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2298     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
2299     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2300     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2301                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
2302       llvm_unreachable("Unexpected abbrev ordering!");
2303   }
2304
2305   { // CE_CAST abbrev for CONSTANTS_BLOCK.
2306     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2307     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
2308     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
2309     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
2310                               VE.computeBitsRequiredForTypeIndicies()));
2311     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
2312
2313     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2314                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
2315       llvm_unreachable("Unexpected abbrev ordering!");
2316   }
2317   { // NULL abbrev for CONSTANTS_BLOCK.
2318     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2319     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
2320     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2321                                    Abbv) != CONSTANTS_NULL_Abbrev)
2322       llvm_unreachable("Unexpected abbrev ordering!");
2323   }
2324
2325   // FIXME: This should only use space for first class types!
2326
2327   { // INST_LOAD abbrev for FUNCTION_BLOCK.
2328     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2329     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
2330     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
2331     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2332                               VE.computeBitsRequiredForTypeIndicies()));
2333     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
2334     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
2335     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2336                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
2337       llvm_unreachable("Unexpected abbrev ordering!");
2338   }
2339   { // INST_BINOP abbrev for FUNCTION_BLOCK.
2340     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2341     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2342     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2343     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2344     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2345     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2346                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
2347       llvm_unreachable("Unexpected abbrev ordering!");
2348   }
2349   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
2350     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2351     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2352     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2353     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2354     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2355     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
2356     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2357                                    Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
2358       llvm_unreachable("Unexpected abbrev ordering!");
2359   }
2360   { // INST_CAST abbrev for FUNCTION_BLOCK.
2361     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2362     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
2363     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
2364     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
2365                               VE.computeBitsRequiredForTypeIndicies()));
2366     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
2367     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2368                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
2369       llvm_unreachable("Unexpected abbrev ordering!");
2370   }
2371
2372   { // INST_RET abbrev for FUNCTION_BLOCK.
2373     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2374     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2375     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2376                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
2377       llvm_unreachable("Unexpected abbrev ordering!");
2378   }
2379   { // INST_RET abbrev for FUNCTION_BLOCK.
2380     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2381     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2382     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
2383     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2384                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
2385       llvm_unreachable("Unexpected abbrev ordering!");
2386   }
2387   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
2388     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2389     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
2390     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2391                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
2392       llvm_unreachable("Unexpected abbrev ordering!");
2393   }
2394   {
2395     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2396     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
2397     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2398     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
2399                               Log2_32_Ceil(VE.getTypes().size() + 1)));
2400     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2401     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2402     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2403         FUNCTION_INST_GEP_ABBREV)
2404       llvm_unreachable("Unexpected abbrev ordering!");
2405   }
2406
2407   Stream.ExitBlock();
2408 }
2409
2410 /// WriteModule - Emit the specified module to the bitstream.
2411 static void WriteModule(const Module *M, BitstreamWriter &Stream,
2412                         bool ShouldPreserveUseListOrder) {
2413   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
2414
2415   SmallVector<unsigned, 1> Vals;
2416   unsigned CurVersion = 1;
2417   Vals.push_back(CurVersion);
2418   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
2419
2420   // Analyze the module, enumerating globals, functions, etc.
2421   ValueEnumerator VE(*M, ShouldPreserveUseListOrder);
2422
2423   // Emit blockinfo, which defines the standard abbreviations etc.
2424   WriteBlockInfo(VE, Stream);
2425
2426   // Emit information about attribute groups.
2427   WriteAttributeGroupTable(VE, Stream);
2428
2429   // Emit information about parameter attributes.
2430   WriteAttributeTable(VE, Stream);
2431
2432   // Emit information describing all of the types in the module.
2433   WriteTypeTable(VE, Stream);
2434
2435   writeComdats(VE, Stream);
2436
2437   // Emit top-level description of module, including target triple, inline asm,
2438   // descriptors for global variables, and function prototype info.
2439   WriteModuleInfo(M, VE, Stream);
2440
2441   // Emit constants.
2442   WriteModuleConstants(VE, Stream);
2443
2444   // Emit metadata.
2445   WriteModuleMetadata(M, VE, Stream);
2446
2447   // Emit metadata.
2448   WriteModuleMetadataStore(M, Stream);
2449
2450   // Emit names for globals/functions etc.
2451   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
2452
2453   // Emit module-level use-lists.
2454   if (VE.shouldPreserveUseListOrder())
2455     WriteUseListBlock(nullptr, VE, Stream);
2456
2457   // Emit function bodies.
2458   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
2459     if (!F->isDeclaration())
2460       WriteFunction(*F, VE, Stream);
2461
2462   Stream.ExitBlock();
2463 }
2464
2465 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
2466 /// header and trailer to make it compatible with the system archiver.  To do
2467 /// this we emit the following header, and then emit a trailer that pads the
2468 /// file out to be a multiple of 16 bytes.
2469 ///
2470 /// struct bc_header {
2471 ///   uint32_t Magic;         // 0x0B17C0DE
2472 ///   uint32_t Version;       // Version, currently always 0.
2473 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
2474 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
2475 ///   uint32_t CPUType;       // CPU specifier.
2476 ///   ... potentially more later ...
2477 /// };
2478 enum {
2479   DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
2480   DarwinBCHeaderSize = 5*4
2481 };
2482
2483 static void WriteInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
2484                                uint32_t &Position) {
2485   support::endian::write32le(&Buffer[Position], Value);
2486   Position += 4;
2487 }
2488
2489 static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
2490                                          const Triple &TT) {
2491   unsigned CPUType = ~0U;
2492
2493   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
2494   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
2495   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
2496   // specific constants here because they are implicitly part of the Darwin ABI.
2497   enum {
2498     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
2499     DARWIN_CPU_TYPE_X86        = 7,
2500     DARWIN_CPU_TYPE_ARM        = 12,
2501     DARWIN_CPU_TYPE_POWERPC    = 18
2502   };
2503
2504   Triple::ArchType Arch = TT.getArch();
2505   if (Arch == Triple::x86_64)
2506     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
2507   else if (Arch == Triple::x86)
2508     CPUType = DARWIN_CPU_TYPE_X86;
2509   else if (Arch == Triple::ppc)
2510     CPUType = DARWIN_CPU_TYPE_POWERPC;
2511   else if (Arch == Triple::ppc64)
2512     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
2513   else if (Arch == Triple::arm || Arch == Triple::thumb)
2514     CPUType = DARWIN_CPU_TYPE_ARM;
2515
2516   // Traditional Bitcode starts after header.
2517   assert(Buffer.size() >= DarwinBCHeaderSize &&
2518          "Expected header size to be reserved");
2519   unsigned BCOffset = DarwinBCHeaderSize;
2520   unsigned BCSize = Buffer.size()-DarwinBCHeaderSize;
2521
2522   // Write the magic and version.
2523   unsigned Position = 0;
2524   WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position);
2525   WriteInt32ToBuffer(0          , Buffer, Position); // Version.
2526   WriteInt32ToBuffer(BCOffset   , Buffer, Position);
2527   WriteInt32ToBuffer(BCSize     , Buffer, Position);
2528   WriteInt32ToBuffer(CPUType    , Buffer, Position);
2529
2530   // If the file is not a multiple of 16 bytes, insert dummy padding.
2531   while (Buffer.size() & 15)
2532     Buffer.push_back(0);
2533 }
2534
2535 /// WriteBitcodeToFile - Write the specified module to the specified output
2536 /// stream.
2537 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out,
2538                               bool ShouldPreserveUseListOrder) {
2539   SmallVector<char, 0> Buffer;
2540   Buffer.reserve(256*1024);
2541
2542   // If this is darwin or another generic macho target, reserve space for the
2543   // header.
2544   Triple TT(M->getTargetTriple());
2545   if (TT.isOSDarwin())
2546     Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0);
2547
2548   // Emit the module into the buffer.
2549   {
2550     BitstreamWriter Stream(Buffer);
2551
2552     // Emit the file header.
2553     Stream.Emit((unsigned)'B', 8);
2554     Stream.Emit((unsigned)'C', 8);
2555     Stream.Emit(0x0, 4);
2556     Stream.Emit(0xC, 4);
2557     Stream.Emit(0xE, 4);
2558     Stream.Emit(0xD, 4);
2559
2560     // Emit the module.
2561     WriteModule(M, Stream, ShouldPreserveUseListOrder);
2562   }
2563
2564   if (TT.isOSDarwin())
2565     EmitDarwinBCHeaderAndTrailer(Buffer, TT);
2566
2567   // Write the generated bitstream to "Out".
2568   Out.write((char*)&Buffer.front(), Buffer.size());
2569 }