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