BitcodeWriter.cpp revision e2e9d8e6aa914b81d79ff496736165f3358c6f3a 
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/Support/Streams.h"
27#include "llvm/Support/raw_ostream.h"
28#include "llvm/System/Program.h"
29using namespace llvm;
30
31/// These are manifest constants used by the bitcode writer. They do not need to
32/// be kept in sync with the reader, but need to be consistent within this file.
33enum {
34  CurVersion = 0,
35
36  // VALUE_SYMTAB_BLOCK abbrev id's.
37  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
38  VST_ENTRY_7_ABBREV,
39  VST_ENTRY_6_ABBREV,
40  VST_BBENTRY_6_ABBREV,
41
42  // CONSTANTS_BLOCK abbrev id's.
43  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
44  CONSTANTS_INTEGER_ABBREV,
45  CONSTANTS_CE_CAST_Abbrev,
46  CONSTANTS_NULL_Abbrev,
47
48  // FUNCTION_BLOCK abbrev id's.
49  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
50  FUNCTION_INST_BINOP_ABBREV,
51  FUNCTION_INST_CAST_ABBREV,
52  FUNCTION_INST_RET_VOID_ABBREV,
53  FUNCTION_INST_RET_VAL_ABBREV,
54  FUNCTION_INST_UNREACHABLE_ABBREV
55};
56
57
58static unsigned GetEncodedCastOpcode(unsigned Opcode) {
59  switch (Opcode) {
60  default: assert(0 && "Unknown cast instruction!");
61  case Instruction::Trunc   : return bitc::CAST_TRUNC;
62  case Instruction::ZExt    : return bitc::CAST_ZEXT;
63  case Instruction::SExt    : return bitc::CAST_SEXT;
64  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
65  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
66  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
67  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
68  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
69  case Instruction::FPExt   : return bitc::CAST_FPEXT;
70  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
71  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
72  case Instruction::BitCast : return bitc::CAST_BITCAST;
73  }
74}
75
76static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
77  switch (Opcode) {
78  default: assert(0 && "Unknown binary instruction!");
79  case Instruction::Add:  return bitc::BINOP_ADD;
80  case Instruction::Sub:  return bitc::BINOP_SUB;
81  case Instruction::Mul:  return bitc::BINOP_MUL;
82  case Instruction::UDiv: return bitc::BINOP_UDIV;
83  case Instruction::FDiv:
84  case Instruction::SDiv: return bitc::BINOP_SDIV;
85  case Instruction::URem: return bitc::BINOP_UREM;
86  case Instruction::FRem:
87  case Instruction::SRem: return bitc::BINOP_SREM;
88  case Instruction::Shl:  return bitc::BINOP_SHL;
89  case Instruction::LShr: return bitc::BINOP_LSHR;
90  case Instruction::AShr: return bitc::BINOP_ASHR;
91  case Instruction::And:  return bitc::BINOP_AND;
92  case Instruction::Or:   return bitc::BINOP_OR;
93  case Instruction::Xor:  return bitc::BINOP_XOR;
94  }
95}
96
97
98
99static void WriteStringRecord(unsigned Code, const std::string &Str,
100                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
101  SmallVector<unsigned, 64> Vals;
102
103  // Code: [strchar x N]
104  for (unsigned i = 0, e = Str.size(); i != e; ++i)
105    Vals.push_back(Str[i]);
106
107  // Emit the finished record.
108  Stream.EmitRecord(Code, Vals, AbbrevToUse);
109}
110
111// Emit information about parameter attributes.
112static void WriteAttributeTable(const ValueEnumerator &VE,
113                                BitstreamWriter &Stream) {
114  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
115  if (Attrs.empty()) return;
116
117  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
118
119  SmallVector<uint64_t, 64> Record;
120  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
121    const AttrListPtr &A = Attrs[i];
122    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
123      const AttributeWithIndex &PAWI = A.getSlot(i);
124      Record.push_back(PAWI.Index);
125      Record.push_back(PAWI.Attrs);
126    }
127
128    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
129    Record.clear();
130  }
131
132  Stream.ExitBlock();
133}
134
135/// WriteTypeTable - Write out the type table for a module.
136static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
137  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
138
139  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
140  SmallVector<uint64_t, 64> TypeVals;
141
142  // Abbrev for TYPE_CODE_POINTER.
143  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
144  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
145  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
146                            Log2_32_Ceil(VE.getTypes().size()+1)));
147  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
148  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
149
150  // Abbrev for TYPE_CODE_FUNCTION.
151  Abbv = new BitCodeAbbrev();
152  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
153  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
154  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
155  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
156  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
157                            Log2_32_Ceil(VE.getTypes().size()+1)));
158  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
159
160  // Abbrev for TYPE_CODE_STRUCT.
161  Abbv = new BitCodeAbbrev();
162  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
163  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
164  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
165  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
166                            Log2_32_Ceil(VE.getTypes().size()+1)));
167  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
168
169  // Abbrev for TYPE_CODE_ARRAY.
170  Abbv = new BitCodeAbbrev();
171  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
172  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
173  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
174                            Log2_32_Ceil(VE.getTypes().size()+1)));
175  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
176
177  // Emit an entry count so the reader can reserve space.
178  TypeVals.push_back(TypeList.size());
179  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
180  TypeVals.clear();
181
182  // Loop over all of the types, emitting each in turn.
183  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
184    const Type *T = TypeList[i].first;
185    int AbbrevToUse = 0;
186    unsigned Code = 0;
187
188    switch (T->getTypeID()) {
189    default: assert(0 && "Unknown type!");
190    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
191    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
192    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
193    case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
194    case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
195    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
196    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
197    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
198    case Type::IntegerTyID:
199      // INTEGER: [width]
200      Code = bitc::TYPE_CODE_INTEGER;
201      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
202      break;
203    case Type::PointerTyID: {
204      const PointerType *PTy = cast<PointerType>(T);
205      // POINTER: [pointee type, address space]
206      Code = bitc::TYPE_CODE_POINTER;
207      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
208      unsigned AddressSpace = PTy->getAddressSpace();
209      TypeVals.push_back(AddressSpace);
210      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
211      break;
212    }
213    case Type::FunctionTyID: {
214      const FunctionType *FT = cast<FunctionType>(T);
215      // FUNCTION: [isvararg, attrid, retty, paramty x N]
216      Code = bitc::TYPE_CODE_FUNCTION;
217      TypeVals.push_back(FT->isVarArg());
218      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
219      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
220      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
221        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
222      AbbrevToUse = FunctionAbbrev;
223      break;
224    }
225    case Type::StructTyID: {
226      const StructType *ST = cast<StructType>(T);
227      // STRUCT: [ispacked, eltty x N]
228      Code = bitc::TYPE_CODE_STRUCT;
229      TypeVals.push_back(ST->isPacked());
230      // Output all of the element types.
231      for (StructType::element_iterator I = ST->element_begin(),
232           E = ST->element_end(); I != E; ++I)
233        TypeVals.push_back(VE.getTypeID(*I));
234      AbbrevToUse = StructAbbrev;
235      break;
236    }
237    case Type::ArrayTyID: {
238      const ArrayType *AT = cast<ArrayType>(T);
239      // ARRAY: [numelts, eltty]
240      Code = bitc::TYPE_CODE_ARRAY;
241      TypeVals.push_back(AT->getNumElements());
242      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
243      AbbrevToUse = ArrayAbbrev;
244      break;
245    }
246    case Type::VectorTyID: {
247      const VectorType *VT = cast<VectorType>(T);
248      // VECTOR [numelts, eltty]
249      Code = bitc::TYPE_CODE_VECTOR;
250      TypeVals.push_back(VT->getNumElements());
251      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
252      break;
253    }
254    }
255
256    // Emit the finished record.
257    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
258    TypeVals.clear();
259  }
260
261  Stream.ExitBlock();
262}
263
264static unsigned getEncodedLinkage(const GlobalValue *GV) {
265  switch (GV->getLinkage()) {
266  default: assert(0 && "Invalid linkage!");
267  case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
268  case GlobalValue::ExternalLinkage:     return 0;
269  case GlobalValue::WeakLinkage:         return 1;
270  case GlobalValue::AppendingLinkage:    return 2;
271  case GlobalValue::InternalLinkage:     return 3;
272  case GlobalValue::LinkOnceLinkage:     return 4;
273  case GlobalValue::DLLImportLinkage:    return 5;
274  case GlobalValue::DLLExportLinkage:    return 6;
275  case GlobalValue::ExternalWeakLinkage: return 7;
276  case GlobalValue::CommonLinkage:       return 8;
277  }
278}
279
280static unsigned getEncodedVisibility(const GlobalValue *GV) {
281  switch (GV->getVisibility()) {
282  default: assert(0 && "Invalid visibility!");
283  case GlobalValue::DefaultVisibility:   return 0;
284  case GlobalValue::HiddenVisibility:    return 1;
285  case GlobalValue::ProtectedVisibility: return 2;
286  }
287}
288
289// Emit top-level description of module, including target triple, inline asm,
290// descriptors for global variables, and function prototype info.
291static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
292                            BitstreamWriter &Stream) {
293  // Emit the list of dependent libraries for the Module.
294  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
295    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
296
297  // Emit various pieces of data attached to a module.
298  if (!M->getTargetTriple().empty())
299    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
300                      0/*TODO*/, Stream);
301  if (!M->getDataLayout().empty())
302    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
303                      0/*TODO*/, Stream);
304  if (!M->getModuleInlineAsm().empty())
305    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
306                      0/*TODO*/, Stream);
307
308  // Emit information about sections and GC, computing how many there are. Also
309  // compute the maximum alignment value.
310  std::map<std::string, unsigned> SectionMap;
311  std::map<std::string, unsigned> GCMap;
312  unsigned MaxAlignment = 0;
313  unsigned MaxGlobalType = 0;
314  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
315       GV != E; ++GV) {
316    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
317    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
318
319    if (!GV->hasSection()) continue;
320    // Give section names unique ID's.
321    unsigned &Entry = SectionMap[GV->getSection()];
322    if (Entry != 0) continue;
323    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
324                      0/*TODO*/, Stream);
325    Entry = SectionMap.size();
326  }
327  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
328    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
329    if (F->hasSection()) {
330      // Give section names unique ID's.
331      unsigned &Entry = SectionMap[F->getSection()];
332      if (!Entry) {
333        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
334                          0/*TODO*/, Stream);
335        Entry = SectionMap.size();
336      }
337    }
338    if (F->hasGC()) {
339      // Same for GC names.
340      unsigned &Entry = GCMap[F->getGC()];
341      if (!Entry) {
342        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
343                          0/*TODO*/, Stream);
344        Entry = GCMap.size();
345      }
346    }
347  }
348
349  // Emit abbrev for globals, now that we know # sections and max alignment.
350  unsigned SimpleGVarAbbrev = 0;
351  if (!M->global_empty()) {
352    // Add an abbrev for common globals with no visibility or thread localness.
353    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
354    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
355    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
356                              Log2_32_Ceil(MaxGlobalType+1)));
357    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
358    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
359    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
360    if (MaxAlignment == 0)                                      // Alignment.
361      Abbv->Add(BitCodeAbbrevOp(0));
362    else {
363      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
364      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
365                               Log2_32_Ceil(MaxEncAlignment+1)));
366    }
367    if (SectionMap.empty())                                    // Section.
368      Abbv->Add(BitCodeAbbrevOp(0));
369    else
370      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
371                               Log2_32_Ceil(SectionMap.size()+1)));
372    // Don't bother emitting vis + thread local.
373    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
374  }
375
376  // Emit the global variable information.
377  SmallVector<unsigned, 64> Vals;
378  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
379       GV != E; ++GV) {
380    unsigned AbbrevToUse = 0;
381
382    // GLOBALVAR: [type, isconst, initid,
383    //             linkage, alignment, section, visibility, threadlocal]
384    Vals.push_back(VE.getTypeID(GV->getType()));
385    Vals.push_back(GV->isConstant());
386    Vals.push_back(GV->isDeclaration() ? 0 :
387                   (VE.getValueID(GV->getInitializer()) + 1));
388    Vals.push_back(getEncodedLinkage(GV));
389    Vals.push_back(Log2_32(GV->getAlignment())+1);
390    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
391    if (GV->isThreadLocal() ||
392        GV->getVisibility() != GlobalValue::DefaultVisibility) {
393      Vals.push_back(getEncodedVisibility(GV));
394      Vals.push_back(GV->isThreadLocal());
395    } else {
396      AbbrevToUse = SimpleGVarAbbrev;
397    }
398
399    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
400    Vals.clear();
401  }
402
403  // Emit the function proto information.
404  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
405    // FUNCTION:  [type, callingconv, isproto, paramattr,
406    //             linkage, alignment, section, visibility, gc]
407    Vals.push_back(VE.getTypeID(F->getType()));
408    Vals.push_back(F->getCallingConv());
409    Vals.push_back(F->isDeclaration());
410    Vals.push_back(getEncodedLinkage(F));
411    Vals.push_back(VE.getAttributeID(F->getAttributes()));
412    Vals.push_back(Log2_32(F->getAlignment())+1);
413    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
414    Vals.push_back(getEncodedVisibility(F));
415    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
416
417    unsigned AbbrevToUse = 0;
418    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
419    Vals.clear();
420  }
421
422
423  // Emit the alias information.
424  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
425       AI != E; ++AI) {
426    Vals.push_back(VE.getTypeID(AI->getType()));
427    Vals.push_back(VE.getValueID(AI->getAliasee()));
428    Vals.push_back(getEncodedLinkage(AI));
429    Vals.push_back(getEncodedVisibility(AI));
430    unsigned AbbrevToUse = 0;
431    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
432    Vals.clear();
433  }
434}
435
436
437static void WriteConstants(unsigned FirstVal, unsigned LastVal,
438                           const ValueEnumerator &VE,
439                           BitstreamWriter &Stream, bool isGlobal) {
440  if (FirstVal == LastVal) return;
441
442  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
443
444  unsigned AggregateAbbrev = 0;
445  unsigned String8Abbrev = 0;
446  unsigned CString7Abbrev = 0;
447  unsigned CString6Abbrev = 0;
448  // If this is a constant pool for the module, emit module-specific abbrevs.
449  if (isGlobal) {
450    // Abbrev for CST_CODE_AGGREGATE.
451    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
452    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
453    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
454    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
455    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
456
457    // Abbrev for CST_CODE_STRING.
458    Abbv = new BitCodeAbbrev();
459    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
460    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
461    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
462    String8Abbrev = Stream.EmitAbbrev(Abbv);
463    // Abbrev for CST_CODE_CSTRING.
464    Abbv = new BitCodeAbbrev();
465    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
466    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
467    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
468    CString7Abbrev = Stream.EmitAbbrev(Abbv);
469    // Abbrev for CST_CODE_CSTRING.
470    Abbv = new BitCodeAbbrev();
471    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
472    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
473    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
474    CString6Abbrev = Stream.EmitAbbrev(Abbv);
475  }
476
477  SmallVector<uint64_t, 64> Record;
478
479  const ValueEnumerator::ValueList &Vals = VE.getValues();
480  const Type *LastTy = 0;
481  for (unsigned i = FirstVal; i != LastVal; ++i) {
482    const Value *V = Vals[i].first;
483    // If we need to switch types, do so now.
484    if (V->getType() != LastTy) {
485      LastTy = V->getType();
486      Record.push_back(VE.getTypeID(LastTy));
487      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
488                        CONSTANTS_SETTYPE_ABBREV);
489      Record.clear();
490    }
491
492    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
493      Record.push_back(unsigned(IA->hasSideEffects()));
494
495      // Add the asm string.
496      const std::string &AsmStr = IA->getAsmString();
497      Record.push_back(AsmStr.size());
498      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
499        Record.push_back(AsmStr[i]);
500
501      // Add the constraint string.
502      const std::string &ConstraintStr = IA->getConstraintString();
503      Record.push_back(ConstraintStr.size());
504      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
505        Record.push_back(ConstraintStr[i]);
506      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
507      Record.clear();
508      continue;
509    }
510    const Constant *C = cast<Constant>(V);
511    unsigned Code = -1U;
512    unsigned AbbrevToUse = 0;
513    if (C->isNullValue()) {
514      Code = bitc::CST_CODE_NULL;
515    } else if (isa<UndefValue>(C)) {
516      Code = bitc::CST_CODE_UNDEF;
517    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
518      if (IV->getBitWidth() <= 64) {
519        int64_t V = IV->getSExtValue();
520        if (V >= 0)
521          Record.push_back(V << 1);
522        else
523          Record.push_back((-V << 1) | 1);
524        Code = bitc::CST_CODE_INTEGER;
525        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
526      } else {                             // Wide integers, > 64 bits in size.
527        // We have an arbitrary precision integer value to write whose
528        // bit width is > 64. However, in canonical unsigned integer
529        // format it is likely that the high bits are going to be zero.
530        // So, we only write the number of active words.
531        unsigned NWords = IV->getValue().getActiveWords();
532        const uint64_t *RawWords = IV->getValue().getRawData();
533        for (unsigned i = 0; i != NWords; ++i) {
534          int64_t V = RawWords[i];
535          if (V >= 0)
536            Record.push_back(V << 1);
537          else
538            Record.push_back((-V << 1) | 1);
539        }
540        Code = bitc::CST_CODE_WIDE_INTEGER;
541      }
542    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
543      Code = bitc::CST_CODE_FLOAT;
544      const Type *Ty = CFP->getType();
545      if (Ty == Type::FloatTy || Ty == Type::DoubleTy) {
546        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
547      } else if (Ty == Type::X86_FP80Ty) {
548        // api needed to prevent premature destruction
549        APInt api = CFP->getValueAPF().bitcastToAPInt();
550        const uint64_t *p = api.getRawData();
551        Record.push_back(p[0]);
552        Record.push_back((uint16_t)p[1]);
553      } else if (Ty == Type::FP128Ty || Ty == Type::PPC_FP128Ty) {
554        APInt api = CFP->getValueAPF().bitcastToAPInt();
555        const uint64_t *p = api.getRawData();
556        Record.push_back(p[0]);
557        Record.push_back(p[1]);
558      } else {
559        assert (0 && "Unknown FP type!");
560      }
561    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
562      // Emit constant strings specially.
563      unsigned NumOps = C->getNumOperands();
564      // If this is a null-terminated string, use the denser CSTRING encoding.
565      if (C->getOperand(NumOps-1)->isNullValue()) {
566        Code = bitc::CST_CODE_CSTRING;
567        --NumOps;  // Don't encode the null, which isn't allowed by char6.
568      } else {
569        Code = bitc::CST_CODE_STRING;
570        AbbrevToUse = String8Abbrev;
571      }
572      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
573      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
574      for (unsigned i = 0; i != NumOps; ++i) {
575        unsigned char V = cast<ConstantInt>(C->getOperand(i))->getZExtValue();
576        Record.push_back(V);
577        isCStr7 &= (V & 128) == 0;
578        if (isCStrChar6)
579          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
580      }
581
582      if (isCStrChar6)
583        AbbrevToUse = CString6Abbrev;
584      else if (isCStr7)
585        AbbrevToUse = CString7Abbrev;
586    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
587               isa<ConstantVector>(V)) {
588      Code = bitc::CST_CODE_AGGREGATE;
589      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
590        Record.push_back(VE.getValueID(C->getOperand(i)));
591      AbbrevToUse = AggregateAbbrev;
592    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
593      switch (CE->getOpcode()) {
594      default:
595        if (Instruction::isCast(CE->getOpcode())) {
596          Code = bitc::CST_CODE_CE_CAST;
597          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
598          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
599          Record.push_back(VE.getValueID(C->getOperand(0)));
600          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
601        } else {
602          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
603          Code = bitc::CST_CODE_CE_BINOP;
604          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
605          Record.push_back(VE.getValueID(C->getOperand(0)));
606          Record.push_back(VE.getValueID(C->getOperand(1)));
607        }
608        break;
609      case Instruction::GetElementPtr:
610        Code = bitc::CST_CODE_CE_GEP;
611        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
612          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
613          Record.push_back(VE.getValueID(C->getOperand(i)));
614        }
615        break;
616      case Instruction::Select:
617        Code = bitc::CST_CODE_CE_SELECT;
618        Record.push_back(VE.getValueID(C->getOperand(0)));
619        Record.push_back(VE.getValueID(C->getOperand(1)));
620        Record.push_back(VE.getValueID(C->getOperand(2)));
621        break;
622      case Instruction::ExtractElement:
623        Code = bitc::CST_CODE_CE_EXTRACTELT;
624        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
625        Record.push_back(VE.getValueID(C->getOperand(0)));
626        Record.push_back(VE.getValueID(C->getOperand(1)));
627        break;
628      case Instruction::InsertElement:
629        Code = bitc::CST_CODE_CE_INSERTELT;
630        Record.push_back(VE.getValueID(C->getOperand(0)));
631        Record.push_back(VE.getValueID(C->getOperand(1)));
632        Record.push_back(VE.getValueID(C->getOperand(2)));
633        break;
634      case Instruction::ShuffleVector:
635        Code = bitc::CST_CODE_CE_SHUFFLEVEC;
636        Record.push_back(VE.getValueID(C->getOperand(0)));
637        Record.push_back(VE.getValueID(C->getOperand(1)));
638        Record.push_back(VE.getValueID(C->getOperand(2)));
639        break;
640      case Instruction::ICmp:
641      case Instruction::FCmp:
642      case Instruction::VICmp:
643      case Instruction::VFCmp:
644        if (isa<VectorType>(C->getOperand(0)->getType())
645            && (CE->getOpcode() == Instruction::ICmp
646                || CE->getOpcode() == Instruction::FCmp)) {
647          // compare returning vector of Int1Ty
648          assert(0 && "Unsupported constant!");
649        } else {
650          Code = bitc::CST_CODE_CE_CMP;
651        }
652        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
653        Record.push_back(VE.getValueID(C->getOperand(0)));
654        Record.push_back(VE.getValueID(C->getOperand(1)));
655        Record.push_back(CE->getPredicate());
656        break;
657      }
658    } else {
659      assert(0 && "Unknown constant!");
660    }
661    Stream.EmitRecord(Code, Record, AbbrevToUse);
662    Record.clear();
663  }
664
665  Stream.ExitBlock();
666}
667
668static void WriteModuleConstants(const ValueEnumerator &VE,
669                                 BitstreamWriter &Stream) {
670  const ValueEnumerator::ValueList &Vals = VE.getValues();
671
672  // Find the first constant to emit, which is the first non-globalvalue value.
673  // We know globalvalues have been emitted by WriteModuleInfo.
674  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
675    if (!isa<GlobalValue>(Vals[i].first)) {
676      WriteConstants(i, Vals.size(), VE, Stream, true);
677      return;
678    }
679  }
680}
681
682/// PushValueAndType - The file has to encode both the value and type id for
683/// many values, because we need to know what type to create for forward
684/// references.  However, most operands are not forward references, so this type
685/// field is not needed.
686///
687/// This function adds V's value ID to Vals.  If the value ID is higher than the
688/// instruction ID, then it is a forward reference, and it also includes the
689/// type ID.
690static bool PushValueAndType(Value *V, unsigned InstID,
691                             SmallVector<unsigned, 64> &Vals,
692                             ValueEnumerator &VE) {
693  unsigned ValID = VE.getValueID(V);
694  Vals.push_back(ValID);
695  if (ValID >= InstID) {
696    Vals.push_back(VE.getTypeID(V->getType()));
697    return true;
698  }
699  return false;
700}
701
702/// WriteInstruction - Emit an instruction to the specified stream.
703static void WriteInstruction(const Instruction &I, unsigned InstID,
704                             ValueEnumerator &VE, BitstreamWriter &Stream,
705                             SmallVector<unsigned, 64> &Vals) {
706  unsigned Code = 0;
707  unsigned AbbrevToUse = 0;
708  switch (I.getOpcode()) {
709  default:
710    if (Instruction::isCast(I.getOpcode())) {
711      Code = bitc::FUNC_CODE_INST_CAST;
712      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
713        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
714      Vals.push_back(VE.getTypeID(I.getType()));
715      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
716    } else {
717      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
718      Code = bitc::FUNC_CODE_INST_BINOP;
719      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
720        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
721      Vals.push_back(VE.getValueID(I.getOperand(1)));
722      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
723    }
724    break;
725
726  case Instruction::GetElementPtr:
727    Code = bitc::FUNC_CODE_INST_GEP;
728    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
729      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
730    break;
731  case Instruction::ExtractValue: {
732    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
733    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
734    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
735    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
736      Vals.push_back(*i);
737    break;
738  }
739  case Instruction::InsertValue: {
740    Code = bitc::FUNC_CODE_INST_INSERTVAL;
741    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
742    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
743    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
744    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
745      Vals.push_back(*i);
746    break;
747  }
748  case Instruction::Select:
749    Code = bitc::FUNC_CODE_INST_VSELECT;
750    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
751    Vals.push_back(VE.getValueID(I.getOperand(2)));
752    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
753    break;
754  case Instruction::ExtractElement:
755    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
756    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
757    Vals.push_back(VE.getValueID(I.getOperand(1)));
758    break;
759  case Instruction::InsertElement:
760    Code = bitc::FUNC_CODE_INST_INSERTELT;
761    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
762    Vals.push_back(VE.getValueID(I.getOperand(1)));
763    Vals.push_back(VE.getValueID(I.getOperand(2)));
764    break;
765  case Instruction::ShuffleVector:
766    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
767    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
768    Vals.push_back(VE.getValueID(I.getOperand(1)));
769    Vals.push_back(VE.getValueID(I.getOperand(2)));
770    break;
771  case Instruction::ICmp:
772  case Instruction::FCmp:
773  case Instruction::VICmp:
774  case Instruction::VFCmp:
775    if (I.getOpcode() == Instruction::ICmp
776        || I.getOpcode() == Instruction::FCmp) {
777      // compare returning Int1Ty or vector of Int1Ty
778      Code = bitc::FUNC_CODE_INST_CMP2;
779    } else {
780      Code = bitc::FUNC_CODE_INST_CMP;
781    }
782    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
783    Vals.push_back(VE.getValueID(I.getOperand(1)));
784    Vals.push_back(cast<CmpInst>(I).getPredicate());
785    break;
786
787  case Instruction::Ret:
788    {
789      Code = bitc::FUNC_CODE_INST_RET;
790      unsigned NumOperands = I.getNumOperands();
791      if (NumOperands == 0)
792        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
793      else if (NumOperands == 1) {
794        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
795          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
796      } else {
797        for (unsigned i = 0, e = NumOperands; i != e; ++i)
798          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
799      }
800    }
801    break;
802  case Instruction::Br:
803    Code = bitc::FUNC_CODE_INST_BR;
804    Vals.push_back(VE.getValueID(I.getOperand(0)));
805    if (cast<BranchInst>(I).isConditional()) {
806      Vals.push_back(VE.getValueID(I.getOperand(1)));
807      Vals.push_back(VE.getValueID(I.getOperand(2)));
808    }
809    break;
810  case Instruction::Switch:
811    Code = bitc::FUNC_CODE_INST_SWITCH;
812    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
813    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
814      Vals.push_back(VE.getValueID(I.getOperand(i)));
815    break;
816  case Instruction::Invoke: {
817    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
818    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
819    Code = bitc::FUNC_CODE_INST_INVOKE;
820
821    const InvokeInst *II = cast<InvokeInst>(&I);
822    Vals.push_back(VE.getAttributeID(II->getAttributes()));
823    Vals.push_back(II->getCallingConv());
824    Vals.push_back(VE.getValueID(I.getOperand(1)));      // normal dest
825    Vals.push_back(VE.getValueID(I.getOperand(2)));      // unwind dest
826    PushValueAndType(I.getOperand(0), InstID, Vals, VE); // callee
827
828    // Emit value #'s for the fixed parameters.
829    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
830      Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
831
832    // Emit type/value pairs for varargs params.
833    if (FTy->isVarArg()) {
834      for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
835           i != e; ++i)
836        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
837    }
838    break;
839  }
840  case Instruction::Unwind:
841    Code = bitc::FUNC_CODE_INST_UNWIND;
842    break;
843  case Instruction::Unreachable:
844    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
845    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
846    break;
847
848  case Instruction::PHI:
849    Code = bitc::FUNC_CODE_INST_PHI;
850    Vals.push_back(VE.getTypeID(I.getType()));
851    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
852      Vals.push_back(VE.getValueID(I.getOperand(i)));
853    break;
854
855  case Instruction::Malloc:
856    Code = bitc::FUNC_CODE_INST_MALLOC;
857    Vals.push_back(VE.getTypeID(I.getType()));
858    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
859    Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
860    break;
861
862  case Instruction::Free:
863    Code = bitc::FUNC_CODE_INST_FREE;
864    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
865    break;
866
867  case Instruction::Alloca:
868    Code = bitc::FUNC_CODE_INST_ALLOCA;
869    Vals.push_back(VE.getTypeID(I.getType()));
870    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
871    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
872    break;
873
874  case Instruction::Load:
875    Code = bitc::FUNC_CODE_INST_LOAD;
876    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
877      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
878
879    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
880    Vals.push_back(cast<LoadInst>(I).isVolatile());
881    break;
882  case Instruction::Store:
883    Code = bitc::FUNC_CODE_INST_STORE2;
884    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
885    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
886    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
887    Vals.push_back(cast<StoreInst>(I).isVolatile());
888    break;
889  case Instruction::Call: {
890    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
891    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
892
893    Code = bitc::FUNC_CODE_INST_CALL;
894
895    const CallInst *CI = cast<CallInst>(&I);
896    Vals.push_back(VE.getAttributeID(CI->getAttributes()));
897    Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
898    PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
899
900    // Emit value #'s for the fixed parameters.
901    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
902      Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
903
904    // Emit type/value pairs for varargs params.
905    if (FTy->isVarArg()) {
906      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
907      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
908           i != e; ++i)
909        PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
910    }
911    break;
912  }
913  case Instruction::VAArg:
914    Code = bitc::FUNC_CODE_INST_VAARG;
915    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
916    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
917    Vals.push_back(VE.getTypeID(I.getType())); // restype.
918    break;
919  }
920
921  Stream.EmitRecord(Code, Vals, AbbrevToUse);
922  Vals.clear();
923}
924
925// Emit names for globals/functions etc.
926static void WriteValueSymbolTable(const ValueSymbolTable &VST,
927                                  const ValueEnumerator &VE,
928                                  BitstreamWriter &Stream) {
929  if (VST.empty()) return;
930  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
931
932  // FIXME: Set up the abbrev, we know how many values there are!
933  // FIXME: We know if the type names can use 7-bit ascii.
934  SmallVector<unsigned, 64> NameVals;
935
936  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
937       SI != SE; ++SI) {
938
939    const ValueName &Name = *SI;
940
941    // Figure out the encoding to use for the name.
942    bool is7Bit = true;
943    bool isChar6 = true;
944    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
945         C != E; ++C) {
946      if (isChar6)
947        isChar6 = BitCodeAbbrevOp::isChar6(*C);
948      if ((unsigned char)*C & 128) {
949        is7Bit = false;
950        break;  // don't bother scanning the rest.
951      }
952    }
953
954    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
955
956    // VST_ENTRY:   [valueid, namechar x N]
957    // VST_BBENTRY: [bbid, namechar x N]
958    unsigned Code;
959    if (isa<BasicBlock>(SI->getValue())) {
960      Code = bitc::VST_CODE_BBENTRY;
961      if (isChar6)
962        AbbrevToUse = VST_BBENTRY_6_ABBREV;
963    } else {
964      Code = bitc::VST_CODE_ENTRY;
965      if (isChar6)
966        AbbrevToUse = VST_ENTRY_6_ABBREV;
967      else if (is7Bit)
968        AbbrevToUse = VST_ENTRY_7_ABBREV;
969    }
970
971    NameVals.push_back(VE.getValueID(SI->getValue()));
972    for (const char *P = Name.getKeyData(),
973         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
974      NameVals.push_back((unsigned char)*P);
975
976    // Emit the finished record.
977    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
978    NameVals.clear();
979  }
980  Stream.ExitBlock();
981}
982
983/// WriteFunction - Emit a function body to the module stream.
984static void WriteFunction(const Function &F, ValueEnumerator &VE,
985                          BitstreamWriter &Stream) {
986  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
987  VE.incorporateFunction(F);
988
989  SmallVector<unsigned, 64> Vals;
990
991  // Emit the number of basic blocks, so the reader can create them ahead of
992  // time.
993  Vals.push_back(VE.getBasicBlocks().size());
994  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
995  Vals.clear();
996
997  // If there are function-local constants, emit them now.
998  unsigned CstStart, CstEnd;
999  VE.getFunctionConstantRange(CstStart, CstEnd);
1000  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1001
1002  // Keep a running idea of what the instruction ID is.
1003  unsigned InstID = CstEnd;
1004
1005  // Finally, emit all the instructions, in order.
1006  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1007    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1008         I != E; ++I) {
1009      WriteInstruction(*I, InstID, VE, Stream, Vals);
1010      if (I->getType() != Type::VoidTy)
1011        ++InstID;
1012    }
1013
1014  // Emit names for all the instructions etc.
1015  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1016
1017  VE.purgeFunction();
1018  Stream.ExitBlock();
1019}
1020
1021/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1022static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1023                                 const ValueEnumerator &VE,
1024                                 BitstreamWriter &Stream) {
1025  if (TST.empty()) return;
1026
1027  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1028
1029  // 7-bit fixed width VST_CODE_ENTRY strings.
1030  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1031  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1032  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1033                            Log2_32_Ceil(VE.getTypes().size()+1)));
1034  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1035  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1036  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1037
1038  SmallVector<unsigned, 64> NameVals;
1039
1040  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1041       TI != TE; ++TI) {
1042    // TST_ENTRY: [typeid, namechar x N]
1043    NameVals.push_back(VE.getTypeID(TI->second));
1044
1045    const std::string &Str = TI->first;
1046    bool is7Bit = true;
1047    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1048      NameVals.push_back((unsigned char)Str[i]);
1049      if (Str[i] & 128)
1050        is7Bit = false;
1051    }
1052
1053    // Emit the finished record.
1054    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1055    NameVals.clear();
1056  }
1057
1058  Stream.ExitBlock();
1059}
1060
1061// Emit blockinfo, which defines the standard abbreviations etc.
1062static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1063  // We only want to emit block info records for blocks that have multiple
1064  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1065  // blocks can defined their abbrevs inline.
1066  Stream.EnterBlockInfoBlock(2);
1067
1068  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1069    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1070    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1071    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1072    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1073    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1074    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1075                                   Abbv) != VST_ENTRY_8_ABBREV)
1076      assert(0 && "Unexpected abbrev ordering!");
1077  }
1078
1079  { // 7-bit fixed width 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::Fixed, 7));
1085    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1086                                   Abbv) != VST_ENTRY_7_ABBREV)
1087      assert(0 && "Unexpected abbrev ordering!");
1088  }
1089  { // 6-bit char6 VST_ENTRY strings.
1090    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1091    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
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_ENTRY_6_ABBREV)
1097      assert(0 && "Unexpected abbrev ordering!");
1098  }
1099  { // 6-bit char6 VST_BBENTRY strings.
1100    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1101    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1102    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1103    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1104    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1105    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1106                                   Abbv) != VST_BBENTRY_6_ABBREV)
1107      assert(0 && "Unexpected abbrev ordering!");
1108  }
1109
1110
1111
1112  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1113    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1114    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1115    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1116                              Log2_32_Ceil(VE.getTypes().size()+1)));
1117    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1118                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1119      assert(0 && "Unexpected abbrev ordering!");
1120  }
1121
1122  { // INTEGER abbrev for CONSTANTS_BLOCK.
1123    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1124    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1125    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1126    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1127                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1128      assert(0 && "Unexpected abbrev ordering!");
1129  }
1130
1131  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1132    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1133    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1134    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1135    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1136                              Log2_32_Ceil(VE.getTypes().size()+1)));
1137    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1138
1139    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1140                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1141      assert(0 && "Unexpected abbrev ordering!");
1142  }
1143  { // NULL abbrev for CONSTANTS_BLOCK.
1144    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1145    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1146    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1147                                   Abbv) != CONSTANTS_NULL_Abbrev)
1148      assert(0 && "Unexpected abbrev ordering!");
1149  }
1150
1151  // FIXME: This should only use space for first class types!
1152
1153  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1154    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1155    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1156    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1157    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1158    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1159    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1160                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1161      assert(0 && "Unexpected abbrev ordering!");
1162  }
1163  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1164    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1165    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1166    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1167    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1168    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1169    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1170                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1171      assert(0 && "Unexpected abbrev ordering!");
1172  }
1173  { // INST_CAST abbrev for FUNCTION_BLOCK.
1174    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1175    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1176    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1177    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1178                              Log2_32_Ceil(VE.getTypes().size()+1)));
1179    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1180    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1181                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1182      assert(0 && "Unexpected abbrev ordering!");
1183  }
1184
1185  { // INST_RET abbrev for FUNCTION_BLOCK.
1186    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1187    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1188    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1189                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1190      assert(0 && "Unexpected abbrev ordering!");
1191  }
1192  { // INST_RET abbrev for FUNCTION_BLOCK.
1193    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1194    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1195    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1196    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1197                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1198      assert(0 && "Unexpected abbrev ordering!");
1199  }
1200  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1201    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1202    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1203    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1204                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1205      assert(0 && "Unexpected abbrev ordering!");
1206  }
1207
1208  Stream.ExitBlock();
1209}
1210
1211
1212/// WriteModule - Emit the specified module to the bitstream.
1213static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1214  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1215
1216  // Emit the version number if it is non-zero.
1217  if (CurVersion) {
1218    SmallVector<unsigned, 1> Vals;
1219    Vals.push_back(CurVersion);
1220    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1221  }
1222
1223  // Analyze the module, enumerating globals, functions, etc.
1224  ValueEnumerator VE(M);
1225
1226  // Emit blockinfo, which defines the standard abbreviations etc.
1227  WriteBlockInfo(VE, Stream);
1228
1229  // Emit information about parameter attributes.
1230  WriteAttributeTable(VE, Stream);
1231
1232  // Emit information describing all of the types in the module.
1233  WriteTypeTable(VE, Stream);
1234
1235  // Emit top-level description of module, including target triple, inline asm,
1236  // descriptors for global variables, and function prototype info.
1237  WriteModuleInfo(M, VE, Stream);
1238
1239  // Emit constants.
1240  WriteModuleConstants(VE, Stream);
1241
1242  // If we have any aggregate values in the value table, purge them - these can
1243  // only be used to initialize global variables.  Doing so makes the value
1244  // namespace smaller for code in functions.
1245  int NumNonAggregates = VE.PurgeAggregateValues();
1246  if (NumNonAggregates != -1) {
1247    SmallVector<unsigned, 1> Vals;
1248    Vals.push_back(NumNonAggregates);
1249    Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
1250  }
1251
1252  // Emit function bodies.
1253  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1254    if (!I->isDeclaration())
1255      WriteFunction(*I, VE, Stream);
1256
1257  // Emit the type symbol table information.
1258  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1259
1260  // Emit names for globals/functions etc.
1261  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1262
1263  Stream.ExitBlock();
1264}
1265
1266/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1267/// header and trailer to make it compatible with the system archiver.  To do
1268/// this we emit the following header, and then emit a trailer that pads the
1269/// file out to be a multiple of 16 bytes.
1270///
1271/// struct bc_header {
1272///   uint32_t Magic;         // 0x0B17C0DE
1273///   uint32_t Version;       // Version, currently always 0.
1274///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1275///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1276///   uint32_t CPUType;       // CPU specifier.
1277///   ... potentially more later ...
1278/// };
1279enum {
1280  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1281  DarwinBCHeaderSize = 5*4
1282};
1283
1284static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1285                               const std::string &TT) {
1286  unsigned CPUType = ~0U;
1287
1288  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*.  The CPUType is a
1289  // magic number from /usr/include/mach/machine.h.  It is ok to reproduce the
1290  // specific constants here because they are implicitly part of the Darwin ABI.
1291  enum {
1292    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1293    DARWIN_CPU_TYPE_X86        = 7,
1294    DARWIN_CPU_TYPE_POWERPC    = 18
1295  };
1296
1297  if (TT.find("x86_64-") == 0)
1298    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1299  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1300           TT[4] == '-' && TT[1] - '3' < 6)
1301    CPUType = DARWIN_CPU_TYPE_X86;
1302  else if (TT.find("powerpc-") == 0)
1303    CPUType = DARWIN_CPU_TYPE_POWERPC;
1304  else if (TT.find("powerpc64-") == 0)
1305    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1306
1307  // Traditional Bitcode starts after header.
1308  unsigned BCOffset = DarwinBCHeaderSize;
1309
1310  Stream.Emit(0x0B17C0DE, 32);
1311  Stream.Emit(0         , 32);  // Version.
1312  Stream.Emit(BCOffset  , 32);
1313  Stream.Emit(0         , 32);  // Filled in later.
1314  Stream.Emit(CPUType   , 32);
1315}
1316
1317/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1318/// finalize the header.
1319static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1320  // Update the size field in the header.
1321  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1322
1323  // If the file is not a multiple of 16 bytes, insert dummy padding.
1324  while (BufferSize & 15) {
1325    Stream.Emit(0, 8);
1326    ++BufferSize;
1327  }
1328}
1329
1330
1331/// WriteBitcodeToFile - Write the specified module to the specified output
1332/// stream.
1333void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
1334  raw_os_ostream RawOut(Out);
1335  // If writing to stdout, set binary mode.
1336  if (llvm::cout == Out)
1337    sys::Program::ChangeStdoutToBinary();
1338  WriteBitcodeToFile(M, RawOut);
1339}
1340
1341/// WriteBitcodeToFile - Write the specified module to the specified output
1342/// stream.
1343void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1344  std::vector<unsigned char> Buffer;
1345  BitstreamWriter Stream(Buffer);
1346
1347  Buffer.reserve(256*1024);
1348
1349  // If this is darwin, emit a file header and trailer if needed.
1350  bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1351  if (isDarwin)
1352    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1353
1354  // Emit the file header.
1355  Stream.Emit((unsigned)'B', 8);
1356  Stream.Emit((unsigned)'C', 8);
1357  Stream.Emit(0x0, 4);
1358  Stream.Emit(0xC, 4);
1359  Stream.Emit(0xE, 4);
1360  Stream.Emit(0xD, 4);
1361
1362  // Emit the module.
1363  WriteModule(M, Stream);
1364
1365  if (isDarwin)
1366    EmitDarwinBCTrailer(Stream, Buffer.size());
1367
1368
1369  // If writing to stdout, set binary mode.
1370  if (&llvm::outs() == &Out)
1371    sys::Program::ChangeStdoutToBinary();
1372
1373  // Write the generated bitstream to "Out".
1374  Out.write((char*)&Buffer.front(), Buffer.size());
1375
1376  // Make sure it hits disk now.
1377  Out.flush();
1378}
1379