lib/Bitcode/Writer/BitcodeWriter.cpp

   1 //===--- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ----------------===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // Bitcode writer implementation.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #include "llvm/Bitcode/ReaderWriter.h"
  15 #include "ValueEnumerator.h"
  16 #include "llvm/ADT/Triple.h"
  17 #include "llvm/Bitcode/BitstreamWriter.h"
  18 #include "llvm/Bitcode/LLVMBitCodes.h"
  19 #include "llvm/IR/Constants.h"
  20 #include "llvm/IR/DebugInfoMetadata.h"
  21 #include "llvm/IR/DerivedTypes.h"
  22 #include "llvm/IR/InlineAsm.h"
  23 #include "llvm/IR/Instructions.h"
  24 #include "llvm/IR/Module.h"
  25 #include "llvm/IR/Operator.h"
  26 #include "llvm/IR/UseListOrder.h"
  27 #include "llvm/IR/ValueSymbolTable.h"
  28 #include "llvm/Support/CommandLine.h"
  29 #include "llvm/Support/ErrorHandling.h"
  30 #include "llvm/Support/MathExtras.h"
  31 #include "llvm/Support/Program.h"
  32 #include "llvm/Support/raw_ostream.h"
  33 #include <cctype>
  34 #include <map>
  35 using namespace llvm;
  36
  37 /// These are manifest constants used by the bitcode writer. They do not need to
  38 /// be kept in sync with the reader, but need to be consistent within this file.
  39 enum {
  40   // VALUE_SYMTAB_BLOCK abbrev id's.
  41   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  42   VST_ENTRY_7_ABBREV,
  43   VST_ENTRY_6_ABBREV,
  44   VST_BBENTRY_6_ABBREV,
  45
  46   // CONSTANTS_BLOCK abbrev id's.
  47   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  48   CONSTANTS_INTEGER_ABBREV,
  49   CONSTANTS_CE_CAST_Abbrev,
  50   CONSTANTS_NULL_Abbrev,
  51
  52   // FUNCTION_BLOCK abbrev id's.
  53   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  54   FUNCTION_INST_BINOP_ABBREV,
  55   FUNCTION_INST_BINOP_FLAGS_ABBREV,
  56   FUNCTION_INST_CAST_ABBREV,
  57   FUNCTION_INST_RET_VOID_ABBREV,
  58   FUNCTION_INST_RET_VAL_ABBREV,
  59   FUNCTION_INST_UNREACHABLE_ABBREV,
  60   FUNCTION_INST_GEP_ABBREV,
  61 };
  62
  63 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
  64   switch (Opcode) {
  65   default: llvm_unreachable("Unknown cast instruction!");
  66   case Instruction::Trunc   : return bitc::CAST_TRUNC;
  67   case Instruction::ZExt    : return bitc::CAST_ZEXT;
  68   case Instruction::SExt    : return bitc::CAST_SEXT;
  69   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
  70   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
  71   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
  72   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
  73   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
  74   case Instruction::FPExt   : return bitc::CAST_FPEXT;
  75   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
  76   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
  77   case Instruction::BitCast : return bitc::CAST_BITCAST;
  78   case Instruction::AddrSpaceCast: return bitc::CAST_ADDRSPACECAST;
  79   }
  80 }
  81
  82 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
  83   switch (Opcode) {
  84   default: llvm_unreachable("Unknown binary instruction!");
  85   case Instruction::Add:
  86   case Instruction::FAdd: return bitc::BINOP_ADD;
  87   case Instruction::Sub:
  88   case Instruction::FSub: return bitc::BINOP_SUB;
  89   case Instruction::Mul:
  90   case Instruction::FMul: return bitc::BINOP_MUL;
  91   case Instruction::UDiv: return bitc::BINOP_UDIV;
  92   case Instruction::FDiv:
  93   case Instruction::SDiv: return bitc::BINOP_SDIV;
  94   case Instruction::URem: return bitc::BINOP_UREM;
  95   case Instruction::FRem:
  96   case Instruction::SRem: return bitc::BINOP_SREM;
  97   case Instruction::Shl:  return bitc::BINOP_SHL;
  98   case Instruction::LShr: return bitc::BINOP_LSHR;
  99   case Instruction::AShr: return bitc::BINOP_ASHR;
 100   case Instruction::And:  return bitc::BINOP_AND;
 101   case Instruction::Or:   return bitc::BINOP_OR;
 102   case Instruction::Xor:  return bitc::BINOP_XOR;
 103   }
 104 }
 105
 106 static unsigned GetEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
 107   switch (Op) {
 108   default: llvm_unreachable("Unknown RMW operation!");
 109   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
 110   case AtomicRMWInst::Add: return bitc::RMW_ADD;
 111   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
 112   case AtomicRMWInst::And: return bitc::RMW_AND;
 113   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
 114   case AtomicRMWInst::Or: return bitc::RMW_OR;
 115   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
 116   case AtomicRMWInst::Max: return bitc::RMW_MAX;
 117   case AtomicRMWInst::Min: return bitc::RMW_MIN;
 118   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
 119   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
 120   }
 121 }
 122
 123 static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
 124   switch (Ordering) {
 125   case NotAtomic: return bitc::ORDERING_NOTATOMIC;
 126   case Unordered: return bitc::ORDERING_UNORDERED;
 127   case Monotonic: return bitc::ORDERING_MONOTONIC;
 128   case Acquire: return bitc::ORDERING_ACQUIRE;
 129   case Release: return bitc::ORDERING_RELEASE;
 130   case AcquireRelease: return bitc::ORDERING_ACQREL;
 131   case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
 132   }
 133   llvm_unreachable("Invalid ordering");
 134 }
 135
 136 static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
 137   switch (SynchScope) {
 138   case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
 139   case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
 140   }
 141   llvm_unreachable("Invalid synch scope");
 142 }
 143
 144 static void WriteStringRecord(unsigned Code, StringRef Str,
 145                               unsigned AbbrevToUse, BitstreamWriter &Stream) {
 146   SmallVector<unsigned, 64> Vals;
 147
 148   // Code: [strchar x N]
 149   for (unsigned i = 0, e = Str.size(); i != e; ++i) {
 150     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
 151       AbbrevToUse = 0;
 152     Vals.push_back(Str[i]);
 153   }
 154
 155   // Emit the finished record.
 156   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 157 }
 158
 159 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
 160   switch (Kind) {
 161   case Attribute::Alignment:
 162     return bitc::ATTR_KIND_ALIGNMENT;
 163   case Attribute::AlwaysInline:
 164     return bitc::ATTR_KIND_ALWAYS_INLINE;
 165   case Attribute::Builtin:
 166     return bitc::ATTR_KIND_BUILTIN;
 167   case Attribute::ByVal:
 168     return bitc::ATTR_KIND_BY_VAL;
 169   case Attribute::InAlloca:
 170     return bitc::ATTR_KIND_IN_ALLOCA;
 171   case Attribute::Cold:
 172     return bitc::ATTR_KIND_COLD;
 173   case Attribute::InlineHint:
 174     return bitc::ATTR_KIND_INLINE_HINT;
 175   case Attribute::InReg:
 176     return bitc::ATTR_KIND_IN_REG;
 177   case Attribute::JumpTable:
 178     return bitc::ATTR_KIND_JUMP_TABLE;
 179   case Attribute::MinSize:
 180     return bitc::ATTR_KIND_MIN_SIZE;
 181   case Attribute::Naked:
 182     return bitc::ATTR_KIND_NAKED;
 183   case Attribute::Nest:
 184     return bitc::ATTR_KIND_NEST;
 185   case Attribute::NoAlias:
 186     return bitc::ATTR_KIND_NO_ALIAS;
 187   case Attribute::NoBuiltin:
 188     return bitc::ATTR_KIND_NO_BUILTIN;
 189   case Attribute::NoCapture:
 190     return bitc::ATTR_KIND_NO_CAPTURE;
 191   case Attribute::NoDuplicate:
 192     return bitc::ATTR_KIND_NO_DUPLICATE;
 193   case Attribute::NoImplicitFloat:
 194     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
 195   case Attribute::NoInline:
 196     return bitc::ATTR_KIND_NO_INLINE;
 197   case Attribute::NonLazyBind:
 198     return bitc::ATTR_KIND_NON_LAZY_BIND;
 199   case Attribute::NonNull:
 200     return bitc::ATTR_KIND_NON_NULL;
 201   case Attribute::Dereferenceable:
 202     return bitc::ATTR_KIND_DEREFERENCEABLE;
 203   case Attribute::NoRedZone:
 204     return bitc::ATTR_KIND_NO_RED_ZONE;
 205   case Attribute::NoReturn:
 206     return bitc::ATTR_KIND_NO_RETURN;
 207   case Attribute::NoUnwind:
 208     return bitc::ATTR_KIND_NO_UNWIND;
 209   case Attribute::OptimizeForSize:
 210     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
 211   case Attribute::OptimizeNone:
 212     return bitc::ATTR_KIND_OPTIMIZE_NONE;
 213   case Attribute::ReadNone:
 214     return bitc::ATTR_KIND_READ_NONE;
 215   case Attribute::ReadOnly:
 216     return bitc::ATTR_KIND_READ_ONLY;
 217   case Attribute::Returned:
 218     return bitc::ATTR_KIND_RETURNED;
 219   case Attribute::ReturnsTwice:
 220     return bitc::ATTR_KIND_RETURNS_TWICE;
 221   case Attribute::SExt:
 222     return bitc::ATTR_KIND_S_EXT;
 223   case Attribute::StackAlignment:
 224     return bitc::ATTR_KIND_STACK_ALIGNMENT;
 225   case Attribute::StackProtect:
 226     return bitc::ATTR_KIND_STACK_PROTECT;
 227   case Attribute::StackProtectReq:
 228     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
 229   case Attribute::StackProtectStrong:
 230     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
 231   case Attribute::StructRet:
 232     return bitc::ATTR_KIND_STRUCT_RET;
 233   case Attribute::SanitizeAddress:
 234     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
 235   case Attribute::SanitizeThread:
 236     return bitc::ATTR_KIND_SANITIZE_THREAD;
 237   case Attribute::SanitizeMemory:
 238     return bitc::ATTR_KIND_SANITIZE_MEMORY;
 239   case Attribute::UWTable:
 240     return bitc::ATTR_KIND_UW_TABLE;
 241   case Attribute::ZExt:
 242     return bitc::ATTR_KIND_Z_EXT;
 243   case Attribute::EndAttrKinds:
 244     llvm_unreachable("Can not encode end-attribute kinds marker.");
 245   case Attribute::None:
 246     llvm_unreachable("Can not encode none-attribute.");
 247   }
 248
 249   llvm_unreachable("Trying to encode unknown attribute");
 250 }
 251
 252 static void WriteAttributeGroupTable(const ValueEnumerator &VE,
 253                                      BitstreamWriter &Stream) {
 254   const std::vector<AttributeSet> &AttrGrps = VE.getAttributeGroups();
 255   if (AttrGrps.empty()) return;
 256
 257   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
 258
 259   SmallVector<uint64_t, 64> Record;
 260   for (unsigned i = 0, e = AttrGrps.size(); i != e; ++i) {
 261     AttributeSet AS = AttrGrps[i];
 262     for (unsigned i = 0, e = AS.getNumSlots(); i != e; ++i) {
 263       AttributeSet A = AS.getSlotAttributes(i);
 264
 265       Record.push_back(VE.getAttributeGroupID(A));
 266       Record.push_back(AS.getSlotIndex(i));
 267
 268       for (AttributeSet::iterator I = AS.begin(0), E = AS.end(0);
 269            I != E; ++I) {
 270         Attribute Attr = *I;
 271         if (Attr.isEnumAttribute()) {
 272           Record.push_back(0);
 273           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 274         } else if (Attr.isIntAttribute()) {
 275           Record.push_back(1);
 276           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 277           Record.push_back(Attr.getValueAsInt());
 278         } else {
 279           StringRef Kind = Attr.getKindAsString();
 280           StringRef Val = Attr.getValueAsString();
 281
 282           Record.push_back(Val.empty() ? 3 : 4);
 283           Record.append(Kind.begin(), Kind.end());
 284           Record.push_back(0);
 285           if (!Val.empty()) {
 286             Record.append(Val.begin(), Val.end());
 287             Record.push_back(0);
 288           }
 289         }
 290       }
 291
 292       Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
 293       Record.clear();
 294     }
 295   }
 296
 297   Stream.ExitBlock();
 298 }
 299
 300 static void WriteAttributeTable(const ValueEnumerator &VE,
 301                                 BitstreamWriter &Stream) {
 302   const std::vector<AttributeSet> &Attrs = VE.getAttributes();
 303   if (Attrs.empty()) return;
 304
 305   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 306
 307   SmallVector<uint64_t, 64> Record;
 308   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
 309     const AttributeSet &A = Attrs[i];
 310     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
 311       Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
 312
 313     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 314     Record.clear();
 315   }
 316
 317   Stream.ExitBlock();
 318 }
 319
 320 /// WriteTypeTable - Write out the type table for a module.
 321 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 322   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 323
 324   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
 325   SmallVector<uint64_t, 64> TypeVals;
 326
 327   uint64_t NumBits = VE.computeBitsRequiredForTypeIndicies();
 328
 329   // Abbrev for TYPE_CODE_POINTER.
 330   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 331   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
 332   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 333   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
 334   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
 335
 336   // Abbrev for TYPE_CODE_FUNCTION.
 337   Abbv = new BitCodeAbbrev();
 338   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
 339   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
 340   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 341   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 342
 343   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 344
 345   // Abbrev for TYPE_CODE_STRUCT_ANON.
 346   Abbv = new BitCodeAbbrev();
 347   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
 348   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 349   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 350   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 351
 352   unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
 353
 354   // Abbrev for TYPE_CODE_STRUCT_NAME.
 355   Abbv = new BitCodeAbbrev();
 356   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
 357   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 358   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 359   unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
 360
 361   // Abbrev for TYPE_CODE_STRUCT_NAMED.
 362   Abbv = new BitCodeAbbrev();
 363   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
 364   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 365   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 366   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 367
 368   unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
 369
 370   // Abbrev for TYPE_CODE_ARRAY.
 371   Abbv = new BitCodeAbbrev();
 372   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 373   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 374   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 375
 376   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 377
 378   // Emit an entry count so the reader can reserve space.
 379   TypeVals.push_back(TypeList.size());
 380   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 381   TypeVals.clear();
 382
 383   // Loop over all of the types, emitting each in turn.
 384   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 385     Type *T = TypeList[i];
 386     int AbbrevToUse = 0;
 387     unsigned Code = 0;
 388
 389     switch (T->getTypeID()) {
 390     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
 391     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
 392     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
 393     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
 394     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
 395     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
 396     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 397     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
 398     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
 399     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
 400     case Type::IntegerTyID:
 401       // INTEGER: [width]
 402       Code = bitc::TYPE_CODE_INTEGER;
 403       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 404       break;
 405     case Type::PointerTyID: {
 406       PointerType *PTy = cast<PointerType>(T);
 407       // POINTER: [pointee type, address space]
 408       Code = bitc::TYPE_CODE_POINTER;
 409       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
 410       unsigned AddressSpace = PTy->getAddressSpace();
 411       TypeVals.push_back(AddressSpace);
 412       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
 413       break;
 414     }
 415     case Type::FunctionTyID: {
 416       FunctionType *FT = cast<FunctionType>(T);
 417       // FUNCTION: [isvararg, retty, paramty x N]
 418       Code = bitc::TYPE_CODE_FUNCTION;
 419       TypeVals.push_back(FT->isVarArg());
 420       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 421       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 422         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 423       AbbrevToUse = FunctionAbbrev;
 424       break;
 425     }
 426     case Type::StructTyID: {
 427       StructType *ST = cast<StructType>(T);
 428       // STRUCT: [ispacked, eltty x N]
 429       TypeVals.push_back(ST->isPacked());
 430       // Output all of the element types.
 431       for (StructType::element_iterator I = ST->element_begin(),
 432            E = ST->element_end(); I != E; ++I)
 433         TypeVals.push_back(VE.getTypeID(*I));
 434
 435       if (ST->isLiteral()) {
 436         Code = bitc::TYPE_CODE_STRUCT_ANON;
 437         AbbrevToUse = StructAnonAbbrev;
 438       } else {
 439         if (ST->isOpaque()) {
 440           Code = bitc::TYPE_CODE_OPAQUE;
 441         } else {
 442           Code = bitc::TYPE_CODE_STRUCT_NAMED;
 443           AbbrevToUse = StructNamedAbbrev;
 444         }
 445
 446         // Emit the name if it is present.
 447         if (!ST->getName().empty())
 448           WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
 449                             StructNameAbbrev, Stream);
 450       }
 451       break;
 452     }
 453     case Type::ArrayTyID: {
 454       ArrayType *AT = cast<ArrayType>(T);
 455       // ARRAY: [numelts, eltty]
 456       Code = bitc::TYPE_CODE_ARRAY;
 457       TypeVals.push_back(AT->getNumElements());
 458       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 459       AbbrevToUse = ArrayAbbrev;
 460       break;
 461     }
 462     case Type::VectorTyID: {
 463       VectorType *VT = cast<VectorType>(T);
 464       // VECTOR [numelts, eltty]
 465       Code = bitc::TYPE_CODE_VECTOR;
 466       TypeVals.push_back(VT->getNumElements());
 467       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 468       break;
 469     }
 470     }
 471
 472     // Emit the finished record.
 473     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 474     TypeVals.clear();
 475   }
 476
 477   Stream.ExitBlock();
 478 }
 479
 480 static unsigned getEncodedLinkage(const GlobalValue &GV) {
 481   switch (GV.getLinkage()) {
 482   case GlobalValue::ExternalLinkage:
 483     return 0;
 484   case GlobalValue::WeakAnyLinkage:
 485     return 16;
 486   case GlobalValue::AppendingLinkage:
 487     return 2;
 488   case GlobalValue::InternalLinkage:
 489     return 3;
 490   case GlobalValue::LinkOnceAnyLinkage:
 491     return 18;
 492   case GlobalValue::ExternalWeakLinkage:
 493     return 7;
 494   case GlobalValue::CommonLinkage:
 495     return 8;
 496   case GlobalValue::PrivateLinkage:
 497     return 9;
 498   case GlobalValue::WeakODRLinkage:
 499     return 17;
 500   case GlobalValue::LinkOnceODRLinkage:
 501     return 19;
 502   case GlobalValue::AvailableExternallyLinkage:
 503     return 12;
 504   }
 505   llvm_unreachable("Invalid linkage");
 506 }
 507
 508 static unsigned getEncodedVisibility(const GlobalValue &GV) {
 509   switch (GV.getVisibility()) {
 510   case GlobalValue::DefaultVisibility:   return 0;
 511   case GlobalValue::HiddenVisibility:    return 1;
 512   case GlobalValue::ProtectedVisibility: return 2;
 513   }
 514   llvm_unreachable("Invalid visibility");
 515 }
 516
 517 static unsigned getEncodedDLLStorageClass(const GlobalValue &GV) {
 518   switch (GV.getDLLStorageClass()) {
 519   case GlobalValue::DefaultStorageClass:   return 0;
 520   case GlobalValue::DLLImportStorageClass: return 1;
 521   case GlobalValue::DLLExportStorageClass: return 2;
 522   }
 523   llvm_unreachable("Invalid DLL storage class");
 524 }
 525
 526 static unsigned getEncodedThreadLocalMode(const GlobalValue &GV) {
 527   switch (GV.getThreadLocalMode()) {
 528     case GlobalVariable::NotThreadLocal:         return 0;
 529     case GlobalVariable::GeneralDynamicTLSModel: return 1;
 530     case GlobalVariable::LocalDynamicTLSModel:   return 2;
 531     case GlobalVariable::InitialExecTLSModel:    return 3;
 532     case GlobalVariable::LocalExecTLSModel:      return 4;
 533   }
 534   llvm_unreachable("Invalid TLS model");
 535 }
 536
 537 static unsigned getEncodedComdatSelectionKind(const Comdat &C) {
 538   switch (C.getSelectionKind()) {
 539   case Comdat::Any:
 540     return bitc::COMDAT_SELECTION_KIND_ANY;
 541   case Comdat::ExactMatch:
 542     return bitc::COMDAT_SELECTION_KIND_EXACT_MATCH;
 543   case Comdat::Largest:
 544     return bitc::COMDAT_SELECTION_KIND_LARGEST;
 545   case Comdat::NoDuplicates:
 546     return bitc::COMDAT_SELECTION_KIND_NO_DUPLICATES;
 547   case Comdat::SameSize:
 548     return bitc::COMDAT_SELECTION_KIND_SAME_SIZE;
 549   }
 550   llvm_unreachable("Invalid selection kind");
 551 }
 552
 553 static void writeComdats(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 554   SmallVector<uint16_t, 64> Vals;
 555   for (const Comdat *C : VE.getComdats()) {
 556     // COMDAT: [selection_kind, name]
 557     Vals.push_back(getEncodedComdatSelectionKind(*C));
 558     size_t Size = C->getName().size();
 559     assert(isUInt<16>(Size));
 560     Vals.push_back(Size);
 561     for (char Chr : C->getName())
 562       Vals.push_back((unsigned char)Chr);
 563     Stream.EmitRecord(bitc::MODULE_CODE_COMDAT, Vals, /*AbbrevToUse=*/0);
 564     Vals.clear();
 565   }
 566 }
 567
 568 // Emit top-level description of module, including target triple, inline asm,
 569 // descriptors for global variables, and function prototype info.
 570 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 571                             BitstreamWriter &Stream) {
 572   // Emit various pieces of data attached to a module.
 573   if (!M->getTargetTriple().empty())
 574     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 575                       0/*TODO*/, Stream);
 576   const std::string &DL = M->getDataLayoutStr();
 577   if (!DL.empty())
 578     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, DL, 0 /*TODO*/, Stream);
 579   if (!M->getModuleInlineAsm().empty())
 580     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 581                       0/*TODO*/, Stream);
 582
 583   // Emit information about sections and GC, computing how many there are. Also
 584   // compute the maximum alignment value.
 585   std::map<std::string, unsigned> SectionMap;
 586   std::map<std::string, unsigned> GCMap;
 587   unsigned MaxAlignment = 0;
 588   unsigned MaxGlobalType = 0;
 589   for (const GlobalValue &GV : M->globals()) {
 590     MaxAlignment = std::max(MaxAlignment, GV.getAlignment());
 591     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getType()));
 592     if (GV.hasSection()) {
 593       // Give section names unique ID's.
 594       unsigned &Entry = SectionMap[GV.getSection()];
 595       if (!Entry) {
 596         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
 597                           0/*TODO*/, Stream);
 598         Entry = SectionMap.size();
 599       }
 600     }
 601   }
 602   for (const Function &F : *M) {
 603     MaxAlignment = std::max(MaxAlignment, F.getAlignment());
 604     if (F.hasSection()) {
 605       // Give section names unique ID's.
 606       unsigned &Entry = SectionMap[F.getSection()];
 607       if (!Entry) {
 608         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
 609                           0/*TODO*/, Stream);
 610         Entry = SectionMap.size();
 611       }
 612     }
 613     if (F.hasGC()) {
 614       // Same for GC names.
 615       unsigned &Entry = GCMap[F.getGC()];
 616       if (!Entry) {
 617         WriteStringRecord(bitc::MODULE_CODE_GCNAME, F.getGC(),
 618                           0/*TODO*/, Stream);
 619         Entry = GCMap.size();
 620       }
 621     }
 622   }
 623
 624   // Emit abbrev for globals, now that we know # sections and max alignment.
 625   unsigned SimpleGVarAbbrev = 0;
 626   if (!M->global_empty()) {
 627     // Add an abbrev for common globals with no visibility or thread localness.
 628     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 629     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 630     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 631                               Log2_32_Ceil(MaxGlobalType+1)));
 632     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
 633     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
 634     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 5));      // Linkage.
 635     if (MaxAlignment == 0)                                      // Alignment.
 636       Abbv->Add(BitCodeAbbrevOp(0));
 637     else {
 638       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 639       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 640                                Log2_32_Ceil(MaxEncAlignment+1)));
 641     }
 642     if (SectionMap.empty())                                    // Section.
 643       Abbv->Add(BitCodeAbbrevOp(0));
 644     else
 645       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 646                                Log2_32_Ceil(SectionMap.size()+1)));
 647     // Don't bother emitting vis + thread local.
 648     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 649   }
 650
 651   // Emit the global variable information.
 652   SmallVector<unsigned, 64> Vals;
 653   for (const GlobalVariable &GV : M->globals()) {
 654     unsigned AbbrevToUse = 0;
 655
 656     // GLOBALVAR: [type, isconst, initid,
 657     //             linkage, alignment, section, visibility, threadlocal,
 658     //             unnamed_addr, externally_initialized, dllstorageclass,
 659     //             comdat]
 660     Vals.push_back(VE.getTypeID(GV.getType()));
 661     Vals.push_back(GV.isConstant());
 662     Vals.push_back(GV.isDeclaration() ? 0 :
 663                    (VE.getValueID(GV.getInitializer()) + 1));
 664     Vals.push_back(getEncodedLinkage(GV));
 665     Vals.push_back(Log2_32(GV.getAlignment())+1);
 666     Vals.push_back(GV.hasSection() ? SectionMap[GV.getSection()] : 0);
 667     if (GV.isThreadLocal() ||
 668         GV.getVisibility() != GlobalValue::DefaultVisibility ||
 669         GV.hasUnnamedAddr() || GV.isExternallyInitialized() ||
 670         GV.getDLLStorageClass() != GlobalValue::DefaultStorageClass ||
 671         GV.hasComdat()) {
 672       Vals.push_back(getEncodedVisibility(GV));
 673       Vals.push_back(getEncodedThreadLocalMode(GV));
 674       Vals.push_back(GV.hasUnnamedAddr());
 675       Vals.push_back(GV.isExternallyInitialized());
 676       Vals.push_back(getEncodedDLLStorageClass(GV));
 677       Vals.push_back(GV.hasComdat() ? VE.getComdatID(GV.getComdat()) : 0);
 678     } else {
 679       AbbrevToUse = SimpleGVarAbbrev;
 680     }
 681
 682     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 683     Vals.clear();
 684   }
 685
 686   // Emit the function proto information.
 687   for (const Function &F : *M) {
 688     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
 689     //             section, visibility, gc, unnamed_addr, prologuedata,
 690     //             dllstorageclass, comdat, prefixdata]
 691     Vals.push_back(VE.getTypeID(F.getType()));
 692     Vals.push_back(F.getCallingConv());
 693     Vals.push_back(F.isDeclaration());
 694     Vals.push_back(getEncodedLinkage(F));
 695     Vals.push_back(VE.getAttributeID(F.getAttributes()));
 696     Vals.push_back(Log2_32(F.getAlignment())+1);
 697     Vals.push_back(F.hasSection() ? SectionMap[F.getSection()] : 0);
 698     Vals.push_back(getEncodedVisibility(F));
 699     Vals.push_back(F.hasGC() ? GCMap[F.getGC()] : 0);
 700     Vals.push_back(F.hasUnnamedAddr());
 701     Vals.push_back(F.hasPrologueData() ? (VE.getValueID(F.getPrologueData()) + 1)
 702                                        : 0);
 703     Vals.push_back(getEncodedDLLStorageClass(F));
 704     Vals.push_back(F.hasComdat() ? VE.getComdatID(F.getComdat()) : 0);
 705     Vals.push_back(F.hasPrefixData() ? (VE.getValueID(F.getPrefixData()) + 1)
 706                                      : 0);
 707
 708     unsigned AbbrevToUse = 0;
 709     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 710     Vals.clear();
 711   }
 712
 713   // Emit the alias information.
 714   for (const GlobalAlias &A : M->aliases()) {
 715     // ALIAS: [alias type, aliasee val#, linkage, visibility]
 716     Vals.push_back(VE.getTypeID(A.getType()));
 717     Vals.push_back(VE.getValueID(A.getAliasee()));
 718     Vals.push_back(getEncodedLinkage(A));
 719     Vals.push_back(getEncodedVisibility(A));
 720     Vals.push_back(getEncodedDLLStorageClass(A));
 721     Vals.push_back(getEncodedThreadLocalMode(A));
 722     Vals.push_back(A.hasUnnamedAddr());
 723     unsigned AbbrevToUse = 0;
 724     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 725     Vals.clear();
 726   }
 727 }
 728
 729 static uint64_t GetOptimizationFlags(const Value *V) {
 730   uint64_t Flags = 0;
 731
 732   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
 733     if (OBO->hasNoSignedWrap())
 734       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
 735     if (OBO->hasNoUnsignedWrap())
 736       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
 737   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
 738     if (PEO->isExact())
 739       Flags |= 1 << bitc::PEO_EXACT;
 740   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
 741     if (FPMO->hasUnsafeAlgebra())
 742       Flags |= FastMathFlags::UnsafeAlgebra;
 743     if (FPMO->hasNoNaNs())
 744       Flags |= FastMathFlags::NoNaNs;
 745     if (FPMO->hasNoInfs())
 746       Flags |= FastMathFlags::NoInfs;
 747     if (FPMO->hasNoSignedZeros())
 748       Flags |= FastMathFlags::NoSignedZeros;
 749     if (FPMO->hasAllowReciprocal())
 750       Flags |= FastMathFlags::AllowReciprocal;
 751   }
 752
 753   return Flags;
 754 }
 755
 756 static void WriteValueAsMetadata(const ValueAsMetadata *MD,
 757                                  const ValueEnumerator &VE,
 758                                  BitstreamWriter &Stream,
 759                                  SmallVectorImpl<uint64_t> &Record) {
 760   // Mimic an MDNode with a value as one operand.
 761   Value *V = MD->getValue();
 762   Record.push_back(VE.getTypeID(V->getType()));
 763   Record.push_back(VE.getValueID(V));
 764   Stream.EmitRecord(bitc::METADATA_VALUE, Record, 0);
 765   Record.clear();
 766 }
 767
 768 static void WriteMDTuple(const MDTuple *N, const ValueEnumerator &VE,
 769                          BitstreamWriter &Stream,
 770                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
 771   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
 772     Metadata *MD = N->getOperand(i);
 773     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
 774            "Unexpected function-local metadata");
 775     Record.push_back(VE.getMetadataOrNullID(MD));
 776   }
 777   Stream.EmitRecord(N->isDistinct() ? bitc::METADATA_DISTINCT_NODE
 778                                     : bitc::METADATA_NODE,
 779                     Record, Abbrev);
 780   Record.clear();
 781 }
 782
 783 static void WriteMDLocation(const MDLocation *N, const ValueEnumerator &VE,
 784                             BitstreamWriter &Stream,
 785                             SmallVectorImpl<uint64_t> &Record,
 786                             unsigned Abbrev) {
 787   Record.push_back(N->isDistinct());
 788   Record.push_back(N->getLine());
 789   Record.push_back(N->getColumn());
 790   Record.push_back(VE.getMetadataID(N->getScope()));
 791   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
 792
 793   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
 794   Record.clear();
 795 }
 796
 797 static void WriteGenericDebugNode(const GenericDebugNode *N,
 798                                   const ValueEnumerator &VE,
 799                                   BitstreamWriter &Stream,
 800                                   SmallVectorImpl<uint64_t> &Record,
 801                                   unsigned Abbrev) {
 802   Record.push_back(N->isDistinct());
 803   Record.push_back(N->getTag());
 804   Record.push_back(0); // Per-tag version field; unused for now.
 805
 806   for (auto &I : N->operands())
 807     Record.push_back(VE.getMetadataOrNullID(I));
 808
 809   Stream.EmitRecord(bitc::METADATA_GENERIC_DEBUG, Record, Abbrev);
 810   Record.clear();
 811 }
 812
 813 static uint64_t rotateSign(int64_t I) {
 814   uint64_t U = I;
 815   return I < 0 ? ~(U << 1) : U << 1;
 816 }
 817
 818 static void WriteMDSubrange(const MDSubrange *N, const ValueEnumerator &,
 819                             BitstreamWriter &Stream,
 820                             SmallVectorImpl<uint64_t> &Record,
 821                             unsigned Abbrev) {
 822   Record.push_back(N->isDistinct());
 823   Record.push_back(N->getCount());
 824   Record.push_back(rotateSign(N->getLowerBound()));
 825
 826   Stream.EmitRecord(bitc::METADATA_SUBRANGE, Record, Abbrev);
 827   Record.clear();
 828 }
 829
 830 static void WriteMDEnumerator(const MDEnumerator *N, const ValueEnumerator &VE,
 831                               BitstreamWriter &Stream,
 832                               SmallVectorImpl<uint64_t> &Record,
 833                               unsigned Abbrev) {
 834   Record.push_back(N->isDistinct());
 835   Record.push_back(rotateSign(N->getValue()));
 836   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 837
 838   Stream.EmitRecord(bitc::METADATA_ENUMERATOR, Record, Abbrev);
 839   Record.clear();
 840 }
 841
 842 static void WriteMDBasicType(const MDBasicType *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(N->getTag());
 848   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 849   Record.push_back(N->getSizeInBits());
 850   Record.push_back(N->getAlignInBits());
 851   Record.push_back(N->getEncoding());
 852
 853   Stream.EmitRecord(bitc::METADATA_BASIC_TYPE, Record, Abbrev);
 854   Record.clear();
 855 }
 856
 857 static void WriteMDDerivedType(const MDDerivedType *N,
 858                                const ValueEnumerator &VE,
 859                                BitstreamWriter &Stream,
 860                                SmallVectorImpl<uint64_t> &Record,
 861                                unsigned Abbrev) {
 862   Record.push_back(N->isDistinct());
 863   Record.push_back(N->getTag());
 864   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 865   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 866   Record.push_back(N->getLine());
 867   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 868   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
 869   Record.push_back(N->getSizeInBits());
 870   Record.push_back(N->getAlignInBits());
 871   Record.push_back(N->getOffsetInBits());
 872   Record.push_back(N->getFlags());
 873   Record.push_back(VE.getMetadataOrNullID(N->getExtraData()));
 874
 875   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
 876   Record.clear();
 877 }
 878
 879 static void WriteMDCompositeType(const MDCompositeType *N,
 880                                  const ValueEnumerator &VE,
 881                                  BitstreamWriter &Stream,
 882                                  SmallVectorImpl<uint64_t> &Record,
 883                                  unsigned Abbrev) {
 884   Record.push_back(N->isDistinct());
 885   Record.push_back(N->getTag());
 886   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 887   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 888   Record.push_back(N->getLine());
 889   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 890   Record.push_back(VE.getMetadataOrNullID(N->getBaseType()));
 891   Record.push_back(N->getSizeInBits());
 892   Record.push_back(N->getAlignInBits());
 893   Record.push_back(N->getOffsetInBits());
 894   Record.push_back(N->getFlags());
 895   Record.push_back(VE.getMetadataOrNullID(N->getElements().get()));
 896   Record.push_back(N->getRuntimeLang());
 897   Record.push_back(VE.getMetadataOrNullID(N->getVTableHolder()));
 898   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
 899   Record.push_back(VE.getMetadataOrNullID(N->getRawIdentifier()));
 900
 901   Stream.EmitRecord(bitc::METADATA_COMPOSITE_TYPE, Record, Abbrev);
 902   Record.clear();
 903 }
 904
 905 static void WriteMDSubroutineType(const MDSubroutineType *N,
 906                                   const ValueEnumerator &VE,
 907                                   BitstreamWriter &Stream,
 908                                   SmallVectorImpl<uint64_t> &Record,
 909                                   unsigned Abbrev) {
 910   Record.push_back(N->isDistinct());
 911   Record.push_back(N->getFlags());
 912   Record.push_back(VE.getMetadataOrNullID(N->getTypeArray().get()));
 913
 914   Stream.EmitRecord(bitc::METADATA_SUBROUTINE_TYPE, Record, Abbrev);
 915   Record.clear();
 916 }
 917
 918 static void WriteMDFile(const MDFile *N, const ValueEnumerator &VE,
 919                         BitstreamWriter &Stream,
 920                         SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
 921   Record.push_back(N->isDistinct());
 922   Record.push_back(VE.getMetadataOrNullID(N->getRawFilename()));
 923   Record.push_back(VE.getMetadataOrNullID(N->getRawDirectory()));
 924
 925   Stream.EmitRecord(bitc::METADATA_FILE, Record, Abbrev);
 926   Record.clear();
 927 }
 928
 929 static void WriteMDCompileUnit(const MDCompileUnit *N,
 930                                const ValueEnumerator &VE,
 931                                BitstreamWriter &Stream,
 932                                SmallVectorImpl<uint64_t> &Record,
 933                                unsigned Abbrev) {
 934   Record.push_back(N->isDistinct());
 935   Record.push_back(N->getSourceLanguage());
 936   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 937   Record.push_back(VE.getMetadataOrNullID(N->getRawProducer()));
 938   Record.push_back(N->isOptimized());
 939   Record.push_back(VE.getMetadataOrNullID(N->getRawFlags()));
 940   Record.push_back(N->getRuntimeVersion());
 941   Record.push_back(VE.getMetadataOrNullID(N->getRawSplitDebugFilename()));
 942   Record.push_back(N->getEmissionKind());
 943   Record.push_back(VE.getMetadataOrNullID(N->getEnumTypes().get()));
 944   Record.push_back(VE.getMetadataOrNullID(N->getRetainedTypes().get()));
 945   Record.push_back(VE.getMetadataOrNullID(N->getSubprograms().get()));
 946   Record.push_back(VE.getMetadataOrNullID(N->getGlobalVariables().get()));
 947   Record.push_back(VE.getMetadataOrNullID(N->getImportedEntities().get()));
 948
 949   Stream.EmitRecord(bitc::METADATA_COMPILE_UNIT, Record, Abbrev);
 950   Record.clear();
 951 }
 952
 953 static void WriteMDSubprogram(const MDSubprogram *N,
 954                                const ValueEnumerator &VE,
 955                                BitstreamWriter &Stream,
 956                                SmallVectorImpl<uint64_t> &Record,
 957                                unsigned Abbrev) {
 958   Record.push_back(N->isDistinct());
 959   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 960   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
 961   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
 962   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 963   Record.push_back(N->getLine());
 964   Record.push_back(VE.getMetadataOrNullID(N->getType()));
 965   Record.push_back(N->isLocalToUnit());
 966   Record.push_back(N->isDefinition());
 967   Record.push_back(N->getScopeLine());
 968   Record.push_back(VE.getMetadataOrNullID(N->getContainingType()));
 969   Record.push_back(N->getVirtuality());
 970   Record.push_back(N->getVirtualIndex());
 971   Record.push_back(N->getFlags());
 972   Record.push_back(N->isOptimized());
 973   Record.push_back(VE.getMetadataOrNullID(N->getRawFunction()));
 974   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams().get()));
 975   Record.push_back(VE.getMetadataOrNullID(N->getDeclaration()));
 976   Record.push_back(VE.getMetadataOrNullID(N->getVariables().get()));
 977
 978   Stream.EmitRecord(bitc::METADATA_SUBPROGRAM, Record, Abbrev);
 979   Record.clear();
 980 }
 981
 982 static void WriteMDLexicalBlock(const MDLexicalBlock *N,
 983                                const ValueEnumerator &VE,
 984                                BitstreamWriter &Stream,
 985                                SmallVectorImpl<uint64_t> &Record,
 986                                unsigned Abbrev) {
 987   Record.push_back(N->isDistinct());
 988   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
 989   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
 990   Record.push_back(N->getLine());
 991   Record.push_back(N->getColumn());
 992
 993   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK, Record, Abbrev);
 994   Record.clear();
 995 }
 996
 997 static void WriteMDLexicalBlockFile(const MDLexicalBlockFile *N,
 998                                     const ValueEnumerator &VE,
 999                                     BitstreamWriter &Stream,
1000                                     SmallVectorImpl<uint64_t> &Record,
1001                                     unsigned Abbrev) {
1002   Record.push_back(N->isDistinct());
1003   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1004   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1005   Record.push_back(N->getDiscriminator());
1006
1007   Stream.EmitRecord(bitc::METADATA_LEXICAL_BLOCK_FILE, Record, Abbrev);
1008   Record.clear();
1009 }
1010
1011 static void WriteMDNamespace(const MDNamespace *N, const ValueEnumerator &VE,
1012                              BitstreamWriter &Stream,
1013                              SmallVectorImpl<uint64_t> &Record,
1014                              unsigned Abbrev) {
1015   Record.push_back(N->isDistinct());
1016   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1017   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1018   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1019   Record.push_back(N->getLine());
1020
1021   Stream.EmitRecord(bitc::METADATA_NAMESPACE, Record, Abbrev);
1022   Record.clear();
1023 }
1024
1025 static void WriteMDTemplateTypeParameter(const MDTemplateTypeParameter *N,
1026                                          const ValueEnumerator &VE,
1027                                          BitstreamWriter &Stream,
1028                                          SmallVectorImpl<uint64_t> &Record,
1029                                          unsigned Abbrev) {
1030   Record.push_back(N->isDistinct());
1031   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1032   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1033
1034   Stream.EmitRecord(bitc::METADATA_TEMPLATE_TYPE, Record, Abbrev);
1035   Record.clear();
1036 }
1037
1038 static void WriteMDTemplateValueParameter(const MDTemplateValueParameter *N,
1039                                           const ValueEnumerator &VE,
1040                                           BitstreamWriter &Stream,
1041                                           SmallVectorImpl<uint64_t> &Record,
1042                                           unsigned Abbrev) {
1043   Record.push_back(N->isDistinct());
1044   Record.push_back(N->getTag());
1045   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1046   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1047   Record.push_back(VE.getMetadataOrNullID(N->getValue()));
1048
1049   Stream.EmitRecord(bitc::METADATA_TEMPLATE_VALUE, Record, Abbrev);
1050   Record.clear();
1051 }
1052
1053 static void WriteMDGlobalVariable(const MDGlobalVariable *N,
1054                                   const ValueEnumerator &VE,
1055                                   BitstreamWriter &Stream,
1056                                   SmallVectorImpl<uint64_t> &Record,
1057                                   unsigned Abbrev) {
1058   Record.push_back(N->isDistinct());
1059   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1060   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1061   Record.push_back(VE.getMetadataOrNullID(N->getRawLinkageName()));
1062   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1063   Record.push_back(N->getLine());
1064   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1065   Record.push_back(N->isLocalToUnit());
1066   Record.push_back(N->isDefinition());
1067   Record.push_back(VE.getMetadataOrNullID(N->getRawVariable()));
1068   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
1069
1070   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
1071   Record.clear();
1072 }
1073
1074 static void WriteMDLocalVariable(const MDLocalVariable *N,
1075                                  const ValueEnumerator &VE,
1076                                  BitstreamWriter &Stream,
1077                                  SmallVectorImpl<uint64_t> &Record,
1078                                  unsigned Abbrev) {
1079   Record.push_back(N->isDistinct());
1080   Record.push_back(N->getTag());
1081   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1082   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1083   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1084   Record.push_back(N->getLine());
1085   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1086   Record.push_back(N->getArg());
1087   Record.push_back(N->getFlags());
1088
1089   Stream.EmitRecord(bitc::METADATA_LOCAL_VAR, Record, Abbrev);
1090   Record.clear();
1091 }
1092
1093 static void WriteMDExpression(const MDExpression *N, const ValueEnumerator &,
1094                               BitstreamWriter &Stream,
1095                               SmallVectorImpl<uint64_t> &Record,
1096                               unsigned Abbrev) {
1097   Record.reserve(N->getElements().size() + 1);
1098
1099   Record.push_back(N->isDistinct());
1100   Record.append(N->elements_begin(), N->elements_end());
1101
1102   Stream.EmitRecord(bitc::METADATA_EXPRESSION, Record, Abbrev);
1103   Record.clear();
1104 }
1105
1106 static void WriteMDObjCProperty(const MDObjCProperty *N,
1107                                  const ValueEnumerator &VE,
1108                                  BitstreamWriter &Stream,
1109                                  SmallVectorImpl<uint64_t> &Record,
1110                                  unsigned Abbrev) {
1111   Record.push_back(N->isDistinct());
1112   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1113   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
1114   Record.push_back(N->getLine());
1115   Record.push_back(VE.getMetadataOrNullID(N->getRawSetterName()));
1116   Record.push_back(VE.getMetadataOrNullID(N->getRawGetterName()));
1117   Record.push_back(N->getAttributes());
1118   Record.push_back(VE.getMetadataOrNullID(N->getType()));
1119
1120   Stream.EmitRecord(bitc::METADATA_OBJC_PROPERTY, Record, Abbrev);
1121   Record.clear();
1122 }
1123
1124 static void WriteMDImportedEntity(const MDImportedEntity *N,
1125                                   const ValueEnumerator &VE,
1126                                   BitstreamWriter &Stream,
1127                                   SmallVectorImpl<uint64_t> &Record,
1128                                   unsigned Abbrev) {
1129   Record.push_back(N->isDistinct());
1130   Record.push_back(N->getTag());
1131   Record.push_back(VE.getMetadataOrNullID(N->getScope()));
1132   Record.push_back(VE.getMetadataOrNullID(N->getEntity()));
1133   Record.push_back(N->getLine());
1134   Record.push_back(VE.getMetadataOrNullID(N->getRawName()));
1135
1136   Stream.EmitRecord(bitc::METADATA_IMPORTED_ENTITY, Record, Abbrev);
1137   Record.clear();
1138 }
1139
1140 static void WriteModuleMetadata(const Module *M,
1141                                 const ValueEnumerator &VE,
1142                                 BitstreamWriter &Stream) {
1143   const auto &MDs = VE.getMDs();
1144   if (MDs.empty() && M->named_metadata_empty())
1145     return;
1146
1147   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1148
1149   unsigned MDSAbbrev = 0;
1150   if (VE.hasMDString()) {
1151     // Abbrev for METADATA_STRING.
1152     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1153     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
1154     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1155     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1156     MDSAbbrev = Stream.EmitAbbrev(Abbv);
1157   }
1158
1159   // Initialize MDNode abbreviations.
1160 #define HANDLE_MDNODE_LEAF(CLASS) unsigned CLASS##Abbrev = 0;
1161 #include "llvm/IR/Metadata.def"
1162
1163   if (VE.hasMDLocation()) {
1164     // Abbrev for METADATA_LOCATION.
1165     //
1166     // Assume the column is usually under 128, and always output the inlined-at
1167     // location (it's never more expensive than building an array size 1).
1168     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1169     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
1170     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1171     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1172     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1173     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1174     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1175     MDLocationAbbrev = Stream.EmitAbbrev(Abbv);
1176   }
1177
1178   if (VE.hasGenericDebugNode()) {
1179     // Abbrev for METADATA_GENERIC_DEBUG.
1180     //
1181     // Assume the column is usually under 128, and always output the inlined-at
1182     // location (it's never more expensive than building an array size 1).
1183     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1184     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_GENERIC_DEBUG));
1185     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1186     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1187     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
1188     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1189     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1190     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
1191     GenericDebugNodeAbbrev = Stream.EmitAbbrev(Abbv);
1192   }
1193
1194   unsigned NameAbbrev = 0;
1195   if (!M->named_metadata_empty()) {
1196     // Abbrev for METADATA_NAME.
1197     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1198     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
1199     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1200     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1201     NameAbbrev = Stream.EmitAbbrev(Abbv);
1202   }
1203
1204   SmallVector<uint64_t, 64> Record;
1205   for (const Metadata *MD : MDs) {
1206     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
1207       assert(N->isResolved() && "Expected forward references to be resolved");
1208
1209       switch (N->getMetadataID()) {
1210       default:
1211         llvm_unreachable("Invalid MDNode subclass");
1212 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
1213   case Metadata::CLASS##Kind:                                                  \
1214     Write##CLASS(cast<CLASS>(N), VE, Stream, Record, CLASS##Abbrev);           \
1215     continue;
1216 #include "llvm/IR/Metadata.def"
1217       }
1218     }
1219     if (const auto *MDC = dyn_cast<ConstantAsMetadata>(MD)) {
1220       WriteValueAsMetadata(MDC, VE, Stream, Record);
1221       continue;
1222     }
1223     const MDString *MDS = cast<MDString>(MD);
1224     // Code: [strchar x N]
1225     Record.append(MDS->bytes_begin(), MDS->bytes_end());
1226
1227     // Emit the finished record.
1228     Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
1229     Record.clear();
1230   }
1231
1232   // Write named metadata.
1233   for (const NamedMDNode &NMD : M->named_metadata()) {
1234     // Write name.
1235     StringRef Str = NMD.getName();
1236     Record.append(Str.bytes_begin(), Str.bytes_end());
1237     Stream.EmitRecord(bitc::METADATA_NAME, Record, NameAbbrev);
1238     Record.clear();
1239
1240     // Write named metadata operands.
1241     for (const MDNode *N : NMD.operands())
1242       Record.push_back(VE.getMetadataID(N));
1243     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
1244     Record.clear();
1245   }
1246
1247   Stream.ExitBlock();
1248 }
1249
1250 static void WriteFunctionLocalMetadata(const Function &F,
1251                                        const ValueEnumerator &VE,
1252                                        BitstreamWriter &Stream) {
1253   bool StartedMetadataBlock = false;
1254   SmallVector<uint64_t, 64> Record;
1255   const SmallVectorImpl<const LocalAsMetadata *> &MDs =
1256       VE.getFunctionLocalMDs();
1257   for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1258     assert(MDs[i] && "Expected valid function-local metadata");
1259     if (!StartedMetadataBlock) {
1260       Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1261       StartedMetadataBlock = true;
1262     }
1263     WriteValueAsMetadata(MDs[i], VE, Stream, Record);
1264   }
1265
1266   if (StartedMetadataBlock)
1267     Stream.ExitBlock();
1268 }
1269
1270 static void WriteMetadataAttachment(const Function &F,
1271                                     const ValueEnumerator &VE,
1272                                     BitstreamWriter &Stream) {
1273   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
1274
1275   SmallVector<uint64_t, 64> Record;
1276
1277   // Write metadata attachments
1278   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
1279   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
1280
1281   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1282     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1283          I != E; ++I) {
1284       MDs.clear();
1285       I->getAllMetadataOtherThanDebugLoc(MDs);
1286
1287       // If no metadata, ignore instruction.
1288       if (MDs.empty()) continue;
1289
1290       Record.push_back(VE.getInstructionID(I));
1291
1292       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
1293         Record.push_back(MDs[i].first);
1294         Record.push_back(VE.getMetadataID(MDs[i].second));
1295       }
1296       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
1297       Record.clear();
1298     }
1299
1300   Stream.ExitBlock();
1301 }
1302
1303 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
1304   SmallVector<uint64_t, 64> Record;
1305
1306   // Write metadata kinds
1307   // METADATA_KIND - [n x [id, name]]
1308   SmallVector<StringRef, 8> Names;
1309   M->getMDKindNames(Names);
1310
1311   if (Names.empty()) return;
1312
1313   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
1314
1315   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
1316     Record.push_back(MDKindID);
1317     StringRef KName = Names[MDKindID];
1318     Record.append(KName.begin(), KName.end());
1319
1320     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
1321     Record.clear();
1322   }
1323
1324   Stream.ExitBlock();
1325 }
1326
1327 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
1328   if ((int64_t)V >= 0)
1329     Vals.push_back(V << 1);
1330   else
1331     Vals.push_back((-V << 1) | 1);
1332 }
1333
1334 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
1335                            const ValueEnumerator &VE,
1336                            BitstreamWriter &Stream, bool isGlobal) {
1337   if (FirstVal == LastVal) return;
1338
1339   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
1340
1341   unsigned AggregateAbbrev = 0;
1342   unsigned String8Abbrev = 0;
1343   unsigned CString7Abbrev = 0;
1344   unsigned CString6Abbrev = 0;
1345   // If this is a constant pool for the module, emit module-specific abbrevs.
1346   if (isGlobal) {
1347     // Abbrev for CST_CODE_AGGREGATE.
1348     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1349     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
1350     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1351     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
1352     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
1353
1354     // Abbrev for CST_CODE_STRING.
1355     Abbv = new BitCodeAbbrev();
1356     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
1357     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1358     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1359     String8Abbrev = Stream.EmitAbbrev(Abbv);
1360     // Abbrev for CST_CODE_CSTRING.
1361     Abbv = new BitCodeAbbrev();
1362     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1363     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1364     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1365     CString7Abbrev = Stream.EmitAbbrev(Abbv);
1366     // Abbrev for CST_CODE_CSTRING.
1367     Abbv = new BitCodeAbbrev();
1368     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
1369     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1370     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1371     CString6Abbrev = Stream.EmitAbbrev(Abbv);
1372   }
1373
1374   SmallVector<uint64_t, 64> Record;
1375
1376   const ValueEnumerator::ValueList &Vals = VE.getValues();
1377   Type *LastTy = nullptr;
1378   for (unsigned i = FirstVal; i != LastVal; ++i) {
1379     const Value *V = Vals[i].first;
1380     // If we need to switch types, do so now.
1381     if (V->getType() != LastTy) {
1382       LastTy = V->getType();
1383       Record.push_back(VE.getTypeID(LastTy));
1384       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
1385                         CONSTANTS_SETTYPE_ABBREV);
1386       Record.clear();
1387     }
1388
1389     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
1390       Record.push_back(unsigned(IA->hasSideEffects()) |
1391                        unsigned(IA->isAlignStack()) << 1 |
1392                        unsigned(IA->getDialect()&1) << 2);
1393
1394       // Add the asm string.
1395       const std::string &AsmStr = IA->getAsmString();
1396       Record.push_back(AsmStr.size());
1397       Record.append(AsmStr.begin(), AsmStr.end());
1398
1399       // Add the constraint string.
1400       const std::string &ConstraintStr = IA->getConstraintString();
1401       Record.push_back(ConstraintStr.size());
1402       Record.append(ConstraintStr.begin(), ConstraintStr.end());
1403       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
1404       Record.clear();
1405       continue;
1406     }
1407     const Constant *C = cast<Constant>(V);
1408     unsigned Code = -1U;
1409     unsigned AbbrevToUse = 0;
1410     if (C->isNullValue()) {
1411       Code = bitc::CST_CODE_NULL;
1412     } else if (isa<UndefValue>(C)) {
1413       Code = bitc::CST_CODE_UNDEF;
1414     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
1415       if (IV->getBitWidth() <= 64) {
1416         uint64_t V = IV->getSExtValue();
1417         emitSignedInt64(Record, V);
1418         Code = bitc::CST_CODE_INTEGER;
1419         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
1420       } else {                             // Wide integers, > 64 bits in size.
1421         // We have an arbitrary precision integer value to write whose
1422         // bit width is > 64. However, in canonical unsigned integer
1423         // format it is likely that the high bits are going to be zero.
1424         // So, we only write the number of active words.
1425         unsigned NWords = IV->getValue().getActiveWords();
1426         const uint64_t *RawWords = IV->getValue().getRawData();
1427         for (unsigned i = 0; i != NWords; ++i) {
1428           emitSignedInt64(Record, RawWords[i]);
1429         }
1430         Code = bitc::CST_CODE_WIDE_INTEGER;
1431       }
1432     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
1433       Code = bitc::CST_CODE_FLOAT;
1434       Type *Ty = CFP->getType();
1435       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
1436         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
1437       } else if (Ty->isX86_FP80Ty()) {
1438         // api needed to prevent premature destruction
1439         // bits are not in the same order as a normal i80 APInt, compensate.
1440         APInt api = CFP->getValueAPF().bitcastToAPInt();
1441         const uint64_t *p = api.getRawData();
1442         Record.push_back((p[1] << 48) | (p[0] >> 16));
1443         Record.push_back(p[0] & 0xffffLL);
1444       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
1445         APInt api = CFP->getValueAPF().bitcastToAPInt();
1446         const uint64_t *p = api.getRawData();
1447         Record.push_back(p[0]);
1448         Record.push_back(p[1]);
1449       } else {
1450         assert (0 && "Unknown FP type!");
1451       }
1452     } else if (isa<ConstantDataSequential>(C) &&
1453                cast<ConstantDataSequential>(C)->isString()) {
1454       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
1455       // Emit constant strings specially.
1456       unsigned NumElts = Str->getNumElements();
1457       // If this is a null-terminated string, use the denser CSTRING encoding.
1458       if (Str->isCString()) {
1459         Code = bitc::CST_CODE_CSTRING;
1460         --NumElts;  // Don't encode the null, which isn't allowed by char6.
1461       } else {
1462         Code = bitc::CST_CODE_STRING;
1463         AbbrevToUse = String8Abbrev;
1464       }
1465       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
1466       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
1467       for (unsigned i = 0; i != NumElts; ++i) {
1468         unsigned char V = Str->getElementAsInteger(i);
1469         Record.push_back(V);
1470         isCStr7 &= (V & 128) == 0;
1471         if (isCStrChar6)
1472           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
1473       }
1474
1475       if (isCStrChar6)
1476         AbbrevToUse = CString6Abbrev;
1477       else if (isCStr7)
1478         AbbrevToUse = CString7Abbrev;
1479     } else if (const ConstantDataSequential *CDS =
1480                   dyn_cast<ConstantDataSequential>(C)) {
1481       Code = bitc::CST_CODE_DATA;
1482       Type *EltTy = CDS->getType()->getElementType();
1483       if (isa<IntegerType>(EltTy)) {
1484         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
1485           Record.push_back(CDS->getElementAsInteger(i));
1486       } else if (EltTy->isFloatTy()) {
1487         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1488           union { float F; uint32_t I; };
1489           F = CDS->getElementAsFloat(i);
1490           Record.push_back(I);
1491         }
1492       } else {
1493         assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
1494         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1495           union { double F; uint64_t I; };
1496           F = CDS->getElementAsDouble(i);
1497           Record.push_back(I);
1498         }
1499       }
1500     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
1501                isa<ConstantVector>(C)) {
1502       Code = bitc::CST_CODE_AGGREGATE;
1503       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
1504         Record.push_back(VE.getValueID(C->getOperand(i)));
1505       AbbrevToUse = AggregateAbbrev;
1506     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
1507       switch (CE->getOpcode()) {
1508       default:
1509         if (Instruction::isCast(CE->getOpcode())) {
1510           Code = bitc::CST_CODE_CE_CAST;
1511           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
1512           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1513           Record.push_back(VE.getValueID(C->getOperand(0)));
1514           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
1515         } else {
1516           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
1517           Code = bitc::CST_CODE_CE_BINOP;
1518           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
1519           Record.push_back(VE.getValueID(C->getOperand(0)));
1520           Record.push_back(VE.getValueID(C->getOperand(1)));
1521           uint64_t Flags = GetOptimizationFlags(CE);
1522           if (Flags != 0)
1523             Record.push_back(Flags);
1524         }
1525         break;
1526       case Instruction::GetElementPtr: {
1527         Code = bitc::CST_CODE_CE_GEP;
1528         const auto *GO = cast<GEPOperator>(C);
1529         if (GO->isInBounds())
1530           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
1531         Record.push_back(VE.getTypeID(GO->getSourceElementType()));
1532         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
1533           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
1534           Record.push_back(VE.getValueID(C->getOperand(i)));
1535         }
1536         break;
1537       }
1538       case Instruction::Select:
1539         Code = bitc::CST_CODE_CE_SELECT;
1540         Record.push_back(VE.getValueID(C->getOperand(0)));
1541         Record.push_back(VE.getValueID(C->getOperand(1)));
1542         Record.push_back(VE.getValueID(C->getOperand(2)));
1543         break;
1544       case Instruction::ExtractElement:
1545         Code = bitc::CST_CODE_CE_EXTRACTELT;
1546         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1547         Record.push_back(VE.getValueID(C->getOperand(0)));
1548         Record.push_back(VE.getTypeID(C->getOperand(1)->getType()));
1549         Record.push_back(VE.getValueID(C->getOperand(1)));
1550         break;
1551       case Instruction::InsertElement:
1552         Code = bitc::CST_CODE_CE_INSERTELT;
1553         Record.push_back(VE.getValueID(C->getOperand(0)));
1554         Record.push_back(VE.getValueID(C->getOperand(1)));
1555         Record.push_back(VE.getTypeID(C->getOperand(2)->getType()));
1556         Record.push_back(VE.getValueID(C->getOperand(2)));
1557         break;
1558       case Instruction::ShuffleVector:
1559         // If the return type and argument types are the same, this is a
1560         // standard shufflevector instruction.  If the types are different,
1561         // then the shuffle is widening or truncating the input vectors, and
1562         // the argument type must also be encoded.
1563         if (C->getType() == C->getOperand(0)->getType()) {
1564           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
1565         } else {
1566           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
1567           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1568         }
1569         Record.push_back(VE.getValueID(C->getOperand(0)));
1570         Record.push_back(VE.getValueID(C->getOperand(1)));
1571         Record.push_back(VE.getValueID(C->getOperand(2)));
1572         break;
1573       case Instruction::ICmp:
1574       case Instruction::FCmp:
1575         Code = bitc::CST_CODE_CE_CMP;
1576         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1577         Record.push_back(VE.getValueID(C->getOperand(0)));
1578         Record.push_back(VE.getValueID(C->getOperand(1)));
1579         Record.push_back(CE->getPredicate());
1580         break;
1581       }
1582     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
1583       Code = bitc::CST_CODE_BLOCKADDRESS;
1584       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
1585       Record.push_back(VE.getValueID(BA->getFunction()));
1586       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
1587     } else {
1588 #ifndef NDEBUG
1589       C->dump();
1590 #endif
1591       llvm_unreachable("Unknown constant!");
1592     }
1593     Stream.EmitRecord(Code, Record, AbbrevToUse);
1594     Record.clear();
1595   }
1596
1597   Stream.ExitBlock();
1598 }
1599
1600 static void WriteModuleConstants(const ValueEnumerator &VE,
1601                                  BitstreamWriter &Stream) {
1602   const ValueEnumerator::ValueList &Vals = VE.getValues();
1603
1604   // Find the first constant to emit, which is the first non-globalvalue value.
1605   // We know globalvalues have been emitted by WriteModuleInfo.
1606   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1607     if (!isa<GlobalValue>(Vals[i].first)) {
1608       WriteConstants(i, Vals.size(), VE, Stream, true);
1609       return;
1610     }
1611   }
1612 }
1613
1614 /// PushValueAndType - The file has to encode both the value and type id for
1615 /// many values, because we need to know what type to create for forward
1616 /// references.  However, most operands are not forward references, so this type
1617 /// field is not needed.
1618 ///
1619 /// This function adds V's value ID to Vals.  If the value ID is higher than the
1620 /// instruction ID, then it is a forward reference, and it also includes the
1621 /// type ID.  The value ID that is written is encoded relative to the InstID.
1622 static bool PushValueAndType(const Value *V, unsigned InstID,
1623                              SmallVectorImpl<unsigned> &Vals,
1624                              ValueEnumerator &VE) {
1625   unsigned ValID = VE.getValueID(V);
1626   // Make encoding relative to the InstID.
1627   Vals.push_back(InstID - ValID);
1628   if (ValID >= InstID) {
1629     Vals.push_back(VE.getTypeID(V->getType()));
1630     return true;
1631   }
1632   return false;
1633 }
1634
1635 /// pushValue - Like PushValueAndType, but where the type of the value is
1636 /// omitted (perhaps it was already encoded in an earlier operand).
1637 static void pushValue(const Value *V, unsigned InstID,
1638                       SmallVectorImpl<unsigned> &Vals,
1639                       ValueEnumerator &VE) {
1640   unsigned ValID = VE.getValueID(V);
1641   Vals.push_back(InstID - ValID);
1642 }
1643
1644 static void pushValueSigned(const Value *V, unsigned InstID,
1645                             SmallVectorImpl<uint64_t> &Vals,
1646                             ValueEnumerator &VE) {
1647   unsigned ValID = VE.getValueID(V);
1648   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
1649   emitSignedInt64(Vals, diff);
1650 }
1651
1652 /// WriteInstruction - Emit an instruction to the specified stream.
1653 static void WriteInstruction(const Instruction &I, unsigned InstID,
1654                              ValueEnumerator &VE, BitstreamWriter &Stream,
1655                              SmallVectorImpl<unsigned> &Vals) {
1656   unsigned Code = 0;
1657   unsigned AbbrevToUse = 0;
1658   VE.setInstructionID(&I);
1659   switch (I.getOpcode()) {
1660   default:
1661     if (Instruction::isCast(I.getOpcode())) {
1662       Code = bitc::FUNC_CODE_INST_CAST;
1663       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1664         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1665       Vals.push_back(VE.getTypeID(I.getType()));
1666       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1667     } else {
1668       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1669       Code = bitc::FUNC_CODE_INST_BINOP;
1670       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1671         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1672       pushValue(I.getOperand(1), InstID, Vals, VE);
1673       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1674       uint64_t Flags = GetOptimizationFlags(&I);
1675       if (Flags != 0) {
1676         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1677           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1678         Vals.push_back(Flags);
1679       }
1680     }
1681     break;
1682
1683   case Instruction::GetElementPtr: {
1684     Code = bitc::FUNC_CODE_INST_GEP;
1685     AbbrevToUse = FUNCTION_INST_GEP_ABBREV;
1686     auto &GEPInst = cast<GetElementPtrInst>(I);
1687     Vals.push_back(GEPInst.isInBounds());
1688     Vals.push_back(VE.getTypeID(GEPInst.getSourceElementType()));
1689     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1690       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1691     break;
1692   }
1693   case Instruction::ExtractValue: {
1694     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1695     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1696     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1697     Vals.append(EVI->idx_begin(), EVI->idx_end());
1698     break;
1699   }
1700   case Instruction::InsertValue: {
1701     Code = bitc::FUNC_CODE_INST_INSERTVAL;
1702     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1703     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1704     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1705     Vals.append(IVI->idx_begin(), IVI->idx_end());
1706     break;
1707   }
1708   case Instruction::Select:
1709     Code = bitc::FUNC_CODE_INST_VSELECT;
1710     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1711     pushValue(I.getOperand(2), InstID, Vals, VE);
1712     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1713     break;
1714   case Instruction::ExtractElement:
1715     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1716     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1717     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1718     break;
1719   case Instruction::InsertElement:
1720     Code = bitc::FUNC_CODE_INST_INSERTELT;
1721     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1722     pushValue(I.getOperand(1), InstID, Vals, VE);
1723     PushValueAndType(I.getOperand(2), InstID, Vals, VE);
1724     break;
1725   case Instruction::ShuffleVector:
1726     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1727     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1728     pushValue(I.getOperand(1), InstID, Vals, VE);
1729     pushValue(I.getOperand(2), InstID, Vals, VE);
1730     break;
1731   case Instruction::ICmp:
1732   case Instruction::FCmp:
1733     // compare returning Int1Ty or vector of Int1Ty
1734     Code = bitc::FUNC_CODE_INST_CMP2;
1735     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1736     pushValue(I.getOperand(1), InstID, Vals, VE);
1737     Vals.push_back(cast<CmpInst>(I).getPredicate());
1738     break;
1739
1740   case Instruction::Ret:
1741     {
1742       Code = bitc::FUNC_CODE_INST_RET;
1743       unsigned NumOperands = I.getNumOperands();
1744       if (NumOperands == 0)
1745         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1746       else if (NumOperands == 1) {
1747         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1748           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1749       } else {
1750         for (unsigned i = 0, e = NumOperands; i != e; ++i)
1751           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1752       }
1753     }
1754     break;
1755   case Instruction::Br:
1756     {
1757       Code = bitc::FUNC_CODE_INST_BR;
1758       const BranchInst &II = cast<BranchInst>(I);
1759       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1760       if (II.isConditional()) {
1761         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1762         pushValue(II.getCondition(), InstID, Vals, VE);
1763       }
1764     }
1765     break;
1766   case Instruction::Switch:
1767     {
1768       Code = bitc::FUNC_CODE_INST_SWITCH;
1769       const SwitchInst &SI = cast<SwitchInst>(I);
1770       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
1771       pushValue(SI.getCondition(), InstID, Vals, VE);
1772       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
1773       for (SwitchInst::ConstCaseIt i = SI.case_begin(), e = SI.case_end();
1774            i != e; ++i) {
1775         Vals.push_back(VE.getValueID(i.getCaseValue()));
1776         Vals.push_back(VE.getValueID(i.getCaseSuccessor()));
1777       }
1778     }
1779     break;
1780   case Instruction::IndirectBr:
1781     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1782     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1783     // Encode the address operand as relative, but not the basic blocks.
1784     pushValue(I.getOperand(0), InstID, Vals, VE);
1785     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
1786       Vals.push_back(VE.getValueID(I.getOperand(i)));
1787     break;
1788
1789   case Instruction::Invoke: {
1790     const InvokeInst *II = cast<InvokeInst>(&I);
1791     const Value *Callee(II->getCalledValue());
1792     PointerType *PTy = cast<PointerType>(Callee->getType());
1793     FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1794     Code = bitc::FUNC_CODE_INST_INVOKE;
1795
1796     Vals.push_back(VE.getAttributeID(II->getAttributes()));
1797     Vals.push_back(II->getCallingConv());
1798     Vals.push_back(VE.getValueID(II->getNormalDest()));
1799     Vals.push_back(VE.getValueID(II->getUnwindDest()));
1800     PushValueAndType(Callee, InstID, Vals, VE);
1801
1802     // Emit value #'s for the fixed parameters.
1803     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1804       pushValue(I.getOperand(i), InstID, Vals, VE);  // fixed param.
1805
1806     // Emit type/value pairs for varargs params.
1807     if (FTy->isVarArg()) {
1808       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1809            i != e; ++i)
1810         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1811     }
1812     break;
1813   }
1814   case Instruction::Resume:
1815     Code = bitc::FUNC_CODE_INST_RESUME;
1816     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1817     break;
1818   case Instruction::Unreachable:
1819     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1820     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1821     break;
1822
1823   case Instruction::PHI: {
1824     const PHINode &PN = cast<PHINode>(I);
1825     Code = bitc::FUNC_CODE_INST_PHI;
1826     // With the newer instruction encoding, forward references could give
1827     // negative valued IDs.  This is most common for PHIs, so we use
1828     // signed VBRs.
1829     SmallVector<uint64_t, 128> Vals64;
1830     Vals64.push_back(VE.getTypeID(PN.getType()));
1831     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1832       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64, VE);
1833       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1834     }
1835     // Emit a Vals64 vector and exit.
1836     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
1837     Vals64.clear();
1838     return;
1839   }
1840
1841   case Instruction::LandingPad: {
1842     const LandingPadInst &LP = cast<LandingPadInst>(I);
1843     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
1844     Vals.push_back(VE.getTypeID(LP.getType()));
1845     PushValueAndType(LP.getPersonalityFn(), InstID, Vals, VE);
1846     Vals.push_back(LP.isCleanup());
1847     Vals.push_back(LP.getNumClauses());
1848     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1849       if (LP.isCatch(I))
1850         Vals.push_back(LandingPadInst::Catch);
1851       else
1852         Vals.push_back(LandingPadInst::Filter);
1853       PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1854     }
1855     break;
1856   }
1857
1858   case Instruction::Alloca: {
1859     Code = bitc::FUNC_CODE_INST_ALLOCA;
1860     Vals.push_back(VE.getTypeID(I.getType()));
1861     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1862     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1863     const AllocaInst &AI = cast<AllocaInst>(I);
1864     unsigned AlignRecord = Log2_32(AI.getAlignment()) + 1;
1865     assert(Log2_32(Value::MaximumAlignment) + 1 < 1 << 5 &&
1866            "not enough bits for maximum alignment");
1867     assert(AlignRecord < 1 << 5 && "alignment greater than 1 << 64");
1868     AlignRecord |= AI.isUsedWithInAlloca() << 5;
1869     Vals.push_back(AlignRecord);
1870     break;
1871   }
1872
1873   case Instruction::Load:
1874     if (cast<LoadInst>(I).isAtomic()) {
1875       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1876       PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1877     } else {
1878       Code = bitc::FUNC_CODE_INST_LOAD;
1879       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1880         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1881     }
1882     Vals.push_back(VE.getTypeID(I.getType()));
1883     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1884     Vals.push_back(cast<LoadInst>(I).isVolatile());
1885     if (cast<LoadInst>(I).isAtomic()) {
1886       Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1887       Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1888     }
1889     break;
1890   case Instruction::Store:
1891     if (cast<StoreInst>(I).isAtomic())
1892       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1893     else
1894       Code = bitc::FUNC_CODE_INST_STORE;
1895     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1896     pushValue(I.getOperand(0), InstID, Vals, VE);         // val.
1897     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1898     Vals.push_back(cast<StoreInst>(I).isVolatile());
1899     if (cast<StoreInst>(I).isAtomic()) {
1900       Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1901       Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1902     }
1903     break;
1904   case Instruction::AtomicCmpXchg:
1905     Code = bitc::FUNC_CODE_INST_CMPXCHG;
1906     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1907     pushValue(I.getOperand(1), InstID, Vals, VE);         // cmp.
1908     pushValue(I.getOperand(2), InstID, Vals, VE);         // newval.
1909     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1910     Vals.push_back(GetEncodedOrdering(
1911                      cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
1912     Vals.push_back(GetEncodedSynchScope(
1913                      cast<AtomicCmpXchgInst>(I).getSynchScope()));
1914     Vals.push_back(GetEncodedOrdering(
1915                      cast<AtomicCmpXchgInst>(I).getFailureOrdering()));
1916     Vals.push_back(cast<AtomicCmpXchgInst>(I).isWeak());
1917     break;
1918   case Instruction::AtomicRMW:
1919     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
1920     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1921     pushValue(I.getOperand(1), InstID, Vals, VE);         // val.
1922     Vals.push_back(GetEncodedRMWOperation(
1923                      cast<AtomicRMWInst>(I).getOperation()));
1924     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
1925     Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
1926     Vals.push_back(GetEncodedSynchScope(
1927                      cast<AtomicRMWInst>(I).getSynchScope()));
1928     break;
1929   case Instruction::Fence:
1930     Code = bitc::FUNC_CODE_INST_FENCE;
1931     Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
1932     Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
1933     break;
1934   case Instruction::Call: {
1935     const CallInst &CI = cast<CallInst>(I);
1936     PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1937     FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1938
1939     Code = bitc::FUNC_CODE_INST_CALL;
1940
1941     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1942     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()) |
1943                    unsigned(CI.isMustTailCall()) << 14);
1944     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1945
1946     // Emit value #'s for the fixed parameters.
1947     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1948       // Check for labels (can happen with asm labels).
1949       if (FTy->getParamType(i)->isLabelTy())
1950         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
1951       else
1952         pushValue(CI.getArgOperand(i), InstID, Vals, VE);  // fixed param.
1953     }
1954
1955     // Emit type/value pairs for varargs params.
1956     if (FTy->isVarArg()) {
1957       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1958            i != e; ++i)
1959         PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1960     }
1961     break;
1962   }
1963   case Instruction::VAArg:
1964     Code = bitc::FUNC_CODE_INST_VAARG;
1965     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1966     pushValue(I.getOperand(0), InstID, Vals, VE); // valist.
1967     Vals.push_back(VE.getTypeID(I.getType())); // restype.
1968     break;
1969   }
1970
1971   Stream.EmitRecord(Code, Vals, AbbrevToUse);
1972   Vals.clear();
1973 }
1974
1975 // Emit names for globals/functions etc.
1976 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1977                                   const ValueEnumerator &VE,
1978                                   BitstreamWriter &Stream) {
1979   if (VST.empty()) return;
1980   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1981
1982   // FIXME: Set up the abbrev, we know how many values there are!
1983   // FIXME: We know if the type names can use 7-bit ascii.
1984   SmallVector<unsigned, 64> NameVals;
1985
1986   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1987        SI != SE; ++SI) {
1988
1989     const ValueName &Name = *SI;
1990
1991     // Figure out the encoding to use for the name.
1992     bool is7Bit = true;
1993     bool isChar6 = true;
1994     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1995          C != E; ++C) {
1996       if (isChar6)
1997         isChar6 = BitCodeAbbrevOp::isChar6(*C);
1998       if ((unsigned char)*C & 128) {
1999         is7Bit = false;
2000         break;  // don't bother scanning the rest.
2001       }
2002     }
2003
2004     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
2005
2006     // VST_ENTRY:   [valueid, namechar x N]
2007     // VST_BBENTRY: [bbid, namechar x N]
2008     unsigned Code;
2009     if (isa<BasicBlock>(SI->getValue())) {
2010       Code = bitc::VST_CODE_BBENTRY;
2011       if (isChar6)
2012         AbbrevToUse = VST_BBENTRY_6_ABBREV;
2013     } else {
2014       Code = bitc::VST_CODE_ENTRY;
2015       if (isChar6)
2016         AbbrevToUse = VST_ENTRY_6_ABBREV;
2017       else if (is7Bit)
2018         AbbrevToUse = VST_ENTRY_7_ABBREV;
2019     }
2020
2021     NameVals.push_back(VE.getValueID(SI->getValue()));
2022     for (const char *P = Name.getKeyData(),
2023          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
2024       NameVals.push_back((unsigned char)*P);
2025
2026     // Emit the finished record.
2027     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
2028     NameVals.clear();
2029   }
2030   Stream.ExitBlock();
2031 }
2032
2033 static void WriteUseList(ValueEnumerator &VE, UseListOrder &&Order,
2034                          BitstreamWriter &Stream) {
2035   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
2036   unsigned Code;
2037   if (isa<BasicBlock>(Order.V))
2038     Code = bitc::USELIST_CODE_BB;
2039   else
2040     Code = bitc::USELIST_CODE_DEFAULT;
2041
2042   SmallVector<uint64_t, 64> Record(Order.Shuffle.begin(), Order.Shuffle.end());
2043   Record.push_back(VE.getValueID(Order.V));
2044   Stream.EmitRecord(Code, Record);
2045 }
2046
2047 static void WriteUseListBlock(const Function *F, ValueEnumerator &VE,
2048                               BitstreamWriter &Stream) {
2049   assert(VE.shouldPreserveUseListOrder() &&
2050          "Expected to be preserving use-list order");
2051
2052   auto hasMore = [&]() {
2053     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
2054   };
2055   if (!hasMore())
2056     // Nothing to do.
2057     return;
2058
2059   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
2060   while (hasMore()) {
2061     WriteUseList(VE, std::move(VE.UseListOrders.back()), Stream);
2062     VE.UseListOrders.pop_back();
2063   }
2064   Stream.ExitBlock();
2065 }
2066
2067 /// WriteFunction - Emit a function body to the module stream.
2068 static void WriteFunction(const Function &F, ValueEnumerator &VE,
2069                           BitstreamWriter &Stream) {
2070   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
2071   VE.incorporateFunction(F);
2072
2073   SmallVector<unsigned, 64> Vals;
2074
2075   // Emit the number of basic blocks, so the reader can create them ahead of
2076   // time.
2077   Vals.push_back(VE.getBasicBlocks().size());
2078   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
2079   Vals.clear();
2080
2081   // If there are function-local constants, emit them now.
2082   unsigned CstStart, CstEnd;
2083   VE.getFunctionConstantRange(CstStart, CstEnd);
2084   WriteConstants(CstStart, CstEnd, VE, Stream, false);
2085
2086   // If there is function-local metadata, emit it now.
2087   WriteFunctionLocalMetadata(F, VE, Stream);
2088
2089   // Keep a running idea of what the instruction ID is.
2090   unsigned InstID = CstEnd;
2091
2092   bool NeedsMetadataAttachment = false;
2093
2094   MDLocation *LastDL = nullptr;
2095
2096   // Finally, emit all the instructions, in order.
2097   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
2098     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
2099          I != E; ++I) {
2100       WriteInstruction(*I, InstID, VE, Stream, Vals);
2101
2102       if (!I->getType()->isVoidTy())
2103         ++InstID;
2104
2105       // If the instruction has metadata, write a metadata attachment later.
2106       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
2107
2108       // If the instruction has a debug location, emit it.
2109       MDLocation *DL = I->getDebugLoc();
2110       if (!DL)
2111         continue;
2112
2113       if (DL == LastDL) {
2114         // Just repeat the same debug loc as last time.
2115         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
2116         continue;
2117       }
2118
2119       Vals.push_back(DL->getLine());
2120       Vals.push_back(DL->getColumn());
2121       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
2122       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
2123       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
2124       Vals.clear();
2125     }
2126
2127   // Emit names for all the instructions etc.
2128   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
2129
2130   if (NeedsMetadataAttachment)
2131     WriteMetadataAttachment(F, VE, Stream);
2132   if (VE.shouldPreserveUseListOrder())
2133     WriteUseListBlock(&F, VE, Stream);
2134   VE.purgeFunction();
2135   Stream.ExitBlock();
2136 }
2137
2138 // Emit blockinfo, which defines the standard abbreviations etc.
2139 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
2140   // We only want to emit block info records for blocks that have multiple
2141   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
2142   // Other blocks can define their abbrevs inline.
2143   Stream.EnterBlockInfoBlock(2);
2144
2145   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
2146     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2147     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
2148     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2149     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2150     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
2151     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2152                                    Abbv) != VST_ENTRY_8_ABBREV)
2153       llvm_unreachable("Unexpected abbrev ordering!");
2154   }
2155
2156   { // 7-bit fixed width VST_ENTRY strings.
2157     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2158     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2159     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2160     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2161     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
2162     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2163                                    Abbv) != VST_ENTRY_7_ABBREV)
2164       llvm_unreachable("Unexpected abbrev ordering!");
2165   }
2166   { // 6-bit char6 VST_ENTRY strings.
2167     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2168     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
2169     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2170     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2171     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2172     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2173                                    Abbv) != VST_ENTRY_6_ABBREV)
2174       llvm_unreachable("Unexpected abbrev ordering!");
2175   }
2176   { // 6-bit char6 VST_BBENTRY strings.
2177     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2178     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
2179     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2180     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2181     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
2182     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
2183                                    Abbv) != VST_BBENTRY_6_ABBREV)
2184       llvm_unreachable("Unexpected abbrev ordering!");
2185   }
2186
2187
2188
2189   { // SETTYPE abbrev for CONSTANTS_BLOCK.
2190     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2191     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
2192     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
2193                               VE.computeBitsRequiredForTypeIndicies()));
2194     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2195                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
2196       llvm_unreachable("Unexpected abbrev ordering!");
2197   }
2198
2199   { // INTEGER abbrev for CONSTANTS_BLOCK.
2200     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2201     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
2202     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
2203     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2204                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
2205       llvm_unreachable("Unexpected abbrev ordering!");
2206   }
2207
2208   { // CE_CAST abbrev for CONSTANTS_BLOCK.
2209     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2210     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
2211     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
2212     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
2213                               VE.computeBitsRequiredForTypeIndicies()));
2214     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
2215
2216     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2217                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
2218       llvm_unreachable("Unexpected abbrev ordering!");
2219   }
2220   { // NULL abbrev for CONSTANTS_BLOCK.
2221     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2222     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
2223     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
2224                                    Abbv) != CONSTANTS_NULL_Abbrev)
2225       llvm_unreachable("Unexpected abbrev ordering!");
2226   }
2227
2228   // FIXME: This should only use space for first class types!
2229
2230   { // INST_LOAD abbrev for FUNCTION_BLOCK.
2231     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2232     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
2233     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
2234     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,    // dest ty
2235                               VE.computeBitsRequiredForTypeIndicies()));
2236     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
2237     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
2238     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2239                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
2240       llvm_unreachable("Unexpected abbrev ordering!");
2241   }
2242   { // INST_BINOP abbrev for FUNCTION_BLOCK.
2243     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2244     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2245     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2246     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2247     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2248     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2249                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
2250       llvm_unreachable("Unexpected abbrev ordering!");
2251   }
2252   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
2253     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2254     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
2255     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
2256     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
2257     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
2258     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
2259     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2260                                    Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
2261       llvm_unreachable("Unexpected abbrev ordering!");
2262   }
2263   { // INST_CAST abbrev for FUNCTION_BLOCK.
2264     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2265     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
2266     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
2267     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
2268                               VE.computeBitsRequiredForTypeIndicies()));
2269     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
2270     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2271                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
2272       llvm_unreachable("Unexpected abbrev ordering!");
2273   }
2274
2275   { // INST_RET abbrev for FUNCTION_BLOCK.
2276     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2277     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2278     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2279                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
2280       llvm_unreachable("Unexpected abbrev ordering!");
2281   }
2282   { // INST_RET abbrev for FUNCTION_BLOCK.
2283     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2284     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
2285     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
2286     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2287                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
2288       llvm_unreachable("Unexpected abbrev ordering!");
2289   }
2290   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
2291     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2292     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
2293     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
2294                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
2295       llvm_unreachable("Unexpected abbrev ordering!");
2296   }
2297   {
2298     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
2299     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_GEP));
2300     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
2301     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, // dest ty
2302                               Log2_32_Ceil(VE.getTypes().size() + 1)));
2303     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
2304     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
2305     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID, Abbv) !=
2306         FUNCTION_INST_GEP_ABBREV)
2307       llvm_unreachable("Unexpected abbrev ordering!");
2308   }
2309
2310   Stream.ExitBlock();
2311 }
2312
2313 /// WriteModule - Emit the specified module to the bitstream.
2314 static void WriteModule(const Module *M, BitstreamWriter &Stream,
2315                         bool ShouldPreserveUseListOrder) {
2316   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
2317
2318   SmallVector<unsigned, 1> Vals;
2319   unsigned CurVersion = 1;
2320   Vals.push_back(CurVersion);
2321   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
2322
2323   // Analyze the module, enumerating globals, functions, etc.
2324   ValueEnumerator VE(*M, ShouldPreserveUseListOrder);
2325
2326   // Emit blockinfo, which defines the standard abbreviations etc.
2327   WriteBlockInfo(VE, Stream);
2328
2329   // Emit information about attribute groups.
2330   WriteAttributeGroupTable(VE, Stream);
2331
2332   // Emit information about parameter attributes.
2333   WriteAttributeTable(VE, Stream);
2334
2335   // Emit information describing all of the types in the module.
2336   WriteTypeTable(VE, Stream);
2337
2338   writeComdats(VE, Stream);
2339
2340   // Emit top-level description of module, including target triple, inline asm,
2341   // descriptors for global variables, and function prototype info.
2342   WriteModuleInfo(M, VE, Stream);
2343
2344   // Emit constants.
2345   WriteModuleConstants(VE, Stream);
2346
2347   // Emit metadata.
2348   WriteModuleMetadata(M, VE, Stream);
2349
2350   // Emit metadata.
2351   WriteModuleMetadataStore(M, Stream);
2352
2353   // Emit names for globals/functions etc.
2354   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
2355
2356   // Emit module-level use-lists.
2357   if (VE.shouldPreserveUseListOrder())
2358     WriteUseListBlock(nullptr, VE, Stream);
2359
2360   // Emit function bodies.
2361   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
2362     if (!F->isDeclaration())
2363       WriteFunction(*F, VE, Stream);
2364
2365   Stream.ExitBlock();
2366 }
2367
2368 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
2369 /// header and trailer to make it compatible with the system archiver.  To do
2370 /// this we emit the following header, and then emit a trailer that pads the
2371 /// file out to be a multiple of 16 bytes.
2372 ///
2373 /// struct bc_header {
2374 ///   uint32_t Magic;         // 0x0B17C0DE
2375 ///   uint32_t Version;       // Version, currently always 0.
2376 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
2377 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
2378 ///   uint32_t CPUType;       // CPU specifier.
2379 ///   ... potentially more later ...
2380 /// };
2381 enum {
2382   DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
2383   DarwinBCHeaderSize = 5*4
2384 };
2385
2386 static void WriteInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
2387                                uint32_t &Position) {
2388   Buffer[Position + 0] = (unsigned char) (Value >>  0);
2389   Buffer[Position + 1] = (unsigned char) (Value >>  8);
2390   Buffer[Position + 2] = (unsigned char) (Value >> 16);
2391   Buffer[Position + 3] = (unsigned char) (Value >> 24);
2392   Position += 4;
2393 }
2394
2395 static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
2396                                          const Triple &TT) {
2397   unsigned CPUType = ~0U;
2398
2399   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
2400   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
2401   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
2402   // specific constants here because they are implicitly part of the Darwin ABI.
2403   enum {
2404     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
2405     DARWIN_CPU_TYPE_X86        = 7,
2406     DARWIN_CPU_TYPE_ARM        = 12,
2407     DARWIN_CPU_TYPE_POWERPC    = 18
2408   };
2409
2410   Triple::ArchType Arch = TT.getArch();
2411   if (Arch == Triple::x86_64)
2412     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
2413   else if (Arch == Triple::x86)
2414     CPUType = DARWIN_CPU_TYPE_X86;
2415   else if (Arch == Triple::ppc)
2416     CPUType = DARWIN_CPU_TYPE_POWERPC;
2417   else if (Arch == Triple::ppc64)
2418     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
2419   else if (Arch == Triple::arm || Arch == Triple::thumb)
2420     CPUType = DARWIN_CPU_TYPE_ARM;
2421
2422   // Traditional Bitcode starts after header.
2423   assert(Buffer.size() >= DarwinBCHeaderSize &&
2424          "Expected header size to be reserved");
2425   unsigned BCOffset = DarwinBCHeaderSize;
2426   unsigned BCSize = Buffer.size()-DarwinBCHeaderSize;
2427
2428   // Write the magic and version.
2429   unsigned Position = 0;
2430   WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position);
2431   WriteInt32ToBuffer(0          , Buffer, Position); // Version.
2432   WriteInt32ToBuffer(BCOffset   , Buffer, Position);
2433   WriteInt32ToBuffer(BCSize     , Buffer, Position);
2434   WriteInt32ToBuffer(CPUType    , Buffer, Position);
2435
2436   // If the file is not a multiple of 16 bytes, insert dummy padding.
2437   while (Buffer.size() & 15)
2438     Buffer.push_back(0);
2439 }
2440
2441 /// WriteBitcodeToFile - Write the specified module to the specified output
2442 /// stream.
2443 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out,
2444                               bool ShouldPreserveUseListOrder) {
2445   SmallVector<char, 0> Buffer;
2446   Buffer.reserve(256*1024);
2447
2448   // If this is darwin or another generic macho target, reserve space for the
2449   // header.
2450   Triple TT(M->getTargetTriple());
2451   if (TT.isOSDarwin())
2452     Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0);
2453
2454   // Emit the module into the buffer.
2455   {
2456     BitstreamWriter Stream(Buffer);
2457
2458     // Emit the file header.
2459     Stream.Emit((unsigned)'B', 8);
2460     Stream.Emit((unsigned)'C', 8);
2461     Stream.Emit(0x0, 4);
2462     Stream.Emit(0xC, 4);
2463     Stream.Emit(0xE, 4);
2464     Stream.Emit(0xD, 4);
2465
2466     // Emit the module.
2467     WriteModule(M, Stream, ShouldPreserveUseListOrder);
2468   }
2469
2470   if (TT.isOSDarwin())
2471     EmitDarwinBCHeaderAndTrailer(Buffer, TT);
2472
2473   // Write the generated bitstream to "Out".
2474   Out.write((char*)&Buffer.front(), Buffer.size());
2475 }