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/DerivedTypes.h"
  21 #include "llvm/IR/InlineAsm.h"
  22 #include "llvm/IR/Instructions.h"
  23 #include "llvm/IR/Module.h"
  24 #include "llvm/IR/Operator.h"
  25 #include "llvm/IR/ValueSymbolTable.h"
  26 #include "llvm/Support/CommandLine.h"
  27 #include "llvm/Support/ErrorHandling.h"
  28 #include "llvm/Support/MathExtras.h"
  29 #include "llvm/Support/Program.h"
  30 #include "llvm/Support/raw_ostream.h"
  31 #include <cctype>
  32 #include <map>
  33 using namespace llvm;
  34
  35 static cl::opt<bool>
  36 EnablePreserveUseListOrdering("enable-bc-uselist-preserve",
  37                               cl::desc("Turn on experimental support for "
  38                                        "use-list order preservation."),
  39                               cl::init(false), cl::Hidden);
  40
  41 /// These are manifest constants used by the bitcode writer. They do not need to
  42 /// be kept in sync with the reader, but need to be consistent within this file.
  43 enum {
  44   // VALUE_SYMTAB_BLOCK abbrev id's.
  45   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  46   VST_ENTRY_7_ABBREV,
  47   VST_ENTRY_6_ABBREV,
  48   VST_BBENTRY_6_ABBREV,
  49
  50   // CONSTANTS_BLOCK abbrev id's.
  51   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  52   CONSTANTS_INTEGER_ABBREV,
  53   CONSTANTS_CE_CAST_Abbrev,
  54   CONSTANTS_NULL_Abbrev,
  55
  56   // FUNCTION_BLOCK abbrev id's.
  57   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
  58   FUNCTION_INST_BINOP_ABBREV,
  59   FUNCTION_INST_BINOP_FLAGS_ABBREV,
  60   FUNCTION_INST_CAST_ABBREV,
  61   FUNCTION_INST_RET_VOID_ABBREV,
  62   FUNCTION_INST_RET_VAL_ABBREV,
  63   FUNCTION_INST_UNREACHABLE_ABBREV,
  64
  65   // SwitchInst Magic
  66   SWITCH_INST_MAGIC = 0x4B5 // May 2012 => 1205 => Hex
  67 };
  68
  69 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
  70   switch (Opcode) {
  71   default: llvm_unreachable("Unknown cast instruction!");
  72   case Instruction::Trunc   : return bitc::CAST_TRUNC;
  73   case Instruction::ZExt    : return bitc::CAST_ZEXT;
  74   case Instruction::SExt    : return bitc::CAST_SEXT;
  75   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
  76   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
  77   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
  78   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
  79   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
  80   case Instruction::FPExt   : return bitc::CAST_FPEXT;
  81   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
  82   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
  83   case Instruction::BitCast : return bitc::CAST_BITCAST;
  84   }
  85 }
  86
  87 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
  88   switch (Opcode) {
  89   default: llvm_unreachable("Unknown binary instruction!");
  90   case Instruction::Add:
  91   case Instruction::FAdd: return bitc::BINOP_ADD;
  92   case Instruction::Sub:
  93   case Instruction::FSub: return bitc::BINOP_SUB;
  94   case Instruction::Mul:
  95   case Instruction::FMul: return bitc::BINOP_MUL;
  96   case Instruction::UDiv: return bitc::BINOP_UDIV;
  97   case Instruction::FDiv:
  98   case Instruction::SDiv: return bitc::BINOP_SDIV;
  99   case Instruction::URem: return bitc::BINOP_UREM;
 100   case Instruction::FRem:
 101   case Instruction::SRem: return bitc::BINOP_SREM;
 102   case Instruction::Shl:  return bitc::BINOP_SHL;
 103   case Instruction::LShr: return bitc::BINOP_LSHR;
 104   case Instruction::AShr: return bitc::BINOP_ASHR;
 105   case Instruction::And:  return bitc::BINOP_AND;
 106   case Instruction::Or:   return bitc::BINOP_OR;
 107   case Instruction::Xor:  return bitc::BINOP_XOR;
 108   }
 109 }
 110
 111 static unsigned GetEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
 112   switch (Op) {
 113   default: llvm_unreachable("Unknown RMW operation!");
 114   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
 115   case AtomicRMWInst::Add: return bitc::RMW_ADD;
 116   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
 117   case AtomicRMWInst::And: return bitc::RMW_AND;
 118   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
 119   case AtomicRMWInst::Or: return bitc::RMW_OR;
 120   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
 121   case AtomicRMWInst::Max: return bitc::RMW_MAX;
 122   case AtomicRMWInst::Min: return bitc::RMW_MIN;
 123   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
 124   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
 125   }
 126 }
 127
 128 static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
 129   switch (Ordering) {
 130   case NotAtomic: return bitc::ORDERING_NOTATOMIC;
 131   case Unordered: return bitc::ORDERING_UNORDERED;
 132   case Monotonic: return bitc::ORDERING_MONOTONIC;
 133   case Acquire: return bitc::ORDERING_ACQUIRE;
 134   case Release: return bitc::ORDERING_RELEASE;
 135   case AcquireRelease: return bitc::ORDERING_ACQREL;
 136   case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
 137   }
 138   llvm_unreachable("Invalid ordering");
 139 }
 140
 141 static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
 142   switch (SynchScope) {
 143   case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
 144   case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
 145   }
 146   llvm_unreachable("Invalid synch scope");
 147 }
 148
 149 static void WriteStringRecord(unsigned Code, StringRef Str,
 150                               unsigned AbbrevToUse, BitstreamWriter &Stream) {
 151   SmallVector<unsigned, 64> Vals;
 152
 153   // Code: [strchar x N]
 154   for (unsigned i = 0, e = Str.size(); i != e; ++i) {
 155     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
 156       AbbrevToUse = 0;
 157     Vals.push_back(Str[i]);
 158   }
 159
 160   // Emit the finished record.
 161   Stream.EmitRecord(Code, Vals, AbbrevToUse);
 162 }
 163
 164 static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
 165   switch (Kind) {
 166   case Attribute::Alignment:
 167     return bitc::ATTR_KIND_ALIGNMENT;
 168   case Attribute::AlwaysInline:
 169     return bitc::ATTR_KIND_ALWAYS_INLINE;
 170   case Attribute::Builtin:
 171     return bitc::ATTR_KIND_BUILTIN;
 172   case Attribute::ByVal:
 173     return bitc::ATTR_KIND_BY_VAL;
 174   case Attribute::Cold:
 175     return bitc::ATTR_KIND_COLD;
 176   case Attribute::InlineHint:
 177     return bitc::ATTR_KIND_INLINE_HINT;
 178   case Attribute::InReg:
 179     return bitc::ATTR_KIND_IN_REG;
 180   case Attribute::MinSize:
 181     return bitc::ATTR_KIND_MIN_SIZE;
 182   case Attribute::Naked:
 183     return bitc::ATTR_KIND_NAKED;
 184   case Attribute::Nest:
 185     return bitc::ATTR_KIND_NEST;
 186   case Attribute::NoAlias:
 187     return bitc::ATTR_KIND_NO_ALIAS;
 188   case Attribute::NoBuiltin:
 189     return bitc::ATTR_KIND_NO_BUILTIN;
 190   case Attribute::NoCapture:
 191     return bitc::ATTR_KIND_NO_CAPTURE;
 192   case Attribute::NoDuplicate:
 193     return bitc::ATTR_KIND_NO_DUPLICATE;
 194   case Attribute::NoImplicitFloat:
 195     return bitc::ATTR_KIND_NO_IMPLICIT_FLOAT;
 196   case Attribute::NoInline:
 197     return bitc::ATTR_KIND_NO_INLINE;
 198   case Attribute::NonLazyBind:
 199     return bitc::ATTR_KIND_NON_LAZY_BIND;
 200   case Attribute::NoRedZone:
 201     return bitc::ATTR_KIND_NO_RED_ZONE;
 202   case Attribute::NoReturn:
 203     return bitc::ATTR_KIND_NO_RETURN;
 204   case Attribute::NoUnwind:
 205     return bitc::ATTR_KIND_NO_UNWIND;
 206   case Attribute::OptimizeForSize:
 207     return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
 208   case Attribute::OptimizeNone:
 209     return bitc::ATTR_KIND_OPTIMIZE_NONE;
 210   case Attribute::ReadNone:
 211     return bitc::ATTR_KIND_READ_NONE;
 212   case Attribute::ReadOnly:
 213     return bitc::ATTR_KIND_READ_ONLY;
 214   case Attribute::Returned:
 215     return bitc::ATTR_KIND_RETURNED;
 216   case Attribute::ReturnsTwice:
 217     return bitc::ATTR_KIND_RETURNS_TWICE;
 218   case Attribute::SExt:
 219     return bitc::ATTR_KIND_S_EXT;
 220   case Attribute::StackAlignment:
 221     return bitc::ATTR_KIND_STACK_ALIGNMENT;
 222   case Attribute::StackProtect:
 223     return bitc::ATTR_KIND_STACK_PROTECT;
 224   case Attribute::StackProtectReq:
 225     return bitc::ATTR_KIND_STACK_PROTECT_REQ;
 226   case Attribute::StackProtectStrong:
 227     return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
 228   case Attribute::StructRet:
 229     return bitc::ATTR_KIND_STRUCT_RET;
 230   case Attribute::SanitizeAddress:
 231     return bitc::ATTR_KIND_SANITIZE_ADDRESS;
 232   case Attribute::SanitizeThread:
 233     return bitc::ATTR_KIND_SANITIZE_THREAD;
 234   case Attribute::SanitizeMemory:
 235     return bitc::ATTR_KIND_SANITIZE_MEMORY;
 236   case Attribute::UWTable:
 237     return bitc::ATTR_KIND_UW_TABLE;
 238   case Attribute::ZExt:
 239     return bitc::ATTR_KIND_Z_EXT;
 240   case Attribute::EndAttrKinds:
 241     llvm_unreachable("Can not encode end-attribute kinds marker.");
 242   case Attribute::None:
 243     llvm_unreachable("Can not encode none-attribute.");
 244   }
 245
 246   llvm_unreachable("Trying to encode unknown attribute");
 247 }
 248
 249 static void WriteAttributeGroupTable(const ValueEnumerator &VE,
 250                                      BitstreamWriter &Stream) {
 251   const std::vector<AttributeSet> &AttrGrps = VE.getAttributeGroups();
 252   if (AttrGrps.empty()) return;
 253
 254   Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
 255
 256   SmallVector<uint64_t, 64> Record;
 257   for (unsigned i = 0, e = AttrGrps.size(); i != e; ++i) {
 258     AttributeSet AS = AttrGrps[i];
 259     for (unsigned i = 0, e = AS.getNumSlots(); i != e; ++i) {
 260       AttributeSet A = AS.getSlotAttributes(i);
 261
 262       Record.push_back(VE.getAttributeGroupID(A));
 263       Record.push_back(AS.getSlotIndex(i));
 264
 265       for (AttributeSet::iterator I = AS.begin(0), E = AS.end(0);
 266            I != E; ++I) {
 267         Attribute Attr = *I;
 268         if (Attr.isEnumAttribute()) {
 269           Record.push_back(0);
 270           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 271         } else if (Attr.isAlignAttribute()) {
 272           Record.push_back(1);
 273           Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
 274           Record.push_back(Attr.getValueAsInt());
 275         } else {
 276           StringRef Kind = Attr.getKindAsString();
 277           StringRef Val = Attr.getValueAsString();
 278
 279           Record.push_back(Val.empty() ? 3 : 4);
 280           Record.append(Kind.begin(), Kind.end());
 281           Record.push_back(0);
 282           if (!Val.empty()) {
 283             Record.append(Val.begin(), Val.end());
 284             Record.push_back(0);
 285           }
 286         }
 287       }
 288
 289       Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
 290       Record.clear();
 291     }
 292   }
 293
 294   Stream.ExitBlock();
 295 }
 296
 297 static void WriteAttributeTable(const ValueEnumerator &VE,
 298                                 BitstreamWriter &Stream) {
 299   const std::vector<AttributeSet> &Attrs = VE.getAttributes();
 300   if (Attrs.empty()) return;
 301
 302   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
 303
 304   SmallVector<uint64_t, 64> Record;
 305   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
 306     const AttributeSet &A = Attrs[i];
 307     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
 308       Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
 309
 310     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
 311     Record.clear();
 312   }
 313
 314   Stream.ExitBlock();
 315 }
 316
 317 /// WriteTypeTable - Write out the type table for a module.
 318 static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
 319   const ValueEnumerator::TypeList &TypeList = VE.getTypes();
 320
 321   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
 322   SmallVector<uint64_t, 64> TypeVals;
 323
 324   uint64_t NumBits = Log2_32_Ceil(VE.getTypes().size()+1);
 325
 326   // Abbrev for TYPE_CODE_POINTER.
 327   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 328   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
 329   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 330   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
 331   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
 332
 333   // Abbrev for TYPE_CODE_FUNCTION.
 334   Abbv = new BitCodeAbbrev();
 335   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
 336   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
 337   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 338   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 339
 340   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
 341
 342   // Abbrev for TYPE_CODE_STRUCT_ANON.
 343   Abbv = new BitCodeAbbrev();
 344   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
 345   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 346   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 347   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 348
 349   unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
 350
 351   // Abbrev for TYPE_CODE_STRUCT_NAME.
 352   Abbv = new BitCodeAbbrev();
 353   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
 354   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 355   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 356   unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
 357
 358   // Abbrev for TYPE_CODE_STRUCT_NAMED.
 359   Abbv = new BitCodeAbbrev();
 360   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
 361   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
 362   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 363   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 364
 365   unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
 366
 367   // Abbrev for TYPE_CODE_ARRAY.
 368   Abbv = new BitCodeAbbrev();
 369   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
 370   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
 371   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
 372
 373   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
 374
 375   // Emit an entry count so the reader can reserve space.
 376   TypeVals.push_back(TypeList.size());
 377   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
 378   TypeVals.clear();
 379
 380   // Loop over all of the types, emitting each in turn.
 381   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
 382     Type *T = TypeList[i];
 383     int AbbrevToUse = 0;
 384     unsigned Code = 0;
 385
 386     switch (T->getTypeID()) {
 387     default: llvm_unreachable("Unknown type!");
 388     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
 389     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
 390     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
 391     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
 392     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
 393     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
 394     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
 395     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
 396     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
 397     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
 398     case Type::IntegerTyID:
 399       // INTEGER: [width]
 400       Code = bitc::TYPE_CODE_INTEGER;
 401       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
 402       break;
 403     case Type::PointerTyID: {
 404       PointerType *PTy = cast<PointerType>(T);
 405       // POINTER: [pointee type, address space]
 406       Code = bitc::TYPE_CODE_POINTER;
 407       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
 408       unsigned AddressSpace = PTy->getAddressSpace();
 409       TypeVals.push_back(AddressSpace);
 410       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
 411       break;
 412     }
 413     case Type::FunctionTyID: {
 414       FunctionType *FT = cast<FunctionType>(T);
 415       // FUNCTION: [isvararg, retty, paramty x N]
 416       Code = bitc::TYPE_CODE_FUNCTION;
 417       TypeVals.push_back(FT->isVarArg());
 418       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
 419       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
 420         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
 421       AbbrevToUse = FunctionAbbrev;
 422       break;
 423     }
 424     case Type::StructTyID: {
 425       StructType *ST = cast<StructType>(T);
 426       // STRUCT: [ispacked, eltty x N]
 427       TypeVals.push_back(ST->isPacked());
 428       // Output all of the element types.
 429       for (StructType::element_iterator I = ST->element_begin(),
 430            E = ST->element_end(); I != E; ++I)
 431         TypeVals.push_back(VE.getTypeID(*I));
 432
 433       if (ST->isLiteral()) {
 434         Code = bitc::TYPE_CODE_STRUCT_ANON;
 435         AbbrevToUse = StructAnonAbbrev;
 436       } else {
 437         if (ST->isOpaque()) {
 438           Code = bitc::TYPE_CODE_OPAQUE;
 439         } else {
 440           Code = bitc::TYPE_CODE_STRUCT_NAMED;
 441           AbbrevToUse = StructNamedAbbrev;
 442         }
 443
 444         // Emit the name if it is present.
 445         if (!ST->getName().empty())
 446           WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
 447                             StructNameAbbrev, Stream);
 448       }
 449       break;
 450     }
 451     case Type::ArrayTyID: {
 452       ArrayType *AT = cast<ArrayType>(T);
 453       // ARRAY: [numelts, eltty]
 454       Code = bitc::TYPE_CODE_ARRAY;
 455       TypeVals.push_back(AT->getNumElements());
 456       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
 457       AbbrevToUse = ArrayAbbrev;
 458       break;
 459     }
 460     case Type::VectorTyID: {
 461       VectorType *VT = cast<VectorType>(T);
 462       // VECTOR [numelts, eltty]
 463       Code = bitc::TYPE_CODE_VECTOR;
 464       TypeVals.push_back(VT->getNumElements());
 465       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
 466       break;
 467     }
 468     }
 469
 470     // Emit the finished record.
 471     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
 472     TypeVals.clear();
 473   }
 474
 475   Stream.ExitBlock();
 476 }
 477
 478 static unsigned getEncodedLinkage(const GlobalValue *GV) {
 479   switch (GV->getLinkage()) {
 480   case GlobalValue::ExternalLinkage:                 return 0;
 481   case GlobalValue::WeakAnyLinkage:                  return 1;
 482   case GlobalValue::AppendingLinkage:                return 2;
 483   case GlobalValue::InternalLinkage:                 return 3;
 484   case GlobalValue::LinkOnceAnyLinkage:              return 4;
 485   case GlobalValue::DLLImportLinkage:                return 5;
 486   case GlobalValue::DLLExportLinkage:                return 6;
 487   case GlobalValue::ExternalWeakLinkage:             return 7;
 488   case GlobalValue::CommonLinkage:                   return 8;
 489   case GlobalValue::PrivateLinkage:                  return 9;
 490   case GlobalValue::WeakODRLinkage:                  return 10;
 491   case GlobalValue::LinkOnceODRLinkage:              return 11;
 492   case GlobalValue::AvailableExternallyLinkage:      return 12;
 493   case GlobalValue::LinkerPrivateLinkage:            return 13;
 494   case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
 495   case GlobalValue::LinkOnceODRAutoHideLinkage:      return 15;
 496   }
 497   llvm_unreachable("Invalid linkage");
 498 }
 499
 500 static unsigned getEncodedVisibility(const GlobalValue *GV) {
 501   switch (GV->getVisibility()) {
 502   case GlobalValue::DefaultVisibility:   return 0;
 503   case GlobalValue::HiddenVisibility:    return 1;
 504   case GlobalValue::ProtectedVisibility: return 2;
 505   }
 506   llvm_unreachable("Invalid visibility");
 507 }
 508
 509 static unsigned getEncodedThreadLocalMode(const GlobalVariable *GV) {
 510   switch (GV->getThreadLocalMode()) {
 511     case GlobalVariable::NotThreadLocal:         return 0;
 512     case GlobalVariable::GeneralDynamicTLSModel: return 1;
 513     case GlobalVariable::LocalDynamicTLSModel:   return 2;
 514     case GlobalVariable::InitialExecTLSModel:    return 3;
 515     case GlobalVariable::LocalExecTLSModel:      return 4;
 516   }
 517   llvm_unreachable("Invalid TLS model");
 518 }
 519
 520 // Emit top-level description of module, including target triple, inline asm,
 521 // descriptors for global variables, and function prototype info.
 522 static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
 523                             BitstreamWriter &Stream) {
 524   // Emit various pieces of data attached to a module.
 525   if (!M->getTargetTriple().empty())
 526     WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
 527                       0/*TODO*/, Stream);
 528   if (!M->getDataLayout().empty())
 529     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
 530                       0/*TODO*/, Stream);
 531   if (!M->getModuleInlineAsm().empty())
 532     WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
 533                       0/*TODO*/, Stream);
 534
 535   // Emit information about sections and GC, computing how many there are. Also
 536   // compute the maximum alignment value.
 537   std::map<std::string, unsigned> SectionMap;
 538   std::map<std::string, unsigned> GCMap;
 539   unsigned MaxAlignment = 0;
 540   unsigned MaxGlobalType = 0;
 541   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 542        GV != E; ++GV) {
 543     MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
 544     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
 545     if (GV->hasSection()) {
 546       // Give section names unique ID's.
 547       unsigned &Entry = SectionMap[GV->getSection()];
 548       if (!Entry) {
 549         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
 550                           0/*TODO*/, Stream);
 551         Entry = SectionMap.size();
 552       }
 553     }
 554   }
 555   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 556     MaxAlignment = std::max(MaxAlignment, F->getAlignment());
 557     if (F->hasSection()) {
 558       // Give section names unique ID's.
 559       unsigned &Entry = SectionMap[F->getSection()];
 560       if (!Entry) {
 561         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
 562                           0/*TODO*/, Stream);
 563         Entry = SectionMap.size();
 564       }
 565     }
 566     if (F->hasGC()) {
 567       // Same for GC names.
 568       unsigned &Entry = GCMap[F->getGC()];
 569       if (!Entry) {
 570         WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
 571                           0/*TODO*/, Stream);
 572         Entry = GCMap.size();
 573       }
 574     }
 575   }
 576
 577   // Emit abbrev for globals, now that we know # sections and max alignment.
 578   unsigned SimpleGVarAbbrev = 0;
 579   if (!M->global_empty()) {
 580     // Add an abbrev for common globals with no visibility or thread localness.
 581     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 582     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
 583     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 584                               Log2_32_Ceil(MaxGlobalType+1)));
 585     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
 586     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
 587     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
 588     if (MaxAlignment == 0)                                      // Alignment.
 589       Abbv->Add(BitCodeAbbrevOp(0));
 590     else {
 591       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
 592       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 593                                Log2_32_Ceil(MaxEncAlignment+1)));
 594     }
 595     if (SectionMap.empty())                                    // Section.
 596       Abbv->Add(BitCodeAbbrevOp(0));
 597     else
 598       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
 599                                Log2_32_Ceil(SectionMap.size()+1)));
 600     // Don't bother emitting vis + thread local.
 601     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
 602   }
 603
 604   // Emit the global variable information.
 605   SmallVector<unsigned, 64> Vals;
 606   for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
 607        GV != E; ++GV) {
 608     unsigned AbbrevToUse = 0;
 609
 610     // GLOBALVAR: [type, isconst, initid,
 611     //             linkage, alignment, section, visibility, threadlocal,
 612     //             unnamed_addr]
 613     Vals.push_back(VE.getTypeID(GV->getType()));
 614     Vals.push_back(GV->isConstant());
 615     Vals.push_back(GV->isDeclaration() ? 0 :
 616                    (VE.getValueID(GV->getInitializer()) + 1));
 617     Vals.push_back(getEncodedLinkage(GV));
 618     Vals.push_back(Log2_32(GV->getAlignment())+1);
 619     Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
 620     if (GV->isThreadLocal() ||
 621         GV->getVisibility() != GlobalValue::DefaultVisibility ||
 622         GV->hasUnnamedAddr() || GV->isExternallyInitialized()) {
 623       Vals.push_back(getEncodedVisibility(GV));
 624       Vals.push_back(getEncodedThreadLocalMode(GV));
 625       Vals.push_back(GV->hasUnnamedAddr());
 626       Vals.push_back(GV->isExternallyInitialized());
 627     } else {
 628       AbbrevToUse = SimpleGVarAbbrev;
 629     }
 630
 631     Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
 632     Vals.clear();
 633   }
 634
 635   // Emit the function proto information.
 636   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
 637     // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
 638     //             section, visibility, gc, unnamed_addr]
 639     Vals.push_back(VE.getTypeID(F->getType()));
 640     Vals.push_back(F->getCallingConv());
 641     Vals.push_back(F->isDeclaration());
 642     Vals.push_back(getEncodedLinkage(F));
 643     Vals.push_back(VE.getAttributeID(F->getAttributes()));
 644     Vals.push_back(Log2_32(F->getAlignment())+1);
 645     Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
 646     Vals.push_back(getEncodedVisibility(F));
 647     Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
 648     Vals.push_back(F->hasUnnamedAddr());
 649
 650     unsigned AbbrevToUse = 0;
 651     Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
 652     Vals.clear();
 653   }
 654
 655   // Emit the alias information.
 656   for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
 657        AI != E; ++AI) {
 658     // ALIAS: [alias type, aliasee val#, linkage, visibility]
 659     Vals.push_back(VE.getTypeID(AI->getType()));
 660     Vals.push_back(VE.getValueID(AI->getAliasee()));
 661     Vals.push_back(getEncodedLinkage(AI));
 662     Vals.push_back(getEncodedVisibility(AI));
 663     unsigned AbbrevToUse = 0;
 664     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
 665     Vals.clear();
 666   }
 667 }
 668
 669 static uint64_t GetOptimizationFlags(const Value *V) {
 670   uint64_t Flags = 0;
 671
 672   if (const OverflowingBinaryOperator *OBO =
 673         dyn_cast<OverflowingBinaryOperator>(V)) {
 674     if (OBO->hasNoSignedWrap())
 675       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
 676     if (OBO->hasNoUnsignedWrap())
 677       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
 678   } else if (const PossiblyExactOperator *PEO =
 679                dyn_cast<PossiblyExactOperator>(V)) {
 680     if (PEO->isExact())
 681       Flags |= 1 << bitc::PEO_EXACT;
 682   } else if (const FPMathOperator *FPMO =
 683              dyn_cast<const FPMathOperator>(V)) {
 684     if (FPMO->hasUnsafeAlgebra())
 685       Flags |= FastMathFlags::UnsafeAlgebra;
 686     if (FPMO->hasNoNaNs())
 687       Flags |= FastMathFlags::NoNaNs;
 688     if (FPMO->hasNoInfs())
 689       Flags |= FastMathFlags::NoInfs;
 690     if (FPMO->hasNoSignedZeros())
 691       Flags |= FastMathFlags::NoSignedZeros;
 692     if (FPMO->hasAllowReciprocal())
 693       Flags |= FastMathFlags::AllowReciprocal;
 694   }
 695
 696   return Flags;
 697 }
 698
 699 static void WriteMDNode(const MDNode *N,
 700                         const ValueEnumerator &VE,
 701                         BitstreamWriter &Stream,
 702                         SmallVectorImpl<uint64_t> &Record) {
 703   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
 704     if (N->getOperand(i)) {
 705       Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
 706       Record.push_back(VE.getValueID(N->getOperand(i)));
 707     } else {
 708       Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
 709       Record.push_back(0);
 710     }
 711   }
 712   unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
 713                                            bitc::METADATA_NODE;
 714   Stream.EmitRecord(MDCode, Record, 0);
 715   Record.clear();
 716 }
 717
 718 static void WriteModuleMetadata(const Module *M,
 719                                 const ValueEnumerator &VE,
 720                                 BitstreamWriter &Stream) {
 721   const ValueEnumerator::ValueList &Vals = VE.getMDValues();
 722   bool StartedMetadataBlock = false;
 723   unsigned MDSAbbrev = 0;
 724   SmallVector<uint64_t, 64> Record;
 725   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
 726
 727     if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
 728       if (!N->isFunctionLocal() || !N->getFunction()) {
 729         if (!StartedMetadataBlock) {
 730           Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 731           StartedMetadataBlock = true;
 732         }
 733         WriteMDNode(N, VE, Stream, Record);
 734       }
 735     } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
 736       if (!StartedMetadataBlock)  {
 737         Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 738
 739         // Abbrev for METADATA_STRING.
 740         BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 741         Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
 742         Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 743         Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 744         MDSAbbrev = Stream.EmitAbbrev(Abbv);
 745         StartedMetadataBlock = true;
 746       }
 747
 748       // Code: [strchar x N]
 749       Record.append(MDS->begin(), MDS->end());
 750
 751       // Emit the finished record.
 752       Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
 753       Record.clear();
 754     }
 755   }
 756
 757   // Write named metadata.
 758   for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
 759        E = M->named_metadata_end(); I != E; ++I) {
 760     const NamedMDNode *NMD = I;
 761     if (!StartedMetadataBlock)  {
 762       Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 763       StartedMetadataBlock = true;
 764     }
 765
 766     // Write name.
 767     StringRef Str = NMD->getName();
 768     for (unsigned i = 0, e = Str.size(); i != e; ++i)
 769       Record.push_back(Str[i]);
 770     Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
 771     Record.clear();
 772
 773     // Write named metadata operands.
 774     for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
 775       Record.push_back(VE.getValueID(NMD->getOperand(i)));
 776     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
 777     Record.clear();
 778   }
 779
 780   if (StartedMetadataBlock)
 781     Stream.ExitBlock();
 782 }
 783
 784 static void WriteFunctionLocalMetadata(const Function &F,
 785                                        const ValueEnumerator &VE,
 786                                        BitstreamWriter &Stream) {
 787   bool StartedMetadataBlock = false;
 788   SmallVector<uint64_t, 64> Record;
 789   const SmallVectorImpl<const MDNode *> &Vals = VE.getFunctionLocalMDValues();
 790   for (unsigned i = 0, e = Vals.size(); i != e; ++i)
 791     if (const MDNode *N = Vals[i])
 792       if (N->isFunctionLocal() && N->getFunction() == &F) {
 793         if (!StartedMetadataBlock) {
 794           Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 795           StartedMetadataBlock = true;
 796         }
 797         WriteMDNode(N, VE, Stream, Record);
 798       }
 799
 800   if (StartedMetadataBlock)
 801     Stream.ExitBlock();
 802 }
 803
 804 static void WriteMetadataAttachment(const Function &F,
 805                                     const ValueEnumerator &VE,
 806                                     BitstreamWriter &Stream) {
 807   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
 808
 809   SmallVector<uint64_t, 64> Record;
 810
 811   // Write metadata attachments
 812   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
 813   SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
 814
 815   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
 816     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
 817          I != E; ++I) {
 818       MDs.clear();
 819       I->getAllMetadataOtherThanDebugLoc(MDs);
 820
 821       // If no metadata, ignore instruction.
 822       if (MDs.empty()) continue;
 823
 824       Record.push_back(VE.getInstructionID(I));
 825
 826       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
 827         Record.push_back(MDs[i].first);
 828         Record.push_back(VE.getValueID(MDs[i].second));
 829       }
 830       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
 831       Record.clear();
 832     }
 833
 834   Stream.ExitBlock();
 835 }
 836
 837 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
 838   SmallVector<uint64_t, 64> Record;
 839
 840   // Write metadata kinds
 841   // METADATA_KIND - [n x [id, name]]
 842   SmallVector<StringRef, 8> Names;
 843   M->getMDKindNames(Names);
 844
 845   if (Names.empty()) return;
 846
 847   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
 848
 849   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
 850     Record.push_back(MDKindID);
 851     StringRef KName = Names[MDKindID];
 852     Record.append(KName.begin(), KName.end());
 853
 854     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
 855     Record.clear();
 856   }
 857
 858   Stream.ExitBlock();
 859 }
 860
 861 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
 862   if ((int64_t)V >= 0)
 863     Vals.push_back(V << 1);
 864   else
 865     Vals.push_back((-V << 1) | 1);
 866 }
 867
 868 static void EmitAPInt(SmallVectorImpl<uint64_t> &Vals,
 869                       unsigned &Code, unsigned &AbbrevToUse, const APInt &Val,
 870                       bool EmitSizeForWideNumbers = false
 871                       ) {
 872   if (Val.getBitWidth() <= 64) {
 873     uint64_t V = Val.getSExtValue();
 874     emitSignedInt64(Vals, V);
 875     Code = bitc::CST_CODE_INTEGER;
 876     AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
 877   } else {
 878     // Wide integers, > 64 bits in size.
 879     // We have an arbitrary precision integer value to write whose
 880     // bit width is > 64. However, in canonical unsigned integer
 881     // format it is likely that the high bits are going to be zero.
 882     // So, we only write the number of active words.
 883     unsigned NWords = Val.getActiveWords();
 884
 885     if (EmitSizeForWideNumbers)
 886       Vals.push_back(NWords);
 887
 888     const uint64_t *RawWords = Val.getRawData();
 889     for (unsigned i = 0; i != NWords; ++i) {
 890       emitSignedInt64(Vals, RawWords[i]);
 891     }
 892     Code = bitc::CST_CODE_WIDE_INTEGER;
 893   }
 894 }
 895
 896 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
 897                            const ValueEnumerator &VE,
 898                            BitstreamWriter &Stream, bool isGlobal) {
 899   if (FirstVal == LastVal) return;
 900
 901   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
 902
 903   unsigned AggregateAbbrev = 0;
 904   unsigned String8Abbrev = 0;
 905   unsigned CString7Abbrev = 0;
 906   unsigned CString6Abbrev = 0;
 907   // If this is a constant pool for the module, emit module-specific abbrevs.
 908   if (isGlobal) {
 909     // Abbrev for CST_CODE_AGGREGATE.
 910     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
 911     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
 912     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 913     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
 914     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
 915
 916     // Abbrev for CST_CODE_STRING.
 917     Abbv = new BitCodeAbbrev();
 918     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
 919     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 920     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
 921     String8Abbrev = Stream.EmitAbbrev(Abbv);
 922     // Abbrev for CST_CODE_CSTRING.
 923     Abbv = new BitCodeAbbrev();
 924     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 925     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 926     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
 927     CString7Abbrev = Stream.EmitAbbrev(Abbv);
 928     // Abbrev for CST_CODE_CSTRING.
 929     Abbv = new BitCodeAbbrev();
 930     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
 931     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
 932     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
 933     CString6Abbrev = Stream.EmitAbbrev(Abbv);
 934   }
 935
 936   SmallVector<uint64_t, 64> Record;
 937
 938   const ValueEnumerator::ValueList &Vals = VE.getValues();
 939   Type *LastTy = 0;
 940   for (unsigned i = FirstVal; i != LastVal; ++i) {
 941     const Value *V = Vals[i].first;
 942     // If we need to switch types, do so now.
 943     if (V->getType() != LastTy) {
 944       LastTy = V->getType();
 945       Record.push_back(VE.getTypeID(LastTy));
 946       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
 947                         CONSTANTS_SETTYPE_ABBREV);
 948       Record.clear();
 949     }
 950
 951     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
 952       Record.push_back(unsigned(IA->hasSideEffects()) |
 953                        unsigned(IA->isAlignStack()) << 1 |
 954                        unsigned(IA->getDialect()&1) << 2);
 955
 956       // Add the asm string.
 957       const std::string &AsmStr = IA->getAsmString();
 958       Record.push_back(AsmStr.size());
 959       for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
 960         Record.push_back(AsmStr[i]);
 961
 962       // Add the constraint string.
 963       const std::string &ConstraintStr = IA->getConstraintString();
 964       Record.push_back(ConstraintStr.size());
 965       for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
 966         Record.push_back(ConstraintStr[i]);
 967       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
 968       Record.clear();
 969       continue;
 970     }
 971     const Constant *C = cast<Constant>(V);
 972     unsigned Code = -1U;
 973     unsigned AbbrevToUse = 0;
 974     if (C->isNullValue()) {
 975       Code = bitc::CST_CODE_NULL;
 976     } else if (isa<UndefValue>(C)) {
 977       Code = bitc::CST_CODE_UNDEF;
 978     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
 979       EmitAPInt(Record, Code, AbbrevToUse, IV->getValue());
 980     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
 981       Code = bitc::CST_CODE_FLOAT;
 982       Type *Ty = CFP->getType();
 983       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
 984         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
 985       } else if (Ty->isX86_FP80Ty()) {
 986         // api needed to prevent premature destruction
 987         // bits are not in the same order as a normal i80 APInt, compensate.
 988         APInt api = CFP->getValueAPF().bitcastToAPInt();
 989         const uint64_t *p = api.getRawData();
 990         Record.push_back((p[1] << 48) | (p[0] >> 16));
 991         Record.push_back(p[0] & 0xffffLL);
 992       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
 993         APInt api = CFP->getValueAPF().bitcastToAPInt();
 994         const uint64_t *p = api.getRawData();
 995         Record.push_back(p[0]);
 996         Record.push_back(p[1]);
 997       } else {
 998         assert (0 && "Unknown FP type!");
 999       }
1000     } else if (isa<ConstantDataSequential>(C) &&
1001                cast<ConstantDataSequential>(C)->isString()) {
1002       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
1003       // Emit constant strings specially.
1004       unsigned NumElts = Str->getNumElements();
1005       // If this is a null-terminated string, use the denser CSTRING encoding.
1006       if (Str->isCString()) {
1007         Code = bitc::CST_CODE_CSTRING;
1008         --NumElts;  // Don't encode the null, which isn't allowed by char6.
1009       } else {
1010         Code = bitc::CST_CODE_STRING;
1011         AbbrevToUse = String8Abbrev;
1012       }
1013       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
1014       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
1015       for (unsigned i = 0; i != NumElts; ++i) {
1016         unsigned char V = Str->getElementAsInteger(i);
1017         Record.push_back(V);
1018         isCStr7 &= (V & 128) == 0;
1019         if (isCStrChar6)
1020           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
1021       }
1022
1023       if (isCStrChar6)
1024         AbbrevToUse = CString6Abbrev;
1025       else if (isCStr7)
1026         AbbrevToUse = CString7Abbrev;
1027     } else if (const ConstantDataSequential *CDS =
1028                   dyn_cast<ConstantDataSequential>(C)) {
1029       Code = bitc::CST_CODE_DATA;
1030       Type *EltTy = CDS->getType()->getElementType();
1031       if (isa<IntegerType>(EltTy)) {
1032         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
1033           Record.push_back(CDS->getElementAsInteger(i));
1034       } else if (EltTy->isFloatTy()) {
1035         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1036           union { float F; uint32_t I; };
1037           F = CDS->getElementAsFloat(i);
1038           Record.push_back(I);
1039         }
1040       } else {
1041         assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
1042         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1043           union { double F; uint64_t I; };
1044           F = CDS->getElementAsDouble(i);
1045           Record.push_back(I);
1046         }
1047       }
1048     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
1049                isa<ConstantVector>(C)) {
1050       Code = bitc::CST_CODE_AGGREGATE;
1051       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
1052         Record.push_back(VE.getValueID(C->getOperand(i)));
1053       AbbrevToUse = AggregateAbbrev;
1054     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
1055       switch (CE->getOpcode()) {
1056       default:
1057         if (Instruction::isCast(CE->getOpcode())) {
1058           Code = bitc::CST_CODE_CE_CAST;
1059           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
1060           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1061           Record.push_back(VE.getValueID(C->getOperand(0)));
1062           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
1063         } else {
1064           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
1065           Code = bitc::CST_CODE_CE_BINOP;
1066           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
1067           Record.push_back(VE.getValueID(C->getOperand(0)));
1068           Record.push_back(VE.getValueID(C->getOperand(1)));
1069           uint64_t Flags = GetOptimizationFlags(CE);
1070           if (Flags != 0)
1071             Record.push_back(Flags);
1072         }
1073         break;
1074       case Instruction::GetElementPtr:
1075         Code = bitc::CST_CODE_CE_GEP;
1076         if (cast<GEPOperator>(C)->isInBounds())
1077           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
1078         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
1079           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
1080           Record.push_back(VE.getValueID(C->getOperand(i)));
1081         }
1082         break;
1083       case Instruction::Select:
1084         Code = bitc::CST_CODE_CE_SELECT;
1085         Record.push_back(VE.getValueID(C->getOperand(0)));
1086         Record.push_back(VE.getValueID(C->getOperand(1)));
1087         Record.push_back(VE.getValueID(C->getOperand(2)));
1088         break;
1089       case Instruction::ExtractElement:
1090         Code = bitc::CST_CODE_CE_EXTRACTELT;
1091         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1092         Record.push_back(VE.getValueID(C->getOperand(0)));
1093         Record.push_back(VE.getValueID(C->getOperand(1)));
1094         break;
1095       case Instruction::InsertElement:
1096         Code = bitc::CST_CODE_CE_INSERTELT;
1097         Record.push_back(VE.getValueID(C->getOperand(0)));
1098         Record.push_back(VE.getValueID(C->getOperand(1)));
1099         Record.push_back(VE.getValueID(C->getOperand(2)));
1100         break;
1101       case Instruction::ShuffleVector:
1102         // If the return type and argument types are the same, this is a
1103         // standard shufflevector instruction.  If the types are different,
1104         // then the shuffle is widening or truncating the input vectors, and
1105         // the argument type must also be encoded.
1106         if (C->getType() == C->getOperand(0)->getType()) {
1107           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
1108         } else {
1109           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
1110           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1111         }
1112         Record.push_back(VE.getValueID(C->getOperand(0)));
1113         Record.push_back(VE.getValueID(C->getOperand(1)));
1114         Record.push_back(VE.getValueID(C->getOperand(2)));
1115         break;
1116       case Instruction::ICmp:
1117       case Instruction::FCmp:
1118         Code = bitc::CST_CODE_CE_CMP;
1119         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1120         Record.push_back(VE.getValueID(C->getOperand(0)));
1121         Record.push_back(VE.getValueID(C->getOperand(1)));
1122         Record.push_back(CE->getPredicate());
1123         break;
1124       }
1125     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
1126       Code = bitc::CST_CODE_BLOCKADDRESS;
1127       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
1128       Record.push_back(VE.getValueID(BA->getFunction()));
1129       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
1130     } else {
1131 #ifndef NDEBUG
1132       C->dump();
1133 #endif
1134       llvm_unreachable("Unknown constant!");
1135     }
1136     Stream.EmitRecord(Code, Record, AbbrevToUse);
1137     Record.clear();
1138   }
1139
1140   Stream.ExitBlock();
1141 }
1142
1143 static void WriteModuleConstants(const ValueEnumerator &VE,
1144                                  BitstreamWriter &Stream) {
1145   const ValueEnumerator::ValueList &Vals = VE.getValues();
1146
1147   // Find the first constant to emit, which is the first non-globalvalue value.
1148   // We know globalvalues have been emitted by WriteModuleInfo.
1149   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1150     if (!isa<GlobalValue>(Vals[i].first)) {
1151       WriteConstants(i, Vals.size(), VE, Stream, true);
1152       return;
1153     }
1154   }
1155 }
1156
1157 /// PushValueAndType - The file has to encode both the value and type id for
1158 /// many values, because we need to know what type to create for forward
1159 /// references.  However, most operands are not forward references, so this type
1160 /// field is not needed.
1161 ///
1162 /// This function adds V's value ID to Vals.  If the value ID is higher than the
1163 /// instruction ID, then it is a forward reference, and it also includes the
1164 /// type ID.  The value ID that is written is encoded relative to the InstID.
1165 static bool PushValueAndType(const Value *V, unsigned InstID,
1166                              SmallVectorImpl<unsigned> &Vals,
1167                              ValueEnumerator &VE) {
1168   unsigned ValID = VE.getValueID(V);
1169   // Make encoding relative to the InstID.
1170   Vals.push_back(InstID - ValID);
1171   if (ValID >= InstID) {
1172     Vals.push_back(VE.getTypeID(V->getType()));
1173     return true;
1174   }
1175   return false;
1176 }
1177
1178 /// pushValue - Like PushValueAndType, but where the type of the value is
1179 /// omitted (perhaps it was already encoded in an earlier operand).
1180 static void pushValue(const Value *V, unsigned InstID,
1181                       SmallVectorImpl<unsigned> &Vals,
1182                       ValueEnumerator &VE) {
1183   unsigned ValID = VE.getValueID(V);
1184   Vals.push_back(InstID - ValID);
1185 }
1186
1187 static void pushValue64(const Value *V, unsigned InstID,
1188                         SmallVectorImpl<uint64_t> &Vals,
1189                         ValueEnumerator &VE) {
1190   uint64_t ValID = VE.getValueID(V);
1191   Vals.push_back(InstID - ValID);
1192 }
1193
1194 static void pushValueSigned(const Value *V, unsigned InstID,
1195                             SmallVectorImpl<uint64_t> &Vals,
1196                             ValueEnumerator &VE) {
1197   unsigned ValID = VE.getValueID(V);
1198   int64_t diff = ((int32_t)InstID - (int32_t)ValID);
1199   emitSignedInt64(Vals, diff);
1200 }
1201
1202 /// WriteInstruction - Emit an instruction to the specified stream.
1203 static void WriteInstruction(const Instruction &I, unsigned InstID,
1204                              ValueEnumerator &VE, BitstreamWriter &Stream,
1205                              SmallVectorImpl<unsigned> &Vals) {
1206   unsigned Code = 0;
1207   unsigned AbbrevToUse = 0;
1208   VE.setInstructionID(&I);
1209   switch (I.getOpcode()) {
1210   default:
1211     if (Instruction::isCast(I.getOpcode())) {
1212       Code = bitc::FUNC_CODE_INST_CAST;
1213       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1214         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1215       Vals.push_back(VE.getTypeID(I.getType()));
1216       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1217     } else {
1218       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1219       Code = bitc::FUNC_CODE_INST_BINOP;
1220       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1221         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1222       pushValue(I.getOperand(1), InstID, Vals, VE);
1223       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1224       uint64_t Flags = GetOptimizationFlags(&I);
1225       if (Flags != 0) {
1226         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1227           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1228         Vals.push_back(Flags);
1229       }
1230     }
1231     break;
1232
1233   case Instruction::GetElementPtr:
1234     Code = bitc::FUNC_CODE_INST_GEP;
1235     if (cast<GEPOperator>(&I)->isInBounds())
1236       Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
1237     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1238       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1239     break;
1240   case Instruction::ExtractValue: {
1241     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1242     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1243     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1244     for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1245       Vals.push_back(*i);
1246     break;
1247   }
1248   case Instruction::InsertValue: {
1249     Code = bitc::FUNC_CODE_INST_INSERTVAL;
1250     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1251     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1252     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1253     for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1254       Vals.push_back(*i);
1255     break;
1256   }
1257   case Instruction::Select:
1258     Code = bitc::FUNC_CODE_INST_VSELECT;
1259     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1260     pushValue(I.getOperand(2), InstID, Vals, VE);
1261     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1262     break;
1263   case Instruction::ExtractElement:
1264     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1265     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1266     pushValue(I.getOperand(1), InstID, Vals, VE);
1267     break;
1268   case Instruction::InsertElement:
1269     Code = bitc::FUNC_CODE_INST_INSERTELT;
1270     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1271     pushValue(I.getOperand(1), InstID, Vals, VE);
1272     pushValue(I.getOperand(2), InstID, Vals, VE);
1273     break;
1274   case Instruction::ShuffleVector:
1275     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1276     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1277     pushValue(I.getOperand(1), InstID, Vals, VE);
1278     pushValue(I.getOperand(2), InstID, Vals, VE);
1279     break;
1280   case Instruction::ICmp:
1281   case Instruction::FCmp:
1282     // compare returning Int1Ty or vector of Int1Ty
1283     Code = bitc::FUNC_CODE_INST_CMP2;
1284     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1285     pushValue(I.getOperand(1), InstID, Vals, VE);
1286     Vals.push_back(cast<CmpInst>(I).getPredicate());
1287     break;
1288
1289   case Instruction::Ret:
1290     {
1291       Code = bitc::FUNC_CODE_INST_RET;
1292       unsigned NumOperands = I.getNumOperands();
1293       if (NumOperands == 0)
1294         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1295       else if (NumOperands == 1) {
1296         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1297           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1298       } else {
1299         for (unsigned i = 0, e = NumOperands; i != e; ++i)
1300           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1301       }
1302     }
1303     break;
1304   case Instruction::Br:
1305     {
1306       Code = bitc::FUNC_CODE_INST_BR;
1307       const BranchInst &II = cast<BranchInst>(I);
1308       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1309       if (II.isConditional()) {
1310         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1311         pushValue(II.getCondition(), InstID, Vals, VE);
1312       }
1313     }
1314     break;
1315   case Instruction::Switch:
1316     {
1317       // Redefine Vals, since here we need to use 64 bit values
1318       // explicitly to store large APInt numbers.
1319       SmallVector<uint64_t, 128> Vals64;
1320
1321       Code = bitc::FUNC_CODE_INST_SWITCH;
1322       const SwitchInst &SI = cast<SwitchInst>(I);
1323
1324       uint32_t SwitchRecordHeader = SI.hash() | (SWITCH_INST_MAGIC << 16);
1325       Vals64.push_back(SwitchRecordHeader);
1326
1327       Vals64.push_back(VE.getTypeID(SI.getCondition()->getType()));
1328       pushValue64(SI.getCondition(), InstID, Vals64, VE);
1329       Vals64.push_back(VE.getValueID(SI.getDefaultDest()));
1330       Vals64.push_back(SI.getNumCases());
1331       for (SwitchInst::ConstCaseIt i = SI.case_begin(), e = SI.case_end();
1332            i != e; ++i) {
1333         const IntegersSubset& CaseRanges = i.getCaseValueEx();
1334         unsigned Code, Abbrev; // will unused.
1335
1336         if (CaseRanges.isSingleNumber()) {
1337           Vals64.push_back(1/*NumItems = 1*/);
1338           Vals64.push_back(true/*IsSingleNumber = true*/);
1339           EmitAPInt(Vals64, Code, Abbrev, CaseRanges.getSingleNumber(0), true);
1340         } else {
1341
1342           Vals64.push_back(CaseRanges.getNumItems());
1343
1344           if (CaseRanges.isSingleNumbersOnly()) {
1345             for (unsigned ri = 0, rn = CaseRanges.getNumItems();
1346                  ri != rn; ++ri) {
1347
1348               Vals64.push_back(true/*IsSingleNumber = true*/);
1349
1350               EmitAPInt(Vals64, Code, Abbrev,
1351                         CaseRanges.getSingleNumber(ri), true);
1352             }
1353           } else
1354             for (unsigned ri = 0, rn = CaseRanges.getNumItems();
1355                  ri != rn; ++ri) {
1356               IntegersSubset::Range r = CaseRanges.getItem(ri);
1357               bool IsSingleNumber = CaseRanges.isSingleNumber(ri);
1358
1359               Vals64.push_back(IsSingleNumber);
1360
1361               EmitAPInt(Vals64, Code, Abbrev, r.getLow(), true);
1362               if (!IsSingleNumber)
1363                 EmitAPInt(Vals64, Code, Abbrev, r.getHigh(), true);
1364             }
1365         }
1366         Vals64.push_back(VE.getValueID(i.getCaseSuccessor()));
1367       }
1368
1369       Stream.EmitRecord(Code, Vals64, AbbrevToUse);
1370
1371       // Also do expected action - clear external Vals collection:
1372       Vals.clear();
1373       return;
1374     }
1375     break;
1376   case Instruction::IndirectBr:
1377     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1378     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1379     // Encode the address operand as relative, but not the basic blocks.
1380     pushValue(I.getOperand(0), InstID, Vals, VE);
1381     for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
1382       Vals.push_back(VE.getValueID(I.getOperand(i)));
1383     break;
1384
1385   case Instruction::Invoke: {
1386     const InvokeInst *II = cast<InvokeInst>(&I);
1387     const Value *Callee(II->getCalledValue());
1388     PointerType *PTy = cast<PointerType>(Callee->getType());
1389     FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1390     Code = bitc::FUNC_CODE_INST_INVOKE;
1391
1392     Vals.push_back(VE.getAttributeID(II->getAttributes()));
1393     Vals.push_back(II->getCallingConv());
1394     Vals.push_back(VE.getValueID(II->getNormalDest()));
1395     Vals.push_back(VE.getValueID(II->getUnwindDest()));
1396     PushValueAndType(Callee, InstID, Vals, VE);
1397
1398     // Emit value #'s for the fixed parameters.
1399     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1400       pushValue(I.getOperand(i), InstID, Vals, VE);  // fixed param.
1401
1402     // Emit type/value pairs for varargs params.
1403     if (FTy->isVarArg()) {
1404       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1405            i != e; ++i)
1406         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1407     }
1408     break;
1409   }
1410   case Instruction::Resume:
1411     Code = bitc::FUNC_CODE_INST_RESUME;
1412     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1413     break;
1414   case Instruction::Unreachable:
1415     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1416     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1417     break;
1418
1419   case Instruction::PHI: {
1420     const PHINode &PN = cast<PHINode>(I);
1421     Code = bitc::FUNC_CODE_INST_PHI;
1422     // With the newer instruction encoding, forward references could give
1423     // negative valued IDs.  This is most common for PHIs, so we use
1424     // signed VBRs.
1425     SmallVector<uint64_t, 128> Vals64;
1426     Vals64.push_back(VE.getTypeID(PN.getType()));
1427     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1428       pushValueSigned(PN.getIncomingValue(i), InstID, Vals64, VE);
1429       Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1430     }
1431     // Emit a Vals64 vector and exit.
1432     Stream.EmitRecord(Code, Vals64, AbbrevToUse);
1433     Vals64.clear();
1434     return;
1435   }
1436
1437   case Instruction::LandingPad: {
1438     const LandingPadInst &LP = cast<LandingPadInst>(I);
1439     Code = bitc::FUNC_CODE_INST_LANDINGPAD;
1440     Vals.push_back(VE.getTypeID(LP.getType()));
1441     PushValueAndType(LP.getPersonalityFn(), InstID, Vals, VE);
1442     Vals.push_back(LP.isCleanup());
1443     Vals.push_back(LP.getNumClauses());
1444     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1445       if (LP.isCatch(I))
1446         Vals.push_back(LandingPadInst::Catch);
1447       else
1448         Vals.push_back(LandingPadInst::Filter);
1449       PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1450     }
1451     break;
1452   }
1453
1454   case Instruction::Alloca:
1455     Code = bitc::FUNC_CODE_INST_ALLOCA;
1456     Vals.push_back(VE.getTypeID(I.getType()));
1457     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1458     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1459     Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1460     break;
1461
1462   case Instruction::Load:
1463     if (cast<LoadInst>(I).isAtomic()) {
1464       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1465       PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1466     } else {
1467       Code = bitc::FUNC_CODE_INST_LOAD;
1468       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1469         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1470     }
1471     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1472     Vals.push_back(cast<LoadInst>(I).isVolatile());
1473     if (cast<LoadInst>(I).isAtomic()) {
1474       Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1475       Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1476     }
1477     break;
1478   case Instruction::Store:
1479     if (cast<StoreInst>(I).isAtomic())
1480       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1481     else
1482       Code = bitc::FUNC_CODE_INST_STORE;
1483     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1484     pushValue(I.getOperand(0), InstID, Vals, VE);         // val.
1485     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1486     Vals.push_back(cast<StoreInst>(I).isVolatile());
1487     if (cast<StoreInst>(I).isAtomic()) {
1488       Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1489       Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1490     }
1491     break;
1492   case Instruction::AtomicCmpXchg:
1493     Code = bitc::FUNC_CODE_INST_CMPXCHG;
1494     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1495     pushValue(I.getOperand(1), InstID, Vals, VE);         // cmp.
1496     pushValue(I.getOperand(2), InstID, Vals, VE);         // newval.
1497     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1498     Vals.push_back(GetEncodedOrdering(
1499                      cast<AtomicCmpXchgInst>(I).getOrdering()));
1500     Vals.push_back(GetEncodedSynchScope(
1501                      cast<AtomicCmpXchgInst>(I).getSynchScope()));
1502     break;
1503   case Instruction::AtomicRMW:
1504     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
1505     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1506     pushValue(I.getOperand(1), InstID, Vals, VE);         // val.
1507     Vals.push_back(GetEncodedRMWOperation(
1508                      cast<AtomicRMWInst>(I).getOperation()));
1509     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
1510     Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
1511     Vals.push_back(GetEncodedSynchScope(
1512                      cast<AtomicRMWInst>(I).getSynchScope()));
1513     break;
1514   case Instruction::Fence:
1515     Code = bitc::FUNC_CODE_INST_FENCE;
1516     Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
1517     Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
1518     break;
1519   case Instruction::Call: {
1520     const CallInst &CI = cast<CallInst>(I);
1521     PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1522     FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1523
1524     Code = bitc::FUNC_CODE_INST_CALL;
1525
1526     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1527     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1528     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1529
1530     // Emit value #'s for the fixed parameters.
1531     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1532       // Check for labels (can happen with asm labels).
1533       if (FTy->getParamType(i)->isLabelTy())
1534         Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
1535       else
1536         pushValue(CI.getArgOperand(i), InstID, Vals, VE);  // fixed param.
1537     }
1538
1539     // Emit type/value pairs for varargs params.
1540     if (FTy->isVarArg()) {
1541       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1542            i != e; ++i)
1543         PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1544     }
1545     break;
1546   }
1547   case Instruction::VAArg:
1548     Code = bitc::FUNC_CODE_INST_VAARG;
1549     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1550     pushValue(I.getOperand(0), InstID, Vals, VE); // valist.
1551     Vals.push_back(VE.getTypeID(I.getType())); // restype.
1552     break;
1553   }
1554
1555   Stream.EmitRecord(Code, Vals, AbbrevToUse);
1556   Vals.clear();
1557 }
1558
1559 // Emit names for globals/functions etc.
1560 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1561                                   const ValueEnumerator &VE,
1562                                   BitstreamWriter &Stream) {
1563   if (VST.empty()) return;
1564   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1565
1566   // FIXME: Set up the abbrev, we know how many values there are!
1567   // FIXME: We know if the type names can use 7-bit ascii.
1568   SmallVector<unsigned, 64> NameVals;
1569
1570   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1571        SI != SE; ++SI) {
1572
1573     const ValueName &Name = *SI;
1574
1575     // Figure out the encoding to use for the name.
1576     bool is7Bit = true;
1577     bool isChar6 = true;
1578     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1579          C != E; ++C) {
1580       if (isChar6)
1581         isChar6 = BitCodeAbbrevOp::isChar6(*C);
1582       if ((unsigned char)*C & 128) {
1583         is7Bit = false;
1584         break;  // don't bother scanning the rest.
1585       }
1586     }
1587
1588     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1589
1590     // VST_ENTRY:   [valueid, namechar x N]
1591     // VST_BBENTRY: [bbid, namechar x N]
1592     unsigned Code;
1593     if (isa<BasicBlock>(SI->getValue())) {
1594       Code = bitc::VST_CODE_BBENTRY;
1595       if (isChar6)
1596         AbbrevToUse = VST_BBENTRY_6_ABBREV;
1597     } else {
1598       Code = bitc::VST_CODE_ENTRY;
1599       if (isChar6)
1600         AbbrevToUse = VST_ENTRY_6_ABBREV;
1601       else if (is7Bit)
1602         AbbrevToUse = VST_ENTRY_7_ABBREV;
1603     }
1604
1605     NameVals.push_back(VE.getValueID(SI->getValue()));
1606     for (const char *P = Name.getKeyData(),
1607          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1608       NameVals.push_back((unsigned char)*P);
1609
1610     // Emit the finished record.
1611     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1612     NameVals.clear();
1613   }
1614   Stream.ExitBlock();
1615 }
1616
1617 /// WriteFunction - Emit a function body to the module stream.
1618 static void WriteFunction(const Function &F, ValueEnumerator &VE,
1619                           BitstreamWriter &Stream) {
1620   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1621   VE.incorporateFunction(F);
1622
1623   SmallVector<unsigned, 64> Vals;
1624
1625   // Emit the number of basic blocks, so the reader can create them ahead of
1626   // time.
1627   Vals.push_back(VE.getBasicBlocks().size());
1628   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1629   Vals.clear();
1630
1631   // If there are function-local constants, emit them now.
1632   unsigned CstStart, CstEnd;
1633   VE.getFunctionConstantRange(CstStart, CstEnd);
1634   WriteConstants(CstStart, CstEnd, VE, Stream, false);
1635
1636   // If there is function-local metadata, emit it now.
1637   WriteFunctionLocalMetadata(F, VE, Stream);
1638
1639   // Keep a running idea of what the instruction ID is.
1640   unsigned InstID = CstEnd;
1641
1642   bool NeedsMetadataAttachment = false;
1643
1644   DebugLoc LastDL;
1645
1646   // Finally, emit all the instructions, in order.
1647   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1648     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1649          I != E; ++I) {
1650       WriteInstruction(*I, InstID, VE, Stream, Vals);
1651
1652       if (!I->getType()->isVoidTy())
1653         ++InstID;
1654
1655       // If the instruction has metadata, write a metadata attachment later.
1656       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1657
1658       // If the instruction has a debug location, emit it.
1659       DebugLoc DL = I->getDebugLoc();
1660       if (DL.isUnknown()) {
1661         // nothing todo.
1662       } else if (DL == LastDL) {
1663         // Just repeat the same debug loc as last time.
1664         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1665       } else {
1666         MDNode *Scope, *IA;
1667         DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1668
1669         Vals.push_back(DL.getLine());
1670         Vals.push_back(DL.getCol());
1671         Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1672         Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1673         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1674         Vals.clear();
1675
1676         LastDL = DL;
1677       }
1678     }
1679
1680   // Emit names for all the instructions etc.
1681   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1682
1683   if (NeedsMetadataAttachment)
1684     WriteMetadataAttachment(F, VE, Stream);
1685   VE.purgeFunction();
1686   Stream.ExitBlock();
1687 }
1688
1689 // Emit blockinfo, which defines the standard abbreviations etc.
1690 static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1691   // We only want to emit block info records for blocks that have multiple
1692   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
1693   // Other blocks can define their abbrevs inline.
1694   Stream.EnterBlockInfoBlock(2);
1695
1696   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1697     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1698     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1699     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1700     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1701     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1702     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1703                                    Abbv) != VST_ENTRY_8_ABBREV)
1704       llvm_unreachable("Unexpected abbrev ordering!");
1705   }
1706
1707   { // 7-bit fixed width VST_ENTRY strings.
1708     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1709     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1710     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1711     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1712     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1713     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1714                                    Abbv) != VST_ENTRY_7_ABBREV)
1715       llvm_unreachable("Unexpected abbrev ordering!");
1716   }
1717   { // 6-bit char6 VST_ENTRY strings.
1718     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1719     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1720     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1721     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1722     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1723     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1724                                    Abbv) != VST_ENTRY_6_ABBREV)
1725       llvm_unreachable("Unexpected abbrev ordering!");
1726   }
1727   { // 6-bit char6 VST_BBENTRY strings.
1728     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1729     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1730     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1731     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1732     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1733     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1734                                    Abbv) != VST_BBENTRY_6_ABBREV)
1735       llvm_unreachable("Unexpected abbrev ordering!");
1736   }
1737
1738
1739
1740   { // SETTYPE abbrev for CONSTANTS_BLOCK.
1741     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1742     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1743     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1744                               Log2_32_Ceil(VE.getTypes().size()+1)));
1745     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1746                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
1747       llvm_unreachable("Unexpected abbrev ordering!");
1748   }
1749
1750   { // INTEGER abbrev for CONSTANTS_BLOCK.
1751     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1752     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1753     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1754     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1755                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
1756       llvm_unreachable("Unexpected abbrev ordering!");
1757   }
1758
1759   { // CE_CAST abbrev for CONSTANTS_BLOCK.
1760     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1761     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1762     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1763     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1764                               Log2_32_Ceil(VE.getTypes().size()+1)));
1765     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1766
1767     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1768                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
1769       llvm_unreachable("Unexpected abbrev ordering!");
1770   }
1771   { // NULL abbrev for CONSTANTS_BLOCK.
1772     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1773     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1774     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1775                                    Abbv) != CONSTANTS_NULL_Abbrev)
1776       llvm_unreachable("Unexpected abbrev ordering!");
1777   }
1778
1779   // FIXME: This should only use space for first class types!
1780
1781   { // INST_LOAD abbrev for FUNCTION_BLOCK.
1782     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1783     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1784     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1785     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1786     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1787     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1788                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
1789       llvm_unreachable("Unexpected abbrev ordering!");
1790   }
1791   { // INST_BINOP abbrev for FUNCTION_BLOCK.
1792     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1793     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1794     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1795     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1796     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1797     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1798                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
1799       llvm_unreachable("Unexpected abbrev ordering!");
1800   }
1801   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1802     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1803     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1804     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1805     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1806     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1807     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1808     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1809                                    Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1810       llvm_unreachable("Unexpected abbrev ordering!");
1811   }
1812   { // INST_CAST abbrev for FUNCTION_BLOCK.
1813     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1814     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1815     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1816     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1817                               Log2_32_Ceil(VE.getTypes().size()+1)));
1818     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1819     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1820                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
1821       llvm_unreachable("Unexpected abbrev ordering!");
1822   }
1823
1824   { // INST_RET abbrev for FUNCTION_BLOCK.
1825     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1826     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1827     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1828                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1829       llvm_unreachable("Unexpected abbrev ordering!");
1830   }
1831   { // INST_RET abbrev for FUNCTION_BLOCK.
1832     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1833     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1834     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1835     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1836                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1837       llvm_unreachable("Unexpected abbrev ordering!");
1838   }
1839   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1840     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1841     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1842     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1843                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1844       llvm_unreachable("Unexpected abbrev ordering!");
1845   }
1846
1847   Stream.ExitBlock();
1848 }
1849
1850 // Sort the Users based on the order in which the reader parses the bitcode
1851 // file.
1852 static bool bitcodereader_order(const User *lhs, const User *rhs) {
1853   // TODO: Implement.
1854   return true;
1855 }
1856
1857 static void WriteUseList(const Value *V, const ValueEnumerator &VE,
1858                          BitstreamWriter &Stream) {
1859
1860   // One or zero uses can't get out of order.
1861   if (V->use_empty() || V->hasNUses(1))
1862     return;
1863
1864   // Make a copy of the in-memory use-list for sorting.
1865   unsigned UseListSize = std::distance(V->use_begin(), V->use_end());
1866   SmallVector<const User*, 8> UseList;
1867   UseList.reserve(UseListSize);
1868   for (Value::const_use_iterator I = V->use_begin(), E = V->use_end();
1869        I != E; ++I) {
1870     const User *U = *I;
1871     UseList.push_back(U);
1872   }
1873
1874   // Sort the copy based on the order read by the BitcodeReader.
1875   std::sort(UseList.begin(), UseList.end(), bitcodereader_order);
1876
1877   // TODO: Generate a diff between the BitcodeWriter in-memory use-list and the
1878   // sorted list (i.e., the expected BitcodeReader in-memory use-list).
1879
1880   // TODO: Emit the USELIST_CODE_ENTRYs.
1881 }
1882
1883 static void WriteFunctionUseList(const Function *F, ValueEnumerator &VE,
1884                                  BitstreamWriter &Stream) {
1885   VE.incorporateFunction(*F);
1886
1887   for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
1888        AI != AE; ++AI)
1889     WriteUseList(AI, VE, Stream);
1890   for (Function::const_iterator BB = F->begin(), FE = F->end(); BB != FE;
1891        ++BB) {
1892     WriteUseList(BB, VE, Stream);
1893     for (BasicBlock::const_iterator II = BB->begin(), IE = BB->end(); II != IE;
1894          ++II) {
1895       WriteUseList(II, VE, Stream);
1896       for (User::const_op_iterator OI = II->op_begin(), E = II->op_end();
1897            OI != E; ++OI) {
1898         if ((isa<Constant>(*OI) && !isa<GlobalValue>(*OI)) ||
1899             isa<InlineAsm>(*OI))
1900           WriteUseList(*OI, VE, Stream);
1901       }
1902     }
1903   }
1904   VE.purgeFunction();
1905 }
1906
1907 // Emit use-lists.
1908 static void WriteModuleUseLists(const Module *M, ValueEnumerator &VE,
1909                                 BitstreamWriter &Stream) {
1910   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
1911
1912   // XXX: this modifies the module, but in a way that should never change the
1913   // behavior of any pass or codegen in LLVM. The problem is that GVs may
1914   // contain entries in the use_list that do not exist in the Module and are
1915   // not stored in the .bc file.
1916   for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
1917        I != E; ++I)
1918     I->removeDeadConstantUsers();
1919
1920   // Write the global variables.
1921   for (Module::const_global_iterator GI = M->global_begin(),
1922          GE = M->global_end(); GI != GE; ++GI) {
1923     WriteUseList(GI, VE, Stream);
1924
1925     // Write the global variable initializers.
1926     if (GI->hasInitializer())
1927       WriteUseList(GI->getInitializer(), VE, Stream);
1928   }
1929
1930   // Write the functions.
1931   for (Module::const_iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI) {
1932     WriteUseList(FI, VE, Stream);
1933     if (!FI->isDeclaration())
1934       WriteFunctionUseList(FI, VE, Stream);
1935   }
1936
1937   // Write the aliases.
1938   for (Module::const_alias_iterator AI = M->alias_begin(), AE = M->alias_end();
1939        AI != AE; ++AI) {
1940     WriteUseList(AI, VE, Stream);
1941     WriteUseList(AI->getAliasee(), VE, Stream);
1942   }
1943
1944   Stream.ExitBlock();
1945 }
1946
1947 /// WriteModule - Emit the specified module to the bitstream.
1948 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1949   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1950
1951   SmallVector<unsigned, 1> Vals;
1952   unsigned CurVersion = 1;
1953   Vals.push_back(CurVersion);
1954   Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1955
1956   // Analyze the module, enumerating globals, functions, etc.
1957   ValueEnumerator VE(M);
1958
1959   // Emit blockinfo, which defines the standard abbreviations etc.
1960   WriteBlockInfo(VE, Stream);
1961
1962   // Emit information about attribute groups.
1963   WriteAttributeGroupTable(VE, Stream);
1964
1965   // Emit information about parameter attributes.
1966   WriteAttributeTable(VE, Stream);
1967
1968   // Emit information describing all of the types in the module.
1969   WriteTypeTable(VE, Stream);
1970
1971   // Emit top-level description of module, including target triple, inline asm,
1972   // descriptors for global variables, and function prototype info.
1973   WriteModuleInfo(M, VE, Stream);
1974
1975   // Emit constants.
1976   WriteModuleConstants(VE, Stream);
1977
1978   // Emit metadata.
1979   WriteModuleMetadata(M, VE, Stream);
1980
1981   // Emit metadata.
1982   WriteModuleMetadataStore(M, Stream);
1983
1984   // Emit names for globals/functions etc.
1985   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1986
1987   // Emit use-lists.
1988   if (EnablePreserveUseListOrdering)
1989     WriteModuleUseLists(M, VE, Stream);
1990
1991   // Emit function bodies.
1992   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1993     if (!F->isDeclaration())
1994       WriteFunction(*F, VE, Stream);
1995
1996   Stream.ExitBlock();
1997 }
1998
1999 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
2000 /// header and trailer to make it compatible with the system archiver.  To do
2001 /// this we emit the following header, and then emit a trailer that pads the
2002 /// file out to be a multiple of 16 bytes.
2003 ///
2004 /// struct bc_header {
2005 ///   uint32_t Magic;         // 0x0B17C0DE
2006 ///   uint32_t Version;       // Version, currently always 0.
2007 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
2008 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
2009 ///   uint32_t CPUType;       // CPU specifier.
2010 ///   ... potentially more later ...
2011 /// };
2012 enum {
2013   DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
2014   DarwinBCHeaderSize = 5*4
2015 };
2016
2017 static void WriteInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
2018                                uint32_t &Position) {
2019   Buffer[Position + 0] = (unsigned char) (Value >>  0);
2020   Buffer[Position + 1] = (unsigned char) (Value >>  8);
2021   Buffer[Position + 2] = (unsigned char) (Value >> 16);
2022   Buffer[Position + 3] = (unsigned char) (Value >> 24);
2023   Position += 4;
2024 }
2025
2026 static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
2027                                          const Triple &TT) {
2028   unsigned CPUType = ~0U;
2029
2030   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
2031   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
2032   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
2033   // specific constants here because they are implicitly part of the Darwin ABI.
2034   enum {
2035     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
2036     DARWIN_CPU_TYPE_X86        = 7,
2037     DARWIN_CPU_TYPE_ARM        = 12,
2038     DARWIN_CPU_TYPE_POWERPC    = 18
2039   };
2040
2041   Triple::ArchType Arch = TT.getArch();
2042   if (Arch == Triple::x86_64)
2043     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
2044   else if (Arch == Triple::x86)
2045     CPUType = DARWIN_CPU_TYPE_X86;
2046   else if (Arch == Triple::ppc)
2047     CPUType = DARWIN_CPU_TYPE_POWERPC;
2048   else if (Arch == Triple::ppc64)
2049     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
2050   else if (Arch == Triple::arm || Arch == Triple::thumb)
2051     CPUType = DARWIN_CPU_TYPE_ARM;
2052
2053   // Traditional Bitcode starts after header.
2054   assert(Buffer.size() >= DarwinBCHeaderSize &&
2055          "Expected header size to be reserved");
2056   unsigned BCOffset = DarwinBCHeaderSize;
2057   unsigned BCSize = Buffer.size()-DarwinBCHeaderSize;
2058
2059   // Write the magic and version.
2060   unsigned Position = 0;
2061   WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position);
2062   WriteInt32ToBuffer(0          , Buffer, Position); // Version.
2063   WriteInt32ToBuffer(BCOffset   , Buffer, Position);
2064   WriteInt32ToBuffer(BCSize     , Buffer, Position);
2065   WriteInt32ToBuffer(CPUType    , Buffer, Position);
2066
2067   // If the file is not a multiple of 16 bytes, insert dummy padding.
2068   while (Buffer.size() & 15)
2069     Buffer.push_back(0);
2070 }
2071
2072 /// WriteBitcodeToFile - Write the specified module to the specified output
2073 /// stream.
2074 void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
2075   SmallVector<char, 0> Buffer;
2076   Buffer.reserve(256*1024);
2077
2078   // If this is darwin or another generic macho target, reserve space for the
2079   // header.
2080   Triple TT(M->getTargetTriple());
2081   if (TT.isOSDarwin())
2082     Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0);
2083
2084   // Emit the module into the buffer.
2085   {
2086     BitstreamWriter Stream(Buffer);
2087
2088     // Emit the file header.
2089     Stream.Emit((unsigned)'B', 8);
2090     Stream.Emit((unsigned)'C', 8);
2091     Stream.Emit(0x0, 4);
2092     Stream.Emit(0xC, 4);
2093     Stream.Emit(0xE, 4);
2094     Stream.Emit(0xD, 4);
2095
2096     // Emit the module.
2097     WriteModule(M, Stream);
2098   }
2099
2100   if (TT.isOSDarwin())
2101     EmitDarwinBCHeaderAndTrailer(Buffer, TT);
2102
2103   // Write the generated bitstream to "Out".
2104   Out.write((char*)&Buffer.front(), Buffer.size());
2105 }