BitcodeWriter.cpp revision d49e18d29f3c5622cfd373fbfa0b954d1c256455 
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/InlineAsm.h"
21#include "llvm/Instructions.h"
22#include "llvm/Module.h"
23#include "llvm/ParameterAttributes.h"
24#include "llvm/TypeSymbolTable.h"
25#include "llvm/ValueSymbolTable.h"
26#include "llvm/Support/MathExtras.h"
27using namespace llvm;
28
29/// These are manifest constants used by the bitcode writer. They do not need to
30/// be kept in sync with the reader, but need to be consistent within this file.
31enum {
32  CurVersion = 0,
33
34  // VALUE_SYMTAB_BLOCK abbrev id's.
35  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
36  VST_ENTRY_7_ABBREV,
37  VST_ENTRY_6_ABBREV,
38  VST_BBENTRY_6_ABBREV,
39
40  // CONSTANTS_BLOCK abbrev id's.
41  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
42  CONSTANTS_INTEGER_ABBREV,
43  CONSTANTS_CE_CAST_Abbrev,
44  CONSTANTS_NULL_Abbrev,
45
46  // FUNCTION_BLOCK abbrev id's.
47  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
48  FUNCTION_INST_BINOP_ABBREV,
49  FUNCTION_INST_CAST_ABBREV,
50  FUNCTION_INST_RET_VOID_ABBREV,
51  FUNCTION_INST_RET_VAL_ABBREV,
52  FUNCTION_INST_UNREACHABLE_ABBREV
53};
54
55
56static unsigned GetEncodedCastOpcode(unsigned Opcode) {
57  switch (Opcode) {
58  default: assert(0 && "Unknown cast instruction!");
59  case Instruction::Trunc   : return bitc::CAST_TRUNC;
60  case Instruction::ZExt    : return bitc::CAST_ZEXT;
61  case Instruction::SExt    : return bitc::CAST_SEXT;
62  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
63  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
64  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
65  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
66  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
67  case Instruction::FPExt   : return bitc::CAST_FPEXT;
68  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
69  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
70  case Instruction::BitCast : return bitc::CAST_BITCAST;
71  }
72}
73
74static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
75  switch (Opcode) {
76  default: assert(0 && "Unknown binary instruction!");
77  case Instruction::Add:  return bitc::BINOP_ADD;
78  case Instruction::Sub:  return bitc::BINOP_SUB;
79  case Instruction::Mul:  return bitc::BINOP_MUL;
80  case Instruction::UDiv: return bitc::BINOP_UDIV;
81  case Instruction::FDiv:
82  case Instruction::SDiv: return bitc::BINOP_SDIV;
83  case Instruction::URem: return bitc::BINOP_UREM;
84  case Instruction::FRem:
85  case Instruction::SRem: return bitc::BINOP_SREM;
86  case Instruction::Shl:  return bitc::BINOP_SHL;
87  case Instruction::LShr: return bitc::BINOP_LSHR;
88  case Instruction::AShr: return bitc::BINOP_ASHR;
89  case Instruction::And:  return bitc::BINOP_AND;
90  case Instruction::Or:   return bitc::BINOP_OR;
91  case Instruction::Xor:  return bitc::BINOP_XOR;
92  }
93}
94
95
96
97static void WriteStringRecord(unsigned Code, const std::string &Str,
98                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
99  SmallVector<unsigned, 64> Vals;
100
101  // Code: [strchar x N]
102  for (unsigned i = 0, e = Str.size(); i != e; ++i)
103    Vals.push_back(Str[i]);
104
105  // Emit the finished record.
106  Stream.EmitRecord(Code, Vals, AbbrevToUse);
107}
108
109// Emit information about parameter attributes.
110static void WriteParamAttrTable(const ValueEnumerator &VE,
111                                BitstreamWriter &Stream) {
112  const std::vector<const ParamAttrsList*> &Attrs = VE.getParamAttrs();
113  if (Attrs.empty()) return;
114
115  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
116
117  SmallVector<uint64_t, 64> Record;
118  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
119    const ParamAttrsList *A = Attrs[i];
120    for (unsigned op = 0, e = A->size(); op != e; ++op) {
121      Record.push_back(A->getParamIndex(op));
122      Record.push_back(A->getParamAttrsAtIndex(op));
123    }
124
125    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
126    Record.clear();
127  }
128
129  Stream.ExitBlock();
130}
131
132/// WriteTypeTable - Write out the type table for a module.
133static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
134  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
135
136  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
137  SmallVector<uint64_t, 64> TypeVals;
138
139  // Abbrev for TYPE_CODE_POINTER.
140  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
141  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
142  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
143                            Log2_32_Ceil(VE.getTypes().size()+1)));
144  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
145  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
146
147  // Abbrev for TYPE_CODE_FUNCTION.
148  Abbv = new BitCodeAbbrev();
149  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
150  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
151  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
152  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
153  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
154                            Log2_32_Ceil(VE.getTypes().size()+1)));
155  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
156
157  // Abbrev for TYPE_CODE_STRUCT.
158  Abbv = new BitCodeAbbrev();
159  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
160  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
161  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
162  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
163                            Log2_32_Ceil(VE.getTypes().size()+1)));
164  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
165
166  // Abbrev for TYPE_CODE_ARRAY.
167  Abbv = new BitCodeAbbrev();
168  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
169  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
170  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
171                            Log2_32_Ceil(VE.getTypes().size()+1)));
172  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
173
174  // Emit an entry count so the reader can reserve space.
175  TypeVals.push_back(TypeList.size());
176  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
177  TypeVals.clear();
178
179  // Loop over all of the types, emitting each in turn.
180  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
181    const Type *T = TypeList[i].first;
182    int AbbrevToUse = 0;
183    unsigned Code = 0;
184
185    switch (T->getTypeID()) {
186    default: assert(0 && "Unknown type!");
187    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
188    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
189    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
190    case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
191    case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
192    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
193    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
194    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
195    case Type::IntegerTyID:
196      // INTEGER: [width]
197      Code = bitc::TYPE_CODE_INTEGER;
198      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
199      break;
200    case Type::PointerTyID: {
201      const PointerType *PTy = cast<PointerType>(T);
202      // POINTER: [pointee type, address space]
203      Code = bitc::TYPE_CODE_POINTER;
204      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
205      unsigned AddressSpace = PTy->getAddressSpace();
206      TypeVals.push_back(AddressSpace);
207      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
208      break;
209    }
210    case Type::FunctionTyID: {
211      const FunctionType *FT = cast<FunctionType>(T);
212      // FUNCTION: [isvararg, attrid, retty, paramty x N]
213      Code = bitc::TYPE_CODE_FUNCTION;
214      TypeVals.push_back(FT->isVarArg());
215      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
216      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
217      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
218        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
219      AbbrevToUse = FunctionAbbrev;
220      break;
221    }
222    case Type::StructTyID: {
223      const StructType *ST = cast<StructType>(T);
224      // STRUCT: [ispacked, eltty x N]
225      Code = bitc::TYPE_CODE_STRUCT;
226      TypeVals.push_back(ST->isPacked());
227      // Output all of the element types.
228      for (StructType::element_iterator I = ST->element_begin(),
229           E = ST->element_end(); I != E; ++I)
230        TypeVals.push_back(VE.getTypeID(*I));
231      AbbrevToUse = StructAbbrev;
232      break;
233    }
234    case Type::ArrayTyID: {
235      const ArrayType *AT = cast<ArrayType>(T);
236      // ARRAY: [numelts, eltty]
237      Code = bitc::TYPE_CODE_ARRAY;
238      TypeVals.push_back(AT->getNumElements());
239      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
240      AbbrevToUse = ArrayAbbrev;
241      break;
242    }
243    case Type::VectorTyID: {
244      const VectorType *VT = cast<VectorType>(T);
245      // VECTOR [numelts, eltty]
246      Code = bitc::TYPE_CODE_VECTOR;
247      TypeVals.push_back(VT->getNumElements());
248      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
249      break;
250    }
251    }
252
253    // Emit the finished record.
254    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
255    TypeVals.clear();
256  }
257
258  Stream.ExitBlock();
259}
260
261static unsigned getEncodedLinkage(const GlobalValue *GV) {
262  switch (GV->getLinkage()) {
263  default: assert(0 && "Invalid linkage!");
264  case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
265  case GlobalValue::ExternalLinkage:     return 0;
266  case GlobalValue::WeakLinkage:         return 1;
267  case GlobalValue::AppendingLinkage:    return 2;
268  case GlobalValue::InternalLinkage:     return 3;
269  case GlobalValue::LinkOnceLinkage:     return 4;
270  case GlobalValue::DLLImportLinkage:    return 5;
271  case GlobalValue::DLLExportLinkage:    return 6;
272  case GlobalValue::ExternalWeakLinkage: return 7;
273  }
274}
275
276static unsigned getEncodedVisibility(const GlobalValue *GV) {
277  switch (GV->getVisibility()) {
278  default: assert(0 && "Invalid visibility!");
279  case GlobalValue::DefaultVisibility:   return 0;
280  case GlobalValue::HiddenVisibility:    return 1;
281  case GlobalValue::ProtectedVisibility: return 2;
282  }
283}
284
285// Emit top-level description of module, including target triple, inline asm,
286// descriptors for global variables, and function prototype info.
287static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
288                            BitstreamWriter &Stream) {
289  // Emit the list of dependent libraries for the Module.
290  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
291    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
292
293  // Emit various pieces of data attached to a module.
294  if (!M->getTargetTriple().empty())
295    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
296                      0/*TODO*/, Stream);
297  if (!M->getDataLayout().empty())
298    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
299                      0/*TODO*/, Stream);
300  if (!M->getModuleInlineAsm().empty())
301    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
302                      0/*TODO*/, Stream);
303
304  // Emit information about sections and collectors, computing how many there
305  // are.  Also compute the maximum alignment value.
306  std::map<std::string, unsigned> SectionMap;
307  std::map<std::string, unsigned> CollectorMap;
308  unsigned MaxAlignment = 0;
309  unsigned MaxGlobalType = 0;
310  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
311       GV != E; ++GV) {
312    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
313    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
314
315    if (!GV->hasSection()) continue;
316    // Give section names unique ID's.
317    unsigned &Entry = SectionMap[GV->getSection()];
318    if (Entry != 0) continue;
319    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
320                      0/*TODO*/, Stream);
321    Entry = SectionMap.size();
322  }
323  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
324    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
325    if (F->hasSection()) {
326      // Give section names unique ID's.
327      unsigned &Entry = SectionMap[F->getSection()];
328      if (!Entry) {
329        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
330                          0/*TODO*/, Stream);
331        Entry = SectionMap.size();
332      }
333    }
334    if (F->hasCollector()) {
335      // Same for collector names.
336      unsigned &Entry = CollectorMap[F->getCollector()];
337      if (!Entry) {
338        WriteStringRecord(bitc::MODULE_CODE_COLLECTORNAME, F->getCollector(),
339                          0/*TODO*/, Stream);
340        Entry = CollectorMap.size();
341      }
342    }
343  }
344
345  // Emit abbrev for globals, now that we know # sections and max alignment.
346  unsigned SimpleGVarAbbrev = 0;
347  if (!M->global_empty()) {
348    // Add an abbrev for common globals with no visibility or thread localness.
349    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
350    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
351    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
352                              Log2_32_Ceil(MaxGlobalType+1)));
353    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
354    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
355    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));      // Linkage.
356    if (MaxAlignment == 0)                                      // Alignment.
357      Abbv->Add(BitCodeAbbrevOp(0));
358    else {
359      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
360      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
361                               Log2_32_Ceil(MaxEncAlignment+1)));
362    }
363    if (SectionMap.empty())                                    // Section.
364      Abbv->Add(BitCodeAbbrevOp(0));
365    else
366      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
367                               Log2_32_Ceil(SectionMap.size()+1)));
368    // Don't bother emitting vis + thread local.
369    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
370  }
371
372  // Emit the global variable information.
373  SmallVector<unsigned, 64> Vals;
374  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
375       GV != E; ++GV) {
376    unsigned AbbrevToUse = 0;
377
378    // GLOBALVAR: [type, isconst, initid,
379    //             linkage, alignment, section, visibility, threadlocal]
380    Vals.push_back(VE.getTypeID(GV->getType()));
381    Vals.push_back(GV->isConstant());
382    Vals.push_back(GV->isDeclaration() ? 0 :
383                   (VE.getValueID(GV->getInitializer()) + 1));
384    Vals.push_back(getEncodedLinkage(GV));
385    Vals.push_back(Log2_32(GV->getAlignment())+1);
386    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
387    if (GV->isThreadLocal() ||
388        GV->getVisibility() != GlobalValue::DefaultVisibility) {
389      Vals.push_back(getEncodedVisibility(GV));
390      Vals.push_back(GV->isThreadLocal());
391    } else {
392      AbbrevToUse = SimpleGVarAbbrev;
393    }
394
395    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
396    Vals.clear();
397  }
398
399  // Emit the function proto information.
400  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
401    // FUNCTION:  [type, callingconv, isproto, paramattr,
402    //             linkage, alignment, section, visibility, collector]
403    Vals.push_back(VE.getTypeID(F->getType()));
404    Vals.push_back(F->getCallingConv());
405    Vals.push_back(F->isDeclaration());
406    Vals.push_back(getEncodedLinkage(F));
407    Vals.push_back(VE.getParamAttrID(F->getParamAttrs()));
408    Vals.push_back(Log2_32(F->getAlignment())+1);
409    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
410    Vals.push_back(getEncodedVisibility(F));
411    Vals.push_back(F->hasCollector() ? CollectorMap[F->getCollector()] : 0);
412
413    unsigned AbbrevToUse = 0;
414    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
415    Vals.clear();
416  }
417
418
419  // Emit the alias information.
420  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
421       AI != E; ++AI) {
422    Vals.push_back(VE.getTypeID(AI->getType()));
423    Vals.push_back(VE.getValueID(AI->getAliasee()));
424    Vals.push_back(getEncodedLinkage(AI));
425    unsigned AbbrevToUse = 0;
426    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
427    Vals.clear();
428  }
429}
430
431
432static void WriteConstants(unsigned FirstVal, unsigned LastVal,
433                           const ValueEnumerator &VE,
434                           BitstreamWriter &Stream, bool isGlobal) {
435  if (FirstVal == LastVal) return;
436
437  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
438
439  unsigned AggregateAbbrev = 0;
440  unsigned String8Abbrev = 0;
441  unsigned CString7Abbrev = 0;
442  unsigned CString6Abbrev = 0;
443  // If this is a constant pool for the module, emit module-specific abbrevs.
444  if (isGlobal) {
445    // Abbrev for CST_CODE_AGGREGATE.
446    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
447    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
448    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
449    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
450    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
451
452    // Abbrev for CST_CODE_STRING.
453    Abbv = new BitCodeAbbrev();
454    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
455    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
456    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
457    String8Abbrev = Stream.EmitAbbrev(Abbv);
458    // Abbrev for CST_CODE_CSTRING.
459    Abbv = new BitCodeAbbrev();
460    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
461    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
462    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
463    CString7Abbrev = Stream.EmitAbbrev(Abbv);
464    // Abbrev for CST_CODE_CSTRING.
465    Abbv = new BitCodeAbbrev();
466    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
467    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
468    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
469    CString6Abbrev = Stream.EmitAbbrev(Abbv);
470  }
471
472  SmallVector<uint64_t, 64> Record;
473
474  const ValueEnumerator::ValueList &Vals = VE.getValues();
475  const Type *LastTy = 0;
476  for (unsigned i = FirstVal; i != LastVal; ++i) {
477    const Value *V = Vals[i].first;
478    // If we need to switch types, do so now.
479    if (V->getType() != LastTy) {
480      LastTy = V->getType();
481      Record.push_back(VE.getTypeID(LastTy));
482      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
483                        CONSTANTS_SETTYPE_ABBREV);
484      Record.clear();
485    }
486
487    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
488      Record.push_back(unsigned(IA->hasSideEffects()));
489
490      // Add the asm string.
491      const std::string &AsmStr = IA->getAsmString();
492      Record.push_back(AsmStr.size());
493      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
494        Record.push_back(AsmStr[i]);
495
496      // Add the constraint string.
497      const std::string &ConstraintStr = IA->getConstraintString();
498      Record.push_back(ConstraintStr.size());
499      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
500        Record.push_back(ConstraintStr[i]);
501      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
502      Record.clear();
503      continue;
504    }
505    const Constant *C = cast<Constant>(V);
506    unsigned Code = -1U;
507    unsigned AbbrevToUse = 0;
508    if (C->isNullValue()) {
509      Code = bitc::CST_CODE_NULL;
510    } else if (isa<UndefValue>(C)) {
511      Code = bitc::CST_CODE_UNDEF;
512    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
513      if (IV->getBitWidth() <= 64) {
514        int64_t V = IV->getSExtValue();
515        if (V >= 0)
516          Record.push_back(V << 1);
517        else
518          Record.push_back((-V << 1) | 1);
519        Code = bitc::CST_CODE_INTEGER;
520        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
521      } else {                             // Wide integers, > 64 bits in size.
522        // We have an arbitrary precision integer value to write whose
523        // bit width is > 64. However, in canonical unsigned integer
524        // format it is likely that the high bits are going to be zero.
525        // So, we only write the number of active words.
526        unsigned NWords = IV->getValue().getActiveWords();
527        const uint64_t *RawWords = IV->getValue().getRawData();
528        for (unsigned i = 0; i != NWords; ++i) {
529          int64_t V = RawWords[i];
530          if (V >= 0)
531            Record.push_back(V << 1);
532          else
533            Record.push_back((-V << 1) | 1);
534        }
535        Code = bitc::CST_CODE_WIDE_INTEGER;
536      }
537    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
538      Code = bitc::CST_CODE_FLOAT;
539      const Type *Ty = CFP->getType();
540      if (Ty == Type::FloatTy || Ty == Type::DoubleTy) {
541        Record.push_back(CFP->getValueAPF().convertToAPInt().getZExtValue());
542      } else if (Ty == Type::X86_FP80Ty) {
543        // api needed to prevent premature destruction
544        APInt api = CFP->getValueAPF().convertToAPInt();
545        const uint64_t *p = api.getRawData();
546        Record.push_back(p[0]);
547        Record.push_back((uint16_t)p[1]);
548      } else if (Ty == Type::FP128Ty || Ty == Type::PPC_FP128Ty) {
549        APInt api = CFP->getValueAPF().convertToAPInt();
550        const uint64_t *p = api.getRawData();
551        Record.push_back(p[0]);
552        Record.push_back(p[1]);
553      } else {
554        assert (0 && "Unknown FP type!");
555      }
556    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
557      // Emit constant strings specially.
558      unsigned NumOps = C->getNumOperands();
559      // If this is a null-terminated string, use the denser CSTRING encoding.
560      if (C->getOperand(NumOps-1)->isNullValue()) {
561        Code = bitc::CST_CODE_CSTRING;
562        --NumOps;  // Don't encode the null, which isn't allowed by char6.
563      } else {
564        Code = bitc::CST_CODE_STRING;
565        AbbrevToUse = String8Abbrev;
566      }
567      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
568      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
569      for (unsigned i = 0; i != NumOps; ++i) {
570        unsigned char V = cast<ConstantInt>(C->getOperand(i))->getZExtValue();
571        Record.push_back(V);
572        isCStr7 &= (V & 128) == 0;
573        if (isCStrChar6)
574          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
575      }
576
577      if (isCStrChar6)
578        AbbrevToUse = CString6Abbrev;
579      else if (isCStr7)
580        AbbrevToUse = CString7Abbrev;
581    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
582               isa<ConstantVector>(V)) {
583      Code = bitc::CST_CODE_AGGREGATE;
584      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
585        Record.push_back(VE.getValueID(C->getOperand(i)));
586      AbbrevToUse = AggregateAbbrev;
587    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
588      switch (CE->getOpcode()) {
589      default:
590        if (Instruction::isCast(CE->getOpcode())) {
591          Code = bitc::CST_CODE_CE_CAST;
592          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
593          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
594          Record.push_back(VE.getValueID(C->getOperand(0)));
595          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
596        } else {
597          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
598          Code = bitc::CST_CODE_CE_BINOP;
599          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
600          Record.push_back(VE.getValueID(C->getOperand(0)));
601          Record.push_back(VE.getValueID(C->getOperand(1)));
602        }
603        break;
604      case Instruction::GetElementPtr:
605        Code = bitc::CST_CODE_CE_GEP;
606        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
607          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
608          Record.push_back(VE.getValueID(C->getOperand(i)));
609        }
610        break;
611      case Instruction::Select:
612        Code = bitc::CST_CODE_CE_SELECT;
613        Record.push_back(VE.getValueID(C->getOperand(0)));
614        Record.push_back(VE.getValueID(C->getOperand(1)));
615        Record.push_back(VE.getValueID(C->getOperand(2)));
616        break;
617      case Instruction::ExtractElement:
618        Code = bitc::CST_CODE_CE_EXTRACTELT;
619        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
620        Record.push_back(VE.getValueID(C->getOperand(0)));
621        Record.push_back(VE.getValueID(C->getOperand(1)));
622        break;
623      case Instruction::InsertElement:
624        Code = bitc::CST_CODE_CE_INSERTELT;
625        Record.push_back(VE.getValueID(C->getOperand(0)));
626        Record.push_back(VE.getValueID(C->getOperand(1)));
627        Record.push_back(VE.getValueID(C->getOperand(2)));
628        break;
629      case Instruction::ShuffleVector:
630        Code = bitc::CST_CODE_CE_SHUFFLEVEC;
631        Record.push_back(VE.getValueID(C->getOperand(0)));
632        Record.push_back(VE.getValueID(C->getOperand(1)));
633        Record.push_back(VE.getValueID(C->getOperand(2)));
634        break;
635      case Instruction::ICmp:
636      case Instruction::FCmp:
637        Code = bitc::CST_CODE_CE_CMP;
638        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
639        Record.push_back(VE.getValueID(C->getOperand(0)));
640        Record.push_back(VE.getValueID(C->getOperand(1)));
641        Record.push_back(CE->getPredicate());
642        break;
643      }
644    } else {
645      assert(0 && "Unknown constant!");
646    }
647    Stream.EmitRecord(Code, Record, AbbrevToUse);
648    Record.clear();
649  }
650
651  Stream.ExitBlock();
652}
653
654static void WriteModuleConstants(const ValueEnumerator &VE,
655                                 BitstreamWriter &Stream) {
656  const ValueEnumerator::ValueList &Vals = VE.getValues();
657
658  // Find the first constant to emit, which is the first non-globalvalue value.
659  // We know globalvalues have been emitted by WriteModuleInfo.
660  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
661    if (!isa<GlobalValue>(Vals[i].first)) {
662      WriteConstants(i, Vals.size(), VE, Stream, true);
663      return;
664    }
665  }
666}
667
668/// PushValueAndType - The file has to encode both the value and type id for
669/// many values, because we need to know what type to create for forward
670/// references.  However, most operands are not forward references, so this type
671/// field is not needed.
672///
673/// This function adds V's value ID to Vals.  If the value ID is higher than the
674/// instruction ID, then it is a forward reference, and it also includes the
675/// type ID.
676static bool PushValueAndType(Value *V, unsigned InstID,
677                             SmallVector<unsigned, 64> &Vals,
678                             ValueEnumerator &VE) {
679  unsigned ValID = VE.getValueID(V);
680  Vals.push_back(ValID);
681  if (ValID >= InstID) {
682    Vals.push_back(VE.getTypeID(V->getType()));
683    return true;
684  }
685  return false;
686}
687
688/// WriteInstruction - Emit an instruction to the specified stream.
689static void WriteInstruction(const Instruction &I, unsigned InstID,
690                             ValueEnumerator &VE, BitstreamWriter &Stream,
691                             SmallVector<unsigned, 64> &Vals) {
692  unsigned Code = 0;
693  unsigned AbbrevToUse = 0;
694  switch (I.getOpcode()) {
695  default:
696    if (Instruction::isCast(I.getOpcode())) {
697      Code = bitc::FUNC_CODE_INST_CAST;
698      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
699        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
700      Vals.push_back(VE.getTypeID(I.getType()));
701      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
702    } else {
703      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
704      Code = bitc::FUNC_CODE_INST_BINOP;
705      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
706        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
707      Vals.push_back(VE.getValueID(I.getOperand(1)));
708      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
709    }
710    break;
711
712  case Instruction::GetElementPtr:
713    Code = bitc::FUNC_CODE_INST_GEP;
714    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
715      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
716    break;
717  case Instruction::Select:
718    Code = bitc::FUNC_CODE_INST_SELECT;
719    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
720    Vals.push_back(VE.getValueID(I.getOperand(2)));
721    Vals.push_back(VE.getValueID(I.getOperand(0)));
722    break;
723  case Instruction::ExtractElement:
724    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
725    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
726    Vals.push_back(VE.getValueID(I.getOperand(1)));
727    break;
728  case Instruction::InsertElement:
729    Code = bitc::FUNC_CODE_INST_INSERTELT;
730    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
731    Vals.push_back(VE.getValueID(I.getOperand(1)));
732    Vals.push_back(VE.getValueID(I.getOperand(2)));
733    break;
734  case Instruction::ShuffleVector:
735    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
736    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
737    Vals.push_back(VE.getValueID(I.getOperand(1)));
738    Vals.push_back(VE.getValueID(I.getOperand(2)));
739    break;
740  case Instruction::ICmp:
741  case Instruction::FCmp:
742    Code = bitc::FUNC_CODE_INST_CMP;
743    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
744    Vals.push_back(VE.getValueID(I.getOperand(1)));
745    Vals.push_back(cast<CmpInst>(I).getPredicate());
746    break;
747
748  case Instruction::Ret:
749    Code = bitc::FUNC_CODE_INST_RET;
750    if (!I.getNumOperands())
751      AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
752    else if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
753      AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
754    break;
755  case Instruction::Br:
756    Code = bitc::FUNC_CODE_INST_BR;
757    Vals.push_back(VE.getValueID(I.getOperand(0)));
758    if (cast<BranchInst>(I).isConditional()) {
759      Vals.push_back(VE.getValueID(I.getOperand(1)));
760      Vals.push_back(VE.getValueID(I.getOperand(2)));
761    }
762    break;
763  case Instruction::Switch:
764    Code = bitc::FUNC_CODE_INST_SWITCH;
765    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
766    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
767      Vals.push_back(VE.getValueID(I.getOperand(i)));
768    break;
769  case Instruction::Invoke: {
770    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
771    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
772    Code = bitc::FUNC_CODE_INST_INVOKE;
773
774    const InvokeInst *II = cast<InvokeInst>(&I);
775    Vals.push_back(VE.getParamAttrID(II->getParamAttrs()));
776    Vals.push_back(II->getCallingConv());
777    Vals.push_back(VE.getValueID(I.getOperand(1)));      // normal dest
778    Vals.push_back(VE.getValueID(I.getOperand(2)));      // unwind dest
779    PushValueAndType(I.getOperand(0), InstID, Vals, VE); // callee
780
781    // Emit value #'s for the fixed parameters.
782    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
783      Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
784
785    // Emit type/value pairs for varargs params.
786    if (FTy->isVarArg()) {
787      for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
788           i != e; ++i)
789        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
790    }
791    break;
792  }
793  case Instruction::Unwind:
794    Code = bitc::FUNC_CODE_INST_UNWIND;
795    break;
796  case Instruction::Unreachable:
797    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
798    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
799    break;
800
801  case Instruction::PHI:
802    Code = bitc::FUNC_CODE_INST_PHI;
803    Vals.push_back(VE.getTypeID(I.getType()));
804    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
805      Vals.push_back(VE.getValueID(I.getOperand(i)));
806    break;
807
808  case Instruction::Malloc:
809    Code = bitc::FUNC_CODE_INST_MALLOC;
810    Vals.push_back(VE.getTypeID(I.getType()));
811    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
812    Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
813    break;
814
815  case Instruction::Free:
816    Code = bitc::FUNC_CODE_INST_FREE;
817    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
818    break;
819
820  case Instruction::Alloca:
821    Code = bitc::FUNC_CODE_INST_ALLOCA;
822    Vals.push_back(VE.getTypeID(I.getType()));
823    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
824    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
825    break;
826
827  case Instruction::Load:
828    Code = bitc::FUNC_CODE_INST_LOAD;
829    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
830      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
831
832    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
833    Vals.push_back(cast<LoadInst>(I).isVolatile());
834    break;
835  case Instruction::Store:
836    Code = bitc::FUNC_CODE_INST_STORE2;
837    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
838    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
839    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
840    Vals.push_back(cast<StoreInst>(I).isVolatile());
841    break;
842  case Instruction::Call: {
843    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
844    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
845
846    Code = bitc::FUNC_CODE_INST_CALL;
847
848    const CallInst *CI = cast<CallInst>(&I);
849    Vals.push_back(VE.getParamAttrID(CI->getParamAttrs()));
850    Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
851    PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
852
853    // Emit value #'s for the fixed parameters.
854    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
855      Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
856
857    // Emit type/value pairs for varargs params.
858    if (FTy->isVarArg()) {
859      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
860      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
861           i != e; ++i)
862        PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
863    }
864    break;
865  }
866  case Instruction::VAArg:
867    Code = bitc::FUNC_CODE_INST_VAARG;
868    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
869    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
870    Vals.push_back(VE.getTypeID(I.getType())); // restype.
871    break;
872  }
873
874  Stream.EmitRecord(Code, Vals, AbbrevToUse);
875  Vals.clear();
876}
877
878// Emit names for globals/functions etc.
879static void WriteValueSymbolTable(const ValueSymbolTable &VST,
880                                  const ValueEnumerator &VE,
881                                  BitstreamWriter &Stream) {
882  if (VST.empty()) return;
883  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
884
885  // FIXME: Set up the abbrev, we know how many values there are!
886  // FIXME: We know if the type names can use 7-bit ascii.
887  SmallVector<unsigned, 64> NameVals;
888
889  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
890       SI != SE; ++SI) {
891
892    const ValueName &Name = *SI;
893
894    // Figure out the encoding to use for the name.
895    bool is7Bit = true;
896    bool isChar6 = true;
897    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
898         C != E; ++C) {
899      if (isChar6)
900        isChar6 = BitCodeAbbrevOp::isChar6(*C);
901      if ((unsigned char)*C & 128) {
902        is7Bit = false;
903        break;  // don't bother scanning the rest.
904      }
905    }
906
907    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
908
909    // VST_ENTRY:   [valueid, namechar x N]
910    // VST_BBENTRY: [bbid, namechar x N]
911    unsigned Code;
912    if (isa<BasicBlock>(SI->getValue())) {
913      Code = bitc::VST_CODE_BBENTRY;
914      if (isChar6)
915        AbbrevToUse = VST_BBENTRY_6_ABBREV;
916    } else {
917      Code = bitc::VST_CODE_ENTRY;
918      if (isChar6)
919        AbbrevToUse = VST_ENTRY_6_ABBREV;
920      else if (is7Bit)
921        AbbrevToUse = VST_ENTRY_7_ABBREV;
922    }
923
924    NameVals.push_back(VE.getValueID(SI->getValue()));
925    for (const char *P = Name.getKeyData(),
926         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
927      NameVals.push_back((unsigned char)*P);
928
929    // Emit the finished record.
930    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
931    NameVals.clear();
932  }
933  Stream.ExitBlock();
934}
935
936/// WriteFunction - Emit a function body to the module stream.
937static void WriteFunction(const Function &F, ValueEnumerator &VE,
938                          BitstreamWriter &Stream) {
939  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
940  VE.incorporateFunction(F);
941
942  SmallVector<unsigned, 64> Vals;
943
944  // Emit the number of basic blocks, so the reader can create them ahead of
945  // time.
946  Vals.push_back(VE.getBasicBlocks().size());
947  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
948  Vals.clear();
949
950  // If there are function-local constants, emit them now.
951  unsigned CstStart, CstEnd;
952  VE.getFunctionConstantRange(CstStart, CstEnd);
953  WriteConstants(CstStart, CstEnd, VE, Stream, false);
954
955  // Keep a running idea of what the instruction ID is.
956  unsigned InstID = CstEnd;
957
958  // Finally, emit all the instructions, in order.
959  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
960    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
961         I != E; ++I) {
962      WriteInstruction(*I, InstID, VE, Stream, Vals);
963      if (I->getType() != Type::VoidTy)
964        ++InstID;
965    }
966
967  // Emit names for all the instructions etc.
968  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
969
970  VE.purgeFunction();
971  Stream.ExitBlock();
972}
973
974/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
975static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
976                                 const ValueEnumerator &VE,
977                                 BitstreamWriter &Stream) {
978  if (TST.empty()) return;
979
980  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
981
982  // 7-bit fixed width VST_CODE_ENTRY strings.
983  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
984  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
985  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
986                            Log2_32_Ceil(VE.getTypes().size()+1)));
987  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
988  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
989  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
990
991  SmallVector<unsigned, 64> NameVals;
992
993  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
994       TI != TE; ++TI) {
995    // TST_ENTRY: [typeid, namechar x N]
996    NameVals.push_back(VE.getTypeID(TI->second));
997
998    const std::string &Str = TI->first;
999    bool is7Bit = true;
1000    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1001      NameVals.push_back((unsigned char)Str[i]);
1002      if (Str[i] & 128)
1003        is7Bit = false;
1004    }
1005
1006    // Emit the finished record.
1007    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1008    NameVals.clear();
1009  }
1010
1011  Stream.ExitBlock();
1012}
1013
1014// Emit blockinfo, which defines the standard abbreviations etc.
1015static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1016  // We only want to emit block info records for blocks that have multiple
1017  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1018  // blocks can defined their abbrevs inline.
1019  Stream.EnterBlockInfoBlock(2);
1020
1021  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1022    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1023    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1024    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1025    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1026    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1027    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1028                                   Abbv) != VST_ENTRY_8_ABBREV)
1029      assert(0 && "Unexpected abbrev ordering!");
1030  }
1031
1032  { // 7-bit fixed width VST_ENTRY strings.
1033    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1034    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1035    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1036    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1037    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1038    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1039                                   Abbv) != VST_ENTRY_7_ABBREV)
1040      assert(0 && "Unexpected abbrev ordering!");
1041  }
1042  { // 6-bit char6 VST_ENTRY strings.
1043    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1044    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1045    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1046    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1047    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1048    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1049                                   Abbv) != VST_ENTRY_6_ABBREV)
1050      assert(0 && "Unexpected abbrev ordering!");
1051  }
1052  { // 6-bit char6 VST_BBENTRY strings.
1053    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1054    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1055    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1056    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1057    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1058    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1059                                   Abbv) != VST_BBENTRY_6_ABBREV)
1060      assert(0 && "Unexpected abbrev ordering!");
1061  }
1062
1063
1064
1065  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1066    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1067    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1068    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1069                              Log2_32_Ceil(VE.getTypes().size()+1)));
1070    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1071                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1072      assert(0 && "Unexpected abbrev ordering!");
1073  }
1074
1075  { // INTEGER abbrev for CONSTANTS_BLOCK.
1076    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1077    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1078    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1079    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1080                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1081      assert(0 && "Unexpected abbrev ordering!");
1082  }
1083
1084  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1085    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1086    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1087    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1088    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1089                              Log2_32_Ceil(VE.getTypes().size()+1)));
1090    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1091
1092    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1093                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1094      assert(0 && "Unexpected abbrev ordering!");
1095  }
1096  { // NULL abbrev for CONSTANTS_BLOCK.
1097    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1098    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1099    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1100                                   Abbv) != CONSTANTS_NULL_Abbrev)
1101      assert(0 && "Unexpected abbrev ordering!");
1102  }
1103
1104  // FIXME: This should only use space for first class types!
1105
1106  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1107    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1108    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1109    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1110    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1111    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1112    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1113                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1114      assert(0 && "Unexpected abbrev ordering!");
1115  }
1116  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1117    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1118    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1119    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1120    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1121    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1122    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1123                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1124      assert(0 && "Unexpected abbrev ordering!");
1125  }
1126  { // INST_CAST abbrev for FUNCTION_BLOCK.
1127    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1128    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1129    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1130    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1131                              Log2_32_Ceil(VE.getTypes().size()+1)));
1132    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1133    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1134                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1135      assert(0 && "Unexpected abbrev ordering!");
1136  }
1137
1138  { // INST_RET abbrev for FUNCTION_BLOCK.
1139    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1140    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1141    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1142                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1143      assert(0 && "Unexpected abbrev ordering!");
1144  }
1145  { // INST_RET abbrev for FUNCTION_BLOCK.
1146    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1147    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1148    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1149    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1150                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1151      assert(0 && "Unexpected abbrev ordering!");
1152  }
1153  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1154    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1155    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1156    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1157                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1158      assert(0 && "Unexpected abbrev ordering!");
1159  }
1160
1161  Stream.ExitBlock();
1162}
1163
1164
1165/// WriteModule - Emit the specified module to the bitstream.
1166static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1167  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1168
1169  // Emit the version number if it is non-zero.
1170  if (CurVersion) {
1171    SmallVector<unsigned, 1> Vals;
1172    Vals.push_back(CurVersion);
1173    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1174  }
1175
1176  // Analyze the module, enumerating globals, functions, etc.
1177  ValueEnumerator VE(M);
1178
1179  // Emit blockinfo, which defines the standard abbreviations etc.
1180  WriteBlockInfo(VE, Stream);
1181
1182  // Emit information about parameter attributes.
1183  WriteParamAttrTable(VE, Stream);
1184
1185  // Emit information describing all of the types in the module.
1186  WriteTypeTable(VE, Stream);
1187
1188  // Emit top-level description of module, including target triple, inline asm,
1189  // descriptors for global variables, and function prototype info.
1190  WriteModuleInfo(M, VE, Stream);
1191
1192  // Emit constants.
1193  WriteModuleConstants(VE, Stream);
1194
1195  // If we have any aggregate values in the value table, purge them - these can
1196  // only be used to initialize global variables.  Doing so makes the value
1197  // namespace smaller for code in functions.
1198  int NumNonAggregates = VE.PurgeAggregateValues();
1199  if (NumNonAggregates != -1) {
1200    SmallVector<unsigned, 1> Vals;
1201    Vals.push_back(NumNonAggregates);
1202    Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
1203  }
1204
1205  // Emit function bodies.
1206  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1207    if (!I->isDeclaration())
1208      WriteFunction(*I, VE, Stream);
1209
1210  // Emit the type symbol table information.
1211  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1212
1213  // Emit names for globals/functions etc.
1214  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1215
1216  Stream.ExitBlock();
1217}
1218
1219
1220/// WriteBitcodeToFile - Write the specified module to the specified output
1221/// stream.
1222void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
1223  std::vector<unsigned char> Buffer;
1224  BitstreamWriter Stream(Buffer);
1225
1226  Buffer.reserve(256*1024);
1227
1228  // Emit the file header.
1229  Stream.Emit((unsigned)'B', 8);
1230  Stream.Emit((unsigned)'C', 8);
1231  Stream.Emit(0x0, 4);
1232  Stream.Emit(0xC, 4);
1233  Stream.Emit(0xE, 4);
1234  Stream.Emit(0xD, 4);
1235
1236  // Emit the module.
1237  WriteModule(M, Stream);
1238
1239  // Write the generated bitstream to "Out".
1240  Out.write((char*)&Buffer.front(), Buffer.size());
1241
1242  // Make sure it hits disk now.
1243  Out.flush();
1244}
1245