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