BitcodeWriter.cpp revision e089160d1065d83986fd97fae7f0af08c03e7d47 
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/TypeSymbolTable.h"
24#include "llvm/ValueSymbolTable.h"
25#include "llvm/Support/MathExtras.h"
26#include "llvm/System/Program.h"
27using namespace llvm;
28
29/// These are manifest constants used by the bitcode writer. They do not need to
30/// be kept in sync with the reader, but need to be consistent within this file.
31enum {
32  CurVersion = 0,
33
34  // VALUE_SYMTAB_BLOCK abbrev id's.
35  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
36  VST_ENTRY_7_ABBREV,
37  VST_ENTRY_6_ABBREV,
38  VST_BBENTRY_6_ABBREV,
39
40  // CONSTANTS_BLOCK abbrev id's.
41  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
42  CONSTANTS_INTEGER_ABBREV,
43  CONSTANTS_CE_CAST_Abbrev,
44  CONSTANTS_NULL_Abbrev,
45
46  // FUNCTION_BLOCK abbrev id's.
47  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
48  FUNCTION_INST_BINOP_ABBREV,
49  FUNCTION_INST_CAST_ABBREV,
50  FUNCTION_INST_RET_VOID_ABBREV,
51  FUNCTION_INST_RET_VAL_ABBREV,
52  FUNCTION_INST_UNREACHABLE_ABBREV
53};
54
55
56static unsigned GetEncodedCastOpcode(unsigned Opcode) {
57  switch (Opcode) {
58  default: assert(0 && "Unknown cast instruction!");
59  case Instruction::Trunc   : return bitc::CAST_TRUNC;
60  case Instruction::ZExt    : return bitc::CAST_ZEXT;
61  case Instruction::SExt    : return bitc::CAST_SEXT;
62  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
63  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
64  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
65  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
66  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
67  case Instruction::FPExt   : return bitc::CAST_FPEXT;
68  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
69  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
70  case Instruction::BitCast : return bitc::CAST_BITCAST;
71  }
72}
73
74static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
75  switch (Opcode) {
76  default: assert(0 && "Unknown binary instruction!");
77  case Instruction::Add:  return bitc::BINOP_ADD;
78  case Instruction::Sub:  return bitc::BINOP_SUB;
79  case Instruction::Mul:  return bitc::BINOP_MUL;
80  case Instruction::UDiv: return bitc::BINOP_UDIV;
81  case Instruction::FDiv:
82  case Instruction::SDiv: return bitc::BINOP_SDIV;
83  case Instruction::URem: return bitc::BINOP_UREM;
84  case Instruction::FRem:
85  case Instruction::SRem: return bitc::BINOP_SREM;
86  case Instruction::Shl:  return bitc::BINOP_SHL;
87  case Instruction::LShr: return bitc::BINOP_LSHR;
88  case Instruction::AShr: return bitc::BINOP_ASHR;
89  case Instruction::And:  return bitc::BINOP_AND;
90  case Instruction::Or:   return bitc::BINOP_OR;
91  case Instruction::Xor:  return bitc::BINOP_XOR;
92  }
93}
94
95
96
97static void WriteStringRecord(unsigned Code, const std::string &Str,
98                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
99  SmallVector<unsigned, 64> Vals;
100
101  // Code: [strchar x N]
102  for (unsigned i = 0, e = Str.size(); i != e; ++i)
103    Vals.push_back(Str[i]);
104
105  // Emit the finished record.
106  Stream.EmitRecord(Code, Vals, AbbrevToUse);
107}
108
109// Emit information about parameter attributes.
110static void WriteParamAttrTable(const ValueEnumerator &VE,
111                                BitstreamWriter &Stream) {
112  const std::vector<PAListPtr> &Attrs = VE.getParamAttrs();
113  if (Attrs.empty()) return;
114
115  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
116
117  SmallVector<uint64_t, 64> Record;
118  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
119    const PAListPtr &A = Attrs[i];
120    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
121      const ParamAttrsWithIndex &PAWI = A.getSlot(i);
122      Record.push_back(PAWI.Index);
123      Record.push_back(PAWI.Attrs);
124    }
125
126    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
127    Record.clear();
128  }
129
130  Stream.ExitBlock();
131}
132
133/// WriteTypeTable - Write out the type table for a module.
134static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
135  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
136
137  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
138  SmallVector<uint64_t, 64> TypeVals;
139
140  // Abbrev for TYPE_CODE_POINTER.
141  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
142  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
143  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
144                            Log2_32_Ceil(VE.getTypes().size()+1)));
145  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
146  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
147
148  // Abbrev for TYPE_CODE_FUNCTION.
149  Abbv = new BitCodeAbbrev();
150  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
151  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
152  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
153  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
154  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
155                            Log2_32_Ceil(VE.getTypes().size()+1)));
156  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
157
158  // Abbrev for TYPE_CODE_STRUCT.
159  Abbv = new BitCodeAbbrev();
160  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
161  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
162  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
163  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
164                            Log2_32_Ceil(VE.getTypes().size()+1)));
165  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
166
167  // Abbrev for TYPE_CODE_ARRAY.
168  Abbv = new BitCodeAbbrev();
169  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
170  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
171  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
172                            Log2_32_Ceil(VE.getTypes().size()+1)));
173  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
174
175  // Emit an entry count so the reader can reserve space.
176  TypeVals.push_back(TypeList.size());
177  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
178  TypeVals.clear();
179
180  // Loop over all of the types, emitting each in turn.
181  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
182    const Type *T = TypeList[i].first;
183    int AbbrevToUse = 0;
184    unsigned Code = 0;
185
186    switch (T->getTypeID()) {
187    default: assert(0 && "Unknown type!");
188    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
189    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
190    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
191    case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
192    case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
193    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
194    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
195    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
196    case Type::IntegerTyID:
197      // INTEGER: [width]
198      Code = bitc::TYPE_CODE_INTEGER;
199      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
200      break;
201    case Type::PointerTyID: {
202      const PointerType *PTy = cast<PointerType>(T);
203      // POINTER: [pointee type, address space]
204      Code = bitc::TYPE_CODE_POINTER;
205      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
206      unsigned AddressSpace = PTy->getAddressSpace();
207      TypeVals.push_back(AddressSpace);
208      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
209      break;
210    }
211    case Type::FunctionTyID: {
212      const FunctionType *FT = cast<FunctionType>(T);
213      // FUNCTION: [isvararg, attrid, retty, paramty x N]
214      Code = bitc::TYPE_CODE_FUNCTION;
215      TypeVals.push_back(FT->isVarArg());
216      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
217      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
218      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
219        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
220      AbbrevToUse = FunctionAbbrev;
221      break;
222    }
223    case Type::StructTyID: {
224      const StructType *ST = cast<StructType>(T);
225      // STRUCT: [ispacked, eltty x N]
226      Code = bitc::TYPE_CODE_STRUCT;
227      TypeVals.push_back(ST->isPacked());
228      // Output all of the element types.
229      for (StructType::element_iterator I = ST->element_begin(),
230           E = ST->element_end(); I != E; ++I)
231        TypeVals.push_back(VE.getTypeID(*I));
232      AbbrevToUse = StructAbbrev;
233      break;
234    }
235    case Type::ArrayTyID: {
236      const ArrayType *AT = cast<ArrayType>(T);
237      // ARRAY: [numelts, eltty]
238      Code = bitc::TYPE_CODE_ARRAY;
239      TypeVals.push_back(AT->getNumElements());
240      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
241      AbbrevToUse = ArrayAbbrev;
242      break;
243    }
244    case Type::VectorTyID: {
245      const VectorType *VT = cast<VectorType>(T);
246      // VECTOR [numelts, eltty]
247      Code = bitc::TYPE_CODE_VECTOR;
248      TypeVals.push_back(VT->getNumElements());
249      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
250      break;
251    }
252    }
253
254    // Emit the finished record.
255    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
256    TypeVals.clear();
257  }
258
259  Stream.ExitBlock();
260}
261
262static unsigned getEncodedLinkage(const GlobalValue *GV) {
263  switch (GV->getLinkage()) {
264  default: assert(0 && "Invalid linkage!");
265  case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
266  case GlobalValue::ExternalLinkage:     return 0;
267  case GlobalValue::WeakLinkage:         return 1;
268  case GlobalValue::AppendingLinkage:    return 2;
269  case GlobalValue::InternalLinkage:     return 3;
270  case GlobalValue::LinkOnceLinkage:     return 4;
271  case GlobalValue::DLLImportLinkage:    return 5;
272  case GlobalValue::DLLExportLinkage:    return 6;
273  case GlobalValue::ExternalWeakLinkage: return 7;
274  case GlobalValue::CommonLinkage:       return 8;
275  }
276}
277
278static unsigned getEncodedVisibility(const GlobalValue *GV) {
279  switch (GV->getVisibility()) {
280  default: assert(0 && "Invalid visibility!");
281  case GlobalValue::DefaultVisibility:   return 0;
282  case GlobalValue::HiddenVisibility:    return 1;
283  case GlobalValue::ProtectedVisibility: return 2;
284  }
285}
286
287// Emit top-level description of module, including target triple, inline asm,
288// descriptors for global variables, and function prototype info.
289static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
290                            BitstreamWriter &Stream) {
291  // Emit the list of dependent libraries for the Module.
292  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
293    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
294
295  // Emit various pieces of data attached to a module.
296  if (!M->getTargetTriple().empty())
297    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
298                      0/*TODO*/, Stream);
299  if (!M->getDataLayout().empty())
300    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
301                      0/*TODO*/, Stream);
302  if (!M->getModuleInlineAsm().empty())
303    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
304                      0/*TODO*/, Stream);
305
306  // Emit information about sections and collectors, computing how many there
307  // are.  Also compute the maximum alignment value.
308  std::map<std::string, unsigned> SectionMap;
309  std::map<std::string, unsigned> CollectorMap;
310  unsigned MaxAlignment = 0;
311  unsigned MaxGlobalType = 0;
312  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
313       GV != E; ++GV) {
314    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
315    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
316
317    if (!GV->hasSection()) continue;
318    // Give section names unique ID's.
319    unsigned &Entry = SectionMap[GV->getSection()];
320    if (Entry != 0) continue;
321    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
322                      0/*TODO*/, Stream);
323    Entry = SectionMap.size();
324  }
325  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
326    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
327    if (F->hasSection()) {
328      // Give section names unique ID's.
329      unsigned &Entry = SectionMap[F->getSection()];
330      if (!Entry) {
331        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
332                          0/*TODO*/, Stream);
333        Entry = SectionMap.size();
334      }
335    }
336    if (F->hasCollector()) {
337      // Same for collector names.
338      unsigned &Entry = CollectorMap[F->getCollector()];
339      if (!Entry) {
340        WriteStringRecord(bitc::MODULE_CODE_COLLECTORNAME, F->getCollector(),
341                          0/*TODO*/, Stream);
342        Entry = CollectorMap.size();
343      }
344    }
345  }
346
347  // Emit abbrev for globals, now that we know # sections and max alignment.
348  unsigned SimpleGVarAbbrev = 0;
349  if (!M->global_empty()) {
350    // Add an abbrev for common globals with no visibility or thread localness.
351    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
352    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
353    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
354                              Log2_32_Ceil(MaxGlobalType+1)));
355    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
356    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
357    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
358    if (MaxAlignment == 0)                                      // Alignment.
359      Abbv->Add(BitCodeAbbrevOp(0));
360    else {
361      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
362      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
363                               Log2_32_Ceil(MaxEncAlignment+1)));
364    }
365    if (SectionMap.empty())                                    // Section.
366      Abbv->Add(BitCodeAbbrevOp(0));
367    else
368      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
369                               Log2_32_Ceil(SectionMap.size()+1)));
370    // Don't bother emitting vis + thread local.
371    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
372  }
373
374  // Emit the global variable information.
375  SmallVector<unsigned, 64> Vals;
376  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
377       GV != E; ++GV) {
378    unsigned AbbrevToUse = 0;
379
380    // GLOBALVAR: [type, isconst, initid,
381    //             linkage, alignment, section, visibility, threadlocal]
382    Vals.push_back(VE.getTypeID(GV->getType()));
383    Vals.push_back(GV->isConstant());
384    Vals.push_back(GV->isDeclaration() ? 0 :
385                   (VE.getValueID(GV->getInitializer()) + 1));
386    Vals.push_back(getEncodedLinkage(GV));
387    Vals.push_back(Log2_32(GV->getAlignment())+1);
388    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
389    if (GV->isThreadLocal() ||
390        GV->getVisibility() != GlobalValue::DefaultVisibility) {
391      Vals.push_back(getEncodedVisibility(GV));
392      Vals.push_back(GV->isThreadLocal());
393    } else {
394      AbbrevToUse = SimpleGVarAbbrev;
395    }
396
397    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
398    Vals.clear();
399  }
400
401  // Emit the function proto information.
402  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
403    // FUNCTION:  [type, callingconv, isproto, paramattr,
404    //             linkage, alignment, section, visibility, collector]
405    Vals.push_back(VE.getTypeID(F->getType()));
406    Vals.push_back(F->getCallingConv());
407    Vals.push_back(F->isDeclaration());
408    Vals.push_back(getEncodedLinkage(F));
409    Vals.push_back(VE.getParamAttrID(F->getParamAttrs()));
410    Vals.push_back(Log2_32(F->getAlignment())+1);
411    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
412    Vals.push_back(getEncodedVisibility(F));
413    Vals.push_back(F->hasCollector() ? CollectorMap[F->getCollector()] : 0);
414
415    unsigned AbbrevToUse = 0;
416    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
417    Vals.clear();
418  }
419
420
421  // Emit the alias information.
422  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
423       AI != E; ++AI) {
424    Vals.push_back(VE.getTypeID(AI->getType()));
425    Vals.push_back(VE.getValueID(AI->getAliasee()));
426    Vals.push_back(getEncodedLinkage(AI));
427    Vals.push_back(getEncodedVisibility(AI));
428    unsigned AbbrevToUse = 0;
429    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
430    Vals.clear();
431  }
432}
433
434
435static void WriteConstants(unsigned FirstVal, unsigned LastVal,
436                           const ValueEnumerator &VE,
437                           BitstreamWriter &Stream, bool isGlobal) {
438  if (FirstVal == LastVal) return;
439
440  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
441
442  unsigned AggregateAbbrev = 0;
443  unsigned String8Abbrev = 0;
444  unsigned CString7Abbrev = 0;
445  unsigned CString6Abbrev = 0;
446  // If this is a constant pool for the module, emit module-specific abbrevs.
447  if (isGlobal) {
448    // Abbrev for CST_CODE_AGGREGATE.
449    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
450    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
451    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
452    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
453    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
454
455    // Abbrev for CST_CODE_STRING.
456    Abbv = new BitCodeAbbrev();
457    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
458    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
459    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
460    String8Abbrev = Stream.EmitAbbrev(Abbv);
461    // Abbrev for CST_CODE_CSTRING.
462    Abbv = new BitCodeAbbrev();
463    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
464    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
465    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
466    CString7Abbrev = Stream.EmitAbbrev(Abbv);
467    // Abbrev for CST_CODE_CSTRING.
468    Abbv = new BitCodeAbbrev();
469    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
470    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
471    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
472    CString6Abbrev = Stream.EmitAbbrev(Abbv);
473  }
474
475  SmallVector<uint64_t, 64> Record;
476
477  const ValueEnumerator::ValueList &Vals = VE.getValues();
478  const Type *LastTy = 0;
479  for (unsigned i = FirstVal; i != LastVal; ++i) {
480    const Value *V = Vals[i].first;
481    // If we need to switch types, do so now.
482    if (V->getType() != LastTy) {
483      LastTy = V->getType();
484      Record.push_back(VE.getTypeID(LastTy));
485      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
486                        CONSTANTS_SETTYPE_ABBREV);
487      Record.clear();
488    }
489
490    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
491      Record.push_back(unsigned(IA->hasSideEffects()));
492
493      // Add the asm string.
494      const std::string &AsmStr = IA->getAsmString();
495      Record.push_back(AsmStr.size());
496      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
497        Record.push_back(AsmStr[i]);
498
499      // Add the constraint string.
500      const std::string &ConstraintStr = IA->getConstraintString();
501      Record.push_back(ConstraintStr.size());
502      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
503        Record.push_back(ConstraintStr[i]);
504      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
505      Record.clear();
506      continue;
507    }
508    const Constant *C = cast<Constant>(V);
509    unsigned Code = -1U;
510    unsigned AbbrevToUse = 0;
511    if (C->isNullValue()) {
512      Code = bitc::CST_CODE_NULL;
513    } else if (isa<UndefValue>(C)) {
514      Code = bitc::CST_CODE_UNDEF;
515    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
516      if (IV->getBitWidth() <= 64) {
517        int64_t V = IV->getSExtValue();
518        if (V >= 0)
519          Record.push_back(V << 1);
520        else
521          Record.push_back((-V << 1) | 1);
522        Code = bitc::CST_CODE_INTEGER;
523        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
524      } else {                             // Wide integers, > 64 bits in size.
525        // We have an arbitrary precision integer value to write whose
526        // bit width is > 64. However, in canonical unsigned integer
527        // format it is likely that the high bits are going to be zero.
528        // So, we only write the number of active words.
529        unsigned NWords = IV->getValue().getActiveWords();
530        const uint64_t *RawWords = IV->getValue().getRawData();
531        for (unsigned i = 0; i != NWords; ++i) {
532          int64_t V = RawWords[i];
533          if (V >= 0)
534            Record.push_back(V << 1);
535          else
536            Record.push_back((-V << 1) | 1);
537        }
538        Code = bitc::CST_CODE_WIDE_INTEGER;
539      }
540    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
541      Code = bitc::CST_CODE_FLOAT;
542      const Type *Ty = CFP->getType();
543      if (Ty == Type::FloatTy || Ty == Type::DoubleTy) {
544        Record.push_back(CFP->getValueAPF().convertToAPInt().getZExtValue());
545      } else if (Ty == Type::X86_FP80Ty) {
546        // api needed to prevent premature destruction
547        APInt api = CFP->getValueAPF().convertToAPInt();
548        const uint64_t *p = api.getRawData();
549        Record.push_back(p[0]);
550        Record.push_back((uint16_t)p[1]);
551      } else if (Ty == Type::FP128Ty || Ty == Type::PPC_FP128Ty) {
552        APInt api = CFP->getValueAPF().convertToAPInt();
553        const uint64_t *p = api.getRawData();
554        Record.push_back(p[0]);
555        Record.push_back(p[1]);
556      } else {
557        assert (0 && "Unknown FP type!");
558      }
559    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
560      // Emit constant strings specially.
561      unsigned NumOps = C->getNumOperands();
562      // If this is a null-terminated string, use the denser CSTRING encoding.
563      if (C->getOperand(NumOps-1)->isNullValue()) {
564        Code = bitc::CST_CODE_CSTRING;
565        --NumOps;  // Don't encode the null, which isn't allowed by char6.
566      } else {
567        Code = bitc::CST_CODE_STRING;
568        AbbrevToUse = String8Abbrev;
569      }
570      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
571      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
572      for (unsigned i = 0; i != NumOps; ++i) {
573        unsigned char V = cast<ConstantInt>(C->getOperand(i))->getZExtValue();
574        Record.push_back(V);
575        isCStr7 &= (V & 128) == 0;
576        if (isCStrChar6)
577          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
578      }
579
580      if (isCStrChar6)
581        AbbrevToUse = CString6Abbrev;
582      else if (isCStr7)
583        AbbrevToUse = CString7Abbrev;
584    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
585               isa<ConstantVector>(V)) {
586      Code = bitc::CST_CODE_AGGREGATE;
587      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
588        Record.push_back(VE.getValueID(C->getOperand(i)));
589      AbbrevToUse = AggregateAbbrev;
590    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
591      switch (CE->getOpcode()) {
592      default:
593        if (Instruction::isCast(CE->getOpcode())) {
594          Code = bitc::CST_CODE_CE_CAST;
595          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
596          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
597          Record.push_back(VE.getValueID(C->getOperand(0)));
598          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
599        } else {
600          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
601          Code = bitc::CST_CODE_CE_BINOP;
602          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
603          Record.push_back(VE.getValueID(C->getOperand(0)));
604          Record.push_back(VE.getValueID(C->getOperand(1)));
605        }
606        break;
607      case Instruction::GetElementPtr:
608        Code = bitc::CST_CODE_CE_GEP;
609        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
610          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
611          Record.push_back(VE.getValueID(C->getOperand(i)));
612        }
613        break;
614      case Instruction::Select:
615        Code = bitc::CST_CODE_CE_SELECT;
616        Record.push_back(VE.getValueID(C->getOperand(0)));
617        Record.push_back(VE.getValueID(C->getOperand(1)));
618        Record.push_back(VE.getValueID(C->getOperand(2)));
619        break;
620      case Instruction::ExtractElement:
621        Code = bitc::CST_CODE_CE_EXTRACTELT;
622        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
623        Record.push_back(VE.getValueID(C->getOperand(0)));
624        Record.push_back(VE.getValueID(C->getOperand(1)));
625        break;
626      case Instruction::InsertElement:
627        Code = bitc::CST_CODE_CE_INSERTELT;
628        Record.push_back(VE.getValueID(C->getOperand(0)));
629        Record.push_back(VE.getValueID(C->getOperand(1)));
630        Record.push_back(VE.getValueID(C->getOperand(2)));
631        break;
632      case Instruction::ShuffleVector:
633        Code = bitc::CST_CODE_CE_SHUFFLEVEC;
634        Record.push_back(VE.getValueID(C->getOperand(0)));
635        Record.push_back(VE.getValueID(C->getOperand(1)));
636        Record.push_back(VE.getValueID(C->getOperand(2)));
637        break;
638      case Instruction::ICmp:
639      case Instruction::FCmp:
640      case Instruction::VICmp:
641      case Instruction::VFCmp:
642        Code = bitc::CST_CODE_CE_CMP;
643        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
644        Record.push_back(VE.getValueID(C->getOperand(0)));
645        Record.push_back(VE.getValueID(C->getOperand(1)));
646        Record.push_back(CE->getPredicate());
647        break;
648      }
649    } else {
650      assert(0 && "Unknown constant!");
651    }
652    Stream.EmitRecord(Code, Record, AbbrevToUse);
653    Record.clear();
654  }
655
656  Stream.ExitBlock();
657}
658
659static void WriteModuleConstants(const ValueEnumerator &VE,
660                                 BitstreamWriter &Stream) {
661  const ValueEnumerator::ValueList &Vals = VE.getValues();
662
663  // Find the first constant to emit, which is the first non-globalvalue value.
664  // We know globalvalues have been emitted by WriteModuleInfo.
665  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
666    if (!isa<GlobalValue>(Vals[i].first)) {
667      WriteConstants(i, Vals.size(), VE, Stream, true);
668      return;
669    }
670  }
671}
672
673/// PushValueAndType - The file has to encode both the value and type id for
674/// many values, because we need to know what type to create for forward
675/// references.  However, most operands are not forward references, so this type
676/// field is not needed.
677///
678/// This function adds V's value ID to Vals.  If the value ID is higher than the
679/// instruction ID, then it is a forward reference, and it also includes the
680/// type ID.
681static bool PushValueAndType(Value *V, unsigned InstID,
682                             SmallVector<unsigned, 64> &Vals,
683                             ValueEnumerator &VE) {
684  unsigned ValID = VE.getValueID(V);
685  Vals.push_back(ValID);
686  if (ValID >= InstID) {
687    Vals.push_back(VE.getTypeID(V->getType()));
688    return true;
689  }
690  return false;
691}
692
693/// WriteInstruction - Emit an instruction to the specified stream.
694static void WriteInstruction(const Instruction &I, unsigned InstID,
695                             ValueEnumerator &VE, BitstreamWriter &Stream,
696                             SmallVector<unsigned, 64> &Vals) {
697  unsigned Code = 0;
698  unsigned AbbrevToUse = 0;
699  switch (I.getOpcode()) {
700  default:
701    if (Instruction::isCast(I.getOpcode())) {
702      Code = bitc::FUNC_CODE_INST_CAST;
703      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
704        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
705      Vals.push_back(VE.getTypeID(I.getType()));
706      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
707    } else {
708      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
709      Code = bitc::FUNC_CODE_INST_BINOP;
710      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
711        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
712      Vals.push_back(VE.getValueID(I.getOperand(1)));
713      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
714    }
715    break;
716
717  case Instruction::GetElementPtr:
718    Code = bitc::FUNC_CODE_INST_GEP;
719    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
720      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
721    break;
722  case Instruction::ExtractValue: {
723    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
724    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
725    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
726    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
727      Vals.push_back(*i);
728    break;
729  }
730  case Instruction::InsertValue: {
731    Code = bitc::FUNC_CODE_INST_INSERTVAL;
732    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
733    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
734    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
735    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
736      Vals.push_back(*i);
737    break;
738  }
739  case Instruction::Select:
740    Code = bitc::FUNC_CODE_INST_SELECT;
741    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
742    Vals.push_back(VE.getValueID(I.getOperand(2)));
743    Vals.push_back(VE.getValueID(I.getOperand(0)));
744    break;
745  case Instruction::ExtractElement:
746    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
747    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
748    Vals.push_back(VE.getValueID(I.getOperand(1)));
749    break;
750  case Instruction::InsertElement:
751    Code = bitc::FUNC_CODE_INST_INSERTELT;
752    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
753    Vals.push_back(VE.getValueID(I.getOperand(1)));
754    Vals.push_back(VE.getValueID(I.getOperand(2)));
755    break;
756  case Instruction::ShuffleVector:
757    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
758    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
759    Vals.push_back(VE.getValueID(I.getOperand(1)));
760    Vals.push_back(VE.getValueID(I.getOperand(2)));
761    break;
762  case Instruction::ICmp:
763  case Instruction::FCmp:
764  case Instruction::VICmp:
765  case Instruction::VFCmp:
766    Code = bitc::FUNC_CODE_INST_CMP;
767    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
768    Vals.push_back(VE.getValueID(I.getOperand(1)));
769    Vals.push_back(cast<CmpInst>(I).getPredicate());
770    break;
771  case Instruction::GetResult:
772    Code = bitc::FUNC_CODE_INST_GETRESULT;
773    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
774    Vals.push_back(cast<GetResultInst>(I).getIndex());
775    break;
776
777  case Instruction::Ret:
778    {
779      Code = bitc::FUNC_CODE_INST_RET;
780      unsigned NumOperands = I.getNumOperands();
781      if (NumOperands == 0)
782        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
783      else if (NumOperands == 1) {
784        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
785          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
786      } else {
787        for (unsigned i = 0, e = NumOperands; i != e; ++i)
788          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
789      }
790    }
791    break;
792  case Instruction::Br:
793    Code = bitc::FUNC_CODE_INST_BR;
794    Vals.push_back(VE.getValueID(I.getOperand(0)));
795    if (cast<BranchInst>(I).isConditional()) {
796      Vals.push_back(VE.getValueID(I.getOperand(1)));
797      Vals.push_back(VE.getValueID(I.getOperand(2)));
798    }
799    break;
800  case Instruction::Switch:
801    Code = bitc::FUNC_CODE_INST_SWITCH;
802    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
803    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
804      Vals.push_back(VE.getValueID(I.getOperand(i)));
805    break;
806  case Instruction::Invoke: {
807    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
808    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
809    Code = bitc::FUNC_CODE_INST_INVOKE;
810
811    const InvokeInst *II = cast<InvokeInst>(&I);
812    Vals.push_back(VE.getParamAttrID(II->getParamAttrs()));
813    Vals.push_back(II->getCallingConv());
814    Vals.push_back(VE.getValueID(I.getOperand(1)));      // normal dest
815    Vals.push_back(VE.getValueID(I.getOperand(2)));      // unwind dest
816    PushValueAndType(I.getOperand(0), InstID, Vals, VE); // callee
817
818    // Emit value #'s for the fixed parameters.
819    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
820      Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
821
822    // Emit type/value pairs for varargs params.
823    if (FTy->isVarArg()) {
824      for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
825           i != e; ++i)
826        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
827    }
828    break;
829  }
830  case Instruction::Unwind:
831    Code = bitc::FUNC_CODE_INST_UNWIND;
832    break;
833  case Instruction::Unreachable:
834    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
835    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
836    break;
837
838  case Instruction::PHI:
839    Code = bitc::FUNC_CODE_INST_PHI;
840    Vals.push_back(VE.getTypeID(I.getType()));
841    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
842      Vals.push_back(VE.getValueID(I.getOperand(i)));
843    break;
844
845  case Instruction::Malloc:
846    Code = bitc::FUNC_CODE_INST_MALLOC;
847    Vals.push_back(VE.getTypeID(I.getType()));
848    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
849    Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
850    break;
851
852  case Instruction::Free:
853    Code = bitc::FUNC_CODE_INST_FREE;
854    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
855    break;
856
857  case Instruction::Alloca:
858    Code = bitc::FUNC_CODE_INST_ALLOCA;
859    Vals.push_back(VE.getTypeID(I.getType()));
860    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
861    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
862    break;
863
864  case Instruction::Load:
865    Code = bitc::FUNC_CODE_INST_LOAD;
866    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
867      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
868
869    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
870    Vals.push_back(cast<LoadInst>(I).isVolatile());
871    break;
872  case Instruction::Store:
873    Code = bitc::FUNC_CODE_INST_STORE2;
874    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
875    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
876    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
877    Vals.push_back(cast<StoreInst>(I).isVolatile());
878    break;
879  case Instruction::Call: {
880    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
881    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
882
883    Code = bitc::FUNC_CODE_INST_CALL;
884
885    const CallInst *CI = cast<CallInst>(&I);
886    Vals.push_back(VE.getParamAttrID(CI->getParamAttrs()));
887    Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
888    PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
889
890    // Emit value #'s for the fixed parameters.
891    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
892      Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
893
894    // Emit type/value pairs for varargs params.
895    if (FTy->isVarArg()) {
896      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
897      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
898           i != e; ++i)
899        PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
900    }
901    break;
902  }
903  case Instruction::VAArg:
904    Code = bitc::FUNC_CODE_INST_VAARG;
905    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
906    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
907    Vals.push_back(VE.getTypeID(I.getType())); // restype.
908    break;
909  }
910
911  Stream.EmitRecord(Code, Vals, AbbrevToUse);
912  Vals.clear();
913}
914
915// Emit names for globals/functions etc.
916static void WriteValueSymbolTable(const ValueSymbolTable &VST,
917                                  const ValueEnumerator &VE,
918                                  BitstreamWriter &Stream) {
919  if (VST.empty()) return;
920  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
921
922  // FIXME: Set up the abbrev, we know how many values there are!
923  // FIXME: We know if the type names can use 7-bit ascii.
924  SmallVector<unsigned, 64> NameVals;
925
926  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
927       SI != SE; ++SI) {
928
929    const ValueName &Name = *SI;
930
931    // Figure out the encoding to use for the name.
932    bool is7Bit = true;
933    bool isChar6 = true;
934    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
935         C != E; ++C) {
936      if (isChar6)
937        isChar6 = BitCodeAbbrevOp::isChar6(*C);
938      if ((unsigned char)*C & 128) {
939        is7Bit = false;
940        break;  // don't bother scanning the rest.
941      }
942    }
943
944    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
945
946    // VST_ENTRY:   [valueid, namechar x N]
947    // VST_BBENTRY: [bbid, namechar x N]
948    unsigned Code;
949    if (isa<BasicBlock>(SI->getValue())) {
950      Code = bitc::VST_CODE_BBENTRY;
951      if (isChar6)
952        AbbrevToUse = VST_BBENTRY_6_ABBREV;
953    } else {
954      Code = bitc::VST_CODE_ENTRY;
955      if (isChar6)
956        AbbrevToUse = VST_ENTRY_6_ABBREV;
957      else if (is7Bit)
958        AbbrevToUse = VST_ENTRY_7_ABBREV;
959    }
960
961    NameVals.push_back(VE.getValueID(SI->getValue()));
962    for (const char *P = Name.getKeyData(),
963         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
964      NameVals.push_back((unsigned char)*P);
965
966    // Emit the finished record.
967    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
968    NameVals.clear();
969  }
970  Stream.ExitBlock();
971}
972
973/// WriteFunction - Emit a function body to the module stream.
974static void WriteFunction(const Function &F, ValueEnumerator &VE,
975                          BitstreamWriter &Stream) {
976  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
977  VE.incorporateFunction(F);
978
979  SmallVector<unsigned, 64> Vals;
980
981  // Emit the number of basic blocks, so the reader can create them ahead of
982  // time.
983  Vals.push_back(VE.getBasicBlocks().size());
984  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
985  Vals.clear();
986
987  // If there are function-local constants, emit them now.
988  unsigned CstStart, CstEnd;
989  VE.getFunctionConstantRange(CstStart, CstEnd);
990  WriteConstants(CstStart, CstEnd, VE, Stream, false);
991
992  // Keep a running idea of what the instruction ID is.
993  unsigned InstID = CstEnd;
994
995  // Finally, emit all the instructions, in order.
996  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
997    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
998         I != E; ++I) {
999      WriteInstruction(*I, InstID, VE, Stream, Vals);
1000      if (I->getType() != Type::VoidTy)
1001        ++InstID;
1002    }
1003
1004  // Emit names for all the instructions etc.
1005  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1006
1007  VE.purgeFunction();
1008  Stream.ExitBlock();
1009}
1010
1011/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1012static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1013                                 const ValueEnumerator &VE,
1014                                 BitstreamWriter &Stream) {
1015  if (TST.empty()) return;
1016
1017  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1018
1019  // 7-bit fixed width VST_CODE_ENTRY strings.
1020  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1021  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1022  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1023                            Log2_32_Ceil(VE.getTypes().size()+1)));
1024  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1025  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1026  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1027
1028  SmallVector<unsigned, 64> NameVals;
1029
1030  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1031       TI != TE; ++TI) {
1032    // TST_ENTRY: [typeid, namechar x N]
1033    NameVals.push_back(VE.getTypeID(TI->second));
1034
1035    const std::string &Str = TI->first;
1036    bool is7Bit = true;
1037    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1038      NameVals.push_back((unsigned char)Str[i]);
1039      if (Str[i] & 128)
1040        is7Bit = false;
1041    }
1042
1043    // Emit the finished record.
1044    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1045    NameVals.clear();
1046  }
1047
1048  Stream.ExitBlock();
1049}
1050
1051// Emit blockinfo, which defines the standard abbreviations etc.
1052static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1053  // We only want to emit block info records for blocks that have multiple
1054  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1055  // blocks can defined their abbrevs inline.
1056  Stream.EnterBlockInfoBlock(2);
1057
1058  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1059    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1060    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1061    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1062    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1063    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1064    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1065                                   Abbv) != VST_ENTRY_8_ABBREV)
1066      assert(0 && "Unexpected abbrev ordering!");
1067  }
1068
1069  { // 7-bit fixed width VST_ENTRY strings.
1070    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1071    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1072    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1073    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1074    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1075    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1076                                   Abbv) != VST_ENTRY_7_ABBREV)
1077      assert(0 && "Unexpected abbrev ordering!");
1078  }
1079  { // 6-bit char6 VST_ENTRY strings.
1080    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1081    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1082    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1083    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1084    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1085    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1086                                   Abbv) != VST_ENTRY_6_ABBREV)
1087      assert(0 && "Unexpected abbrev ordering!");
1088  }
1089  { // 6-bit char6 VST_BBENTRY strings.
1090    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1091    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1092    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1093    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1094    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1095    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1096                                   Abbv) != VST_BBENTRY_6_ABBREV)
1097      assert(0 && "Unexpected abbrev ordering!");
1098  }
1099
1100
1101
1102  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1103    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1104    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1105    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1106                              Log2_32_Ceil(VE.getTypes().size()+1)));
1107    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1108                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1109      assert(0 && "Unexpected abbrev ordering!");
1110  }
1111
1112  { // INTEGER abbrev for CONSTANTS_BLOCK.
1113    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1114    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1115    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1116    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1117                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1118      assert(0 && "Unexpected abbrev ordering!");
1119  }
1120
1121  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1122    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1123    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1124    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1125    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1126                              Log2_32_Ceil(VE.getTypes().size()+1)));
1127    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1128
1129    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1130                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1131      assert(0 && "Unexpected abbrev ordering!");
1132  }
1133  { // NULL abbrev for CONSTANTS_BLOCK.
1134    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1135    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1136    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1137                                   Abbv) != CONSTANTS_NULL_Abbrev)
1138      assert(0 && "Unexpected abbrev ordering!");
1139  }
1140
1141  // FIXME: This should only use space for first class types!
1142
1143  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1144    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1145    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1146    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1147    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1148    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1149    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1150                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1151      assert(0 && "Unexpected abbrev ordering!");
1152  }
1153  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1154    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1155    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1156    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1157    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1158    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1159    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1160                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1161      assert(0 && "Unexpected abbrev ordering!");
1162  }
1163  { // INST_CAST abbrev for FUNCTION_BLOCK.
1164    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1165    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1166    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1167    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1168                              Log2_32_Ceil(VE.getTypes().size()+1)));
1169    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1170    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1171                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1172      assert(0 && "Unexpected abbrev ordering!");
1173  }
1174
1175  { // INST_RET abbrev for FUNCTION_BLOCK.
1176    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1177    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1178    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1179                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1180      assert(0 && "Unexpected abbrev ordering!");
1181  }
1182  { // INST_RET abbrev for FUNCTION_BLOCK.
1183    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1184    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1185    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1186    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1187                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1188      assert(0 && "Unexpected abbrev ordering!");
1189  }
1190  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1191    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1192    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1193    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1194                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1195      assert(0 && "Unexpected abbrev ordering!");
1196  }
1197
1198  Stream.ExitBlock();
1199}
1200
1201
1202/// WriteModule - Emit the specified module to the bitstream.
1203static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1204  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1205
1206  // Emit the version number if it is non-zero.
1207  if (CurVersion) {
1208    SmallVector<unsigned, 1> Vals;
1209    Vals.push_back(CurVersion);
1210    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1211  }
1212
1213  // Analyze the module, enumerating globals, functions, etc.
1214  ValueEnumerator VE(M);
1215
1216  // Emit blockinfo, which defines the standard abbreviations etc.
1217  WriteBlockInfo(VE, Stream);
1218
1219  // Emit information about parameter attributes.
1220  WriteParamAttrTable(VE, Stream);
1221
1222  // Emit information describing all of the types in the module.
1223  WriteTypeTable(VE, Stream);
1224
1225  // Emit top-level description of module, including target triple, inline asm,
1226  // descriptors for global variables, and function prototype info.
1227  WriteModuleInfo(M, VE, Stream);
1228
1229  // Emit constants.
1230  WriteModuleConstants(VE, Stream);
1231
1232  // If we have any aggregate values in the value table, purge them - these can
1233  // only be used to initialize global variables.  Doing so makes the value
1234  // namespace smaller for code in functions.
1235  int NumNonAggregates = VE.PurgeAggregateValues();
1236  if (NumNonAggregates != -1) {
1237    SmallVector<unsigned, 1> Vals;
1238    Vals.push_back(NumNonAggregates);
1239    Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
1240  }
1241
1242  // Emit function bodies.
1243  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1244    if (!I->isDeclaration())
1245      WriteFunction(*I, VE, Stream);
1246
1247  // Emit the type symbol table information.
1248  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1249
1250  // Emit names for globals/functions etc.
1251  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1252
1253  Stream.ExitBlock();
1254}
1255
1256/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1257/// header and trailer to make it compatible with the system archiver.  To do
1258/// this we emit the following header, and then emit a trailer that pads the
1259/// file out to be a multiple of 16 bytes.
1260///
1261/// struct bc_header {
1262///   uint32_t Magic;         // 0x0B17C0DE
1263///   uint32_t Version;       // Version, currently always 0.
1264///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1265///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1266///   uint32_t CPUType;       // CPU specifier.
1267///   ... potentially more later ...
1268/// };
1269enum {
1270  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1271  DarwinBCHeaderSize = 5*4
1272};
1273
1274static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1275                               const std::string &TT) {
1276  unsigned CPUType = ~0U;
1277
1278  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*.  The CPUType is a
1279  // magic number from /usr/include/mach/machine.h.  It is ok to reproduce the
1280  // specific constants here because they are implicitly part of the Darwin ABI.
1281  enum {
1282    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1283    DARWIN_CPU_TYPE_X86        = 7,
1284    DARWIN_CPU_TYPE_POWERPC    = 18
1285  };
1286
1287  if (TT.find("x86_64-") == 0)
1288    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1289  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1290           TT[4] == '-' && TT[1] - '3' < 6)
1291    CPUType = DARWIN_CPU_TYPE_X86;
1292  else if (TT.find("powerpc-") == 0)
1293    CPUType = DARWIN_CPU_TYPE_POWERPC;
1294  else if (TT.find("powerpc64-") == 0)
1295    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1296
1297  // Traditional Bitcode starts after header.
1298  unsigned BCOffset = DarwinBCHeaderSize;
1299
1300  Stream.Emit(0x0B17C0DE, 32);
1301  Stream.Emit(0         , 32);  // Version.
1302  Stream.Emit(BCOffset  , 32);
1303  Stream.Emit(0         , 32);  // Filled in later.
1304  Stream.Emit(CPUType   , 32);
1305}
1306
1307/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1308/// finalize the header.
1309static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1310  // Update the size field in the header.
1311  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1312
1313  // If the file is not a multiple of 16 bytes, insert dummy padding.
1314  while (BufferSize & 15) {
1315    Stream.Emit(0, 8);
1316    ++BufferSize;
1317  }
1318}
1319
1320
1321/// WriteBitcodeToFile - Write the specified module to the specified output
1322/// stream.
1323void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
1324  std::vector<unsigned char> Buffer;
1325  BitstreamWriter Stream(Buffer);
1326
1327  Buffer.reserve(256*1024);
1328
1329  // If this is darwin, emit a file header and trailer if needed.
1330  bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1331  if (isDarwin)
1332    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1333
1334  // Emit the file header.
1335  Stream.Emit((unsigned)'B', 8);
1336  Stream.Emit((unsigned)'C', 8);
1337  Stream.Emit(0x0, 4);
1338  Stream.Emit(0xC, 4);
1339  Stream.Emit(0xE, 4);
1340  Stream.Emit(0xD, 4);
1341
1342  // Emit the module.
1343  WriteModule(M, Stream);
1344
1345  if (isDarwin)
1346    EmitDarwinBCTrailer(Stream, Buffer.size());
1347
1348
1349  // If writing to stdout, set binary mode.
1350  if (llvm::cout == Out)
1351    sys::Program::ChangeStdoutToBinary();
1352
1353  // Write the generated bitstream to "Out".
1354  Out.write((char*)&Buffer.front(), Buffer.size());
1355
1356  // Make sure it hits disk now.
1357  Out.flush();
1358}
1359