BitcodeWriter.cpp revision f4c8e5243376af58e52c4a0930d838509bbbea2f 
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
84/// WriteTypeTable - Write out the type table for a module.
85static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
86  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
87
88  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
89  SmallVector<uint64_t, 64> TypeVals;
90
91  // FIXME: Set up abbrevs now that we know the width of the type fields, etc.
92
93  // Emit an entry count so the reader can reserve space.
94  TypeVals.push_back(TypeList.size());
95  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
96  TypeVals.clear();
97
98  // Loop over all of the types, emitting each in turn.
99  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
100    const Type *T = TypeList[i].first;
101    int AbbrevToUse = 0;
102    unsigned Code = 0;
103
104    switch (T->getTypeID()) {
105    case Type::PackedStructTyID: // FIXME: Delete Type::PackedStructTyID.
106    default: assert(0 && "Unknown type!");
107    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
108    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
109    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
110    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
111    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
112    case Type::IntegerTyID:
113      // INTEGER: [width]
114      Code = bitc::TYPE_CODE_INTEGER;
115      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
116      break;
117    case Type::PointerTyID:
118      // POINTER: [pointee type]
119      Code = bitc::TYPE_CODE_POINTER;
120      TypeVals.push_back(VE.getTypeID(cast<PointerType>(T)->getElementType()));
121      break;
122
123    case Type::FunctionTyID: {
124      const FunctionType *FT = cast<FunctionType>(T);
125      // FUNCTION: [isvararg, #pararms, paramty x N]
126      Code = bitc::TYPE_CODE_FUNCTION;
127      TypeVals.push_back(FT->isVarArg());
128      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
129      // FIXME: PARAM ATTR ID!
130      TypeVals.push_back(FT->getNumParams());
131      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
132        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
133      break;
134    }
135    case Type::StructTyID: {
136      const StructType *ST = cast<StructType>(T);
137      // STRUCT: [ispacked, #elts, eltty x N]
138      Code = bitc::TYPE_CODE_STRUCT;
139      TypeVals.push_back(ST->isPacked());
140      TypeVals.push_back(ST->getNumElements());
141      // Output all of the element types...
142      for (StructType::element_iterator I = ST->element_begin(),
143           E = ST->element_end(); I != E; ++I)
144        TypeVals.push_back(VE.getTypeID(*I));
145      break;
146    }
147    case Type::ArrayTyID: {
148      const ArrayType *AT = cast<ArrayType>(T);
149      // ARRAY: [numelts, eltty]
150      Code = bitc::TYPE_CODE_ARRAY;
151      TypeVals.push_back(AT->getNumElements());
152      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
153      break;
154    }
155    case Type::VectorTyID: {
156      const VectorType *VT = cast<VectorType>(T);
157      // VECTOR [numelts, eltty]
158      Code = bitc::TYPE_CODE_VECTOR;
159      TypeVals.push_back(VT->getNumElements());
160      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
161      break;
162    }
163    }
164
165    // Emit the finished record.
166    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
167    TypeVals.clear();
168  }
169
170  Stream.ExitBlock();
171}
172
173static unsigned getEncodedLinkage(const GlobalValue *GV) {
174  switch (GV->getLinkage()) {
175  default: assert(0 && "Invalid linkage!");
176  case GlobalValue::ExternalLinkage:     return 0;
177  case GlobalValue::WeakLinkage:         return 1;
178  case GlobalValue::AppendingLinkage:    return 2;
179  case GlobalValue::InternalLinkage:     return 3;
180  case GlobalValue::LinkOnceLinkage:     return 4;
181  case GlobalValue::DLLImportLinkage:    return 5;
182  case GlobalValue::DLLExportLinkage:    return 6;
183  case GlobalValue::ExternalWeakLinkage: return 7;
184  }
185}
186
187static unsigned getEncodedVisibility(const GlobalValue *GV) {
188  switch (GV->getVisibility()) {
189  default: assert(0 && "Invalid visibility!");
190  case GlobalValue::DefaultVisibility:   return 0;
191  case GlobalValue::HiddenVisibility:    return 1;
192  case GlobalValue::ProtectedVisibility: return 2;
193  }
194}
195
196// Emit top-level description of module, including target triple, inline asm,
197// descriptors for global variables, and function prototype info.
198static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
199                            BitstreamWriter &Stream) {
200  // Emit the list of dependent libraries for the Module.
201  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
202    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
203
204  // Emit various pieces of data attached to a module.
205  if (!M->getTargetTriple().empty())
206    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
207                      0/*TODO*/, Stream);
208  if (!M->getDataLayout().empty())
209    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
210                      0/*TODO*/, Stream);
211  if (!M->getModuleInlineAsm().empty())
212    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
213                      0/*TODO*/, Stream);
214
215  // Emit information about sections, computing how many there are.  Also
216  // compute the maximum alignment value.
217  std::map<std::string, unsigned> SectionMap;
218  unsigned MaxAlignment = 0;
219  unsigned MaxGlobalType = 0;
220  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
221       GV != E; ++GV) {
222    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
223    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
224
225    if (!GV->hasSection()) continue;
226    // Give section names unique ID's.
227    unsigned &Entry = SectionMap[GV->getSection()];
228    if (Entry != 0) continue;
229    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
230                      0/*TODO*/, Stream);
231    Entry = SectionMap.size();
232  }
233  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
234    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
235    if (!F->hasSection()) continue;
236    // Give section names unique ID's.
237    unsigned &Entry = SectionMap[F->getSection()];
238    if (Entry != 0) continue;
239    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
240                      0/*TODO*/, Stream);
241    Entry = SectionMap.size();
242  }
243
244  // Emit abbrev for globals, now that we know # sections and max alignment.
245  unsigned SimpleGVarAbbrev = 0;
246  if (!M->global_empty()) {
247    // Add an abbrev for common globals with no visibility or thread localness.
248    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
249    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
250    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth,
251                              Log2_32_Ceil(MaxGlobalType+1)));
252    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth, 1)); // Constant.
253    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
254    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth, 3)); // Linkage.
255    if (MaxAlignment == 0)                                     // Alignment.
256      Abbv->Add(BitCodeAbbrevOp(0));
257    else {
258      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
259      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth,
260                               Log2_32_Ceil(MaxEncAlignment+1)));
261    }
262    if (SectionMap.empty())                                    // Section.
263      Abbv->Add(BitCodeAbbrevOp(0));
264    else
265      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::FixedWidth,
266                               Log2_32_Ceil(SectionMap.size()+1)));
267    // Don't bother emitting vis + thread local.
268    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
269  }
270
271  // Emit the global variable information.
272  SmallVector<unsigned, 64> Vals;
273  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
274       GV != E; ++GV) {
275    unsigned AbbrevToUse = 0;
276
277    // GLOBALVAR: [type, isconst, initid,
278    //             linkage, alignment, section, visibility, threadlocal]
279    Vals.push_back(VE.getTypeID(GV->getType()));
280    Vals.push_back(GV->isConstant());
281    Vals.push_back(GV->isDeclaration() ? 0 :
282                   (VE.getValueID(GV->getInitializer()) + 1));
283    Vals.push_back(getEncodedLinkage(GV));
284    Vals.push_back(Log2_32(GV->getAlignment())+1);
285    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
286    if (GV->isThreadLocal() ||
287        GV->getVisibility() != GlobalValue::DefaultVisibility) {
288      Vals.push_back(getEncodedVisibility(GV));
289      Vals.push_back(GV->isThreadLocal());
290    } else {
291      AbbrevToUse = SimpleGVarAbbrev;
292    }
293
294    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
295    Vals.clear();
296  }
297
298  // Emit the function proto information.
299  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
300    // FUNCTION:  [type, callingconv, isproto, linkage, alignment, section,
301    //             visibility]
302    Vals.push_back(VE.getTypeID(F->getType()));
303    Vals.push_back(F->getCallingConv());
304    Vals.push_back(F->isDeclaration());
305    Vals.push_back(getEncodedLinkage(F));
306    Vals.push_back(Log2_32(F->getAlignment())+1);
307    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
308    Vals.push_back(getEncodedVisibility(F));
309
310    unsigned AbbrevToUse = 0;
311    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
312    Vals.clear();
313  }
314
315
316  // Emit the alias information.
317  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
318       AI != E; ++AI) {
319    Vals.push_back(VE.getTypeID(AI->getType()));
320    Vals.push_back(VE.getValueID(AI->getAliasee()));
321    Vals.push_back(getEncodedLinkage(AI));
322    unsigned AbbrevToUse = 0;
323    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
324    Vals.clear();
325  }
326}
327
328
329static void WriteConstants(unsigned FirstVal, unsigned LastVal,
330                           const ValueEnumerator &VE,
331                           BitstreamWriter &Stream) {
332  if (FirstVal == LastVal) return;
333
334  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 2);
335
336  // FIXME: Install and use abbrevs to reduce size.  Install them globally so
337  // they don't need to be reemitted for each function body.
338
339  SmallVector<uint64_t, 64> Record;
340
341  const ValueEnumerator::ValueList &Vals = VE.getValues();
342  const Type *LastTy = 0;
343  for (unsigned i = FirstVal; i != LastVal; ++i) {
344    const Value *V = Vals[i].first;
345    // If we need to switch types, do so now.
346    if (V->getType() != LastTy) {
347      LastTy = V->getType();
348      Record.push_back(VE.getTypeID(LastTy));
349      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record);
350      Record.clear();
351    }
352
353    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
354      assert(0 && IA && "FIXME: Inline asm writing unimp!");
355      continue;
356    }
357    const Constant *C = cast<Constant>(V);
358    unsigned Code = -1U;
359    unsigned AbbrevToUse = 0;
360    if (C->isNullValue()) {
361      Code = bitc::CST_CODE_NULL;
362    } else if (isa<UndefValue>(C)) {
363      Code = bitc::CST_CODE_UNDEF;
364    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
365      if (IV->getBitWidth() <= 64) {
366        int64_t V = IV->getSExtValue();
367        if (V >= 0)
368          Record.push_back(V << 1);
369        else
370          Record.push_back((-V << 1) | 1);
371        Code = bitc::CST_CODE_INTEGER;
372      } else {                             // Wide integers, > 64 bits in size.
373        // We have an arbitrary precision integer value to write whose
374        // bit width is > 64. However, in canonical unsigned integer
375        // format it is likely that the high bits are going to be zero.
376        // So, we only write the number of active words.
377        unsigned NWords = IV->getValue().getActiveWords();
378        const uint64_t *RawWords = IV->getValue().getRawData();
379        Record.push_back(NWords);
380        for (unsigned i = 0; i != NWords; ++i) {
381          int64_t V = RawWords[i];
382          if (V >= 0)
383            Record.push_back(V << 1);
384          else
385            Record.push_back((-V << 1) | 1);
386        }
387        Code = bitc::CST_CODE_WIDE_INTEGER;
388      }
389    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
390      Code = bitc::CST_CODE_FLOAT;
391      if (CFP->getType() == Type::FloatTy) {
392        Record.push_back(FloatToBits((float)CFP->getValue()));
393      } else {
394        assert (CFP->getType() == Type::DoubleTy && "Unknown FP type!");
395        Record.push_back(DoubleToBits((double)CFP->getValue()));
396      }
397    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
398               isa<ConstantVector>(V)) {
399      Code = bitc::CST_CODE_AGGREGATE;
400      Record.push_back(C->getNumOperands());
401      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
402        Record.push_back(VE.getValueID(C->getOperand(i)));
403    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
404      switch (CE->getOpcode()) {
405      default:
406        if (Instruction::isCast(CE->getOpcode())) {
407          Code = bitc::CST_CODE_CE_CAST;
408          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
409          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
410          Record.push_back(VE.getValueID(C->getOperand(0)));
411        } else {
412          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
413          Code = bitc::CST_CODE_CE_BINOP;
414          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
415          Record.push_back(VE.getValueID(C->getOperand(0)));
416          Record.push_back(VE.getValueID(C->getOperand(1)));
417        }
418        break;
419      case Instruction::GetElementPtr:
420        Code = bitc::CST_CODE_CE_GEP;
421        Record.push_back(CE->getNumOperands());
422        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
423          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
424          Record.push_back(VE.getValueID(C->getOperand(i)));
425        }
426        break;
427      case Instruction::Select:
428        Code = bitc::CST_CODE_CE_SELECT;
429        Record.push_back(VE.getValueID(C->getOperand(0)));
430        Record.push_back(VE.getValueID(C->getOperand(1)));
431        Record.push_back(VE.getValueID(C->getOperand(2)));
432        break;
433      case Instruction::ExtractElement:
434        Code = bitc::CST_CODE_CE_EXTRACTELT;
435        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
436        Record.push_back(VE.getValueID(C->getOperand(0)));
437        Record.push_back(VE.getValueID(C->getOperand(1)));
438        break;
439      case Instruction::InsertElement:
440        Code = bitc::CST_CODE_CE_INSERTELT;
441        Record.push_back(VE.getValueID(C->getOperand(0)));
442        Record.push_back(VE.getValueID(C->getOperand(1)));
443        Record.push_back(VE.getValueID(C->getOperand(2)));
444        break;
445      case Instruction::ShuffleVector:
446        Code = bitc::CST_CODE_CE_SHUFFLEVEC;
447        Record.push_back(VE.getValueID(C->getOperand(0)));
448        Record.push_back(VE.getValueID(C->getOperand(1)));
449        Record.push_back(VE.getValueID(C->getOperand(2)));
450        break;
451      case Instruction::ICmp:
452      case Instruction::FCmp:
453        Code = bitc::CST_CODE_CE_CMP;
454        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
455        Record.push_back(VE.getValueID(C->getOperand(0)));
456        Record.push_back(VE.getValueID(C->getOperand(1)));
457        Record.push_back(CE->getPredicate());
458        break;
459      }
460    } else {
461      assert(0 && "Unknown constant!");
462    }
463    Stream.EmitRecord(Code, Record, AbbrevToUse);
464    Record.clear();
465  }
466
467  Stream.ExitBlock();
468}
469
470static void WriteModuleConstants(const ValueEnumerator &VE,
471                                 BitstreamWriter &Stream) {
472  const ValueEnumerator::ValueList &Vals = VE.getValues();
473
474  // Find the first constant to emit, which is the first non-globalvalue value.
475  // We know globalvalues have been emitted by WriteModuleInfo.
476  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
477    if (!isa<GlobalValue>(Vals[i].first)) {
478      WriteConstants(i, Vals.size(), VE, Stream);
479      return;
480    }
481  }
482}
483
484/// WriteInstruction - Emit an instruction to the specified stream.
485static void WriteInstruction(const Instruction &I, ValueEnumerator &VE,
486                             BitstreamWriter &Stream,
487                             SmallVector<unsigned, 64> &Vals) {
488  unsigned Code = 0;
489  unsigned AbbrevToUse = 0;
490  switch (I.getOpcode()) {
491  default:
492    if (Instruction::isCast(I.getOpcode())) {
493      Code = bitc::FUNC_CODE_INST_CAST;
494      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
495      Vals.push_back(VE.getTypeID(I.getType()));
496      Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
497      Vals.push_back(VE.getValueID(I.getOperand(0)));
498    } else {
499      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
500      Code = bitc::FUNC_CODE_INST_BINOP;
501      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
502      Vals.push_back(VE.getTypeID(I.getType()));
503      Vals.push_back(VE.getValueID(I.getOperand(0)));
504      Vals.push_back(VE.getValueID(I.getOperand(1)));
505    }
506    break;
507
508  case Instruction::GetElementPtr:
509    Code = bitc::FUNC_CODE_INST_GEP;
510    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i) {
511      Vals.push_back(VE.getTypeID(I.getOperand(i)->getType()));
512      Vals.push_back(VE.getValueID(I.getOperand(i)));
513    }
514    break;
515  case Instruction::Select:
516    Code = bitc::FUNC_CODE_INST_SELECT;
517    Vals.push_back(VE.getTypeID(I.getType()));
518    Vals.push_back(VE.getValueID(I.getOperand(0)));
519    Vals.push_back(VE.getValueID(I.getOperand(1)));
520    Vals.push_back(VE.getValueID(I.getOperand(2)));
521    break;
522  case Instruction::ExtractElement:
523    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
524    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
525    Vals.push_back(VE.getValueID(I.getOperand(0)));
526    Vals.push_back(VE.getValueID(I.getOperand(1)));
527    break;
528  case Instruction::InsertElement:
529    Code = bitc::FUNC_CODE_INST_INSERTELT;
530    Vals.push_back(VE.getTypeID(I.getType()));
531    Vals.push_back(VE.getValueID(I.getOperand(0)));
532    Vals.push_back(VE.getValueID(I.getOperand(1)));
533    Vals.push_back(VE.getValueID(I.getOperand(2)));
534    break;
535  case Instruction::ShuffleVector:
536    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
537    Vals.push_back(VE.getTypeID(I.getType()));
538    Vals.push_back(VE.getValueID(I.getOperand(0)));
539    Vals.push_back(VE.getValueID(I.getOperand(1)));
540    Vals.push_back(VE.getValueID(I.getOperand(2)));
541    break;
542  case Instruction::ICmp:
543  case Instruction::FCmp:
544    Code = bitc::FUNC_CODE_INST_CMP;
545    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
546    Vals.push_back(VE.getValueID(I.getOperand(0)));
547    Vals.push_back(VE.getValueID(I.getOperand(1)));
548    Vals.push_back(cast<CmpInst>(I).getPredicate());
549    break;
550
551  case Instruction::Ret:
552    Code = bitc::FUNC_CODE_INST_RET;
553    if (I.getNumOperands()) {
554      Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
555      Vals.push_back(VE.getValueID(I.getOperand(0)));
556    }
557    break;
558  case Instruction::Br:
559    Code = bitc::FUNC_CODE_INST_BR;
560    Vals.push_back(VE.getValueID(I.getOperand(0)));
561    if (cast<BranchInst>(I).isConditional()) {
562      Vals.push_back(VE.getValueID(I.getOperand(1)));
563      Vals.push_back(VE.getValueID(I.getOperand(2)));
564    }
565    break;
566  case Instruction::Switch:
567    Code = bitc::FUNC_CODE_INST_SWITCH;
568    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
569    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
570      Vals.push_back(VE.getValueID(I.getOperand(i)));
571    break;
572  case Instruction::Invoke: {
573    Code = bitc::FUNC_CODE_INST_INVOKE;
574    // FIXME: param attrs
575    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
576    Vals.push_back(VE.getValueID(I.getOperand(0)));  // callee
577    Vals.push_back(VE.getValueID(I.getOperand(1)));  // normal
578    Vals.push_back(VE.getValueID(I.getOperand(2)));  // unwind
579
580    // Emit value #'s for the fixed parameters.
581    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
582    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
583    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
584      Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
585
586    // Emit type/value pairs for varargs params.
587    if (FTy->isVarArg()) {
588      unsigned NumVarargs = I.getNumOperands()-3-FTy->getNumParams();
589      Vals.push_back(NumVarargs);
590      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
591           i != e; ++i) {
592        Vals.push_back(VE.getTypeID(I.getOperand(i)->getType()));
593        Vals.push_back(VE.getValueID(I.getOperand(i)));
594      }
595    }
596    break;
597  }
598  case Instruction::Unwind:
599    Code = bitc::FUNC_CODE_INST_UNWIND;
600    break;
601  case Instruction::Unreachable:
602    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
603    break;
604
605  case Instruction::PHI:
606    Code = bitc::FUNC_CODE_INST_PHI;
607    Vals.push_back(VE.getTypeID(I.getType()));
608    Vals.push_back(I.getNumOperands());
609    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
610      Vals.push_back(VE.getValueID(I.getOperand(i)));
611    break;
612
613  case Instruction::Malloc:
614    Code = bitc::FUNC_CODE_INST_MALLOC;
615    Vals.push_back(VE.getTypeID(I.getType()));
616    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
617    Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
618    break;
619
620  case Instruction::Free:
621    Code = bitc::FUNC_CODE_INST_FREE;
622    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
623    Vals.push_back(VE.getValueID(I.getOperand(0)));
624    break;
625
626  case Instruction::Alloca:
627    Code = bitc::FUNC_CODE_INST_ALLOCA;
628    Vals.push_back(VE.getTypeID(I.getType()));
629    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
630    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
631    break;
632
633  case Instruction::Load:
634    Code = bitc::FUNC_CODE_INST_LOAD;
635    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
636    Vals.push_back(VE.getValueID(I.getOperand(0))); // ptr.
637    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
638    Vals.push_back(cast<LoadInst>(I).isVolatile());
639    break;
640  case Instruction::Store:
641    Code = bitc::FUNC_CODE_INST_STORE;
642    Vals.push_back(VE.getTypeID(I.getOperand(1)->getType()));   // Pointer
643    Vals.push_back(VE.getValueID(I.getOperand(0))); // val.
644    Vals.push_back(VE.getValueID(I.getOperand(1))); // ptr.
645    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
646    Vals.push_back(cast<StoreInst>(I).isVolatile());
647    break;
648  case Instruction::Call: {
649    Code = bitc::FUNC_CODE_INST_CALL;
650    // FIXME: param attrs
651    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
652    Vals.push_back(VE.getValueID(I.getOperand(0)));  // callee
653
654    // Emit value #'s for the fixed parameters.
655    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
656    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
657    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
658      Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
659
660    // Emit type/value pairs for varargs params.
661    if (FTy->isVarArg()) {
662      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
663      Vals.push_back(NumVarargs);
664      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
665           i != e; ++i) {
666        Vals.push_back(VE.getTypeID(I.getOperand(i)->getType()));
667        Vals.push_back(VE.getValueID(I.getOperand(i)));
668      }
669    }
670    break;
671  }
672
673  case Instruction::VAArg:
674    Code = bitc::FUNC_CODE_INST_VAARG;
675    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
676    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
677    Vals.push_back(VE.getTypeID(I.getType())); // restype.
678    break;
679  }
680
681  Stream.EmitRecord(Code, Vals, AbbrevToUse);
682  Vals.clear();
683}
684
685// Emit names for globals/functions etc.
686static void WriteValueSymbolTable(const ValueSymbolTable &VST,
687                                  const ValueEnumerator &VE,
688                                  BitstreamWriter &Stream) {
689  if (VST.empty()) return;
690  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 3);
691
692  // FIXME: Set up the abbrev, we know how many values there are!
693  // FIXME: We know if the type names can use 7-bit ascii.
694  SmallVector<unsigned, 64> NameVals;
695
696  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
697       SI != SE; ++SI) {
698    unsigned AbbrevToUse = 0;
699
700    // VST_ENTRY: [valueid, namelen, namechar x N]
701    NameVals.push_back(VE.getValueID(SI->getValue()));
702
703    NameVals.push_back(SI->getKeyLength());
704    for (const char *P = SI->getKeyData(),
705         *E = SI->getKeyData()+SI->getKeyLength(); P != E; ++P)
706      NameVals.push_back((unsigned char)*P);
707
708    // Emit the finished record.
709    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, AbbrevToUse);
710    NameVals.clear();
711  }
712  Stream.ExitBlock();
713}
714
715/// WriteFunction - Emit a function body to the module stream.
716static void WriteFunction(const Function &F, ValueEnumerator &VE,
717                          BitstreamWriter &Stream) {
718  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 3);
719  VE.incorporateFunction(F);
720
721  SmallVector<unsigned, 64> Vals;
722
723  // Emit the number of basic blocks, so the reader can create them ahead of
724  // time.
725  Vals.push_back(VE.getBasicBlocks().size());
726  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
727  Vals.clear();
728
729  // FIXME: Function attributes?
730
731  // If there are function-local constants, emit them now.
732  unsigned CstStart, CstEnd;
733  VE.getFunctionConstantRange(CstStart, CstEnd);
734  WriteConstants(CstStart, CstEnd, VE, Stream);
735
736  // Finally, emit all the instructions, in order.
737  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
738    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end(); I != E; ++I)
739      WriteInstruction(*I, VE, Stream, Vals);
740
741  // Emit names for all the instructions etc.
742  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
743
744  VE.purgeFunction();
745  Stream.ExitBlock();
746}
747
748/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
749static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
750                                 const ValueEnumerator &VE,
751                                 BitstreamWriter &Stream) {
752  if (TST.empty()) return;
753
754  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
755
756  // FIXME: Set up the abbrev, we know how many types there are!
757  // FIXME: We know if the type names can use 7-bit ascii.
758
759  SmallVector<unsigned, 64> NameVals;
760
761  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
762       TI != TE; ++TI) {
763    unsigned AbbrevToUse = 0;
764
765    // TST_ENTRY: [typeid, namelen, namechar x N]
766    NameVals.push_back(VE.getTypeID(TI->second));
767
768    const std::string &Str = TI->first;
769    NameVals.push_back(Str.size());
770    for (unsigned i = 0, e = Str.size(); i != e; ++i)
771      NameVals.push_back(Str[i]);
772
773    // Emit the finished record.
774    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, AbbrevToUse);
775    NameVals.clear();
776  }
777
778  Stream.ExitBlock();
779}
780
781
782/// WriteModule - Emit the specified module to the bitstream.
783static void WriteModule(const Module *M, BitstreamWriter &Stream) {
784  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
785
786  // Emit the version number if it is non-zero.
787  if (CurVersion) {
788    SmallVector<unsigned, 1> Vals;
789    Vals.push_back(CurVersion);
790    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
791  }
792
793  // Analyze the module, enumerating globals, functions, etc.
794  ValueEnumerator VE(M);
795
796  // Emit information describing all of the types in the module.
797  WriteTypeTable(VE, Stream);
798
799  // Emit top-level description of module, including target triple, inline asm,
800  // descriptors for global variables, and function prototype info.
801  WriteModuleInfo(M, VE, Stream);
802
803  // Emit constants.
804  WriteModuleConstants(VE, Stream);
805
806  // If we have any aggregate values in the value table, purge them - these can
807  // only be used to initialize global variables.  Doing so makes the value
808  // namespace smaller for code in functions.
809  int NumNonAggregates = VE.PurgeAggregateValues();
810  if (NumNonAggregates != -1) {
811    SmallVector<unsigned, 1> Vals;
812    Vals.push_back(NumNonAggregates);
813    Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
814  }
815
816  // Emit function bodies.
817  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
818    if (!I->isDeclaration())
819      WriteFunction(*I, VE, Stream);
820
821  // Emit the type symbol table information.
822  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
823
824  // Emit names for globals/functions etc.
825  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
826
827  Stream.ExitBlock();
828}
829
830/// WriteBitcodeToFile - Write the specified module to the specified output
831/// stream.
832void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
833  std::vector<unsigned char> Buffer;
834  BitstreamWriter Stream(Buffer);
835
836  Buffer.reserve(256*1024);
837
838  // Emit the file header.
839  Stream.Emit((unsigned)'B', 8);
840  Stream.Emit((unsigned)'C', 8);
841  Stream.Emit(0x0, 4);
842  Stream.Emit(0xC, 4);
843  Stream.Emit(0xE, 4);
844  Stream.Emit(0xD, 4);
845
846  // Emit the module.
847  WriteModule(M, Stream);
848
849  // Write the generated bitstream to "Out".
850  Out.write((char*)&Buffer.front(), Buffer.size());
851}
852