BitcodeWriter.cpp revision 8ec3bc862ac51f49e06bc465a6eb51871ce9d5da 
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 "ReaderWriter_2_9.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/ErrorHandling.h"
27#include "llvm/Support/MathExtras.h"
28#include "llvm/Support/raw_ostream.h"
29#include "llvm/Support/Program.h"
30#include <cctype>
31#include <map>
32using namespace llvm;
33
34// Redefine older bitcode opcodes for use here. Note that these come from
35// LLVM 2.7 (which is what HC shipped with).
36#define METADATA_NODE_2_7             2
37#define METADATA_FN_NODE_2_7          3
38#define METADATA_NAMED_NODE_2_7       5
39#define METADATA_ATTACHMENT_2_7       7
40#define FUNC_CODE_INST_CALL_2_7       22
41#define FUNC_CODE_DEBUG_LOC_2_7       32
42
43/// These are manifest constants used by the bitcode writer. They do not need to
44/// be kept in sync with the reader, but need to be consistent within this file.
45enum {
46  CurVersion = 0,
47
48  // VALUE_SYMTAB_BLOCK abbrev id's.
49  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
50  VST_ENTRY_7_ABBREV,
51  VST_ENTRY_6_ABBREV,
52  VST_BBENTRY_6_ABBREV,
53
54  // CONSTANTS_BLOCK abbrev id's.
55  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
56  CONSTANTS_INTEGER_ABBREV,
57  CONSTANTS_CE_CAST_Abbrev,
58  CONSTANTS_NULL_Abbrev,
59
60  // FUNCTION_BLOCK abbrev id's.
61  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
62  FUNCTION_INST_BINOP_ABBREV,
63  FUNCTION_INST_BINOP_FLAGS_ABBREV,
64  FUNCTION_INST_CAST_ABBREV,
65  FUNCTION_INST_RET_VOID_ABBREV,
66  FUNCTION_INST_RET_VAL_ABBREV,
67  FUNCTION_INST_UNREACHABLE_ABBREV
68};
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 void WriteStringRecord(unsigned Code, StringRef Str,
114                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
115  SmallVector<unsigned, 64> Vals;
116
117  // Code: [strchar x N]
118  for (unsigned i = 0, e = Str.size(); i != e; ++i) {
119    if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
120      AbbrevToUse = 0;
121    Vals.push_back(Str[i]);
122  }
123
124  // Emit the finished record.
125  Stream.EmitRecord(Code, Vals, AbbrevToUse);
126}
127
128// Emit information about parameter attributes.
129static void WriteAttributeTable(const ValueEnumerator &VE,
130                                BitstreamWriter &Stream) {
131  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
132  if (Attrs.empty()) return;
133
134  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
135
136  SmallVector<uint64_t, 64> Record;
137  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
138    const AttrListPtr &A = Attrs[i];
139    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
140      const AttributeWithIndex &PAWI = A.getSlot(i);
141      Record.push_back(PAWI.Index);
142
143      // FIXME: remove in LLVM 3.0
144      // Store the alignment in the bitcode as a 16-bit raw value instead of a
145      // 5-bit log2 encoded value. Shift the bits above the alignment up by
146      // 11 bits.
147      uint64_t FauxAttr = PAWI.Attrs & 0xffff;
148      if (PAWI.Attrs & Attribute::Alignment)
149        FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
150      FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
151
152      Record.push_back(FauxAttr);
153    }
154
155    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
156    Record.clear();
157  }
158
159  Stream.ExitBlock();
160}
161
162static void WriteTypeSymbolTable(const ValueEnumerator &VE,
163                                 BitstreamWriter &Stream) {
164  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
165  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID_OLD, 3);
166
167  // 7-bit fixed width VST_CODE_ENTRY strings.
168  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
169  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
170  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
171                            Log2_32_Ceil(VE.getTypes().size()+1)));
172  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
173  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
174  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
175
176  SmallVector<unsigned, 64> NameVals;
177
178  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
179    Type *T = TypeList[i];
180
181    switch (T->getTypeID()) {
182    case Type::StructTyID: {
183      StructType *ST = cast<StructType>(T);
184      if (ST->isLiteral()) {
185        // Skip anonymous struct definitions in type symbol table
186        // FIXME(srhines)
187        break;
188      }
189
190      // TST_ENTRY: [typeid, namechar x N]
191      NameVals.push_back(i);
192
193      const std::string &Str = ST->getName();
194      bool is7Bit = true;
195      for (unsigned i = 0, e = Str.size(); i != e; ++i) {
196        NameVals.push_back((unsigned char)Str[i]);
197        if (Str[i] & 128)
198          is7Bit = false;
199      }
200
201      // Emit the finished record.
202      Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
203      NameVals.clear();
204
205      break;
206    }
207    default: break;
208    }
209  }
210
211#if 0
212  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
213       TI != TE; ++TI) {
214    // TST_ENTRY: [typeid, namechar x N]
215    NameVals.push_back(VE.getTypeID(TI->second));
216
217    const std::string &Str = TI->first;
218    bool is7Bit = true;
219    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
220      NameVals.push_back((unsigned char)Str[i]);
221      if (Str[i] & 128)
222        is7Bit = false;
223    }
224
225    // Emit the finished record.
226    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
227    NameVals.clear();
228  }
229#endif
230
231  Stream.ExitBlock();
232}
233
234/// WriteTypeTable - Write out the type table for a module.
235static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
236  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
237
238  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_OLD, 4 /*count from # abbrevs */);
239  SmallVector<uint64_t, 64> TypeVals;
240
241  // Abbrev for TYPE_CODE_POINTER.
242  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
243  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
244  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
245                            Log2_32_Ceil(VE.getTypes().size()+1)));
246  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
247  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
248
249  // Abbrev for TYPE_CODE_FUNCTION.
250  Abbv = new BitCodeAbbrev();
251  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION_OLD));
252  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
253  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
254  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
255  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
256                            Log2_32_Ceil(VE.getTypes().size()+1)));
257  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
258
259#if 0
260  // Abbrev for TYPE_CODE_STRUCT_ANON.
261  Abbv = new BitCodeAbbrev();
262  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
263  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
264  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
265  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
266                            Log2_32_Ceil(VE.getTypes().size()+1)));
267  unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
268
269  // Abbrev for TYPE_CODE_STRUCT_NAME.
270  Abbv = new BitCodeAbbrev();
271  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
272  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
273  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
274  unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
275
276  // Abbrev for TYPE_CODE_STRUCT_NAMED.
277  Abbv = new BitCodeAbbrev();
278  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
279  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
280  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
281  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
282                            Log2_32_Ceil(VE.getTypes().size()+1)));
283  unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
284#endif
285
286  // Abbrev for TYPE_CODE_STRUCT.
287  Abbv = new BitCodeAbbrev();
288  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_OLD));
289  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
290  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
291  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
292                            Log2_32_Ceil(VE.getTypes().size()+1)));
293  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
294
295  // Abbrev for TYPE_CODE_ARRAY.
296  Abbv = new BitCodeAbbrev();
297  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
298  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
299  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
300                            Log2_32_Ceil(VE.getTypes().size()+1)));
301  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
302
303  // Emit an entry count so the reader can reserve space.
304  TypeVals.push_back(TypeList.size());
305  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
306  TypeVals.clear();
307
308  // Loop over all of the types, emitting each in turn.
309  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
310    Type *T = TypeList[i];
311    int AbbrevToUse = 0;
312    unsigned Code = 0;
313
314    switch (T->getTypeID()) {
315    default: llvm_unreachable("Unknown type!");
316    case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;   break;
317    case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;  break;
318    case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE; break;
319    case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80; break;
320    case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128; break;
321    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
322    case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;  break;
323    case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA; break;
324    case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX; break;
325    case Type::IntegerTyID:
326      // INTEGER: [width]
327      Code = bitc::TYPE_CODE_INTEGER;
328      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
329      break;
330    case Type::PointerTyID: {
331      PointerType *PTy = cast<PointerType>(T);
332      // POINTER: [pointee type, address space]
333      Code = bitc::TYPE_CODE_POINTER;
334      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
335      unsigned AddressSpace = PTy->getAddressSpace();
336      TypeVals.push_back(AddressSpace);
337      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
338      break;
339    }
340    case Type::FunctionTyID: {
341      FunctionType *FT = cast<FunctionType>(T);
342      // FUNCTION: [isvararg, attrid, retty, paramty x N]
343      Code = bitc::TYPE_CODE_FUNCTION_OLD;
344      TypeVals.push_back(FT->isVarArg());
345      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
346      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
347      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
348        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
349      AbbrevToUse = FunctionAbbrev;
350      break;
351    }
352    case Type::StructTyID: {
353      StructType *ST = cast<StructType>(T);
354      // STRUCT: [ispacked, eltty x N]
355      TypeVals.push_back(ST->isPacked());
356      // Output all of the element types.
357      for (StructType::element_iterator I = ST->element_begin(),
358           E = ST->element_end(); I != E; ++I)
359        TypeVals.push_back(VE.getTypeID(*I));
360      AbbrevToUse = StructAbbrev;
361      break;
362    }
363    case Type::ArrayTyID: {
364      ArrayType *AT = cast<ArrayType>(T);
365      // ARRAY: [numelts, eltty]
366      Code = bitc::TYPE_CODE_ARRAY;
367      TypeVals.push_back(AT->getNumElements());
368      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
369      AbbrevToUse = ArrayAbbrev;
370      break;
371    }
372    case Type::VectorTyID: {
373      VectorType *VT = cast<VectorType>(T);
374      // VECTOR [numelts, eltty]
375      Code = bitc::TYPE_CODE_VECTOR;
376      TypeVals.push_back(VT->getNumElements());
377      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
378      break;
379    }
380    }
381
382    // Emit the finished record.
383    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
384    TypeVals.clear();
385  }
386
387  Stream.ExitBlock();
388
389  WriteTypeSymbolTable(VE, Stream);
390}
391
392static unsigned getEncodedLinkage(const GlobalValue *GV) {
393  switch (GV->getLinkage()) {
394  default: llvm_unreachable("Invalid linkage!");
395  case GlobalValue::ExternalLinkage:                 return 0;
396  case GlobalValue::WeakAnyLinkage:                  return 1;
397  case GlobalValue::AppendingLinkage:                return 2;
398  case GlobalValue::InternalLinkage:                 return 3;
399  case GlobalValue::LinkOnceAnyLinkage:              return 4;
400  case GlobalValue::DLLImportLinkage:                return 5;
401  case GlobalValue::DLLExportLinkage:                return 6;
402  case GlobalValue::ExternalWeakLinkage:             return 7;
403  case GlobalValue::CommonLinkage:                   return 8;
404  case GlobalValue::PrivateLinkage:                  return 9;
405  case GlobalValue::WeakODRLinkage:                  return 10;
406  case GlobalValue::LinkOnceODRLinkage:              return 11;
407  case GlobalValue::AvailableExternallyLinkage:      return 12;
408  case GlobalValue::LinkerPrivateLinkage:            return 13;
409  case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
410  case GlobalValue::LinkerPrivateWeakDefAutoLinkage: return 15;
411  }
412}
413
414static unsigned getEncodedVisibility(const GlobalValue *GV) {
415  switch (GV->getVisibility()) {
416  default: llvm_unreachable("Invalid visibility!");
417  case GlobalValue::DefaultVisibility:   return 0;
418  case GlobalValue::HiddenVisibility:    return 1;
419  case GlobalValue::ProtectedVisibility: return 2;
420  }
421}
422
423// Emit top-level description of module, including target triple, inline asm,
424// descriptors for global variables, and function prototype info.
425static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
426                            BitstreamWriter &Stream) {
427  // Emit the list of dependent libraries for the Module.
428  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
429    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
430
431  // Emit various pieces of data attached to a module.
432  if (!M->getTargetTriple().empty())
433    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
434                      0/*TODO*/, Stream);
435  if (!M->getDataLayout().empty())
436    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
437                      0/*TODO*/, Stream);
438  if (!M->getModuleInlineAsm().empty())
439    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
440                      0/*TODO*/, Stream);
441
442  // Emit information about sections and GC, computing how many there are. Also
443  // compute the maximum alignment value.
444  std::map<std::string, unsigned> SectionMap;
445  std::map<std::string, unsigned> GCMap;
446  unsigned MaxAlignment = 0;
447  unsigned MaxGlobalType = 0;
448  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
449       GV != E; ++GV) {
450    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
451    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
452
453    if (!GV->hasSection()) continue;
454    // Give section names unique ID's.
455    unsigned &Entry = SectionMap[GV->getSection()];
456    if (Entry != 0) continue;
457    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
458                      0/*TODO*/, Stream);
459    Entry = SectionMap.size();
460  }
461  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
462    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
463    if (F->hasSection()) {
464      // Give section names unique ID's.
465      unsigned &Entry = SectionMap[F->getSection()];
466      if (!Entry) {
467        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
468                          0/*TODO*/, Stream);
469        Entry = SectionMap.size();
470      }
471    }
472    if (F->hasGC()) {
473      // Same for GC names.
474      unsigned &Entry = GCMap[F->getGC()];
475      if (!Entry) {
476        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
477                          0/*TODO*/, Stream);
478        Entry = GCMap.size();
479      }
480    }
481  }
482
483  // Emit abbrev for globals, now that we know # sections and max alignment.
484  unsigned SimpleGVarAbbrev = 0;
485  if (!M->global_empty()) {
486    // Add an abbrev for common globals with no visibility or thread localness.
487    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
488    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
489    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
490                              Log2_32_Ceil(MaxGlobalType+1)));
491    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
492    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
493    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
494    if (MaxAlignment == 0)                                      // Alignment.
495      Abbv->Add(BitCodeAbbrevOp(0));
496    else {
497      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
498      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
499                               Log2_32_Ceil(MaxEncAlignment+1)));
500    }
501    if (SectionMap.empty())                                    // Section.
502      Abbv->Add(BitCodeAbbrevOp(0));
503    else
504      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
505                               Log2_32_Ceil(SectionMap.size()+1)));
506    // Don't bother emitting vis + thread local.
507    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
508  }
509
510  // Emit the global variable information.
511  SmallVector<unsigned, 64> Vals;
512  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
513       GV != E; ++GV) {
514    unsigned AbbrevToUse = 0;
515
516    // GLOBALVAR: [type, isconst, initid,
517    //             linkage, alignment, section, visibility, threadlocal,
518    //             unnamed_addr]
519    Vals.push_back(VE.getTypeID(GV->getType()));
520    Vals.push_back(GV->isConstant());
521    Vals.push_back(GV->isDeclaration() ? 0 :
522                   (VE.getValueID(GV->getInitializer()) + 1));
523    Vals.push_back(getEncodedLinkage(GV));
524    Vals.push_back(Log2_32(GV->getAlignment())+1);
525    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
526    if (GV->isThreadLocal() ||
527        GV->getVisibility() != GlobalValue::DefaultVisibility ||
528        GV->hasUnnamedAddr()) {
529      Vals.push_back(getEncodedVisibility(GV));
530      Vals.push_back(GV->isThreadLocal());
531      Vals.push_back(GV->hasUnnamedAddr());
532    } else {
533      AbbrevToUse = SimpleGVarAbbrev;
534    }
535
536    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
537    Vals.clear();
538  }
539
540  // Emit the function proto information.
541  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
542    // FUNCTION:  [type, callingconv, isproto, paramattr,
543    //             linkage, alignment, section, visibility, gc, unnamed_addr]
544    Vals.push_back(VE.getTypeID(F->getType()));
545    Vals.push_back(F->getCallingConv());
546    Vals.push_back(F->isDeclaration());
547    Vals.push_back(getEncodedLinkage(F));
548    Vals.push_back(VE.getAttributeID(F->getAttributes()));
549    Vals.push_back(Log2_32(F->getAlignment())+1);
550    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
551    Vals.push_back(getEncodedVisibility(F));
552    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
553    Vals.push_back(F->hasUnnamedAddr());
554
555    unsigned AbbrevToUse = 0;
556    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
557    Vals.clear();
558  }
559
560  // Emit the alias information.
561  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
562       AI != E; ++AI) {
563    Vals.push_back(VE.getTypeID(AI->getType()));
564    Vals.push_back(VE.getValueID(AI->getAliasee()));
565    Vals.push_back(getEncodedLinkage(AI));
566    Vals.push_back(getEncodedVisibility(AI));
567    unsigned AbbrevToUse = 0;
568    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
569    Vals.clear();
570  }
571}
572
573static uint64_t GetOptimizationFlags(const Value *V) {
574  uint64_t Flags = 0;
575
576  if (const OverflowingBinaryOperator *OBO =
577        dyn_cast<OverflowingBinaryOperator>(V)) {
578    if (OBO->hasNoSignedWrap())
579      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
580    if (OBO->hasNoUnsignedWrap())
581      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
582  } else if (const PossiblyExactOperator *PEO =
583               dyn_cast<PossiblyExactOperator>(V)) {
584    if (PEO->isExact())
585      Flags |= 1 << bitc::PEO_EXACT;
586  }
587
588  return Flags;
589}
590
591static void WriteMDNode(const MDNode *N,
592                        const ValueEnumerator &VE,
593                        BitstreamWriter &Stream,
594                        SmallVector<uint64_t, 64> &Record) {
595  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
596    if (N->getOperand(i)) {
597      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
598      Record.push_back(VE.getValueID(N->getOperand(i)));
599    } else {
600      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
601      Record.push_back(0);
602    }
603  }
604  unsigned MDCode = N->isFunctionLocal() ? METADATA_FN_NODE_2_7 :
605                                           METADATA_NODE_2_7;
606  Stream.EmitRecord(MDCode, Record, 0);
607  Record.clear();
608}
609
610static void WriteModuleMetadata(const Module *M,
611                                const ValueEnumerator &VE,
612                                BitstreamWriter &Stream) {
613  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
614  bool StartedMetadataBlock = false;
615  unsigned MDSAbbrev = 0;
616  SmallVector<uint64_t, 64> Record;
617  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
618
619    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
620      if (!N->isFunctionLocal() || !N->getFunction()) {
621        if (!StartedMetadataBlock) {
622          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
623          StartedMetadataBlock = true;
624        }
625        WriteMDNode(N, VE, Stream, Record);
626      }
627    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
628      if (!StartedMetadataBlock)  {
629        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
630
631        // Abbrev for METADATA_STRING.
632        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
633        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
634        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
635        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
636        MDSAbbrev = Stream.EmitAbbrev(Abbv);
637        StartedMetadataBlock = true;
638      }
639
640      // Code: [strchar x N]
641      Record.append(MDS->begin(), MDS->end());
642
643      // Emit the finished record.
644      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
645      Record.clear();
646    }
647  }
648
649  // Write named metadata.
650  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
651       E = M->named_metadata_end(); I != E; ++I) {
652    const NamedMDNode *NMD = I;
653    if (!StartedMetadataBlock)  {
654      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
655      StartedMetadataBlock = true;
656    }
657
658    // Write name.
659    StringRef Str = NMD->getName();
660    for (unsigned i = 0, e = Str.size(); i != e; ++i)
661      Record.push_back(Str[i]);
662    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
663    Record.clear();
664
665    // Write named metadata operands.
666    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
667      Record.push_back(VE.getValueID(NMD->getOperand(i)));
668    Stream.EmitRecord(METADATA_NAMED_NODE_2_7, Record, 0);
669    Record.clear();
670  }
671
672  if (StartedMetadataBlock)
673    Stream.ExitBlock();
674}
675
676static void WriteFunctionLocalMetadata(const Function &F,
677                                       const ValueEnumerator &VE,
678                                       BitstreamWriter &Stream) {
679  bool StartedMetadataBlock = false;
680  SmallVector<uint64_t, 64> Record;
681  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
682  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
683    if (const MDNode *N = Vals[i])
684      if (N->isFunctionLocal() && N->getFunction() == &F) {
685        if (!StartedMetadataBlock) {
686          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
687          StartedMetadataBlock = true;
688        }
689        WriteMDNode(N, VE, Stream, Record);
690      }
691
692  if (StartedMetadataBlock)
693    Stream.ExitBlock();
694}
695
696static void WriteMetadataAttachment(const Function &F,
697                                    const ValueEnumerator &VE,
698                                    BitstreamWriter &Stream) {
699  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
700
701  SmallVector<uint64_t, 64> Record;
702
703  // Write metadata attachments
704  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
705  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
706
707  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
708    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
709         I != E; ++I) {
710      MDs.clear();
711      I->getAllMetadataOtherThanDebugLoc(MDs);
712
713      // If no metadata, ignore instruction.
714      if (MDs.empty()) continue;
715
716      Record.push_back(VE.getInstructionID(I));
717
718      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
719        Record.push_back(MDs[i].first);
720        Record.push_back(VE.getValueID(MDs[i].second));
721      }
722      Stream.EmitRecord(METADATA_ATTACHMENT_2_7, Record, 0);
723      Record.clear();
724    }
725
726  Stream.ExitBlock();
727}
728
729static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
730  SmallVector<uint64_t, 64> Record;
731
732  // Write metadata kinds
733  // METADATA_KIND - [n x [id, name]]
734  SmallVector<StringRef, 4> Names;
735  M->getMDKindNames(Names);
736
737  if (Names.empty()) return;
738
739  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
740
741  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
742    Record.push_back(MDKindID);
743    StringRef KName = Names[MDKindID];
744    Record.append(KName.begin(), KName.end());
745
746    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
747    Record.clear();
748  }
749
750  Stream.ExitBlock();
751}
752
753static void WriteConstants(unsigned FirstVal, unsigned LastVal,
754                           const ValueEnumerator &VE,
755                           BitstreamWriter &Stream, bool isGlobal) {
756  if (FirstVal == LastVal) return;
757
758  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
759
760  unsigned AggregateAbbrev = 0;
761  unsigned String8Abbrev = 0;
762  unsigned CString7Abbrev = 0;
763  unsigned CString6Abbrev = 0;
764  // If this is a constant pool for the module, emit module-specific abbrevs.
765  if (isGlobal) {
766    // Abbrev for CST_CODE_AGGREGATE.
767    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
768    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
769    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
770    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
771    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
772
773    // Abbrev for CST_CODE_STRING.
774    Abbv = new BitCodeAbbrev();
775    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
776    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
777    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
778    String8Abbrev = Stream.EmitAbbrev(Abbv);
779    // Abbrev for CST_CODE_CSTRING.
780    Abbv = new BitCodeAbbrev();
781    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
782    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
783    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
784    CString7Abbrev = Stream.EmitAbbrev(Abbv);
785    // Abbrev for CST_CODE_CSTRING.
786    Abbv = new BitCodeAbbrev();
787    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
788    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
789    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
790    CString6Abbrev = Stream.EmitAbbrev(Abbv);
791  }
792
793  SmallVector<uint64_t, 64> Record;
794
795  const ValueEnumerator::ValueList &Vals = VE.getValues();
796  Type *LastTy = 0;
797  for (unsigned i = FirstVal; i != LastVal; ++i) {
798    const Value *V = Vals[i].first;
799    // If we need to switch types, do so now.
800    if (V->getType() != LastTy) {
801      LastTy = V->getType();
802      Record.push_back(VE.getTypeID(LastTy));
803      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
804                        CONSTANTS_SETTYPE_ABBREV);
805      Record.clear();
806    }
807
808    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
809      Record.push_back(unsigned(IA->hasSideEffects()) |
810                       unsigned(IA->isAlignStack()) << 1);
811
812      // Add the asm string.
813      const std::string &AsmStr = IA->getAsmString();
814      Record.push_back(AsmStr.size());
815      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
816        Record.push_back(AsmStr[i]);
817
818      // Add the constraint string.
819      const std::string &ConstraintStr = IA->getConstraintString();
820      Record.push_back(ConstraintStr.size());
821      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
822        Record.push_back(ConstraintStr[i]);
823      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
824      Record.clear();
825      continue;
826    }
827    const Constant *C = cast<Constant>(V);
828    unsigned Code = -1U;
829    unsigned AbbrevToUse = 0;
830    if (C->isNullValue()) {
831      Code = bitc::CST_CODE_NULL;
832    } else if (isa<UndefValue>(C)) {
833      Code = bitc::CST_CODE_UNDEF;
834    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
835      if (IV->getBitWidth() <= 64) {
836        uint64_t V = IV->getSExtValue();
837        if ((int64_t)V >= 0)
838          Record.push_back(V << 1);
839        else
840          Record.push_back((-V << 1) | 1);
841        Code = bitc::CST_CODE_INTEGER;
842        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
843      } else {                             // Wide integers, > 64 bits in size.
844        // We have an arbitrary precision integer value to write whose
845        // bit width is > 64. However, in canonical unsigned integer
846        // format it is likely that the high bits are going to be zero.
847        // So, we only write the number of active words.
848        unsigned NWords = IV->getValue().getActiveWords();
849        const uint64_t *RawWords = IV->getValue().getRawData();
850        for (unsigned i = 0; i != NWords; ++i) {
851          int64_t V = RawWords[i];
852          if (V >= 0)
853            Record.push_back(V << 1);
854          else
855            Record.push_back((-V << 1) | 1);
856        }
857        Code = bitc::CST_CODE_WIDE_INTEGER;
858      }
859    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
860      Code = bitc::CST_CODE_FLOAT;
861      Type *Ty = CFP->getType();
862      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
863        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
864      } else if (Ty->isX86_FP80Ty()) {
865        // api needed to prevent premature destruction
866        // bits are not in the same order as a normal i80 APInt, compensate.
867        APInt api = CFP->getValueAPF().bitcastToAPInt();
868        const uint64_t *p = api.getRawData();
869        Record.push_back((p[1] << 48) | (p[0] >> 16));
870        Record.push_back(p[0] & 0xffffLL);
871      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
872        APInt api = CFP->getValueAPF().bitcastToAPInt();
873        const uint64_t *p = api.getRawData();
874        Record.push_back(p[0]);
875        Record.push_back(p[1]);
876      } else {
877        assert (0 && "Unknown FP type!");
878      }
879    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
880      const ConstantArray *CA = cast<ConstantArray>(C);
881      // Emit constant strings specially.
882      unsigned NumOps = CA->getNumOperands();
883      // If this is a null-terminated string, use the denser CSTRING encoding.
884      if (CA->getOperand(NumOps-1)->isNullValue()) {
885        Code = bitc::CST_CODE_CSTRING;
886        --NumOps;  // Don't encode the null, which isn't allowed by char6.
887      } else {
888        Code = bitc::CST_CODE_STRING;
889        AbbrevToUse = String8Abbrev;
890      }
891      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
892      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
893      for (unsigned i = 0; i != NumOps; ++i) {
894        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
895        Record.push_back(V);
896        isCStr7 &= (V & 128) == 0;
897        if (isCStrChar6)
898          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
899      }
900
901      if (isCStrChar6)
902        AbbrevToUse = CString6Abbrev;
903      else if (isCStr7)
904        AbbrevToUse = CString7Abbrev;
905    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
906               isa<ConstantVector>(V)) {
907      Code = bitc::CST_CODE_AGGREGATE;
908      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
909        Record.push_back(VE.getValueID(C->getOperand(i)));
910      AbbrevToUse = AggregateAbbrev;
911    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
912      switch (CE->getOpcode()) {
913      default:
914        if (Instruction::isCast(CE->getOpcode())) {
915          Code = bitc::CST_CODE_CE_CAST;
916          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
917          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
918          Record.push_back(VE.getValueID(C->getOperand(0)));
919          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
920        } else {
921          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
922          Code = bitc::CST_CODE_CE_BINOP;
923          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
924          Record.push_back(VE.getValueID(C->getOperand(0)));
925          Record.push_back(VE.getValueID(C->getOperand(1)));
926          uint64_t Flags = GetOptimizationFlags(CE);
927          if (Flags != 0)
928            Record.push_back(Flags);
929        }
930        break;
931      case Instruction::GetElementPtr:
932        Code = bitc::CST_CODE_CE_GEP;
933        if (cast<GEPOperator>(C)->isInBounds())
934          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
935        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
936          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
937          Record.push_back(VE.getValueID(C->getOperand(i)));
938        }
939        break;
940      case Instruction::Select:
941        Code = bitc::CST_CODE_CE_SELECT;
942        Record.push_back(VE.getValueID(C->getOperand(0)));
943        Record.push_back(VE.getValueID(C->getOperand(1)));
944        Record.push_back(VE.getValueID(C->getOperand(2)));
945        break;
946      case Instruction::ExtractElement:
947        Code = bitc::CST_CODE_CE_EXTRACTELT;
948        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
949        Record.push_back(VE.getValueID(C->getOperand(0)));
950        Record.push_back(VE.getValueID(C->getOperand(1)));
951        break;
952      case Instruction::InsertElement:
953        Code = bitc::CST_CODE_CE_INSERTELT;
954        Record.push_back(VE.getValueID(C->getOperand(0)));
955        Record.push_back(VE.getValueID(C->getOperand(1)));
956        Record.push_back(VE.getValueID(C->getOperand(2)));
957        break;
958      case Instruction::ShuffleVector:
959        // If the return type and argument types are the same, this is a
960        // standard shufflevector instruction.  If the types are different,
961        // then the shuffle is widening or truncating the input vectors, and
962        // the argument type must also be encoded.
963        if (C->getType() == C->getOperand(0)->getType()) {
964          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
965        } else {
966          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
967          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
968        }
969        Record.push_back(VE.getValueID(C->getOperand(0)));
970        Record.push_back(VE.getValueID(C->getOperand(1)));
971        Record.push_back(VE.getValueID(C->getOperand(2)));
972        break;
973      case Instruction::ICmp:
974      case Instruction::FCmp:
975        Code = bitc::CST_CODE_CE_CMP;
976        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
977        Record.push_back(VE.getValueID(C->getOperand(0)));
978        Record.push_back(VE.getValueID(C->getOperand(1)));
979        Record.push_back(CE->getPredicate());
980        break;
981      }
982    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
983      Code = bitc::CST_CODE_BLOCKADDRESS;
984      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
985      Record.push_back(VE.getValueID(BA->getFunction()));
986      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
987    } else {
988#ifndef NDEBUG
989      C->dump();
990#endif
991      llvm_unreachable("Unknown constant!");
992    }
993    Stream.EmitRecord(Code, Record, AbbrevToUse);
994    Record.clear();
995  }
996
997  Stream.ExitBlock();
998}
999
1000static void WriteModuleConstants(const ValueEnumerator &VE,
1001                                 BitstreamWriter &Stream) {
1002  const ValueEnumerator::ValueList &Vals = VE.getValues();
1003
1004  // Find the first constant to emit, which is the first non-globalvalue value.
1005  // We know globalvalues have been emitted by WriteModuleInfo.
1006  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1007    if (!isa<GlobalValue>(Vals[i].first)) {
1008      WriteConstants(i, Vals.size(), VE, Stream, true);
1009      return;
1010    }
1011  }
1012}
1013
1014/// PushValueAndType - The file has to encode both the value and type id for
1015/// many values, because we need to know what type to create for forward
1016/// references.  However, most operands are not forward references, so this type
1017/// field is not needed.
1018///
1019/// This function adds V's value ID to Vals.  If the value ID is higher than the
1020/// instruction ID, then it is a forward reference, and it also includes the
1021/// type ID.
1022static bool PushValueAndType(const Value *V, unsigned InstID,
1023                             SmallVector<unsigned, 64> &Vals,
1024                             ValueEnumerator &VE) {
1025  unsigned ValID = VE.getValueID(V);
1026  Vals.push_back(ValID);
1027  if (ValID >= InstID) {
1028    Vals.push_back(VE.getTypeID(V->getType()));
1029    return true;
1030  }
1031  return false;
1032}
1033
1034/// WriteInstruction - Emit an instruction to the specified stream.
1035static void WriteInstruction(const Instruction &I, unsigned InstID,
1036                             ValueEnumerator &VE, BitstreamWriter &Stream,
1037                             SmallVector<unsigned, 64> &Vals) {
1038  unsigned Code = 0;
1039  unsigned AbbrevToUse = 0;
1040  VE.setInstructionID(&I);
1041  switch (I.getOpcode()) {
1042  default:
1043    if (Instruction::isCast(I.getOpcode())) {
1044      Code = bitc::FUNC_CODE_INST_CAST;
1045      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1046        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1047      Vals.push_back(VE.getTypeID(I.getType()));
1048      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1049    } else {
1050      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1051      Code = bitc::FUNC_CODE_INST_BINOP;
1052      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1053        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1054      Vals.push_back(VE.getValueID(I.getOperand(1)));
1055      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1056      uint64_t Flags = GetOptimizationFlags(&I);
1057      if (Flags != 0) {
1058        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1059          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1060        Vals.push_back(Flags);
1061      }
1062    }
1063    break;
1064
1065  case Instruction::GetElementPtr:
1066    Code = bitc::FUNC_CODE_INST_GEP;
1067    if (cast<GEPOperator>(&I)->isInBounds())
1068      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
1069    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1070      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1071    break;
1072  case Instruction::ExtractValue: {
1073    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1074    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1075    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1076    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1077      Vals.push_back(*i);
1078    break;
1079  }
1080  case Instruction::InsertValue: {
1081    Code = bitc::FUNC_CODE_INST_INSERTVAL;
1082    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1083    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1084    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1085    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1086      Vals.push_back(*i);
1087    break;
1088  }
1089  case Instruction::Select:
1090    Code = bitc::FUNC_CODE_INST_VSELECT;
1091    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1092    Vals.push_back(VE.getValueID(I.getOperand(2)));
1093    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1094    break;
1095  case Instruction::ExtractElement:
1096    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1097    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1098    Vals.push_back(VE.getValueID(I.getOperand(1)));
1099    break;
1100  case Instruction::InsertElement:
1101    Code = bitc::FUNC_CODE_INST_INSERTELT;
1102    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1103    Vals.push_back(VE.getValueID(I.getOperand(1)));
1104    Vals.push_back(VE.getValueID(I.getOperand(2)));
1105    break;
1106  case Instruction::ShuffleVector:
1107    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1108    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1109    Vals.push_back(VE.getValueID(I.getOperand(1)));
1110    Vals.push_back(VE.getValueID(I.getOperand(2)));
1111    break;
1112  case Instruction::ICmp:
1113  case Instruction::FCmp:
1114    // compare returning Int1Ty or vector of Int1Ty
1115    Code = bitc::FUNC_CODE_INST_CMP2;
1116    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1117    Vals.push_back(VE.getValueID(I.getOperand(1)));
1118    Vals.push_back(cast<CmpInst>(I).getPredicate());
1119    break;
1120
1121  case Instruction::Ret:
1122    {
1123      Code = bitc::FUNC_CODE_INST_RET;
1124      unsigned NumOperands = I.getNumOperands();
1125      if (NumOperands == 0)
1126        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1127      else if (NumOperands == 1) {
1128        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1129          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1130      } else {
1131        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1132          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1133      }
1134    }
1135    break;
1136  case Instruction::Br:
1137    {
1138      Code = bitc::FUNC_CODE_INST_BR;
1139      BranchInst &II = cast<BranchInst>(I);
1140      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1141      if (II.isConditional()) {
1142        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1143        Vals.push_back(VE.getValueID(II.getCondition()));
1144      }
1145    }
1146    break;
1147  case Instruction::Switch:
1148    Code = bitc::FUNC_CODE_INST_SWITCH;
1149    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1150    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1151      Vals.push_back(VE.getValueID(I.getOperand(i)));
1152    break;
1153  case Instruction::IndirectBr:
1154    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1155    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1156    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1157      Vals.push_back(VE.getValueID(I.getOperand(i)));
1158    break;
1159
1160  case Instruction::Invoke: {
1161    const InvokeInst *II = cast<InvokeInst>(&I);
1162    const Value *Callee(II->getCalledValue());
1163    PointerType *PTy = cast<PointerType>(Callee->getType());
1164    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1165    Code = bitc::FUNC_CODE_INST_INVOKE;
1166
1167    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1168    Vals.push_back(II->getCallingConv());
1169    Vals.push_back(VE.getValueID(II->getNormalDest()));
1170    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1171    PushValueAndType(Callee, InstID, Vals, VE);
1172
1173    // Emit value #'s for the fixed parameters.
1174    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1175      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1176
1177    // Emit type/value pairs for varargs params.
1178    if (FTy->isVarArg()) {
1179      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1180           i != e; ++i)
1181        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1182    }
1183    break;
1184  }
1185  case Instruction::Unwind:
1186    Code = bitc::FUNC_CODE_INST_UNWIND;
1187    break;
1188  case Instruction::Unreachable:
1189    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1190    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1191    break;
1192
1193  case Instruction::PHI: {
1194    const PHINode &PN = cast<PHINode>(I);
1195    Code = bitc::FUNC_CODE_INST_PHI;
1196    Vals.push_back(VE.getTypeID(PN.getType()));
1197    for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1198      Vals.push_back(VE.getValueID(PN.getIncomingValue(i)));
1199      Vals.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1200    }
1201    break;
1202  }
1203
1204  case Instruction::Alloca:
1205    Code = bitc::FUNC_CODE_INST_ALLOCA;
1206    Vals.push_back(VE.getTypeID(I.getType()));
1207    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1208    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1209    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1210    break;
1211
1212  case Instruction::Load:
1213    Code = bitc::FUNC_CODE_INST_LOAD;
1214    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1215      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1216
1217    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1218    Vals.push_back(cast<LoadInst>(I).isVolatile());
1219    break;
1220  case Instruction::Store:
1221    Code = bitc::FUNC_CODE_INST_STORE;
1222    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1223    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1224    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1225    Vals.push_back(cast<StoreInst>(I).isVolatile());
1226    break;
1227  case Instruction::Call: {
1228    const CallInst &CI = cast<CallInst>(I);
1229    PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1230    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1231
1232    Code = FUNC_CODE_INST_CALL_2_7;
1233
1234    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1235    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1236    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1237
1238    // Emit value #'s for the fixed parameters.
1239    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1240      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1241
1242    // Emit type/value pairs for varargs params.
1243    if (FTy->isVarArg()) {
1244      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1245           i != e; ++i)
1246        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1247    }
1248    break;
1249  }
1250  case Instruction::VAArg:
1251    Code = bitc::FUNC_CODE_INST_VAARG;
1252    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1253    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1254    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1255    break;
1256  }
1257
1258  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1259  Vals.clear();
1260}
1261
1262// Emit names for globals/functions etc.
1263static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1264                                  const ValueEnumerator &VE,
1265                                  BitstreamWriter &Stream) {
1266  if (VST.empty()) return;
1267  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1268
1269  // FIXME: Set up the abbrev, we know how many values there are!
1270  // FIXME: We know if the type names can use 7-bit ascii.
1271  SmallVector<unsigned, 64> NameVals;
1272
1273  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1274       SI != SE; ++SI) {
1275
1276    const ValueName &Name = *SI;
1277
1278    // Figure out the encoding to use for the name.
1279    bool is7Bit = true;
1280    bool isChar6 = true;
1281    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1282         C != E; ++C) {
1283      if (isChar6)
1284        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1285      if ((unsigned char)*C & 128) {
1286        is7Bit = false;
1287        break;  // don't bother scanning the rest.
1288      }
1289    }
1290
1291    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1292
1293    // VST_ENTRY:   [valueid, namechar x N]
1294    // VST_BBENTRY: [bbid, namechar x N]
1295    unsigned Code;
1296    if (isa<BasicBlock>(SI->getValue())) {
1297      Code = bitc::VST_CODE_BBENTRY;
1298      if (isChar6)
1299        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1300    } else {
1301      Code = bitc::VST_CODE_ENTRY;
1302      if (isChar6)
1303        AbbrevToUse = VST_ENTRY_6_ABBREV;
1304      else if (is7Bit)
1305        AbbrevToUse = VST_ENTRY_7_ABBREV;
1306    }
1307
1308    NameVals.push_back(VE.getValueID(SI->getValue()));
1309    for (const char *P = Name.getKeyData(),
1310         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1311      NameVals.push_back((unsigned char)*P);
1312
1313    // Emit the finished record.
1314    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1315    NameVals.clear();
1316  }
1317  Stream.ExitBlock();
1318}
1319
1320/// WriteFunction - Emit a function body to the module stream.
1321static void WriteFunction(const Function &F, ValueEnumerator &VE,
1322                          BitstreamWriter &Stream) {
1323  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1324  VE.incorporateFunction(F);
1325
1326  SmallVector<unsigned, 64> Vals;
1327
1328  // Emit the number of basic blocks, so the reader can create them ahead of
1329  // time.
1330  Vals.push_back(VE.getBasicBlocks().size());
1331  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1332  Vals.clear();
1333
1334  // If there are function-local constants, emit them now.
1335  unsigned CstStart, CstEnd;
1336  VE.getFunctionConstantRange(CstStart, CstEnd);
1337  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1338
1339  // If there is function-local metadata, emit it now.
1340  WriteFunctionLocalMetadata(F, VE, Stream);
1341
1342  // Keep a running idea of what the instruction ID is.
1343  unsigned InstID = CstEnd;
1344
1345  bool NeedsMetadataAttachment = false;
1346
1347  DebugLoc LastDL;
1348
1349  // Finally, emit all the instructions, in order.
1350  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1351    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1352         I != E; ++I) {
1353      WriteInstruction(*I, InstID, VE, Stream, Vals);
1354
1355      if (!I->getType()->isVoidTy())
1356        ++InstID;
1357
1358      // If the instruction has metadata, write a metadata attachment later.
1359      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1360
1361      // If the instruction has a debug location, emit it.
1362      DebugLoc DL = I->getDebugLoc();
1363      if (DL.isUnknown()) {
1364        // nothing todo.
1365      } else if (DL == LastDL) {
1366        // Just repeat the same debug loc as last time.
1367        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1368      } else {
1369        MDNode *Scope, *IA;
1370        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1371
1372        Vals.push_back(DL.getLine());
1373        Vals.push_back(DL.getCol());
1374        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1375        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1376        Stream.EmitRecord(FUNC_CODE_DEBUG_LOC_2_7, Vals);
1377        Vals.clear();
1378
1379        LastDL = DL;
1380      }
1381    }
1382
1383  // Emit names for all the instructions etc.
1384  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1385
1386  if (NeedsMetadataAttachment)
1387    WriteMetadataAttachment(F, VE, Stream);
1388  VE.purgeFunction();
1389  Stream.ExitBlock();
1390}
1391
1392// Emit blockinfo, which defines the standard abbreviations etc.
1393static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1394  // We only want to emit block info records for blocks that have multiple
1395  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1396  // blocks can defined their abbrevs inline.
1397  Stream.EnterBlockInfoBlock(2);
1398
1399  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1400    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1401    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1402    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1403    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1404    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1405    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1406                                   Abbv) != VST_ENTRY_8_ABBREV)
1407      llvm_unreachable("Unexpected abbrev ordering!");
1408  }
1409
1410  { // 7-bit fixed width VST_ENTRY strings.
1411    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1412    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1413    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1414    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1415    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1416    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1417                                   Abbv) != VST_ENTRY_7_ABBREV)
1418      llvm_unreachable("Unexpected abbrev ordering!");
1419  }
1420  { // 6-bit char6 VST_ENTRY strings.
1421    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1422    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1423    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1424    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1425    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1426    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1427                                   Abbv) != VST_ENTRY_6_ABBREV)
1428      llvm_unreachable("Unexpected abbrev ordering!");
1429  }
1430  { // 6-bit char6 VST_BBENTRY strings.
1431    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1432    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1433    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1434    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1435    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1436    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1437                                   Abbv) != VST_BBENTRY_6_ABBREV)
1438      llvm_unreachable("Unexpected abbrev ordering!");
1439  }
1440
1441
1442
1443  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1444    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1445    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1446    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1447                              Log2_32_Ceil(VE.getTypes().size()+1)));
1448    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1449                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1450      llvm_unreachable("Unexpected abbrev ordering!");
1451  }
1452
1453  { // INTEGER abbrev for CONSTANTS_BLOCK.
1454    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1455    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1456    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1457    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1458                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1459      llvm_unreachable("Unexpected abbrev ordering!");
1460  }
1461
1462  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1463    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1464    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1465    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1466    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1467                              Log2_32_Ceil(VE.getTypes().size()+1)));
1468    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1469
1470    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1471                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1472      llvm_unreachable("Unexpected abbrev ordering!");
1473  }
1474  { // NULL abbrev for CONSTANTS_BLOCK.
1475    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1476    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1477    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1478                                   Abbv) != CONSTANTS_NULL_Abbrev)
1479      llvm_unreachable("Unexpected abbrev ordering!");
1480  }
1481
1482  // FIXME: This should only use space for first class types!
1483
1484  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1485    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1486    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1487    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1488    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1489    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1490    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1491                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1492      llvm_unreachable("Unexpected abbrev ordering!");
1493  }
1494  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1495    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1496    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1497    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1498    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1499    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1500    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1501                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1502      llvm_unreachable("Unexpected abbrev ordering!");
1503  }
1504  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1505    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1506    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1507    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1508    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1509    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1510    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1511    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1512                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1513      llvm_unreachable("Unexpected abbrev ordering!");
1514  }
1515  { // INST_CAST abbrev for FUNCTION_BLOCK.
1516    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1517    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1518    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1519    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1520                              Log2_32_Ceil(VE.getTypes().size()+1)));
1521    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1522    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1523                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1524      llvm_unreachable("Unexpected abbrev ordering!");
1525  }
1526
1527  { // INST_RET abbrev for FUNCTION_BLOCK.
1528    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1529    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1530    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1531                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1532      llvm_unreachable("Unexpected abbrev ordering!");
1533  }
1534  { // INST_RET abbrev for FUNCTION_BLOCK.
1535    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1536    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1537    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1538    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1539                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1540      llvm_unreachable("Unexpected abbrev ordering!");
1541  }
1542  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1543    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1544    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1545    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1546                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1547      llvm_unreachable("Unexpected abbrev ordering!");
1548  }
1549
1550  Stream.ExitBlock();
1551}
1552
1553
1554/// WriteModule - Emit the specified module to the bitstream.
1555static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1556  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1557
1558  // Emit the version number if it is non-zero.
1559  if (CurVersion) {
1560    SmallVector<unsigned, 1> Vals;
1561    Vals.push_back(CurVersion);
1562    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1563  }
1564
1565  // Analyze the module, enumerating globals, functions, etc.
1566  ValueEnumerator VE(M);
1567
1568  // Emit blockinfo, which defines the standard abbreviations etc.
1569  WriteBlockInfo(VE, Stream);
1570
1571  // Emit information about parameter attributes.
1572  WriteAttributeTable(VE, Stream);
1573
1574  // Emit information describing all of the types in the module.
1575  WriteTypeTable(VE, Stream);
1576
1577  // Emit top-level description of module, including target triple, inline asm,
1578  // descriptors for global variables, and function prototype info.
1579  WriteModuleInfo(M, VE, Stream);
1580
1581  // Emit constants.
1582  WriteModuleConstants(VE, Stream);
1583
1584  // Emit metadata.
1585  WriteModuleMetadata(M, VE, Stream);
1586
1587  // Emit function bodies.
1588  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1589    if (!F->isDeclaration())
1590      WriteFunction(*F, VE, Stream);
1591
1592  // Emit metadata.
1593  WriteModuleMetadataStore(M, Stream);
1594
1595  // Emit names for globals/functions etc.
1596  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1597
1598  Stream.ExitBlock();
1599}
1600
1601/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1602/// header and trailer to make it compatible with the system archiver.  To do
1603/// this we emit the following header, and then emit a trailer that pads the
1604/// file out to be a multiple of 16 bytes.
1605///
1606/// struct bc_header {
1607///   uint32_t Magic;         // 0x0B17C0DE
1608///   uint32_t Version;       // Version, currently always 0.
1609///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1610///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1611///   uint32_t CPUType;       // CPU specifier.
1612///   ... potentially more later ...
1613/// };
1614enum {
1615  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1616  DarwinBCHeaderSize = 5*4
1617};
1618
1619static void EmitDarwinBCHeader(BitstreamWriter &Stream, const Triple &TT) {
1620  unsigned CPUType = ~0U;
1621
1622  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1623  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1624  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1625  // specific constants here because they are implicitly part of the Darwin ABI.
1626  enum {
1627    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1628    DARWIN_CPU_TYPE_X86        = 7,
1629    DARWIN_CPU_TYPE_ARM        = 12,
1630    DARWIN_CPU_TYPE_POWERPC    = 18
1631  };
1632
1633  Triple::ArchType Arch = TT.getArch();
1634  if (Arch == Triple::x86_64)
1635    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1636  else if (Arch == Triple::x86)
1637    CPUType = DARWIN_CPU_TYPE_X86;
1638  else if (Arch == Triple::ppc)
1639    CPUType = DARWIN_CPU_TYPE_POWERPC;
1640  else if (Arch == Triple::ppc64)
1641    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1642  else if (Arch == Triple::arm || Arch == Triple::thumb)
1643    CPUType = DARWIN_CPU_TYPE_ARM;
1644
1645  // Traditional Bitcode starts after header.
1646  unsigned BCOffset = DarwinBCHeaderSize;
1647
1648  Stream.Emit(0x0B17C0DE, 32);
1649  Stream.Emit(0         , 32);  // Version.
1650  Stream.Emit(BCOffset  , 32);
1651  Stream.Emit(0         , 32);  // Filled in later.
1652  Stream.Emit(CPUType   , 32);
1653}
1654
1655/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1656/// finalize the header.
1657static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1658  // Update the size field in the header.
1659  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1660
1661  // If the file is not a multiple of 16 bytes, insert dummy padding.
1662  while (BufferSize & 15) {
1663    Stream.Emit(0, 8);
1664    ++BufferSize;
1665  }
1666}
1667
1668
1669/// WriteBitcodeToFile - Write the specified module to the specified output
1670/// stream.
1671void llvm_2_9::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1672  std::vector<unsigned char> Buffer;
1673  BitstreamWriter Stream(Buffer);
1674
1675  Buffer.reserve(256*1024);
1676
1677  WriteBitcodeToStream( M, Stream );
1678
1679  // Write the generated bitstream to "Out".
1680  Out.write((char*)&Buffer.front(), Buffer.size());
1681}
1682
1683/// WriteBitcodeToStream - Write the specified module to the specified output
1684/// stream.
1685void llvm_2_9::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1686  // If this is darwin or another generic macho target, emit a file header and
1687  // trailer if needed.
1688  Triple TT(M->getTargetTriple());
1689  if (TT.isOSDarwin())
1690    EmitDarwinBCHeader(Stream, TT);
1691
1692  // Emit the file header.
1693  Stream.Emit((unsigned)'B', 8);
1694  Stream.Emit((unsigned)'C', 8);
1695  Stream.Emit(0x0, 4);
1696  Stream.Emit(0xC, 4);
1697  Stream.Emit(0xE, 4);
1698  Stream.Emit(0xD, 4);
1699
1700  // Emit the module.
1701  WriteModule(M, Stream);
1702
1703  if (TT.isOSDarwin())
1704    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1705}
1706