BitcodeWriter.cpp revision 62bbeea8ea526ffe20226c82a17ab51b7efa4a7e 
1//===--- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ----------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by Chris Lattner and is distributed under
6// the University of Illinois Open Source 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/Instructions.h"
21#include "llvm/Module.h"
22#include "llvm/TypeSymbolTable.h"
23#include "llvm/ValueSymbolTable.h"
24#include "llvm/Support/MathExtras.h"
25using namespace llvm;
26
27static const unsigned CurVersion = 0;
28
29static unsigned GetEncodedCastOpcode(unsigned Opcode) {
30  switch (Opcode) {
31  default: assert(0 && "Unknown cast instruction!");
32  case Instruction::Trunc   : return bitc::CAST_TRUNC;
33  case Instruction::ZExt    : return bitc::CAST_ZEXT;
34  case Instruction::SExt    : return bitc::CAST_SEXT;
35  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
36  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
37  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
38  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
39  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
40  case Instruction::FPExt   : return bitc::CAST_FPEXT;
41  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
42  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
43  case Instruction::BitCast : return bitc::CAST_BITCAST;
44  }
45}
46
47static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
48  switch (Opcode) {
49  default: assert(0 && "Unknown binary instruction!");
50  case Instruction::Add:  return bitc::BINOP_ADD;
51  case Instruction::Sub:  return bitc::BINOP_SUB;
52  case Instruction::Mul:  return bitc::BINOP_MUL;
53  case Instruction::UDiv: return bitc::BINOP_UDIV;
54  case Instruction::FDiv:
55  case Instruction::SDiv: return bitc::BINOP_SDIV;
56  case Instruction::URem: return bitc::BINOP_UREM;
57  case Instruction::FRem:
58  case Instruction::SRem: return bitc::BINOP_SREM;
59  case Instruction::Shl:  return bitc::BINOP_SHL;
60  case Instruction::LShr: return bitc::BINOP_LSHR;
61  case Instruction::AShr: return bitc::BINOP_ASHR;
62  case Instruction::And:  return bitc::BINOP_AND;
63  case Instruction::Or:   return bitc::BINOP_OR;
64  case Instruction::Xor:  return bitc::BINOP_XOR;
65  }
66}
67
68
69
70static void WriteStringRecord(unsigned Code, const std::string &Str,
71                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
72  SmallVector<unsigned, 64> Vals;
73
74  // Code: [strlen, strchar x N]
75  Vals.push_back(Str.size());
76  for (unsigned i = 0, e = Str.size(); i != e; ++i)
77    Vals.push_back(Str[i]);
78
79  // Emit the finished record.
80  Stream.EmitRecord(Code, Vals, AbbrevToUse);
81}
82
83// Emit information about parameter attributes.
84static void WriteParamAttrTable(const ValueEnumerator &VE,
85                                BitstreamWriter &Stream) {
86  const std::vector<const ParamAttrsList*> &Attrs = VE.getParamAttrs();
87  if (Attrs.empty()) return;
88
89
90
91}
92
93/// WriteTypeTable - Write out the type table for a module.
94static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
95  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
96
97  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
98  SmallVector<uint64_t, 64> TypeVals;
99
100  // FIXME: Set up abbrevs now that we know the width of the type fields, etc.
101
102  // Emit an entry count so the reader can reserve space.
103  TypeVals.push_back(TypeList.size());
104  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
105  TypeVals.clear();
106
107  // Loop over all of the types, emitting each in turn.
108  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
109    const Type *T = TypeList[i].first;
110    int AbbrevToUse = 0;
111    unsigned Code = 0;
112
113    switch (T->getTypeID()) {
114    case Type::PackedStructTyID: // FIXME: Delete Type::PackedStructTyID.
115    default: assert(0 && "Unknown type!");
116    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
117    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
118    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
119    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
120    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
121    case Type::IntegerTyID:
122      // INTEGER: [width]
123      Code = bitc::TYPE_CODE_INTEGER;
124      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
125      break;
126    case Type::PointerTyID:
127      // POINTER: [pointee type]
128      Code = bitc::TYPE_CODE_POINTER;
129      TypeVals.push_back(VE.getTypeID(cast<PointerType>(T)->getElementType()));
130      break;
131
132    case Type::FunctionTyID: {
133      const FunctionType *FT = cast<FunctionType>(T);
134      // FUNCTION: [isvararg, #pararms, paramty x N]
135      Code = bitc::TYPE_CODE_FUNCTION;
136      TypeVals.push_back(FT->isVarArg());
137      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
138      // FIXME: PARAM ATTR ID!
139      TypeVals.push_back(FT->getNumParams());
140      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
141        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
142      break;
143    }
144    case Type::StructTyID: {
145      const StructType *ST = cast<StructType>(T);
146      // STRUCT: [ispacked, #elts, eltty x N]
147      Code = bitc::TYPE_CODE_STRUCT;
148      TypeVals.push_back(ST->isPacked());
149      TypeVals.push_back(ST->getNumElements());
150      // Output all of the element types...
151      for (StructType::element_iterator I = ST->element_begin(),
152           E = ST->element_end(); I != E; ++I)
153        TypeVals.push_back(VE.getTypeID(*I));
154      break;
155    }
156    case Type::ArrayTyID: {
157      const ArrayType *AT = cast<ArrayType>(T);
158      // ARRAY: [numelts, eltty]
159      Code = bitc::TYPE_CODE_ARRAY;
160      TypeVals.push_back(AT->getNumElements());
161      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
162      break;
163    }
164    case Type::VectorTyID: {
165      const VectorType *VT = cast<VectorType>(T);
166      // VECTOR [numelts, eltty]
167      Code = bitc::TYPE_CODE_VECTOR;
168      TypeVals.push_back(VT->getNumElements());
169      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
170      break;
171    }
172    }
173
174    // Emit the finished record.
175    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
176    TypeVals.clear();
177  }
178
179  Stream.ExitBlock();
180}
181
182static unsigned getEncodedLinkage(const GlobalValue *GV) {
183  switch (GV->getLinkage()) {
184  default: assert(0 && "Invalid linkage!");
185  case GlobalValue::ExternalLinkage:     return 0;
186  case GlobalValue::WeakLinkage:         return 1;
187  case GlobalValue::AppendingLinkage:    return 2;
188  case GlobalValue::InternalLinkage:     return 3;
189  case GlobalValue::LinkOnceLinkage:     return 4;
190  case GlobalValue::DLLImportLinkage:    return 5;
191  case GlobalValue::DLLExportLinkage:    return 6;
192  case GlobalValue::ExternalWeakLinkage: return 7;
193  }
194}
195
196static unsigned getEncodedVisibility(const GlobalValue *GV) {
197  switch (GV->getVisibility()) {
198  default: assert(0 && "Invalid visibility!");
199  case GlobalValue::DefaultVisibility:   return 0;
200  case GlobalValue::HiddenVisibility:    return 1;
201  case GlobalValue::ProtectedVisibility: return 2;
202  }
203}
204
205// Emit top-level description of module, including target triple, inline asm,
206// descriptors for global variables, and function prototype info.
207static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
208                            BitstreamWriter &Stream) {
209  // Emit the list of dependent libraries for the Module.
210  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
211    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
212
213  // Emit various pieces of data attached to a module.
214  if (!M->getTargetTriple().empty())
215    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
216                      0/*TODO*/, Stream);
217  if (!M->getDataLayout().empty())
218    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
219                      0/*TODO*/, Stream);
220  if (!M->getModuleInlineAsm().empty())
221    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
222                      0/*TODO*/, Stream);
223
224  // Emit information about sections, computing how many there are.  Also
225  // compute the maximum alignment value.
226  std::map<std::string, unsigned> SectionMap;
227  unsigned MaxAlignment = 0;
228  unsigned MaxGlobalType = 0;
229  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
230       GV != E; ++GV) {
231    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
232    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
233
234    if (!GV->hasSection()) continue;
235    // Give section names unique ID's.
236    unsigned &Entry = SectionMap[GV->getSection()];
237    if (Entry != 0) continue;
238    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
239                      0/*TODO*/, Stream);
240    Entry = SectionMap.size();
241  }
242  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
243    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
244    if (!F->hasSection()) continue;
245    // Give section names unique ID's.
246    unsigned &Entry = SectionMap[F->getSection()];
247    if (Entry != 0) continue;
248    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
249                      0/*TODO*/, Stream);
250    Entry = SectionMap.size();
251  }
252
253  // Emit abbrev for globals, now that we know # sections and max alignment.
254  unsigned SimpleGVarAbbrev = 0;
255  if (!M->global_empty()) {
256    // Add an abbrev for common globals with no visibility or thread localness.
257    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
258    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
259    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth,
260                              Log2_32_Ceil(MaxGlobalType+1)));
261    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth, 1)); // Constant.
262    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
263    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth, 3)); // Linkage.
264    if (MaxAlignment == 0)                                     // Alignment.
265      Abbv->Add(BitCodeAbbrevOp(0));
266    else {
267      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
268      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth,
269                               Log2_32_Ceil(MaxEncAlignment+1)));
270    }
271    if (SectionMap.empty())                                    // Section.
272      Abbv->Add(BitCodeAbbrevOp(0));
273    else
274      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth,
275                               Log2_32_Ceil(SectionMap.size()+1)));
276    // Don't bother emitting vis + thread local.
277    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
278  }
279
280  // Emit the global variable information.
281  SmallVector<unsigned, 64> Vals;
282  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
283       GV != E; ++GV) {
284    unsigned AbbrevToUse = 0;
285
286    // GLOBALVAR: [type, isconst, initid,
287    //             linkage, alignment, section, visibility, threadlocal]
288    Vals.push_back(VE.getTypeID(GV->getType()));
289    Vals.push_back(GV->isConstant());
290    Vals.push_back(GV->isDeclaration() ? 0 :
291                   (VE.getValueID(GV->getInitializer()) + 1));
292    Vals.push_back(getEncodedLinkage(GV));
293    Vals.push_back(Log2_32(GV->getAlignment())+1);
294    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
295    if (GV->isThreadLocal() ||
296        GV->getVisibility() != GlobalValue::DefaultVisibility) {
297      Vals.push_back(getEncodedVisibility(GV));
298      Vals.push_back(GV->isThreadLocal());
299    } else {
300      AbbrevToUse = SimpleGVarAbbrev;
301    }
302
303    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
304    Vals.clear();
305  }
306
307  // Emit the function proto information.
308  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
309    // FUNCTION:  [type, callingconv, isproto, linkage, alignment, section,
310    //             visibility]
311    Vals.push_back(VE.getTypeID(F->getType()));
312    Vals.push_back(F->getCallingConv());
313    Vals.push_back(F->isDeclaration());
314    Vals.push_back(getEncodedLinkage(F));
315    Vals.push_back(Log2_32(F->getAlignment())+1);
316    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
317    Vals.push_back(getEncodedVisibility(F));
318
319    unsigned AbbrevToUse = 0;
320    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
321    Vals.clear();
322  }
323
324
325  // Emit the alias information.
326  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
327       AI != E; ++AI) {
328    Vals.push_back(VE.getTypeID(AI->getType()));
329    Vals.push_back(VE.getValueID(AI->getAliasee()));
330    Vals.push_back(getEncodedLinkage(AI));
331    unsigned AbbrevToUse = 0;
332    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
333    Vals.clear();
334  }
335}
336
337
338static void WriteConstants(unsigned FirstVal, unsigned LastVal,
339                           const ValueEnumerator &VE,
340                           BitstreamWriter &Stream) {
341  if (FirstVal == LastVal) return;
342
343  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 2);
344
345  // FIXME: Install and use abbrevs to reduce size.  Install them globally so
346  // they don't need to be reemitted for each function body.
347
348  SmallVector<uint64_t, 64> Record;
349
350  const ValueEnumerator::ValueList &Vals = VE.getValues();
351  const Type *LastTy = 0;
352  for (unsigned i = FirstVal; i != LastVal; ++i) {
353    const Value *V = Vals[i].first;
354    // If we need to switch types, do so now.
355    if (V->getType() != LastTy) {
356      LastTy = V->getType();
357      Record.push_back(VE.getTypeID(LastTy));
358      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record);
359      Record.clear();
360    }
361
362    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
363      assert(0 && IA && "FIXME: Inline asm writing unimp!");
364      continue;
365    }
366    const Constant *C = cast<Constant>(V);
367    unsigned Code = -1U;
368    unsigned AbbrevToUse = 0;
369    if (C->isNullValue()) {
370      Code = bitc::CST_CODE_NULL;
371    } else if (isa<UndefValue>(C)) {
372      Code = bitc::CST_CODE_UNDEF;
373    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
374      if (IV->getBitWidth() <= 64) {
375        int64_t V = IV->getSExtValue();
376        if (V >= 0)
377          Record.push_back(V << 1);
378        else
379          Record.push_back((-V << 1) | 1);
380        Code = bitc::CST_CODE_INTEGER;
381      } else {                             // Wide integers, > 64 bits in size.
382        // We have an arbitrary precision integer value to write whose
383        // bit width is > 64. However, in canonical unsigned integer
384        // format it is likely that the high bits are going to be zero.
385        // So, we only write the number of active words.
386        unsigned NWords = IV->getValue().getActiveWords();
387        const uint64_t *RawWords = IV->getValue().getRawData();
388        Record.push_back(NWords);
389        for (unsigned i = 0; i != NWords; ++i) {
390          int64_t V = RawWords[i];
391          if (V >= 0)
392            Record.push_back(V << 1);
393          else
394            Record.push_back((-V << 1) | 1);
395        }
396        Code = bitc::CST_CODE_WIDE_INTEGER;
397      }
398    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
399      Code = bitc::CST_CODE_FLOAT;
400      if (CFP->getType() == Type::FloatTy) {
401        Record.push_back(FloatToBits((float)CFP->getValue()));
402      } else {
403        assert (CFP->getType() == Type::DoubleTy && "Unknown FP type!");
404        Record.push_back(DoubleToBits((double)CFP->getValue()));
405      }
406    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
407               isa<ConstantVector>(V)) {
408      Code = bitc::CST_CODE_AGGREGATE;
409      Record.push_back(C->getNumOperands());
410      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
411        Record.push_back(VE.getValueID(C->getOperand(i)));
412    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
413      switch (CE->getOpcode()) {
414      default:
415        if (Instruction::isCast(CE->getOpcode())) {
416          Code = bitc::CST_CODE_CE_CAST;
417          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
418          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
419          Record.push_back(VE.getValueID(C->getOperand(0)));
420        } else {
421          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
422          Code = bitc::CST_CODE_CE_BINOP;
423          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
424          Record.push_back(VE.getValueID(C->getOperand(0)));
425          Record.push_back(VE.getValueID(C->getOperand(1)));
426        }
427        break;
428      case Instruction::GetElementPtr:
429        Code = bitc::CST_CODE_CE_GEP;
430        Record.push_back(CE->getNumOperands());
431        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
432          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
433          Record.push_back(VE.getValueID(C->getOperand(i)));
434        }
435        break;
436      case Instruction::Select:
437        Code = bitc::CST_CODE_CE_SELECT;
438        Record.push_back(VE.getValueID(C->getOperand(0)));
439        Record.push_back(VE.getValueID(C->getOperand(1)));
440        Record.push_back(VE.getValueID(C->getOperand(2)));
441        break;
442      case Instruction::ExtractElement:
443        Code = bitc::CST_CODE_CE_EXTRACTELT;
444        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
445        Record.push_back(VE.getValueID(C->getOperand(0)));
446        Record.push_back(VE.getValueID(C->getOperand(1)));
447        break;
448      case Instruction::InsertElement:
449        Code = bitc::CST_CODE_CE_INSERTELT;
450        Record.push_back(VE.getValueID(C->getOperand(0)));
451        Record.push_back(VE.getValueID(C->getOperand(1)));
452        Record.push_back(VE.getValueID(C->getOperand(2)));
453        break;
454      case Instruction::ShuffleVector:
455        Code = bitc::CST_CODE_CE_SHUFFLEVEC;
456        Record.push_back(VE.getValueID(C->getOperand(0)));
457        Record.push_back(VE.getValueID(C->getOperand(1)));
458        Record.push_back(VE.getValueID(C->getOperand(2)));
459        break;
460      case Instruction::ICmp:
461      case Instruction::FCmp:
462        Code = bitc::CST_CODE_CE_CMP;
463        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
464        Record.push_back(VE.getValueID(C->getOperand(0)));
465        Record.push_back(VE.getValueID(C->getOperand(1)));
466        Record.push_back(CE->getPredicate());
467        break;
468      }
469    } else {
470      assert(0 && "Unknown constant!");
471    }
472    Stream.EmitRecord(Code, Record, AbbrevToUse);
473    Record.clear();
474  }
475
476  Stream.ExitBlock();
477}
478
479static void WriteModuleConstants(const ValueEnumerator &VE,
480                                 BitstreamWriter &Stream) {
481  const ValueEnumerator::ValueList &Vals = VE.getValues();
482
483  // Find the first constant to emit, which is the first non-globalvalue value.
484  // We know globalvalues have been emitted by WriteModuleInfo.
485  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
486    if (!isa<GlobalValue>(Vals[i].first)) {
487      WriteConstants(i, Vals.size(), VE, Stream);
488      return;
489    }
490  }
491}
492
493/// WriteInstruction - Emit an instruction to the specified stream.
494static void WriteInstruction(const Instruction &I, ValueEnumerator &VE,
495                             BitstreamWriter &Stream,
496                             SmallVector<unsigned, 64> &Vals) {
497  unsigned Code = 0;
498  unsigned AbbrevToUse = 0;
499  switch (I.getOpcode()) {
500  default:
501    if (Instruction::isCast(I.getOpcode())) {
502      Code = bitc::FUNC_CODE_INST_CAST;
503      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
504      Vals.push_back(VE.getTypeID(I.getType()));
505      Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
506      Vals.push_back(VE.getValueID(I.getOperand(0)));
507    } else {
508      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
509      Code = bitc::FUNC_CODE_INST_BINOP;
510      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
511      Vals.push_back(VE.getTypeID(I.getType()));
512      Vals.push_back(VE.getValueID(I.getOperand(0)));
513      Vals.push_back(VE.getValueID(I.getOperand(1)));
514    }
515    break;
516
517  case Instruction::GetElementPtr:
518    Code = bitc::FUNC_CODE_INST_GEP;
519    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i) {
520      Vals.push_back(VE.getTypeID(I.getOperand(i)->getType()));
521      Vals.push_back(VE.getValueID(I.getOperand(i)));
522    }
523    break;
524  case Instruction::Select:
525    Code = bitc::FUNC_CODE_INST_SELECT;
526    Vals.push_back(VE.getTypeID(I.getType()));
527    Vals.push_back(VE.getValueID(I.getOperand(0)));
528    Vals.push_back(VE.getValueID(I.getOperand(1)));
529    Vals.push_back(VE.getValueID(I.getOperand(2)));
530    break;
531  case Instruction::ExtractElement:
532    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
533    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
534    Vals.push_back(VE.getValueID(I.getOperand(0)));
535    Vals.push_back(VE.getValueID(I.getOperand(1)));
536    break;
537  case Instruction::InsertElement:
538    Code = bitc::FUNC_CODE_INST_INSERTELT;
539    Vals.push_back(VE.getTypeID(I.getType()));
540    Vals.push_back(VE.getValueID(I.getOperand(0)));
541    Vals.push_back(VE.getValueID(I.getOperand(1)));
542    Vals.push_back(VE.getValueID(I.getOperand(2)));
543    break;
544  case Instruction::ShuffleVector:
545    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
546    Vals.push_back(VE.getTypeID(I.getType()));
547    Vals.push_back(VE.getValueID(I.getOperand(0)));
548    Vals.push_back(VE.getValueID(I.getOperand(1)));
549    Vals.push_back(VE.getValueID(I.getOperand(2)));
550    break;
551  case Instruction::ICmp:
552  case Instruction::FCmp:
553    Code = bitc::FUNC_CODE_INST_CMP;
554    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
555    Vals.push_back(VE.getValueID(I.getOperand(0)));
556    Vals.push_back(VE.getValueID(I.getOperand(1)));
557    Vals.push_back(cast<CmpInst>(I).getPredicate());
558    break;
559
560  case Instruction::Ret:
561    Code = bitc::FUNC_CODE_INST_RET;
562    if (I.getNumOperands()) {
563      Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
564      Vals.push_back(VE.getValueID(I.getOperand(0)));
565    }
566    break;
567  case Instruction::Br:
568    Code = bitc::FUNC_CODE_INST_BR;
569    Vals.push_back(VE.getValueID(I.getOperand(0)));
570    if (cast<BranchInst>(I).isConditional()) {
571      Vals.push_back(VE.getValueID(I.getOperand(1)));
572      Vals.push_back(VE.getValueID(I.getOperand(2)));
573    }
574    break;
575  case Instruction::Switch:
576    Code = bitc::FUNC_CODE_INST_SWITCH;
577    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
578    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
579      Vals.push_back(VE.getValueID(I.getOperand(i)));
580    break;
581  case Instruction::Invoke: {
582    Code = bitc::FUNC_CODE_INST_INVOKE;
583    Vals.push_back(cast<InvokeInst>(I).getCallingConv());
584    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
585    Vals.push_back(VE.getValueID(I.getOperand(0)));  // callee
586    Vals.push_back(VE.getValueID(I.getOperand(1)));  // normal
587    Vals.push_back(VE.getValueID(I.getOperand(2)));  // unwind
588
589    // Emit value #'s for the fixed parameters.
590    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
591    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
592    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
593      Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
594
595    // Emit type/value pairs for varargs params.
596    if (FTy->isVarArg()) {
597      unsigned NumVarargs = I.getNumOperands()-3-FTy->getNumParams();
598      Vals.push_back(NumVarargs);
599      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
600           i != e; ++i) {
601        Vals.push_back(VE.getTypeID(I.getOperand(i)->getType()));
602        Vals.push_back(VE.getValueID(I.getOperand(i)));
603      }
604    }
605    break;
606  }
607  case Instruction::Unwind:
608    Code = bitc::FUNC_CODE_INST_UNWIND;
609    break;
610  case Instruction::Unreachable:
611    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
612    break;
613
614  case Instruction::PHI:
615    Code = bitc::FUNC_CODE_INST_PHI;
616    Vals.push_back(VE.getTypeID(I.getType()));
617    Vals.push_back(I.getNumOperands());
618    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
619      Vals.push_back(VE.getValueID(I.getOperand(i)));
620    break;
621
622  case Instruction::Malloc:
623    Code = bitc::FUNC_CODE_INST_MALLOC;
624    Vals.push_back(VE.getTypeID(I.getType()));
625    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
626    Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
627    break;
628
629  case Instruction::Free:
630    Code = bitc::FUNC_CODE_INST_FREE;
631    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
632    Vals.push_back(VE.getValueID(I.getOperand(0)));
633    break;
634
635  case Instruction::Alloca:
636    Code = bitc::FUNC_CODE_INST_ALLOCA;
637    Vals.push_back(VE.getTypeID(I.getType()));
638    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
639    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
640    break;
641
642  case Instruction::Load:
643    Code = bitc::FUNC_CODE_INST_LOAD;
644    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
645    Vals.push_back(VE.getValueID(I.getOperand(0))); // ptr.
646    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
647    Vals.push_back(cast<LoadInst>(I).isVolatile());
648    break;
649  case Instruction::Store:
650    Code = bitc::FUNC_CODE_INST_STORE;
651    Vals.push_back(VE.getTypeID(I.getOperand(1)->getType()));   // Pointer
652    Vals.push_back(VE.getValueID(I.getOperand(0))); // val.
653    Vals.push_back(VE.getValueID(I.getOperand(1))); // ptr.
654    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
655    Vals.push_back(cast<StoreInst>(I).isVolatile());
656    break;
657  case Instruction::Call: {
658    Code = bitc::FUNC_CODE_INST_CALL;
659    Vals.push_back((cast<CallInst>(I).getCallingConv() << 1) |
660                   cast<CallInst>(I).isTailCall());
661    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
662    Vals.push_back(VE.getValueID(I.getOperand(0)));  // callee
663
664    // Emit value #'s for the fixed parameters.
665    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
666    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
667    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
668      Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
669
670    // Emit type/value pairs for varargs params.
671    if (FTy->isVarArg()) {
672      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
673      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
674           i != e; ++i) {
675        Vals.push_back(VE.getTypeID(I.getOperand(i)->getType()));
676        Vals.push_back(VE.getValueID(I.getOperand(i)));
677      }
678    }
679    break;
680  }
681  case Instruction::VAArg:
682    Code = bitc::FUNC_CODE_INST_VAARG;
683    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
684    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
685    Vals.push_back(VE.getTypeID(I.getType())); // restype.
686    break;
687  }
688
689  Stream.EmitRecord(Code, Vals, AbbrevToUse);
690  Vals.clear();
691}
692
693// Emit names for globals/functions etc.
694static void WriteValueSymbolTable(const ValueSymbolTable &VST,
695                                  const ValueEnumerator &VE,
696                                  BitstreamWriter &Stream) {
697  if (VST.empty()) return;
698  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 3);
699
700  // FIXME: Set up the abbrev, we know how many values there are!
701  // FIXME: We know if the type names can use 7-bit ascii.
702  SmallVector<unsigned, 64> NameVals;
703
704  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
705       SI != SE; ++SI) {
706    unsigned AbbrevToUse = 0;
707
708    // VST_ENTRY:   [valueid, namelen, namechar x N]
709    // VST_BBENTRY: [bbid, namelen, namechar x N]
710    unsigned Code;
711    if (isa<BasicBlock>(SI->getValue())) {
712      Code = bitc::VST_CODE_BBENTRY;
713    } else {
714      Code = bitc::VST_CODE_ENTRY;
715    }
716
717    NameVals.push_back(VE.getValueID(SI->getValue()));
718    NameVals.push_back(SI->getKeyLength());
719    for (const char *P = SI->getKeyData(),
720         *E = SI->getKeyData()+SI->getKeyLength(); P != E; ++P)
721      NameVals.push_back((unsigned char)*P);
722
723    // Emit the finished record.
724    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
725    NameVals.clear();
726  }
727  Stream.ExitBlock();
728}
729
730/// WriteFunction - Emit a function body to the module stream.
731static void WriteFunction(const Function &F, ValueEnumerator &VE,
732                          BitstreamWriter &Stream) {
733  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 3);
734  VE.incorporateFunction(F);
735
736  SmallVector<unsigned, 64> Vals;
737
738  // Emit the number of basic blocks, so the reader can create them ahead of
739  // time.
740  Vals.push_back(VE.getBasicBlocks().size());
741  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
742  Vals.clear();
743
744  // FIXME: Function attributes?
745
746  // If there are function-local constants, emit them now.
747  unsigned CstStart, CstEnd;
748  VE.getFunctionConstantRange(CstStart, CstEnd);
749  WriteConstants(CstStart, CstEnd, VE, Stream);
750
751  // Finally, emit all the instructions, in order.
752  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
753    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I)
754      WriteInstruction(*I, VE, Stream, Vals);
755
756  // Emit names for all the instructions etc.
757  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
758
759  VE.purgeFunction();
760  Stream.ExitBlock();
761}
762
763/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
764static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
765                                 const ValueEnumerator &VE,
766                                 BitstreamWriter &Stream) {
767  if (TST.empty()) return;
768
769  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
770
771  // FIXME: Set up the abbrev, we know how many types there are!
772  // FIXME: We know if the type names can use 7-bit ascii.
773
774  SmallVector<unsigned, 64> NameVals;
775
776  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
777       TI != TE; ++TI) {
778    unsigned AbbrevToUse = 0;
779
780    // TST_ENTRY: [typeid, namelen, namechar x N]
781    NameVals.push_back(VE.getTypeID(TI->second));
782
783    const std::string &Str = TI->first;
784    NameVals.push_back(Str.size());
785    for (unsigned i = 0, e = Str.size(); i != e; ++i)
786      NameVals.push_back(Str[i]);
787
788    // Emit the finished record.
789    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, AbbrevToUse);
790    NameVals.clear();
791  }
792
793  Stream.ExitBlock();
794}
795
796
797/// WriteModule - Emit the specified module to the bitstream.
798static void WriteModule(const Module *M, BitstreamWriter &Stream) {
799  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
800
801  // Emit the version number if it is non-zero.
802  if (CurVersion) {
803    SmallVector<unsigned, 1> Vals;
804    Vals.push_back(CurVersion);
805    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
806  }
807
808  // Analyze the module, enumerating globals, functions, etc.
809  ValueEnumerator VE(M);
810
811  // Emit information about parameter attributes.
812  WriteParamAttrTable(VE, Stream);
813
814  // Emit information describing all of the types in the module.
815  WriteTypeTable(VE, Stream);
816
817  // Emit top-level description of module, including target triple, inline asm,
818  // descriptors for global variables, and function prototype info.
819  WriteModuleInfo(M, VE, Stream);
820
821  // Emit constants.
822  WriteModuleConstants(VE, Stream);
823
824  // If we have any aggregate values in the value table, purge them - these can
825  // only be used to initialize global variables.  Doing so makes the value
826  // namespace smaller for code in functions.
827  int NumNonAggregates = VE.PurgeAggregateValues();
828  if (NumNonAggregates != -1) {
829    SmallVector<unsigned, 1> Vals;
830    Vals.push_back(NumNonAggregates);
831    Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
832  }
833
834  // Emit function bodies.
835  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
836    if (!I->isDeclaration())
837      WriteFunction(*I, VE, Stream);
838
839  // Emit the type symbol table information.
840  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
841
842  // Emit names for globals/functions etc.
843  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
844
845  Stream.ExitBlock();
846}
847
848/// WriteBitcodeToFile - Write the specified module to the specified output
849/// stream.
850void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
851  std::vector<unsigned char> Buffer;
852  BitstreamWriter Stream(Buffer);
853
854  Buffer.reserve(256*1024);
855
856  // Emit the file header.
857  Stream.Emit((unsigned)'B', 8);
858  Stream.Emit((unsigned)'C', 8);
859  Stream.Emit(0x0, 4);
860  Stream.Emit(0xC, 4);
861  Stream.Emit(0xE, 4);
862  Stream.Emit(0xD, 4);
863
864  // Emit the module.
865  WriteModule(M, Stream);
866
867  // Write the generated bitstream to "Out".
868  Out.write((char*)&Buffer.front(), Buffer.size());
869}
870