BitcodeWriter.cpp revision 59d3ae6cdc4316ad338cd848251f33a236ccb36c 
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>
33using namespace llvm;
34
35static cl::opt<bool>
36EnablePreserveUseListOrdering("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.
43enum {
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
66static unsigned GetEncodedCastOpcode(unsigned Opcode) {
67  switch (Opcode) {
68  default: llvm_unreachable("Unknown cast instruction!");
69  case Instruction::Trunc   : return bitc::CAST_TRUNC;
70  case Instruction::ZExt    : return bitc::CAST_ZEXT;
71  case Instruction::SExt    : return bitc::CAST_SEXT;
72  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
73  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
74  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
75  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
76  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
77  case Instruction::FPExt   : return bitc::CAST_FPEXT;
78  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
79  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
80  case Instruction::BitCast : return bitc::CAST_BITCAST;
81  case Instruction::AddrSpaceCast : return bitc::CAST_ADDRSPACECAST;
82  }
83}
84
85static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
86  switch (Opcode) {
87  default: llvm_unreachable("Unknown binary instruction!");
88  case Instruction::Add:
89  case Instruction::FAdd: return bitc::BINOP_ADD;
90  case Instruction::Sub:
91  case Instruction::FSub: return bitc::BINOP_SUB;
92  case Instruction::Mul:
93  case Instruction::FMul: return bitc::BINOP_MUL;
94  case Instruction::UDiv: return bitc::BINOP_UDIV;
95  case Instruction::FDiv:
96  case Instruction::SDiv: return bitc::BINOP_SDIV;
97  case Instruction::URem: return bitc::BINOP_UREM;
98  case Instruction::FRem:
99  case Instruction::SRem: return bitc::BINOP_SREM;
100  case Instruction::Shl:  return bitc::BINOP_SHL;
101  case Instruction::LShr: return bitc::BINOP_LSHR;
102  case Instruction::AShr: return bitc::BINOP_ASHR;
103  case Instruction::And:  return bitc::BINOP_AND;
104  case Instruction::Or:   return bitc::BINOP_OR;
105  case Instruction::Xor:  return bitc::BINOP_XOR;
106  }
107}
108
109static unsigned GetEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
110  switch (Op) {
111  default: llvm_unreachable("Unknown RMW operation!");
112  case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
113  case AtomicRMWInst::Add: return bitc::RMW_ADD;
114  case AtomicRMWInst::Sub: return bitc::RMW_SUB;
115  case AtomicRMWInst::And: return bitc::RMW_AND;
116  case AtomicRMWInst::Nand: return bitc::RMW_NAND;
117  case AtomicRMWInst::Or: return bitc::RMW_OR;
118  case AtomicRMWInst::Xor: return bitc::RMW_XOR;
119  case AtomicRMWInst::Max: return bitc::RMW_MAX;
120  case AtomicRMWInst::Min: return bitc::RMW_MIN;
121  case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
122  case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
123  }
124}
125
126static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
127  switch (Ordering) {
128  case NotAtomic: return bitc::ORDERING_NOTATOMIC;
129  case Unordered: return bitc::ORDERING_UNORDERED;
130  case Monotonic: return bitc::ORDERING_MONOTONIC;
131  case Acquire: return bitc::ORDERING_ACQUIRE;
132  case Release: return bitc::ORDERING_RELEASE;
133  case AcquireRelease: return bitc::ORDERING_ACQREL;
134  case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
135  }
136  llvm_unreachable("Invalid ordering");
137}
138
139static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
140  switch (SynchScope) {
141  case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
142  case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
143  }
144  llvm_unreachable("Invalid synch scope");
145}
146
147static void WriteStringRecord(unsigned Code, StringRef Str,
148                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
149  SmallVector<unsigned, 64> Vals;
150
151  // Code: [strchar x N]
152  for (unsigned i = 0, e = Str.size(); i != e; ++i) {
153    if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
154      AbbrevToUse = 0;
155    Vals.push_back(Str[i]);
156  }
157
158  // Emit the finished record.
159  Stream.EmitRecord(Code, Vals, AbbrevToUse);
160}
161
162static uint64_t getAttrKindEncoding(Attribute::AttrKind Kind) {
163  switch (Kind) {
164  case Attribute::Alignment:
165    return bitc::ATTR_KIND_ALIGNMENT;
166  case Attribute::AlwaysInline:
167    return bitc::ATTR_KIND_ALWAYS_INLINE;
168  case Attribute::Builtin:
169    return bitc::ATTR_KIND_BUILTIN;
170  case Attribute::ByVal:
171    return bitc::ATTR_KIND_BY_VAL;
172  case Attribute::Cold:
173    return bitc::ATTR_KIND_COLD;
174  case Attribute::InlineHint:
175    return bitc::ATTR_KIND_INLINE_HINT;
176  case Attribute::InReg:
177    return bitc::ATTR_KIND_IN_REG;
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::NoRedZone:
199    return bitc::ATTR_KIND_NO_RED_ZONE;
200  case Attribute::NoReturn:
201    return bitc::ATTR_KIND_NO_RETURN;
202  case Attribute::NoUnwind:
203    return bitc::ATTR_KIND_NO_UNWIND;
204  case Attribute::OptimizeForSize:
205    return bitc::ATTR_KIND_OPTIMIZE_FOR_SIZE;
206  case Attribute::OptimizeNone:
207    return bitc::ATTR_KIND_OPTIMIZE_NONE;
208  case Attribute::ReadNone:
209    return bitc::ATTR_KIND_READ_NONE;
210  case Attribute::ReadOnly:
211    return bitc::ATTR_KIND_READ_ONLY;
212  case Attribute::Returned:
213    return bitc::ATTR_KIND_RETURNED;
214  case Attribute::ReturnsTwice:
215    return bitc::ATTR_KIND_RETURNS_TWICE;
216  case Attribute::SExt:
217    return bitc::ATTR_KIND_S_EXT;
218  case Attribute::StackAlignment:
219    return bitc::ATTR_KIND_STACK_ALIGNMENT;
220  case Attribute::StackProtect:
221    return bitc::ATTR_KIND_STACK_PROTECT;
222  case Attribute::StackProtectReq:
223    return bitc::ATTR_KIND_STACK_PROTECT_REQ;
224  case Attribute::StackProtectStrong:
225    return bitc::ATTR_KIND_STACK_PROTECT_STRONG;
226  case Attribute::StructRet:
227    return bitc::ATTR_KIND_STRUCT_RET;
228  case Attribute::SanitizeAddress:
229    return bitc::ATTR_KIND_SANITIZE_ADDRESS;
230  case Attribute::SanitizeThread:
231    return bitc::ATTR_KIND_SANITIZE_THREAD;
232  case Attribute::SanitizeMemory:
233    return bitc::ATTR_KIND_SANITIZE_MEMORY;
234  case Attribute::UWTable:
235    return bitc::ATTR_KIND_UW_TABLE;
236  case Attribute::ZExt:
237    return bitc::ATTR_KIND_Z_EXT;
238  case Attribute::EndAttrKinds:
239    llvm_unreachable("Can not encode end-attribute kinds marker.");
240  case Attribute::None:
241    llvm_unreachable("Can not encode none-attribute.");
242  }
243
244  llvm_unreachable("Trying to encode unknown attribute");
245}
246
247static void WriteAttributeGroupTable(const ValueEnumerator &VE,
248                                     BitstreamWriter &Stream) {
249  const std::vector<AttributeSet> &AttrGrps = VE.getAttributeGroups();
250  if (AttrGrps.empty()) return;
251
252  Stream.EnterSubblock(bitc::PARAMATTR_GROUP_BLOCK_ID, 3);
253
254  SmallVector<uint64_t, 64> Record;
255  for (unsigned i = 0, e = AttrGrps.size(); i != e; ++i) {
256    AttributeSet AS = AttrGrps[i];
257    for (unsigned i = 0, e = AS.getNumSlots(); i != e; ++i) {
258      AttributeSet A = AS.getSlotAttributes(i);
259
260      Record.push_back(VE.getAttributeGroupID(A));
261      Record.push_back(AS.getSlotIndex(i));
262
263      for (AttributeSet::iterator I = AS.begin(0), E = AS.end(0);
264           I != E; ++I) {
265        Attribute Attr = *I;
266        if (Attr.isEnumAttribute()) {
267          Record.push_back(0);
268          Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
269        } else if (Attr.isAlignAttribute()) {
270          Record.push_back(1);
271          Record.push_back(getAttrKindEncoding(Attr.getKindAsEnum()));
272          Record.push_back(Attr.getValueAsInt());
273        } else {
274          StringRef Kind = Attr.getKindAsString();
275          StringRef Val = Attr.getValueAsString();
276
277          Record.push_back(Val.empty() ? 3 : 4);
278          Record.append(Kind.begin(), Kind.end());
279          Record.push_back(0);
280          if (!Val.empty()) {
281            Record.append(Val.begin(), Val.end());
282            Record.push_back(0);
283          }
284        }
285      }
286
287      Stream.EmitRecord(bitc::PARAMATTR_GRP_CODE_ENTRY, Record);
288      Record.clear();
289    }
290  }
291
292  Stream.ExitBlock();
293}
294
295static void WriteAttributeTable(const ValueEnumerator &VE,
296                                BitstreamWriter &Stream) {
297  const std::vector<AttributeSet> &Attrs = VE.getAttributes();
298  if (Attrs.empty()) return;
299
300  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
301
302  SmallVector<uint64_t, 64> Record;
303  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
304    const AttributeSet &A = Attrs[i];
305    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i)
306      Record.push_back(VE.getAttributeGroupID(A.getSlotAttributes(i)));
307
308    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
309    Record.clear();
310  }
311
312  Stream.ExitBlock();
313}
314
315/// WriteTypeTable - Write out the type table for a module.
316static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
317  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
318
319  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
320  SmallVector<uint64_t, 64> TypeVals;
321
322  uint64_t NumBits = Log2_32_Ceil(VE.getTypes().size()+1);
323
324  // Abbrev for TYPE_CODE_POINTER.
325  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
326  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
327  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
328  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
329  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
330
331  // Abbrev for TYPE_CODE_FUNCTION.
332  Abbv = new BitCodeAbbrev();
333  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
334  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
335  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
336  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
337
338  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
339
340  // Abbrev for TYPE_CODE_STRUCT_ANON.
341  Abbv = new BitCodeAbbrev();
342  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
343  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
344  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
345  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
346
347  unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
348
349  // Abbrev for TYPE_CODE_STRUCT_NAME.
350  Abbv = new BitCodeAbbrev();
351  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
352  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
353  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
354  unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
355
356  // Abbrev for TYPE_CODE_STRUCT_NAMED.
357  Abbv = new BitCodeAbbrev();
358  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
359  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
360  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
361  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
362
363  unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
364
365  // Abbrev for TYPE_CODE_ARRAY.
366  Abbv = new BitCodeAbbrev();
367  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
368  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
369  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
370
371  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
372
373  // Emit an entry count so the reader can reserve space.
374  TypeVals.push_back(TypeList.size());
375  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
376  TypeVals.clear();
377
378  // Loop over all of the types, emitting each in turn.
379  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
380    Type *T = TypeList[i];
381    int AbbrevToUse = 0;
382    unsigned Code = 0;
383
384    switch (T->getTypeID()) {
385    default: llvm_unreachable("Unknown type!");
386    case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
387    case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
388    case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
389    case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
390    case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
391    case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
392    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
393    case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
394    case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
395    case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
396    case Type::IntegerTyID:
397      // INTEGER: [width]
398      Code = bitc::TYPE_CODE_INTEGER;
399      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
400      break;
401    case Type::PointerTyID: {
402      PointerType *PTy = cast<PointerType>(T);
403      // POINTER: [pointee type, address space]
404      Code = bitc::TYPE_CODE_POINTER;
405      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
406      unsigned AddressSpace = PTy->getAddressSpace();
407      TypeVals.push_back(AddressSpace);
408      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
409      break;
410    }
411    case Type::FunctionTyID: {
412      FunctionType *FT = cast<FunctionType>(T);
413      // FUNCTION: [isvararg, retty, paramty x N]
414      Code = bitc::TYPE_CODE_FUNCTION;
415      TypeVals.push_back(FT->isVarArg());
416      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
417      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
418        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
419      AbbrevToUse = FunctionAbbrev;
420      break;
421    }
422    case Type::StructTyID: {
423      StructType *ST = cast<StructType>(T);
424      // STRUCT: [ispacked, eltty x N]
425      TypeVals.push_back(ST->isPacked());
426      // Output all of the element types.
427      for (StructType::element_iterator I = ST->element_begin(),
428           E = ST->element_end(); I != E; ++I)
429        TypeVals.push_back(VE.getTypeID(*I));
430
431      if (ST->isLiteral()) {
432        Code = bitc::TYPE_CODE_STRUCT_ANON;
433        AbbrevToUse = StructAnonAbbrev;
434      } else {
435        if (ST->isOpaque()) {
436          Code = bitc::TYPE_CODE_OPAQUE;
437        } else {
438          Code = bitc::TYPE_CODE_STRUCT_NAMED;
439          AbbrevToUse = StructNamedAbbrev;
440        }
441
442        // Emit the name if it is present.
443        if (!ST->getName().empty())
444          WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
445                            StructNameAbbrev, Stream);
446      }
447      break;
448    }
449    case Type::ArrayTyID: {
450      ArrayType *AT = cast<ArrayType>(T);
451      // ARRAY: [numelts, eltty]
452      Code = bitc::TYPE_CODE_ARRAY;
453      TypeVals.push_back(AT->getNumElements());
454      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
455      AbbrevToUse = ArrayAbbrev;
456      break;
457    }
458    case Type::VectorTyID: {
459      VectorType *VT = cast<VectorType>(T);
460      // VECTOR [numelts, eltty]
461      Code = bitc::TYPE_CODE_VECTOR;
462      TypeVals.push_back(VT->getNumElements());
463      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
464      break;
465    }
466    }
467
468    // Emit the finished record.
469    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
470    TypeVals.clear();
471  }
472
473  Stream.ExitBlock();
474}
475
476static unsigned getEncodedLinkage(const GlobalValue *GV) {
477  switch (GV->getLinkage()) {
478  case GlobalValue::ExternalLinkage:                 return 0;
479  case GlobalValue::WeakAnyLinkage:                  return 1;
480  case GlobalValue::AppendingLinkage:                return 2;
481  case GlobalValue::InternalLinkage:                 return 3;
482  case GlobalValue::LinkOnceAnyLinkage:              return 4;
483  case GlobalValue::DLLImportLinkage:                return 5;
484  case GlobalValue::DLLExportLinkage:                return 6;
485  case GlobalValue::ExternalWeakLinkage:             return 7;
486  case GlobalValue::CommonLinkage:                   return 8;
487  case GlobalValue::PrivateLinkage:                  return 9;
488  case GlobalValue::WeakODRLinkage:                  return 10;
489  case GlobalValue::LinkOnceODRLinkage:              return 11;
490  case GlobalValue::AvailableExternallyLinkage:      return 12;
491  case GlobalValue::LinkerPrivateLinkage:            return 13;
492  case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
493  }
494  llvm_unreachable("Invalid linkage");
495}
496
497static unsigned getEncodedVisibility(const GlobalValue *GV) {
498  switch (GV->getVisibility()) {
499  case GlobalValue::DefaultVisibility:   return 0;
500  case GlobalValue::HiddenVisibility:    return 1;
501  case GlobalValue::ProtectedVisibility: return 2;
502  }
503  llvm_unreachable("Invalid visibility");
504}
505
506static unsigned getEncodedThreadLocalMode(const GlobalVariable *GV) {
507  switch (GV->getThreadLocalMode()) {
508    case GlobalVariable::NotThreadLocal:         return 0;
509    case GlobalVariable::GeneralDynamicTLSModel: return 1;
510    case GlobalVariable::LocalDynamicTLSModel:   return 2;
511    case GlobalVariable::InitialExecTLSModel:    return 3;
512    case GlobalVariable::LocalExecTLSModel:      return 4;
513  }
514  llvm_unreachable("Invalid TLS model");
515}
516
517// Emit top-level description of module, including target triple, inline asm,
518// descriptors for global variables, and function prototype info.
519static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
520                            BitstreamWriter &Stream) {
521  // Emit various pieces of data attached to a module.
522  if (!M->getTargetTriple().empty())
523    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
524                      0/*TODO*/, Stream);
525  if (!M->getDataLayout().empty())
526    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
527                      0/*TODO*/, Stream);
528  if (!M->getModuleInlineAsm().empty())
529    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
530                      0/*TODO*/, Stream);
531
532  // Emit information about sections and GC, computing how many there are. Also
533  // compute the maximum alignment value.
534  std::map<std::string, unsigned> SectionMap;
535  std::map<std::string, unsigned> GCMap;
536  unsigned MaxAlignment = 0;
537  unsigned MaxGlobalType = 0;
538  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
539       GV != E; ++GV) {
540    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
541    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
542    if (GV->hasSection()) {
543      // Give section names unique ID's.
544      unsigned &Entry = SectionMap[GV->getSection()];
545      if (!Entry) {
546        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
547                          0/*TODO*/, Stream);
548        Entry = SectionMap.size();
549      }
550    }
551  }
552  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
553    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
554    if (F->hasSection()) {
555      // Give section names unique ID's.
556      unsigned &Entry = SectionMap[F->getSection()];
557      if (!Entry) {
558        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
559                          0/*TODO*/, Stream);
560        Entry = SectionMap.size();
561      }
562    }
563    if (F->hasGC()) {
564      // Same for GC names.
565      unsigned &Entry = GCMap[F->getGC()];
566      if (!Entry) {
567        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
568                          0/*TODO*/, Stream);
569        Entry = GCMap.size();
570      }
571    }
572  }
573
574  // Emit abbrev for globals, now that we know # sections and max alignment.
575  unsigned SimpleGVarAbbrev = 0;
576  if (!M->global_empty()) {
577    // Add an abbrev for common globals with no visibility or thread localness.
578    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
579    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
580    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
581                              Log2_32_Ceil(MaxGlobalType+1)));
582    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
583    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
584    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
585    if (MaxAlignment == 0)                                      // Alignment.
586      Abbv->Add(BitCodeAbbrevOp(0));
587    else {
588      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
589      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
590                               Log2_32_Ceil(MaxEncAlignment+1)));
591    }
592    if (SectionMap.empty())                                    // Section.
593      Abbv->Add(BitCodeAbbrevOp(0));
594    else
595      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
596                               Log2_32_Ceil(SectionMap.size()+1)));
597    // Don't bother emitting vis + thread local.
598    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
599  }
600
601  // Emit the global variable information.
602  SmallVector<unsigned, 64> Vals;
603  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
604       GV != E; ++GV) {
605    unsigned AbbrevToUse = 0;
606
607    // GLOBALVAR: [type, isconst, initid,
608    //             linkage, alignment, section, visibility, threadlocal,
609    //             unnamed_addr, externally_initialized]
610    Vals.push_back(VE.getTypeID(GV->getType()));
611    Vals.push_back(GV->isConstant());
612    Vals.push_back(GV->isDeclaration() ? 0 :
613                   (VE.getValueID(GV->getInitializer()) + 1));
614    Vals.push_back(getEncodedLinkage(GV));
615    Vals.push_back(Log2_32(GV->getAlignment())+1);
616    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
617    if (GV->isThreadLocal() ||
618        GV->getVisibility() != GlobalValue::DefaultVisibility ||
619        GV->hasUnnamedAddr() || GV->isExternallyInitialized()) {
620      Vals.push_back(getEncodedVisibility(GV));
621      Vals.push_back(getEncodedThreadLocalMode(GV));
622      Vals.push_back(GV->hasUnnamedAddr());
623      Vals.push_back(GV->isExternallyInitialized());
624    } else {
625      AbbrevToUse = SimpleGVarAbbrev;
626    }
627
628    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
629    Vals.clear();
630  }
631
632  // Emit the function proto information.
633  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
634    // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
635    //             section, visibility, gc, unnamed_addr, prefix]
636    Vals.push_back(VE.getTypeID(F->getType()));
637    Vals.push_back(F->getCallingConv());
638    Vals.push_back(F->isDeclaration());
639    Vals.push_back(getEncodedLinkage(F));
640    Vals.push_back(VE.getAttributeID(F->getAttributes()));
641    Vals.push_back(Log2_32(F->getAlignment())+1);
642    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
643    Vals.push_back(getEncodedVisibility(F));
644    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
645    Vals.push_back(F->hasUnnamedAddr());
646    Vals.push_back(F->hasPrefixData() ? (VE.getValueID(F->getPrefixData()) + 1)
647                                      : 0);
648
649    unsigned AbbrevToUse = 0;
650    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
651    Vals.clear();
652  }
653
654  // Emit the alias information.
655  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
656       AI != E; ++AI) {
657    // ALIAS: [alias type, aliasee val#, linkage, visibility]
658    Vals.push_back(VE.getTypeID(AI->getType()));
659    Vals.push_back(VE.getValueID(AI->getAliasee()));
660    Vals.push_back(getEncodedLinkage(AI));
661    Vals.push_back(getEncodedVisibility(AI));
662    unsigned AbbrevToUse = 0;
663    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
664    Vals.clear();
665  }
666}
667
668static uint64_t GetOptimizationFlags(const Value *V) {
669  uint64_t Flags = 0;
670
671  if (const OverflowingBinaryOperator *OBO =
672        dyn_cast<OverflowingBinaryOperator>(V)) {
673    if (OBO->hasNoSignedWrap())
674      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
675    if (OBO->hasNoUnsignedWrap())
676      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
677  } else if (const PossiblyExactOperator *PEO =
678               dyn_cast<PossiblyExactOperator>(V)) {
679    if (PEO->isExact())
680      Flags |= 1 << bitc::PEO_EXACT;
681  } else if (const FPMathOperator *FPMO =
682             dyn_cast<const FPMathOperator>(V)) {
683    if (FPMO->hasUnsafeAlgebra())
684      Flags |= FastMathFlags::UnsafeAlgebra;
685    if (FPMO->hasNoNaNs())
686      Flags |= FastMathFlags::NoNaNs;
687    if (FPMO->hasNoInfs())
688      Flags |= FastMathFlags::NoInfs;
689    if (FPMO->hasNoSignedZeros())
690      Flags |= FastMathFlags::NoSignedZeros;
691    if (FPMO->hasAllowReciprocal())
692      Flags |= FastMathFlags::AllowReciprocal;
693  }
694
695  return Flags;
696}
697
698static void WriteMDNode(const MDNode *N,
699                        const ValueEnumerator &VE,
700                        BitstreamWriter &Stream,
701                        SmallVectorImpl<uint64_t> &Record) {
702  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
703    if (N->getOperand(i)) {
704      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
705      Record.push_back(VE.getValueID(N->getOperand(i)));
706    } else {
707      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
708      Record.push_back(0);
709    }
710  }
711  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
712                                           bitc::METADATA_NODE;
713  Stream.EmitRecord(MDCode, Record, 0);
714  Record.clear();
715}
716
717static void WriteModuleMetadata(const Module *M,
718                                const ValueEnumerator &VE,
719                                BitstreamWriter &Stream) {
720  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
721  bool StartedMetadataBlock = false;
722  unsigned MDSAbbrev = 0;
723  SmallVector<uint64_t, 64> Record;
724  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
725
726    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
727      if (!N->isFunctionLocal() || !N->getFunction()) {
728        if (!StartedMetadataBlock) {
729          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
730          StartedMetadataBlock = true;
731        }
732        WriteMDNode(N, VE, Stream, Record);
733      }
734    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
735      if (!StartedMetadataBlock)  {
736        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
737
738        // Abbrev for METADATA_STRING.
739        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
740        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
741        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
742        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
743        MDSAbbrev = Stream.EmitAbbrev(Abbv);
744        StartedMetadataBlock = true;
745      }
746
747      // Code: [strchar x N]
748      Record.append(MDS->begin(), MDS->end());
749
750      // Emit the finished record.
751      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
752      Record.clear();
753    }
754  }
755
756  // Write named metadata.
757  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
758       E = M->named_metadata_end(); I != E; ++I) {
759    const NamedMDNode *NMD = I;
760    if (!StartedMetadataBlock)  {
761      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
762      StartedMetadataBlock = true;
763    }
764
765    // Write name.
766    StringRef Str = NMD->getName();
767    for (unsigned i = 0, e = Str.size(); i != e; ++i)
768      Record.push_back(Str[i]);
769    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
770    Record.clear();
771
772    // Write named metadata operands.
773    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
774      Record.push_back(VE.getValueID(NMD->getOperand(i)));
775    Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
776    Record.clear();
777  }
778
779  if (StartedMetadataBlock)
780    Stream.ExitBlock();
781}
782
783static void WriteFunctionLocalMetadata(const Function &F,
784                                       const ValueEnumerator &VE,
785                                       BitstreamWriter &Stream) {
786  bool StartedMetadataBlock = false;
787  SmallVector<uint64_t, 64> Record;
788  const SmallVectorImpl<const MDNode *> &Vals = VE.getFunctionLocalMDValues();
789  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
790    if (const MDNode *N = Vals[i])
791      if (N->isFunctionLocal() && N->getFunction() == &F) {
792        if (!StartedMetadataBlock) {
793          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
794          StartedMetadataBlock = true;
795        }
796        WriteMDNode(N, VE, Stream, Record);
797      }
798
799  if (StartedMetadataBlock)
800    Stream.ExitBlock();
801}
802
803static void WriteMetadataAttachment(const Function &F,
804                                    const ValueEnumerator &VE,
805                                    BitstreamWriter &Stream) {
806  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
807
808  SmallVector<uint64_t, 64> Record;
809
810  // Write metadata attachments
811  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
812  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
813
814  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
815    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
816         I != E; ++I) {
817      MDs.clear();
818      I->getAllMetadataOtherThanDebugLoc(MDs);
819
820      // If no metadata, ignore instruction.
821      if (MDs.empty()) continue;
822
823      Record.push_back(VE.getInstructionID(I));
824
825      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
826        Record.push_back(MDs[i].first);
827        Record.push_back(VE.getValueID(MDs[i].second));
828      }
829      Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
830      Record.clear();
831    }
832
833  Stream.ExitBlock();
834}
835
836static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
837  SmallVector<uint64_t, 64> Record;
838
839  // Write metadata kinds
840  // METADATA_KIND - [n x [id, name]]
841  SmallVector<StringRef, 8> Names;
842  M->getMDKindNames(Names);
843
844  if (Names.empty()) return;
845
846  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
847
848  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
849    Record.push_back(MDKindID);
850    StringRef KName = Names[MDKindID];
851    Record.append(KName.begin(), KName.end());
852
853    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
854    Record.clear();
855  }
856
857  Stream.ExitBlock();
858}
859
860static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
861  if ((int64_t)V >= 0)
862    Vals.push_back(V << 1);
863  else
864    Vals.push_back((-V << 1) | 1);
865}
866
867static void WriteConstants(unsigned FirstVal, unsigned LastVal,
868                           const ValueEnumerator &VE,
869                           BitstreamWriter &Stream, bool isGlobal) {
870  if (FirstVal == LastVal) return;
871
872  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
873
874  unsigned AggregateAbbrev = 0;
875  unsigned String8Abbrev = 0;
876  unsigned CString7Abbrev = 0;
877  unsigned CString6Abbrev = 0;
878  // If this is a constant pool for the module, emit module-specific abbrevs.
879  if (isGlobal) {
880    // Abbrev for CST_CODE_AGGREGATE.
881    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
882    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
883    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
884    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
885    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
886
887    // Abbrev for CST_CODE_STRING.
888    Abbv = new BitCodeAbbrev();
889    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
890    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
891    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
892    String8Abbrev = Stream.EmitAbbrev(Abbv);
893    // Abbrev for CST_CODE_CSTRING.
894    Abbv = new BitCodeAbbrev();
895    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
896    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
897    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
898    CString7Abbrev = Stream.EmitAbbrev(Abbv);
899    // Abbrev for CST_CODE_CSTRING.
900    Abbv = new BitCodeAbbrev();
901    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
902    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
903    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
904    CString6Abbrev = Stream.EmitAbbrev(Abbv);
905  }
906
907  SmallVector<uint64_t, 64> Record;
908
909  const ValueEnumerator::ValueList &Vals = VE.getValues();
910  Type *LastTy = 0;
911  for (unsigned i = FirstVal; i != LastVal; ++i) {
912    const Value *V = Vals[i].first;
913    // If we need to switch types, do so now.
914    if (V->getType() != LastTy) {
915      LastTy = V->getType();
916      Record.push_back(VE.getTypeID(LastTy));
917      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
918                        CONSTANTS_SETTYPE_ABBREV);
919      Record.clear();
920    }
921
922    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
923      Record.push_back(unsigned(IA->hasSideEffects()) |
924                       unsigned(IA->isAlignStack()) << 1 |
925                       unsigned(IA->getDialect()&1) << 2);
926
927      // Add the asm string.
928      const std::string &AsmStr = IA->getAsmString();
929      Record.push_back(AsmStr.size());
930      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
931        Record.push_back(AsmStr[i]);
932
933      // Add the constraint string.
934      const std::string &ConstraintStr = IA->getConstraintString();
935      Record.push_back(ConstraintStr.size());
936      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
937        Record.push_back(ConstraintStr[i]);
938      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
939      Record.clear();
940      continue;
941    }
942    const Constant *C = cast<Constant>(V);
943    unsigned Code = -1U;
944    unsigned AbbrevToUse = 0;
945    if (C->isNullValue()) {
946      Code = bitc::CST_CODE_NULL;
947    } else if (isa<UndefValue>(C)) {
948      Code = bitc::CST_CODE_UNDEF;
949    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
950      if (IV->getBitWidth() <= 64) {
951        uint64_t V = IV->getSExtValue();
952        emitSignedInt64(Record, V);
953        Code = bitc::CST_CODE_INTEGER;
954        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
955      } else {                             // Wide integers, > 64 bits in size.
956        // We have an arbitrary precision integer value to write whose
957        // bit width is > 64. However, in canonical unsigned integer
958        // format it is likely that the high bits are going to be zero.
959        // So, we only write the number of active words.
960        unsigned NWords = IV->getValue().getActiveWords();
961        const uint64_t *RawWords = IV->getValue().getRawData();
962        for (unsigned i = 0; i != NWords; ++i) {
963          emitSignedInt64(Record, RawWords[i]);
964        }
965        Code = bitc::CST_CODE_WIDE_INTEGER;
966      }
967    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
968      Code = bitc::CST_CODE_FLOAT;
969      Type *Ty = CFP->getType();
970      if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
971        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
972      } else if (Ty->isX86_FP80Ty()) {
973        // api needed to prevent premature destruction
974        // bits are not in the same order as a normal i80 APInt, compensate.
975        APInt api = CFP->getValueAPF().bitcastToAPInt();
976        const uint64_t *p = api.getRawData();
977        Record.push_back((p[1] << 48) | (p[0] >> 16));
978        Record.push_back(p[0] & 0xffffLL);
979      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
980        APInt api = CFP->getValueAPF().bitcastToAPInt();
981        const uint64_t *p = api.getRawData();
982        Record.push_back(p[0]);
983        Record.push_back(p[1]);
984      } else {
985        assert (0 && "Unknown FP type!");
986      }
987    } else if (isa<ConstantDataSequential>(C) &&
988               cast<ConstantDataSequential>(C)->isString()) {
989      const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
990      // Emit constant strings specially.
991      unsigned NumElts = Str->getNumElements();
992      // If this is a null-terminated string, use the denser CSTRING encoding.
993      if (Str->isCString()) {
994        Code = bitc::CST_CODE_CSTRING;
995        --NumElts;  // Don't encode the null, which isn't allowed by char6.
996      } else {
997        Code = bitc::CST_CODE_STRING;
998        AbbrevToUse = String8Abbrev;
999      }
1000      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
1001      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
1002      for (unsigned i = 0; i != NumElts; ++i) {
1003        unsigned char V = Str->getElementAsInteger(i);
1004        Record.push_back(V);
1005        isCStr7 &= (V & 128) == 0;
1006        if (isCStrChar6)
1007          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
1008      }
1009
1010      if (isCStrChar6)
1011        AbbrevToUse = CString6Abbrev;
1012      else if (isCStr7)
1013        AbbrevToUse = CString7Abbrev;
1014    } else if (const ConstantDataSequential *CDS =
1015                  dyn_cast<ConstantDataSequential>(C)) {
1016      Code = bitc::CST_CODE_DATA;
1017      Type *EltTy = CDS->getType()->getElementType();
1018      if (isa<IntegerType>(EltTy)) {
1019        for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
1020          Record.push_back(CDS->getElementAsInteger(i));
1021      } else if (EltTy->isFloatTy()) {
1022        for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1023          union { float F; uint32_t I; };
1024          F = CDS->getElementAsFloat(i);
1025          Record.push_back(I);
1026        }
1027      } else {
1028        assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
1029        for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
1030          union { double F; uint64_t I; };
1031          F = CDS->getElementAsDouble(i);
1032          Record.push_back(I);
1033        }
1034      }
1035    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
1036               isa<ConstantVector>(C)) {
1037      Code = bitc::CST_CODE_AGGREGATE;
1038      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
1039        Record.push_back(VE.getValueID(C->getOperand(i)));
1040      AbbrevToUse = AggregateAbbrev;
1041    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
1042      switch (CE->getOpcode()) {
1043      default:
1044        if (Instruction::isCast(CE->getOpcode())) {
1045          Code = bitc::CST_CODE_CE_CAST;
1046          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
1047          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1048          Record.push_back(VE.getValueID(C->getOperand(0)));
1049          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
1050        } else {
1051          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
1052          Code = bitc::CST_CODE_CE_BINOP;
1053          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
1054          Record.push_back(VE.getValueID(C->getOperand(0)));
1055          Record.push_back(VE.getValueID(C->getOperand(1)));
1056          uint64_t Flags = GetOptimizationFlags(CE);
1057          if (Flags != 0)
1058            Record.push_back(Flags);
1059        }
1060        break;
1061      case Instruction::GetElementPtr:
1062        Code = bitc::CST_CODE_CE_GEP;
1063        if (cast<GEPOperator>(C)->isInBounds())
1064          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
1065        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
1066          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
1067          Record.push_back(VE.getValueID(C->getOperand(i)));
1068        }
1069        break;
1070      case Instruction::Select:
1071        Code = bitc::CST_CODE_CE_SELECT;
1072        Record.push_back(VE.getValueID(C->getOperand(0)));
1073        Record.push_back(VE.getValueID(C->getOperand(1)));
1074        Record.push_back(VE.getValueID(C->getOperand(2)));
1075        break;
1076      case Instruction::ExtractElement:
1077        Code = bitc::CST_CODE_CE_EXTRACTELT;
1078        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1079        Record.push_back(VE.getValueID(C->getOperand(0)));
1080        Record.push_back(VE.getValueID(C->getOperand(1)));
1081        break;
1082      case Instruction::InsertElement:
1083        Code = bitc::CST_CODE_CE_INSERTELT;
1084        Record.push_back(VE.getValueID(C->getOperand(0)));
1085        Record.push_back(VE.getValueID(C->getOperand(1)));
1086        Record.push_back(VE.getValueID(C->getOperand(2)));
1087        break;
1088      case Instruction::ShuffleVector:
1089        // If the return type and argument types are the same, this is a
1090        // standard shufflevector instruction.  If the types are different,
1091        // then the shuffle is widening or truncating the input vectors, and
1092        // the argument type must also be encoded.
1093        if (C->getType() == C->getOperand(0)->getType()) {
1094          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
1095        } else {
1096          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
1097          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1098        }
1099        Record.push_back(VE.getValueID(C->getOperand(0)));
1100        Record.push_back(VE.getValueID(C->getOperand(1)));
1101        Record.push_back(VE.getValueID(C->getOperand(2)));
1102        break;
1103      case Instruction::ICmp:
1104      case Instruction::FCmp:
1105        Code = bitc::CST_CODE_CE_CMP;
1106        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1107        Record.push_back(VE.getValueID(C->getOperand(0)));
1108        Record.push_back(VE.getValueID(C->getOperand(1)));
1109        Record.push_back(CE->getPredicate());
1110        break;
1111      }
1112    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
1113      Code = bitc::CST_CODE_BLOCKADDRESS;
1114      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
1115      Record.push_back(VE.getValueID(BA->getFunction()));
1116      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
1117    } else {
1118#ifndef NDEBUG
1119      C->dump();
1120#endif
1121      llvm_unreachable("Unknown constant!");
1122    }
1123    Stream.EmitRecord(Code, Record, AbbrevToUse);
1124    Record.clear();
1125  }
1126
1127  Stream.ExitBlock();
1128}
1129
1130static void WriteModuleConstants(const ValueEnumerator &VE,
1131                                 BitstreamWriter &Stream) {
1132  const ValueEnumerator::ValueList &Vals = VE.getValues();
1133
1134  // Find the first constant to emit, which is the first non-globalvalue value.
1135  // We know globalvalues have been emitted by WriteModuleInfo.
1136  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1137    if (!isa<GlobalValue>(Vals[i].first)) {
1138      WriteConstants(i, Vals.size(), VE, Stream, true);
1139      return;
1140    }
1141  }
1142}
1143
1144/// PushValueAndType - The file has to encode both the value and type id for
1145/// many values, because we need to know what type to create for forward
1146/// references.  However, most operands are not forward references, so this type
1147/// field is not needed.
1148///
1149/// This function adds V's value ID to Vals.  If the value ID is higher than the
1150/// instruction ID, then it is a forward reference, and it also includes the
1151/// type ID.  The value ID that is written is encoded relative to the InstID.
1152static bool PushValueAndType(const Value *V, unsigned InstID,
1153                             SmallVectorImpl<unsigned> &Vals,
1154                             ValueEnumerator &VE) {
1155  unsigned ValID = VE.getValueID(V);
1156  // Make encoding relative to the InstID.
1157  Vals.push_back(InstID - ValID);
1158  if (ValID >= InstID) {
1159    Vals.push_back(VE.getTypeID(V->getType()));
1160    return true;
1161  }
1162  return false;
1163}
1164
1165/// pushValue - Like PushValueAndType, but where the type of the value is
1166/// omitted (perhaps it was already encoded in an earlier operand).
1167static void pushValue(const Value *V, unsigned InstID,
1168                      SmallVectorImpl<unsigned> &Vals,
1169                      ValueEnumerator &VE) {
1170  unsigned ValID = VE.getValueID(V);
1171  Vals.push_back(InstID - ValID);
1172}
1173
1174static void pushValueSigned(const Value *V, unsigned InstID,
1175                            SmallVectorImpl<uint64_t> &Vals,
1176                            ValueEnumerator &VE) {
1177  unsigned ValID = VE.getValueID(V);
1178  int64_t diff = ((int32_t)InstID - (int32_t)ValID);
1179  emitSignedInt64(Vals, diff);
1180}
1181
1182/// WriteInstruction - Emit an instruction to the specified stream.
1183static void WriteInstruction(const Instruction &I, unsigned InstID,
1184                             ValueEnumerator &VE, BitstreamWriter &Stream,
1185                             SmallVectorImpl<unsigned> &Vals) {
1186  unsigned Code = 0;
1187  unsigned AbbrevToUse = 0;
1188  VE.setInstructionID(&I);
1189  switch (I.getOpcode()) {
1190  default:
1191    if (Instruction::isCast(I.getOpcode())) {
1192      Code = bitc::FUNC_CODE_INST_CAST;
1193      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1194        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1195      Vals.push_back(VE.getTypeID(I.getType()));
1196      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1197    } else {
1198      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1199      Code = bitc::FUNC_CODE_INST_BINOP;
1200      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1201        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1202      pushValue(I.getOperand(1), InstID, Vals, VE);
1203      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1204      uint64_t Flags = GetOptimizationFlags(&I);
1205      if (Flags != 0) {
1206        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1207          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1208        Vals.push_back(Flags);
1209      }
1210    }
1211    break;
1212
1213  case Instruction::GetElementPtr:
1214    Code = bitc::FUNC_CODE_INST_GEP;
1215    if (cast<GEPOperator>(&I)->isInBounds())
1216      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
1217    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1218      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1219    break;
1220  case Instruction::ExtractValue: {
1221    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1222    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1223    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1224    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1225      Vals.push_back(*i);
1226    break;
1227  }
1228  case Instruction::InsertValue: {
1229    Code = bitc::FUNC_CODE_INST_INSERTVAL;
1230    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1231    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1232    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1233    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1234      Vals.push_back(*i);
1235    break;
1236  }
1237  case Instruction::Select:
1238    Code = bitc::FUNC_CODE_INST_VSELECT;
1239    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1240    pushValue(I.getOperand(2), InstID, Vals, VE);
1241    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1242    break;
1243  case Instruction::ExtractElement:
1244    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1245    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1246    pushValue(I.getOperand(1), InstID, Vals, VE);
1247    break;
1248  case Instruction::InsertElement:
1249    Code = bitc::FUNC_CODE_INST_INSERTELT;
1250    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1251    pushValue(I.getOperand(1), InstID, Vals, VE);
1252    pushValue(I.getOperand(2), InstID, Vals, VE);
1253    break;
1254  case Instruction::ShuffleVector:
1255    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1256    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1257    pushValue(I.getOperand(1), InstID, Vals, VE);
1258    pushValue(I.getOperand(2), InstID, Vals, VE);
1259    break;
1260  case Instruction::ICmp:
1261  case Instruction::FCmp:
1262    // compare returning Int1Ty or vector of Int1Ty
1263    Code = bitc::FUNC_CODE_INST_CMP2;
1264    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1265    pushValue(I.getOperand(1), InstID, Vals, VE);
1266    Vals.push_back(cast<CmpInst>(I).getPredicate());
1267    break;
1268
1269  case Instruction::Ret:
1270    {
1271      Code = bitc::FUNC_CODE_INST_RET;
1272      unsigned NumOperands = I.getNumOperands();
1273      if (NumOperands == 0)
1274        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1275      else if (NumOperands == 1) {
1276        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1277          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1278      } else {
1279        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1280          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1281      }
1282    }
1283    break;
1284  case Instruction::Br:
1285    {
1286      Code = bitc::FUNC_CODE_INST_BR;
1287      const BranchInst &II = cast<BranchInst>(I);
1288      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1289      if (II.isConditional()) {
1290        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1291        pushValue(II.getCondition(), InstID, Vals, VE);
1292      }
1293    }
1294    break;
1295  case Instruction::Switch:
1296    {
1297      Code = bitc::FUNC_CODE_INST_SWITCH;
1298      const SwitchInst &SI = cast<SwitchInst>(I);
1299      Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
1300      pushValue(SI.getCondition(), InstID, Vals, VE);
1301      Vals.push_back(VE.getValueID(SI.getDefaultDest()));
1302      for (SwitchInst::ConstCaseIt i = SI.case_begin(), e = SI.case_end();
1303           i != e; ++i) {
1304        Vals.push_back(VE.getValueID(i.getCaseValue()));
1305        Vals.push_back(VE.getValueID(i.getCaseSuccessor()));
1306      }
1307    }
1308    break;
1309  case Instruction::IndirectBr:
1310    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1311    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1312    // Encode the address operand as relative, but not the basic blocks.
1313    pushValue(I.getOperand(0), InstID, Vals, VE);
1314    for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
1315      Vals.push_back(VE.getValueID(I.getOperand(i)));
1316    break;
1317
1318  case Instruction::Invoke: {
1319    const InvokeInst *II = cast<InvokeInst>(&I);
1320    const Value *Callee(II->getCalledValue());
1321    PointerType *PTy = cast<PointerType>(Callee->getType());
1322    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1323    Code = bitc::FUNC_CODE_INST_INVOKE;
1324
1325    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1326    Vals.push_back(II->getCallingConv());
1327    Vals.push_back(VE.getValueID(II->getNormalDest()));
1328    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1329    PushValueAndType(Callee, InstID, Vals, VE);
1330
1331    // Emit value #'s for the fixed parameters.
1332    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1333      pushValue(I.getOperand(i), InstID, Vals, VE);  // fixed param.
1334
1335    // Emit type/value pairs for varargs params.
1336    if (FTy->isVarArg()) {
1337      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1338           i != e; ++i)
1339        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1340    }
1341    break;
1342  }
1343  case Instruction::Resume:
1344    Code = bitc::FUNC_CODE_INST_RESUME;
1345    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1346    break;
1347  case Instruction::Unreachable:
1348    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1349    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1350    break;
1351
1352  case Instruction::PHI: {
1353    const PHINode &PN = cast<PHINode>(I);
1354    Code = bitc::FUNC_CODE_INST_PHI;
1355    // With the newer instruction encoding, forward references could give
1356    // negative valued IDs.  This is most common for PHIs, so we use
1357    // signed VBRs.
1358    SmallVector<uint64_t, 128> Vals64;
1359    Vals64.push_back(VE.getTypeID(PN.getType()));
1360    for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1361      pushValueSigned(PN.getIncomingValue(i), InstID, Vals64, VE);
1362      Vals64.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1363    }
1364    // Emit a Vals64 vector and exit.
1365    Stream.EmitRecord(Code, Vals64, AbbrevToUse);
1366    Vals64.clear();
1367    return;
1368  }
1369
1370  case Instruction::LandingPad: {
1371    const LandingPadInst &LP = cast<LandingPadInst>(I);
1372    Code = bitc::FUNC_CODE_INST_LANDINGPAD;
1373    Vals.push_back(VE.getTypeID(LP.getType()));
1374    PushValueAndType(LP.getPersonalityFn(), InstID, Vals, VE);
1375    Vals.push_back(LP.isCleanup());
1376    Vals.push_back(LP.getNumClauses());
1377    for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1378      if (LP.isCatch(I))
1379        Vals.push_back(LandingPadInst::Catch);
1380      else
1381        Vals.push_back(LandingPadInst::Filter);
1382      PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1383    }
1384    break;
1385  }
1386
1387  case Instruction::Alloca:
1388    Code = bitc::FUNC_CODE_INST_ALLOCA;
1389    Vals.push_back(VE.getTypeID(I.getType()));
1390    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1391    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1392    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1393    break;
1394
1395  case Instruction::Load:
1396    if (cast<LoadInst>(I).isAtomic()) {
1397      Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1398      PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1399    } else {
1400      Code = bitc::FUNC_CODE_INST_LOAD;
1401      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1402        AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1403    }
1404    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1405    Vals.push_back(cast<LoadInst>(I).isVolatile());
1406    if (cast<LoadInst>(I).isAtomic()) {
1407      Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1408      Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1409    }
1410    break;
1411  case Instruction::Store:
1412    if (cast<StoreInst>(I).isAtomic())
1413      Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1414    else
1415      Code = bitc::FUNC_CODE_INST_STORE;
1416    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1417    pushValue(I.getOperand(0), InstID, Vals, VE);         // val.
1418    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1419    Vals.push_back(cast<StoreInst>(I).isVolatile());
1420    if (cast<StoreInst>(I).isAtomic()) {
1421      Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1422      Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1423    }
1424    break;
1425  case Instruction::AtomicCmpXchg:
1426    Code = bitc::FUNC_CODE_INST_CMPXCHG;
1427    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1428    pushValue(I.getOperand(1), InstID, Vals, VE);         // cmp.
1429    pushValue(I.getOperand(2), InstID, Vals, VE);         // newval.
1430    Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1431    Vals.push_back(GetEncodedOrdering(
1432                     cast<AtomicCmpXchgInst>(I).getOrdering()));
1433    Vals.push_back(GetEncodedSynchScope(
1434                     cast<AtomicCmpXchgInst>(I).getSynchScope()));
1435    break;
1436  case Instruction::AtomicRMW:
1437    Code = bitc::FUNC_CODE_INST_ATOMICRMW;
1438    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1439    pushValue(I.getOperand(1), InstID, Vals, VE);         // val.
1440    Vals.push_back(GetEncodedRMWOperation(
1441                     cast<AtomicRMWInst>(I).getOperation()));
1442    Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
1443    Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
1444    Vals.push_back(GetEncodedSynchScope(
1445                     cast<AtomicRMWInst>(I).getSynchScope()));
1446    break;
1447  case Instruction::Fence:
1448    Code = bitc::FUNC_CODE_INST_FENCE;
1449    Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
1450    Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
1451    break;
1452  case Instruction::Call: {
1453    const CallInst &CI = cast<CallInst>(I);
1454    PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1455    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1456
1457    Code = bitc::FUNC_CODE_INST_CALL;
1458
1459    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1460    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1461    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1462
1463    // Emit value #'s for the fixed parameters.
1464    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i) {
1465      // Check for labels (can happen with asm labels).
1466      if (FTy->getParamType(i)->isLabelTy())
1467        Vals.push_back(VE.getValueID(CI.getArgOperand(i)));
1468      else
1469        pushValue(CI.getArgOperand(i), InstID, Vals, VE);  // fixed param.
1470    }
1471
1472    // Emit type/value pairs for varargs params.
1473    if (FTy->isVarArg()) {
1474      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1475           i != e; ++i)
1476        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1477    }
1478    break;
1479  }
1480  case Instruction::VAArg:
1481    Code = bitc::FUNC_CODE_INST_VAARG;
1482    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1483    pushValue(I.getOperand(0), InstID, Vals, VE); // valist.
1484    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1485    break;
1486  }
1487
1488  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1489  Vals.clear();
1490}
1491
1492// Emit names for globals/functions etc.
1493static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1494                                  const ValueEnumerator &VE,
1495                                  BitstreamWriter &Stream) {
1496  if (VST.empty()) return;
1497  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1498
1499  // FIXME: Set up the abbrev, we know how many values there are!
1500  // FIXME: We know if the type names can use 7-bit ascii.
1501  SmallVector<unsigned, 64> NameVals;
1502
1503  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1504       SI != SE; ++SI) {
1505
1506    const ValueName &Name = *SI;
1507
1508    // Figure out the encoding to use for the name.
1509    bool is7Bit = true;
1510    bool isChar6 = true;
1511    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1512         C != E; ++C) {
1513      if (isChar6)
1514        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1515      if ((unsigned char)*C & 128) {
1516        is7Bit = false;
1517        break;  // don't bother scanning the rest.
1518      }
1519    }
1520
1521    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1522
1523    // VST_ENTRY:   [valueid, namechar x N]
1524    // VST_BBENTRY: [bbid, namechar x N]
1525    unsigned Code;
1526    if (isa<BasicBlock>(SI->getValue())) {
1527      Code = bitc::VST_CODE_BBENTRY;
1528      if (isChar6)
1529        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1530    } else {
1531      Code = bitc::VST_CODE_ENTRY;
1532      if (isChar6)
1533        AbbrevToUse = VST_ENTRY_6_ABBREV;
1534      else if (is7Bit)
1535        AbbrevToUse = VST_ENTRY_7_ABBREV;
1536    }
1537
1538    NameVals.push_back(VE.getValueID(SI->getValue()));
1539    for (const char *P = Name.getKeyData(),
1540         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1541      NameVals.push_back((unsigned char)*P);
1542
1543    // Emit the finished record.
1544    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1545    NameVals.clear();
1546  }
1547  Stream.ExitBlock();
1548}
1549
1550/// WriteFunction - Emit a function body to the module stream.
1551static void WriteFunction(const Function &F, ValueEnumerator &VE,
1552                          BitstreamWriter &Stream) {
1553  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1554  VE.incorporateFunction(F);
1555
1556  SmallVector<unsigned, 64> Vals;
1557
1558  // Emit the number of basic blocks, so the reader can create them ahead of
1559  // time.
1560  Vals.push_back(VE.getBasicBlocks().size());
1561  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1562  Vals.clear();
1563
1564  // If there are function-local constants, emit them now.
1565  unsigned CstStart, CstEnd;
1566  VE.getFunctionConstantRange(CstStart, CstEnd);
1567  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1568
1569  // If there is function-local metadata, emit it now.
1570  WriteFunctionLocalMetadata(F, VE, Stream);
1571
1572  // Keep a running idea of what the instruction ID is.
1573  unsigned InstID = CstEnd;
1574
1575  bool NeedsMetadataAttachment = false;
1576
1577  DebugLoc LastDL;
1578
1579  // Finally, emit all the instructions, in order.
1580  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1581    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1582         I != E; ++I) {
1583      WriteInstruction(*I, InstID, VE, Stream, Vals);
1584
1585      if (!I->getType()->isVoidTy())
1586        ++InstID;
1587
1588      // If the instruction has metadata, write a metadata attachment later.
1589      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1590
1591      // If the instruction has a debug location, emit it.
1592      DebugLoc DL = I->getDebugLoc();
1593      if (DL.isUnknown()) {
1594        // nothing todo.
1595      } else if (DL == LastDL) {
1596        // Just repeat the same debug loc as last time.
1597        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1598      } else {
1599        MDNode *Scope, *IA;
1600        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1601
1602        Vals.push_back(DL.getLine());
1603        Vals.push_back(DL.getCol());
1604        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1605        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1606        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1607        Vals.clear();
1608
1609        LastDL = DL;
1610      }
1611    }
1612
1613  // Emit names for all the instructions etc.
1614  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1615
1616  if (NeedsMetadataAttachment)
1617    WriteMetadataAttachment(F, VE, Stream);
1618  VE.purgeFunction();
1619  Stream.ExitBlock();
1620}
1621
1622// Emit blockinfo, which defines the standard abbreviations etc.
1623static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1624  // We only want to emit block info records for blocks that have multiple
1625  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.
1626  // Other blocks can define their abbrevs inline.
1627  Stream.EnterBlockInfoBlock(2);
1628
1629  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1630    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1631    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1632    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1633    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1634    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1635    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1636                                   Abbv) != VST_ENTRY_8_ABBREV)
1637      llvm_unreachable("Unexpected abbrev ordering!");
1638  }
1639
1640  { // 7-bit fixed width VST_ENTRY strings.
1641    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1642    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1643    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1644    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1645    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1646    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1647                                   Abbv) != VST_ENTRY_7_ABBREV)
1648      llvm_unreachable("Unexpected abbrev ordering!");
1649  }
1650  { // 6-bit char6 VST_ENTRY strings.
1651    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1652    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1653    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1654    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1655    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1656    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1657                                   Abbv) != VST_ENTRY_6_ABBREV)
1658      llvm_unreachable("Unexpected abbrev ordering!");
1659  }
1660  { // 6-bit char6 VST_BBENTRY strings.
1661    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1662    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1663    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1664    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1665    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1666    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1667                                   Abbv) != VST_BBENTRY_6_ABBREV)
1668      llvm_unreachable("Unexpected abbrev ordering!");
1669  }
1670
1671
1672
1673  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1674    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1675    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1676    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1677                              Log2_32_Ceil(VE.getTypes().size()+1)));
1678    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1679                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1680      llvm_unreachable("Unexpected abbrev ordering!");
1681  }
1682
1683  { // INTEGER abbrev for CONSTANTS_BLOCK.
1684    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1685    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1686    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1687    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1688                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1689      llvm_unreachable("Unexpected abbrev ordering!");
1690  }
1691
1692  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1693    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1694    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1695    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1696    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1697                              Log2_32_Ceil(VE.getTypes().size()+1)));
1698    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1699
1700    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1701                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1702      llvm_unreachable("Unexpected abbrev ordering!");
1703  }
1704  { // NULL abbrev for CONSTANTS_BLOCK.
1705    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1706    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1707    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1708                                   Abbv) != CONSTANTS_NULL_Abbrev)
1709      llvm_unreachable("Unexpected abbrev ordering!");
1710  }
1711
1712  // FIXME: This should only use space for first class types!
1713
1714  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1715    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1716    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1717    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1718    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1719    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1720    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1721                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1722      llvm_unreachable("Unexpected abbrev ordering!");
1723  }
1724  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1725    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1726    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1727    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1728    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1729    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1730    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1731                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1732      llvm_unreachable("Unexpected abbrev ordering!");
1733  }
1734  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1735    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1736    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1737    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1738    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1739    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1740    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1741    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1742                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1743      llvm_unreachable("Unexpected abbrev ordering!");
1744  }
1745  { // INST_CAST abbrev for FUNCTION_BLOCK.
1746    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1747    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1748    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1749    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1750                              Log2_32_Ceil(VE.getTypes().size()+1)));
1751    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1752    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1753                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1754      llvm_unreachable("Unexpected abbrev ordering!");
1755  }
1756
1757  { // INST_RET abbrev for FUNCTION_BLOCK.
1758    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1759    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1760    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1761                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1762      llvm_unreachable("Unexpected abbrev ordering!");
1763  }
1764  { // INST_RET abbrev for FUNCTION_BLOCK.
1765    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1766    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1767    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1768    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1769                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1770      llvm_unreachable("Unexpected abbrev ordering!");
1771  }
1772  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1773    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1774    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1775    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1776                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1777      llvm_unreachable("Unexpected abbrev ordering!");
1778  }
1779
1780  Stream.ExitBlock();
1781}
1782
1783// Sort the Users based on the order in which the reader parses the bitcode
1784// file.
1785static bool bitcodereader_order(const User *lhs, const User *rhs) {
1786  // TODO: Implement.
1787  return true;
1788}
1789
1790static void WriteUseList(const Value *V, const ValueEnumerator &VE,
1791                         BitstreamWriter &Stream) {
1792
1793  // One or zero uses can't get out of order.
1794  if (V->use_empty() || V->hasNUses(1))
1795    return;
1796
1797  // Make a copy of the in-memory use-list for sorting.
1798  unsigned UseListSize = std::distance(V->use_begin(), V->use_end());
1799  SmallVector<const User*, 8> UseList;
1800  UseList.reserve(UseListSize);
1801  for (Value::const_use_iterator I = V->use_begin(), E = V->use_end();
1802       I != E; ++I) {
1803    const User *U = *I;
1804    UseList.push_back(U);
1805  }
1806
1807  // Sort the copy based on the order read by the BitcodeReader.
1808  std::sort(UseList.begin(), UseList.end(), bitcodereader_order);
1809
1810  // TODO: Generate a diff between the BitcodeWriter in-memory use-list and the
1811  // sorted list (i.e., the expected BitcodeReader in-memory use-list).
1812
1813  // TODO: Emit the USELIST_CODE_ENTRYs.
1814}
1815
1816static void WriteFunctionUseList(const Function *F, ValueEnumerator &VE,
1817                                 BitstreamWriter &Stream) {
1818  VE.incorporateFunction(*F);
1819
1820  for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
1821       AI != AE; ++AI)
1822    WriteUseList(AI, VE, Stream);
1823  for (Function::const_iterator BB = F->begin(), FE = F->end(); BB != FE;
1824       ++BB) {
1825    WriteUseList(BB, VE, Stream);
1826    for (BasicBlock::const_iterator II = BB->begin(), IE = BB->end(); II != IE;
1827         ++II) {
1828      WriteUseList(II, VE, Stream);
1829      for (User::const_op_iterator OI = II->op_begin(), E = II->op_end();
1830           OI != E; ++OI) {
1831        if ((isa<Constant>(*OI) && !isa<GlobalValue>(*OI)) ||
1832            isa<InlineAsm>(*OI))
1833          WriteUseList(*OI, VE, Stream);
1834      }
1835    }
1836  }
1837  VE.purgeFunction();
1838}
1839
1840// Emit use-lists.
1841static void WriteModuleUseLists(const Module *M, ValueEnumerator &VE,
1842                                BitstreamWriter &Stream) {
1843  Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
1844
1845  // XXX: this modifies the module, but in a way that should never change the
1846  // behavior of any pass or codegen in LLVM. The problem is that GVs may
1847  // contain entries in the use_list that do not exist in the Module and are
1848  // not stored in the .bc file.
1849  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
1850       I != E; ++I)
1851    I->removeDeadConstantUsers();
1852
1853  // Write the global variables.
1854  for (Module::const_global_iterator GI = M->global_begin(),
1855         GE = M->global_end(); GI != GE; ++GI) {
1856    WriteUseList(GI, VE, Stream);
1857
1858    // Write the global variable initializers.
1859    if (GI->hasInitializer())
1860      WriteUseList(GI->getInitializer(), VE, Stream);
1861  }
1862
1863  // Write the functions.
1864  for (Module::const_iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI) {
1865    WriteUseList(FI, VE, Stream);
1866    if (!FI->isDeclaration())
1867      WriteFunctionUseList(FI, VE, Stream);
1868    if (FI->hasPrefixData())
1869      WriteUseList(FI->getPrefixData(), VE, Stream);
1870  }
1871
1872  // Write the aliases.
1873  for (Module::const_alias_iterator AI = M->alias_begin(), AE = M->alias_end();
1874       AI != AE; ++AI) {
1875    WriteUseList(AI, VE, Stream);
1876    WriteUseList(AI->getAliasee(), VE, Stream);
1877  }
1878
1879  Stream.ExitBlock();
1880}
1881
1882/// WriteModule - Emit the specified module to the bitstream.
1883static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1884  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1885
1886  SmallVector<unsigned, 1> Vals;
1887  unsigned CurVersion = 1;
1888  Vals.push_back(CurVersion);
1889  Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1890
1891  // Analyze the module, enumerating globals, functions, etc.
1892  ValueEnumerator VE(M);
1893
1894  // Emit blockinfo, which defines the standard abbreviations etc.
1895  WriteBlockInfo(VE, Stream);
1896
1897  // Emit information about attribute groups.
1898  WriteAttributeGroupTable(VE, Stream);
1899
1900  // Emit information about parameter attributes.
1901  WriteAttributeTable(VE, Stream);
1902
1903  // Emit information describing all of the types in the module.
1904  WriteTypeTable(VE, Stream);
1905
1906  // Emit top-level description of module, including target triple, inline asm,
1907  // descriptors for global variables, and function prototype info.
1908  WriteModuleInfo(M, VE, Stream);
1909
1910  // Emit constants.
1911  WriteModuleConstants(VE, Stream);
1912
1913  // Emit metadata.
1914  WriteModuleMetadata(M, VE, Stream);
1915
1916  // Emit metadata.
1917  WriteModuleMetadataStore(M, Stream);
1918
1919  // Emit names for globals/functions etc.
1920  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1921
1922  // Emit use-lists.
1923  if (EnablePreserveUseListOrdering)
1924    WriteModuleUseLists(M, VE, Stream);
1925
1926  // Emit function bodies.
1927  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1928    if (!F->isDeclaration())
1929      WriteFunction(*F, VE, Stream);
1930
1931  Stream.ExitBlock();
1932}
1933
1934/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1935/// header and trailer to make it compatible with the system archiver.  To do
1936/// this we emit the following header, and then emit a trailer that pads the
1937/// file out to be a multiple of 16 bytes.
1938///
1939/// struct bc_header {
1940///   uint32_t Magic;         // 0x0B17C0DE
1941///   uint32_t Version;       // Version, currently always 0.
1942///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1943///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1944///   uint32_t CPUType;       // CPU specifier.
1945///   ... potentially more later ...
1946/// };
1947enum {
1948  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1949  DarwinBCHeaderSize = 5*4
1950};
1951
1952static void WriteInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
1953                               uint32_t &Position) {
1954  Buffer[Position + 0] = (unsigned char) (Value >>  0);
1955  Buffer[Position + 1] = (unsigned char) (Value >>  8);
1956  Buffer[Position + 2] = (unsigned char) (Value >> 16);
1957  Buffer[Position + 3] = (unsigned char) (Value >> 24);
1958  Position += 4;
1959}
1960
1961static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
1962                                         const Triple &TT) {
1963  unsigned CPUType = ~0U;
1964
1965  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1966  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1967  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1968  // specific constants here because they are implicitly part of the Darwin ABI.
1969  enum {
1970    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1971    DARWIN_CPU_TYPE_X86        = 7,
1972    DARWIN_CPU_TYPE_ARM        = 12,
1973    DARWIN_CPU_TYPE_POWERPC    = 18
1974  };
1975
1976  Triple::ArchType Arch = TT.getArch();
1977  if (Arch == Triple::x86_64)
1978    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1979  else if (Arch == Triple::x86)
1980    CPUType = DARWIN_CPU_TYPE_X86;
1981  else if (Arch == Triple::ppc)
1982    CPUType = DARWIN_CPU_TYPE_POWERPC;
1983  else if (Arch == Triple::ppc64)
1984    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1985  else if (Arch == Triple::arm || Arch == Triple::thumb)
1986    CPUType = DARWIN_CPU_TYPE_ARM;
1987
1988  // Traditional Bitcode starts after header.
1989  assert(Buffer.size() >= DarwinBCHeaderSize &&
1990         "Expected header size to be reserved");
1991  unsigned BCOffset = DarwinBCHeaderSize;
1992  unsigned BCSize = Buffer.size()-DarwinBCHeaderSize;
1993
1994  // Write the magic and version.
1995  unsigned Position = 0;
1996  WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position);
1997  WriteInt32ToBuffer(0          , Buffer, Position); // Version.
1998  WriteInt32ToBuffer(BCOffset   , Buffer, Position);
1999  WriteInt32ToBuffer(BCSize     , Buffer, Position);
2000  WriteInt32ToBuffer(CPUType    , Buffer, Position);
2001
2002  // If the file is not a multiple of 16 bytes, insert dummy padding.
2003  while (Buffer.size() & 15)
2004    Buffer.push_back(0);
2005}
2006
2007/// WriteBitcodeToFile - Write the specified module to the specified output
2008/// stream.
2009void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
2010  SmallVector<char, 0> Buffer;
2011  Buffer.reserve(256*1024);
2012
2013  // If this is darwin or another generic macho target, reserve space for the
2014  // header.
2015  Triple TT(M->getTargetTriple());
2016  if (TT.isOSDarwin())
2017    Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0);
2018
2019  // Emit the module into the buffer.
2020  {
2021    BitstreamWriter Stream(Buffer);
2022
2023    // Emit the file header.
2024    Stream.Emit((unsigned)'B', 8);
2025    Stream.Emit((unsigned)'C', 8);
2026    Stream.Emit(0x0, 4);
2027    Stream.Emit(0xC, 4);
2028    Stream.Emit(0xE, 4);
2029    Stream.Emit(0xD, 4);
2030
2031    // Emit the module.
2032    WriteModule(M, Stream);
2033  }
2034
2035  if (TT.isOSDarwin())
2036    EmitDarwinBCHeaderAndTrailer(Buffer, TT);
2037
2038  // Write the generated bitstream to "Out".
2039  Out.write((char*)&Buffer.front(), Buffer.size());
2040}
2041