BitcodeWriter.cpp revision 382da62ec274feead85e7be364ab5d4fd0281d98 
1//===--- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ----------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Bitcode writer implementation.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Bitcode/ReaderWriter.h"
15#include "llvm/Bitcode/BitstreamWriter.h"
16#include "llvm/Bitcode/LLVMBitCodes.h"
17#include "ValueEnumerator.h"
18#include "llvm/Constants.h"
19#include "llvm/DerivedTypes.h"
20#include "llvm/InlineAsm.h"
21#include "llvm/Instructions.h"
22#include "llvm/Module.h"
23#include "llvm/TypeSymbolTable.h"
24#include "llvm/ValueSymbolTable.h"
25#include "llvm/Support/MathExtras.h"
26#include "llvm/Support/Streams.h"
27#include "llvm/Support/raw_ostream.h"
28#include "llvm/System/Program.h"
29using namespace llvm;
30
31/// These are manifest constants used by the bitcode writer. They do not need to
32/// be kept in sync with the reader, but need to be consistent within this file.
33enum {
34  CurVersion = 0,
35
36  // VALUE_SYMTAB_BLOCK abbrev id's.
37  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
38  VST_ENTRY_7_ABBREV,
39  VST_ENTRY_6_ABBREV,
40  VST_BBENTRY_6_ABBREV,
41
42  // CONSTANTS_BLOCK abbrev id's.
43  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
44  CONSTANTS_INTEGER_ABBREV,
45  CONSTANTS_CE_CAST_Abbrev,
46  CONSTANTS_NULL_Abbrev,
47
48  // FUNCTION_BLOCK abbrev id's.
49  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
50  FUNCTION_INST_BINOP_ABBREV,
51  FUNCTION_INST_CAST_ABBREV,
52  FUNCTION_INST_RET_VOID_ABBREV,
53  FUNCTION_INST_RET_VAL_ABBREV,
54  FUNCTION_INST_UNREACHABLE_ABBREV
55};
56
57
58static unsigned GetEncodedCastOpcode(unsigned Opcode) {
59  switch (Opcode) {
60  default: assert(0 && "Unknown cast instruction!");
61  case Instruction::Trunc   : return bitc::CAST_TRUNC;
62  case Instruction::ZExt    : return bitc::CAST_ZEXT;
63  case Instruction::SExt    : return bitc::CAST_SEXT;
64  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
65  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
66  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
67  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
68  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
69  case Instruction::FPExt   : return bitc::CAST_FPEXT;
70  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
71  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
72  case Instruction::BitCast : return bitc::CAST_BITCAST;
73  }
74}
75
76static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
77  switch (Opcode) {
78  default: assert(0 && "Unknown binary instruction!");
79  case Instruction::Add:  return bitc::BINOP_ADD;
80  case Instruction::Sub:  return bitc::BINOP_SUB;
81  case Instruction::Mul:  return bitc::BINOP_MUL;
82  case Instruction::UDiv: return bitc::BINOP_UDIV;
83  case Instruction::FDiv:
84  case Instruction::SDiv: return bitc::BINOP_SDIV;
85  case Instruction::URem: return bitc::BINOP_UREM;
86  case Instruction::FRem:
87  case Instruction::SRem: return bitc::BINOP_SREM;
88  case Instruction::Shl:  return bitc::BINOP_SHL;
89  case Instruction::LShr: return bitc::BINOP_LSHR;
90  case Instruction::AShr: return bitc::BINOP_ASHR;
91  case Instruction::And:  return bitc::BINOP_AND;
92  case Instruction::Or:   return bitc::BINOP_OR;
93  case Instruction::Xor:  return bitc::BINOP_XOR;
94  }
95}
96
97
98
99static void WriteStringRecord(unsigned Code, const std::string &Str,
100                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
101  SmallVector<unsigned, 64> Vals;
102
103  // Code: [strchar x N]
104  for (unsigned i = 0, e = Str.size(); i != e; ++i)
105    Vals.push_back(Str[i]);
106
107  // Emit the finished record.
108  Stream.EmitRecord(Code, Vals, AbbrevToUse);
109}
110
111// Emit information about parameter attributes.
112static void WriteAttributeTable(const ValueEnumerator &VE,
113                                BitstreamWriter &Stream) {
114  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
115  if (Attrs.empty()) return;
116
117  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
118
119  SmallVector<uint64_t, 64> Record;
120  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
121    const AttrListPtr &A = Attrs[i];
122    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
123      const AttributeWithIndex &PAWI = A.getSlot(i);
124      Record.push_back(PAWI.Index);
125
126      // FIXME: remove in LLVM 3.0
127      // Store the alignment in the bitcode as a 16-bit raw value instead of a
128      // 5-bit log2 encoded value. Shift the bits above the alignment up by
129      // 11 bits.
130      uint64_t FauxAttr = PAWI.Attrs & 0xffff;
131      if (PAWI.Attrs & Attribute::Alignment)
132        FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
133      FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
134
135      Record.push_back(FauxAttr);
136    }
137
138    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
139    Record.clear();
140  }
141
142  Stream.ExitBlock();
143}
144
145/// WriteTypeTable - Write out the type table for a module.
146static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
147  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
148
149  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
150  SmallVector<uint64_t, 64> TypeVals;
151
152  // Abbrev for TYPE_CODE_POINTER.
153  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
154  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
155  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
156                            Log2_32_Ceil(VE.getTypes().size()+1)));
157  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
158  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
159
160  // Abbrev for TYPE_CODE_FUNCTION.
161  Abbv = new BitCodeAbbrev();
162  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
163  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
164  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
165  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
166  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
167                            Log2_32_Ceil(VE.getTypes().size()+1)));
168  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
169
170  // Abbrev for TYPE_CODE_STRUCT.
171  Abbv = new BitCodeAbbrev();
172  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
173  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
174  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
175  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
176                            Log2_32_Ceil(VE.getTypes().size()+1)));
177  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
178
179  // Abbrev for TYPE_CODE_ARRAY.
180  Abbv = new BitCodeAbbrev();
181  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
182  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
183  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
184                            Log2_32_Ceil(VE.getTypes().size()+1)));
185  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
186
187  // Emit an entry count so the reader can reserve space.
188  TypeVals.push_back(TypeList.size());
189  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
190  TypeVals.clear();
191
192  // Loop over all of the types, emitting each in turn.
193  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
194    const Type *T = TypeList[i].first;
195    int AbbrevToUse = 0;
196    unsigned Code = 0;
197
198    switch (T->getTypeID()) {
199    default: assert(0 && "Unknown type!");
200    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
201    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
202    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
203    case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
204    case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
205    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
206    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
207    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
208    case Type::IntegerTyID:
209      // INTEGER: [width]
210      Code = bitc::TYPE_CODE_INTEGER;
211      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
212      break;
213    case Type::PointerTyID: {
214      const PointerType *PTy = cast<PointerType>(T);
215      // POINTER: [pointee type, address space]
216      Code = bitc::TYPE_CODE_POINTER;
217      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
218      unsigned AddressSpace = PTy->getAddressSpace();
219      TypeVals.push_back(AddressSpace);
220      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
221      break;
222    }
223    case Type::FunctionTyID: {
224      const FunctionType *FT = cast<FunctionType>(T);
225      // FUNCTION: [isvararg, attrid, retty, paramty x N]
226      Code = bitc::TYPE_CODE_FUNCTION;
227      TypeVals.push_back(FT->isVarArg());
228      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
229      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
230      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
231        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
232      AbbrevToUse = FunctionAbbrev;
233      break;
234    }
235    case Type::StructTyID: {
236      const StructType *ST = cast<StructType>(T);
237      // STRUCT: [ispacked, eltty x N]
238      Code = bitc::TYPE_CODE_STRUCT;
239      TypeVals.push_back(ST->isPacked());
240      // Output all of the element types.
241      for (StructType::element_iterator I = ST->element_begin(),
242           E = ST->element_end(); I != E; ++I)
243        TypeVals.push_back(VE.getTypeID(*I));
244      AbbrevToUse = StructAbbrev;
245      break;
246    }
247    case Type::ArrayTyID: {
248      const ArrayType *AT = cast<ArrayType>(T);
249      // ARRAY: [numelts, eltty]
250      Code = bitc::TYPE_CODE_ARRAY;
251      TypeVals.push_back(AT->getNumElements());
252      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
253      AbbrevToUse = ArrayAbbrev;
254      break;
255    }
256    case Type::VectorTyID: {
257      const VectorType *VT = cast<VectorType>(T);
258      // VECTOR [numelts, eltty]
259      Code = bitc::TYPE_CODE_VECTOR;
260      TypeVals.push_back(VT->getNumElements());
261      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
262      break;
263    }
264    }
265
266    // Emit the finished record.
267    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
268    TypeVals.clear();
269  }
270
271  Stream.ExitBlock();
272}
273
274static unsigned getEncodedLinkage(const GlobalValue *GV) {
275  switch (GV->getLinkage()) {
276  default: assert(0 && "Invalid linkage!");
277  case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
278  case GlobalValue::ExternalLinkage:     return 0;
279  case GlobalValue::WeakLinkage:         return 1;
280  case GlobalValue::AppendingLinkage:    return 2;
281  case GlobalValue::InternalLinkage:     return 3;
282  case GlobalValue::LinkOnceLinkage:     return 4;
283  case GlobalValue::DLLImportLinkage:    return 5;
284  case GlobalValue::DLLExportLinkage:    return 6;
285  case GlobalValue::ExternalWeakLinkage: return 7;
286  case GlobalValue::CommonLinkage:       return 8;
287  }
288}
289
290static unsigned getEncodedVisibility(const GlobalValue *GV) {
291  switch (GV->getVisibility()) {
292  default: assert(0 && "Invalid visibility!");
293  case GlobalValue::DefaultVisibility:   return 0;
294  case GlobalValue::HiddenVisibility:    return 1;
295  case GlobalValue::ProtectedVisibility: return 2;
296  }
297}
298
299// Emit top-level description of module, including target triple, inline asm,
300// descriptors for global variables, and function prototype info.
301static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
302                            BitstreamWriter &Stream) {
303  // Emit the list of dependent libraries for the Module.
304  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
305    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
306
307  // Emit various pieces of data attached to a module.
308  if (!M->getTargetTriple().empty())
309    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
310                      0/*TODO*/, Stream);
311  if (!M->getDataLayout().empty())
312    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
313                      0/*TODO*/, Stream);
314  if (!M->getModuleInlineAsm().empty())
315    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
316                      0/*TODO*/, Stream);
317
318  // Emit information about sections and GC, computing how many there are. Also
319  // compute the maximum alignment value.
320  std::map<std::string, unsigned> SectionMap;
321  std::map<std::string, unsigned> GCMap;
322  unsigned MaxAlignment = 0;
323  unsigned MaxGlobalType = 0;
324  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
325       GV != E; ++GV) {
326    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
327    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
328
329    if (!GV->hasSection()) continue;
330    // Give section names unique ID's.
331    unsigned &Entry = SectionMap[GV->getSection()];
332    if (Entry != 0) continue;
333    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
334                      0/*TODO*/, Stream);
335    Entry = SectionMap.size();
336  }
337  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
338    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
339    if (F->hasSection()) {
340      // Give section names unique ID's.
341      unsigned &Entry = SectionMap[F->getSection()];
342      if (!Entry) {
343        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
344                          0/*TODO*/, Stream);
345        Entry = SectionMap.size();
346      }
347    }
348    if (F->hasGC()) {
349      // Same for GC names.
350      unsigned &Entry = GCMap[F->getGC()];
351      if (!Entry) {
352        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
353                          0/*TODO*/, Stream);
354        Entry = GCMap.size();
355      }
356    }
357  }
358
359  // Emit abbrev for globals, now that we know # sections and max alignment.
360  unsigned SimpleGVarAbbrev = 0;
361  if (!M->global_empty()) {
362    // Add an abbrev for common globals with no visibility or thread localness.
363    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
364    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
365    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
366                              Log2_32_Ceil(MaxGlobalType+1)));
367    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
368    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
369    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
370    if (MaxAlignment == 0)                                      // Alignment.
371      Abbv->Add(BitCodeAbbrevOp(0));
372    else {
373      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
374      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
375                               Log2_32_Ceil(MaxEncAlignment+1)));
376    }
377    if (SectionMap.empty())                                    // Section.
378      Abbv->Add(BitCodeAbbrevOp(0));
379    else
380      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
381                               Log2_32_Ceil(SectionMap.size()+1)));
382    // Don't bother emitting vis + thread local.
383    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
384  }
385
386  // Emit the global variable information.
387  SmallVector<unsigned, 64> Vals;
388  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
389       GV != E; ++GV) {
390    unsigned AbbrevToUse = 0;
391
392    // GLOBALVAR: [type, isconst, initid,
393    //             linkage, alignment, section, visibility, threadlocal]
394    Vals.push_back(VE.getTypeID(GV->getType()));
395    Vals.push_back(GV->isConstant());
396    Vals.push_back(GV->isDeclaration() ? 0 :
397                   (VE.getValueID(GV->getInitializer()) + 1));
398    Vals.push_back(getEncodedLinkage(GV));
399    Vals.push_back(Log2_32(GV->getAlignment())+1);
400    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
401    if (GV->isThreadLocal() ||
402        GV->getVisibility() != GlobalValue::DefaultVisibility) {
403      Vals.push_back(getEncodedVisibility(GV));
404      Vals.push_back(GV->isThreadLocal());
405    } else {
406      AbbrevToUse = SimpleGVarAbbrev;
407    }
408
409    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
410    Vals.clear();
411  }
412
413  // Emit the function proto information.
414  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
415    // FUNCTION:  [type, callingconv, isproto, paramattr,
416    //             linkage, alignment, section, visibility, gc]
417    Vals.push_back(VE.getTypeID(F->getType()));
418    Vals.push_back(F->getCallingConv());
419    Vals.push_back(F->isDeclaration());
420    Vals.push_back(getEncodedLinkage(F));
421    Vals.push_back(VE.getAttributeID(F->getAttributes()));
422    Vals.push_back(Log2_32(F->getAlignment())+1);
423    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
424    Vals.push_back(getEncodedVisibility(F));
425    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
426
427    unsigned AbbrevToUse = 0;
428    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
429    Vals.clear();
430  }
431
432
433  // Emit the alias information.
434  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
435       AI != E; ++AI) {
436    Vals.push_back(VE.getTypeID(AI->getType()));
437    Vals.push_back(VE.getValueID(AI->getAliasee()));
438    Vals.push_back(getEncodedLinkage(AI));
439    Vals.push_back(getEncodedVisibility(AI));
440    unsigned AbbrevToUse = 0;
441    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
442    Vals.clear();
443  }
444}
445
446
447static void WriteConstants(unsigned FirstVal, unsigned LastVal,
448                           const ValueEnumerator &VE,
449                           BitstreamWriter &Stream, bool isGlobal) {
450  if (FirstVal == LastVal) return;
451
452  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
453
454  unsigned AggregateAbbrev = 0;
455  unsigned String8Abbrev = 0;
456  unsigned CString7Abbrev = 0;
457  unsigned CString6Abbrev = 0;
458  // If this is a constant pool for the module, emit module-specific abbrevs.
459  if (isGlobal) {
460    // Abbrev for CST_CODE_AGGREGATE.
461    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
462    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
463    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
464    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
465    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
466
467    // Abbrev for CST_CODE_STRING.
468    Abbv = new BitCodeAbbrev();
469    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
470    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
471    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
472    String8Abbrev = Stream.EmitAbbrev(Abbv);
473    // Abbrev for CST_CODE_CSTRING.
474    Abbv = new BitCodeAbbrev();
475    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
476    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
477    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
478    CString7Abbrev = Stream.EmitAbbrev(Abbv);
479    // Abbrev for CST_CODE_CSTRING.
480    Abbv = new BitCodeAbbrev();
481    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
482    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
483    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
484    CString6Abbrev = Stream.EmitAbbrev(Abbv);
485  }
486
487  SmallVector<uint64_t, 64> Record;
488
489  const ValueEnumerator::ValueList &Vals = VE.getValues();
490  const Type *LastTy = 0;
491  for (unsigned i = FirstVal; i != LastVal; ++i) {
492    const Value *V = Vals[i].first;
493    // If we need to switch types, do so now.
494    if (V->getType() != LastTy) {
495      LastTy = V->getType();
496      Record.push_back(VE.getTypeID(LastTy));
497      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
498                        CONSTANTS_SETTYPE_ABBREV);
499      Record.clear();
500    }
501
502    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
503      Record.push_back(unsigned(IA->hasSideEffects()));
504
505      // Add the asm string.
506      const std::string &AsmStr = IA->getAsmString();
507      Record.push_back(AsmStr.size());
508      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
509        Record.push_back(AsmStr[i]);
510
511      // Add the constraint string.
512      const std::string &ConstraintStr = IA->getConstraintString();
513      Record.push_back(ConstraintStr.size());
514      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
515        Record.push_back(ConstraintStr[i]);
516      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
517      Record.clear();
518      continue;
519    }
520    const Constant *C = cast<Constant>(V);
521    unsigned Code = -1U;
522    unsigned AbbrevToUse = 0;
523    if (C->isNullValue()) {
524      Code = bitc::CST_CODE_NULL;
525    } else if (isa<UndefValue>(C)) {
526      Code = bitc::CST_CODE_UNDEF;
527    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
528      if (IV->getBitWidth() <= 64) {
529        int64_t V = IV->getSExtValue();
530        if (V >= 0)
531          Record.push_back(V << 1);
532        else
533          Record.push_back((-V << 1) | 1);
534        Code = bitc::CST_CODE_INTEGER;
535        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
536      } else {                             // Wide integers, > 64 bits in size.
537        // We have an arbitrary precision integer value to write whose
538        // bit width is > 64. However, in canonical unsigned integer
539        // format it is likely that the high bits are going to be zero.
540        // So, we only write the number of active words.
541        unsigned NWords = IV->getValue().getActiveWords();
542        const uint64_t *RawWords = IV->getValue().getRawData();
543        for (unsigned i = 0; i != NWords; ++i) {
544          int64_t V = RawWords[i];
545          if (V >= 0)
546            Record.push_back(V << 1);
547          else
548            Record.push_back((-V << 1) | 1);
549        }
550        Code = bitc::CST_CODE_WIDE_INTEGER;
551      }
552    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
553      Code = bitc::CST_CODE_FLOAT;
554      const Type *Ty = CFP->getType();
555      if (Ty == Type::FloatTy || Ty == Type::DoubleTy) {
556        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
557      } else if (Ty == Type::X86_FP80Ty) {
558        // api needed to prevent premature destruction
559        APInt api = CFP->getValueAPF().bitcastToAPInt();
560        const uint64_t *p = api.getRawData();
561        Record.push_back(p[0]);
562        Record.push_back((uint16_t)p[1]);
563      } else if (Ty == Type::FP128Ty || Ty == Type::PPC_FP128Ty) {
564        APInt api = CFP->getValueAPF().bitcastToAPInt();
565        const uint64_t *p = api.getRawData();
566        Record.push_back(p[0]);
567        Record.push_back(p[1]);
568      } else {
569        assert (0 && "Unknown FP type!");
570      }
571    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
572      // Emit constant strings specially.
573      unsigned NumOps = C->getNumOperands();
574      // If this is a null-terminated string, use the denser CSTRING encoding.
575      if (C->getOperand(NumOps-1)->isNullValue()) {
576        Code = bitc::CST_CODE_CSTRING;
577        --NumOps;  // Don't encode the null, which isn't allowed by char6.
578      } else {
579        Code = bitc::CST_CODE_STRING;
580        AbbrevToUse = String8Abbrev;
581      }
582      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
583      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
584      for (unsigned i = 0; i != NumOps; ++i) {
585        unsigned char V = cast<ConstantInt>(C->getOperand(i))->getZExtValue();
586        Record.push_back(V);
587        isCStr7 &= (V & 128) == 0;
588        if (isCStrChar6)
589          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
590      }
591
592      if (isCStrChar6)
593        AbbrevToUse = CString6Abbrev;
594      else if (isCStr7)
595        AbbrevToUse = CString7Abbrev;
596    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
597               isa<ConstantVector>(V)) {
598      Code = bitc::CST_CODE_AGGREGATE;
599      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
600        Record.push_back(VE.getValueID(C->getOperand(i)));
601      AbbrevToUse = AggregateAbbrev;
602    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
603      switch (CE->getOpcode()) {
604      default:
605        if (Instruction::isCast(CE->getOpcode())) {
606          Code = bitc::CST_CODE_CE_CAST;
607          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
608          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
609          Record.push_back(VE.getValueID(C->getOperand(0)));
610          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
611        } else {
612          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
613          Code = bitc::CST_CODE_CE_BINOP;
614          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
615          Record.push_back(VE.getValueID(C->getOperand(0)));
616          Record.push_back(VE.getValueID(C->getOperand(1)));
617        }
618        break;
619      case Instruction::GetElementPtr:
620        Code = bitc::CST_CODE_CE_GEP;
621        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
622          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
623          Record.push_back(VE.getValueID(C->getOperand(i)));
624        }
625        break;
626      case Instruction::Select:
627        Code = bitc::CST_CODE_CE_SELECT;
628        Record.push_back(VE.getValueID(C->getOperand(0)));
629        Record.push_back(VE.getValueID(C->getOperand(1)));
630        Record.push_back(VE.getValueID(C->getOperand(2)));
631        break;
632      case Instruction::ExtractElement:
633        Code = bitc::CST_CODE_CE_EXTRACTELT;
634        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
635        Record.push_back(VE.getValueID(C->getOperand(0)));
636        Record.push_back(VE.getValueID(C->getOperand(1)));
637        break;
638      case Instruction::InsertElement:
639        Code = bitc::CST_CODE_CE_INSERTELT;
640        Record.push_back(VE.getValueID(C->getOperand(0)));
641        Record.push_back(VE.getValueID(C->getOperand(1)));
642        Record.push_back(VE.getValueID(C->getOperand(2)));
643        break;
644      case Instruction::ShuffleVector:
645        Code = bitc::CST_CODE_CE_SHUFFLEVEC;
646        Record.push_back(VE.getValueID(C->getOperand(0)));
647        Record.push_back(VE.getValueID(C->getOperand(1)));
648        Record.push_back(VE.getValueID(C->getOperand(2)));
649        break;
650      case Instruction::ICmp:
651      case Instruction::FCmp:
652      case Instruction::VICmp:
653      case Instruction::VFCmp:
654        if (isa<VectorType>(C->getOperand(0)->getType())
655            && (CE->getOpcode() == Instruction::ICmp
656                || CE->getOpcode() == Instruction::FCmp)) {
657          // compare returning vector of Int1Ty
658          assert(0 && "Unsupported constant!");
659        } else {
660          Code = bitc::CST_CODE_CE_CMP;
661        }
662        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
663        Record.push_back(VE.getValueID(C->getOperand(0)));
664        Record.push_back(VE.getValueID(C->getOperand(1)));
665        Record.push_back(CE->getPredicate());
666        break;
667      }
668    } else {
669      assert(0 && "Unknown constant!");
670    }
671    Stream.EmitRecord(Code, Record, AbbrevToUse);
672    Record.clear();
673  }
674
675  Stream.ExitBlock();
676}
677
678static void WriteModuleConstants(const ValueEnumerator &VE,
679                                 BitstreamWriter &Stream) {
680  const ValueEnumerator::ValueList &Vals = VE.getValues();
681
682  // Find the first constant to emit, which is the first non-globalvalue value.
683  // We know globalvalues have been emitted by WriteModuleInfo.
684  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
685    if (!isa<GlobalValue>(Vals[i].first)) {
686      WriteConstants(i, Vals.size(), VE, Stream, true);
687      return;
688    }
689  }
690}
691
692/// PushValueAndType - The file has to encode both the value and type id for
693/// many values, because we need to know what type to create for forward
694/// references.  However, most operands are not forward references, so this type
695/// field is not needed.
696///
697/// This function adds V's value ID to Vals.  If the value ID is higher than the
698/// instruction ID, then it is a forward reference, and it also includes the
699/// type ID.
700static bool PushValueAndType(Value *V, unsigned InstID,
701                             SmallVector<unsigned, 64> &Vals,
702                             ValueEnumerator &VE) {
703  unsigned ValID = VE.getValueID(V);
704  Vals.push_back(ValID);
705  if (ValID >= InstID) {
706    Vals.push_back(VE.getTypeID(V->getType()));
707    return true;
708  }
709  return false;
710}
711
712/// WriteInstruction - Emit an instruction to the specified stream.
713static void WriteInstruction(const Instruction &I, unsigned InstID,
714                             ValueEnumerator &VE, BitstreamWriter &Stream,
715                             SmallVector<unsigned, 64> &Vals) {
716  unsigned Code = 0;
717  unsigned AbbrevToUse = 0;
718  switch (I.getOpcode()) {
719  default:
720    if (Instruction::isCast(I.getOpcode())) {
721      Code = bitc::FUNC_CODE_INST_CAST;
722      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
723        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
724      Vals.push_back(VE.getTypeID(I.getType()));
725      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
726    } else {
727      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
728      Code = bitc::FUNC_CODE_INST_BINOP;
729      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
730        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
731      Vals.push_back(VE.getValueID(I.getOperand(1)));
732      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
733    }
734    break;
735
736  case Instruction::GetElementPtr:
737    Code = bitc::FUNC_CODE_INST_GEP;
738    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
739      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
740    break;
741  case Instruction::ExtractValue: {
742    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
743    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
744    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
745    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
746      Vals.push_back(*i);
747    break;
748  }
749  case Instruction::InsertValue: {
750    Code = bitc::FUNC_CODE_INST_INSERTVAL;
751    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
752    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
753    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
754    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
755      Vals.push_back(*i);
756    break;
757  }
758  case Instruction::Select:
759    Code = bitc::FUNC_CODE_INST_VSELECT;
760    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
761    Vals.push_back(VE.getValueID(I.getOperand(2)));
762    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
763    break;
764  case Instruction::ExtractElement:
765    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
766    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
767    Vals.push_back(VE.getValueID(I.getOperand(1)));
768    break;
769  case Instruction::InsertElement:
770    Code = bitc::FUNC_CODE_INST_INSERTELT;
771    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
772    Vals.push_back(VE.getValueID(I.getOperand(1)));
773    Vals.push_back(VE.getValueID(I.getOperand(2)));
774    break;
775  case Instruction::ShuffleVector:
776    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
777    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
778    Vals.push_back(VE.getValueID(I.getOperand(1)));
779    Vals.push_back(VE.getValueID(I.getOperand(2)));
780    break;
781  case Instruction::ICmp:
782  case Instruction::FCmp:
783  case Instruction::VICmp:
784  case Instruction::VFCmp:
785    if (I.getOpcode() == Instruction::ICmp
786        || I.getOpcode() == Instruction::FCmp) {
787      // compare returning Int1Ty or vector of Int1Ty
788      Code = bitc::FUNC_CODE_INST_CMP2;
789    } else {
790      Code = bitc::FUNC_CODE_INST_CMP;
791    }
792    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
793    Vals.push_back(VE.getValueID(I.getOperand(1)));
794    Vals.push_back(cast<CmpInst>(I).getPredicate());
795    break;
796
797  case Instruction::Ret:
798    {
799      Code = bitc::FUNC_CODE_INST_RET;
800      unsigned NumOperands = I.getNumOperands();
801      if (NumOperands == 0)
802        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
803      else if (NumOperands == 1) {
804        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
805          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
806      } else {
807        for (unsigned i = 0, e = NumOperands; i != e; ++i)
808          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
809      }
810    }
811    break;
812  case Instruction::Br:
813    Code = bitc::FUNC_CODE_INST_BR;
814    Vals.push_back(VE.getValueID(I.getOperand(0)));
815    if (cast<BranchInst>(I).isConditional()) {
816      Vals.push_back(VE.getValueID(I.getOperand(1)));
817      Vals.push_back(VE.getValueID(I.getOperand(2)));
818    }
819    break;
820  case Instruction::Switch:
821    Code = bitc::FUNC_CODE_INST_SWITCH;
822    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
823    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
824      Vals.push_back(VE.getValueID(I.getOperand(i)));
825    break;
826  case Instruction::Invoke: {
827    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
828    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
829    Code = bitc::FUNC_CODE_INST_INVOKE;
830
831    const InvokeInst *II = cast<InvokeInst>(&I);
832    Vals.push_back(VE.getAttributeID(II->getAttributes()));
833    Vals.push_back(II->getCallingConv());
834    Vals.push_back(VE.getValueID(I.getOperand(1)));      // normal dest
835    Vals.push_back(VE.getValueID(I.getOperand(2)));      // unwind dest
836    PushValueAndType(I.getOperand(0), InstID, Vals, VE); // callee
837
838    // Emit value #'s for the fixed parameters.
839    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
840      Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
841
842    // Emit type/value pairs for varargs params.
843    if (FTy->isVarArg()) {
844      for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
845           i != e; ++i)
846        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
847    }
848    break;
849  }
850  case Instruction::Unwind:
851    Code = bitc::FUNC_CODE_INST_UNWIND;
852    break;
853  case Instruction::Unreachable:
854    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
855    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
856    break;
857
858  case Instruction::PHI:
859    Code = bitc::FUNC_CODE_INST_PHI;
860    Vals.push_back(VE.getTypeID(I.getType()));
861    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
862      Vals.push_back(VE.getValueID(I.getOperand(i)));
863    break;
864
865  case Instruction::Malloc:
866    Code = bitc::FUNC_CODE_INST_MALLOC;
867    Vals.push_back(VE.getTypeID(I.getType()));
868    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
869    Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
870    break;
871
872  case Instruction::Free:
873    Code = bitc::FUNC_CODE_INST_FREE;
874    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
875    break;
876
877  case Instruction::Alloca:
878    Code = bitc::FUNC_CODE_INST_ALLOCA;
879    Vals.push_back(VE.getTypeID(I.getType()));
880    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
881    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
882    break;
883
884  case Instruction::Load:
885    Code = bitc::FUNC_CODE_INST_LOAD;
886    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
887      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
888
889    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
890    Vals.push_back(cast<LoadInst>(I).isVolatile());
891    break;
892  case Instruction::Store:
893    Code = bitc::FUNC_CODE_INST_STORE2;
894    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
895    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
896    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
897    Vals.push_back(cast<StoreInst>(I).isVolatile());
898    break;
899  case Instruction::Call: {
900    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
901    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
902
903    Code = bitc::FUNC_CODE_INST_CALL;
904
905    const CallInst *CI = cast<CallInst>(&I);
906    Vals.push_back(VE.getAttributeID(CI->getAttributes()));
907    Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
908    PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
909
910    // Emit value #'s for the fixed parameters.
911    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
912      Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
913
914    // Emit type/value pairs for varargs params.
915    if (FTy->isVarArg()) {
916      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
917      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
918           i != e; ++i)
919        PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
920    }
921    break;
922  }
923  case Instruction::VAArg:
924    Code = bitc::FUNC_CODE_INST_VAARG;
925    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
926    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
927    Vals.push_back(VE.getTypeID(I.getType())); // restype.
928    break;
929  }
930
931  Stream.EmitRecord(Code, Vals, AbbrevToUse);
932  Vals.clear();
933}
934
935// Emit names for globals/functions etc.
936static void WriteValueSymbolTable(const ValueSymbolTable &VST,
937                                  const ValueEnumerator &VE,
938                                  BitstreamWriter &Stream) {
939  if (VST.empty()) return;
940  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
941
942  // FIXME: Set up the abbrev, we know how many values there are!
943  // FIXME: We know if the type names can use 7-bit ascii.
944  SmallVector<unsigned, 64> NameVals;
945
946  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
947       SI != SE; ++SI) {
948
949    const ValueName &Name = *SI;
950
951    // Figure out the encoding to use for the name.
952    bool is7Bit = true;
953    bool isChar6 = true;
954    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
955         C != E; ++C) {
956      if (isChar6)
957        isChar6 = BitCodeAbbrevOp::isChar6(*C);
958      if ((unsigned char)*C & 128) {
959        is7Bit = false;
960        break;  // don't bother scanning the rest.
961      }
962    }
963
964    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
965
966    // VST_ENTRY:   [valueid, namechar x N]
967    // VST_BBENTRY: [bbid, namechar x N]
968    unsigned Code;
969    if (isa<BasicBlock>(SI->getValue())) {
970      Code = bitc::VST_CODE_BBENTRY;
971      if (isChar6)
972        AbbrevToUse = VST_BBENTRY_6_ABBREV;
973    } else {
974      Code = bitc::VST_CODE_ENTRY;
975      if (isChar6)
976        AbbrevToUse = VST_ENTRY_6_ABBREV;
977      else if (is7Bit)
978        AbbrevToUse = VST_ENTRY_7_ABBREV;
979    }
980
981    NameVals.push_back(VE.getValueID(SI->getValue()));
982    for (const char *P = Name.getKeyData(),
983         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
984      NameVals.push_back((unsigned char)*P);
985
986    // Emit the finished record.
987    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
988    NameVals.clear();
989  }
990  Stream.ExitBlock();
991}
992
993/// WriteFunction - Emit a function body to the module stream.
994static void WriteFunction(const Function &F, ValueEnumerator &VE,
995                          BitstreamWriter &Stream) {
996  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
997  VE.incorporateFunction(F);
998
999  SmallVector<unsigned, 64> Vals;
1000
1001  // Emit the number of basic blocks, so the reader can create them ahead of
1002  // time.
1003  Vals.push_back(VE.getBasicBlocks().size());
1004  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1005  Vals.clear();
1006
1007  // If there are function-local constants, emit them now.
1008  unsigned CstStart, CstEnd;
1009  VE.getFunctionConstantRange(CstStart, CstEnd);
1010  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1011
1012  // Keep a running idea of what the instruction ID is.
1013  unsigned InstID = CstEnd;
1014
1015  // Finally, emit all the instructions, in order.
1016  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1017    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1018         I != E; ++I) {
1019      WriteInstruction(*I, InstID, VE, Stream, Vals);
1020      if (I->getType() != Type::VoidTy)
1021        ++InstID;
1022    }
1023
1024  // Emit names for all the instructions etc.
1025  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1026
1027  VE.purgeFunction();
1028  Stream.ExitBlock();
1029}
1030
1031/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1032static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1033                                 const ValueEnumerator &VE,
1034                                 BitstreamWriter &Stream) {
1035  if (TST.empty()) return;
1036
1037  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1038
1039  // 7-bit fixed width VST_CODE_ENTRY strings.
1040  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1041  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1042  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1043                            Log2_32_Ceil(VE.getTypes().size()+1)));
1044  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1045  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1046  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1047
1048  SmallVector<unsigned, 64> NameVals;
1049
1050  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1051       TI != TE; ++TI) {
1052    // TST_ENTRY: [typeid, namechar x N]
1053    NameVals.push_back(VE.getTypeID(TI->second));
1054
1055    const std::string &Str = TI->first;
1056    bool is7Bit = true;
1057    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1058      NameVals.push_back((unsigned char)Str[i]);
1059      if (Str[i] & 128)
1060        is7Bit = false;
1061    }
1062
1063    // Emit the finished record.
1064    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1065    NameVals.clear();
1066  }
1067
1068  Stream.ExitBlock();
1069}
1070
1071// Emit blockinfo, which defines the standard abbreviations etc.
1072static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1073  // We only want to emit block info records for blocks that have multiple
1074  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1075  // blocks can defined their abbrevs inline.
1076  Stream.EnterBlockInfoBlock(2);
1077
1078  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1079    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1080    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1081    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1082    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1083    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1084    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1085                                   Abbv) != VST_ENTRY_8_ABBREV)
1086      assert(0 && "Unexpected abbrev ordering!");
1087  }
1088
1089  { // 7-bit fixed width VST_ENTRY strings.
1090    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1091    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1092    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1093    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1094    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1095    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1096                                   Abbv) != VST_ENTRY_7_ABBREV)
1097      assert(0 && "Unexpected abbrev ordering!");
1098  }
1099  { // 6-bit char6 VST_ENTRY strings.
1100    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1101    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1102    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1103    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1104    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1105    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1106                                   Abbv) != VST_ENTRY_6_ABBREV)
1107      assert(0 && "Unexpected abbrev ordering!");
1108  }
1109  { // 6-bit char6 VST_BBENTRY strings.
1110    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1111    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1112    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1113    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1114    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1115    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1116                                   Abbv) != VST_BBENTRY_6_ABBREV)
1117      assert(0 && "Unexpected abbrev ordering!");
1118  }
1119
1120
1121
1122  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1123    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1124    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1125    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1126                              Log2_32_Ceil(VE.getTypes().size()+1)));
1127    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1128                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1129      assert(0 && "Unexpected abbrev ordering!");
1130  }
1131
1132  { // INTEGER abbrev for CONSTANTS_BLOCK.
1133    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1134    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1135    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1136    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1137                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1138      assert(0 && "Unexpected abbrev ordering!");
1139  }
1140
1141  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1142    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1143    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1144    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1145    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1146                              Log2_32_Ceil(VE.getTypes().size()+1)));
1147    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1148
1149    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1150                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1151      assert(0 && "Unexpected abbrev ordering!");
1152  }
1153  { // NULL abbrev for CONSTANTS_BLOCK.
1154    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1155    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1156    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1157                                   Abbv) != CONSTANTS_NULL_Abbrev)
1158      assert(0 && "Unexpected abbrev ordering!");
1159  }
1160
1161  // FIXME: This should only use space for first class types!
1162
1163  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1164    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1165    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1166    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1167    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1168    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1169    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1170                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1171      assert(0 && "Unexpected abbrev ordering!");
1172  }
1173  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1174    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1175    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1176    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1177    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1178    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1179    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1180                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1181      assert(0 && "Unexpected abbrev ordering!");
1182  }
1183  { // INST_CAST abbrev for FUNCTION_BLOCK.
1184    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1185    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1186    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1187    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1188                              Log2_32_Ceil(VE.getTypes().size()+1)));
1189    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1190    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1191                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1192      assert(0 && "Unexpected abbrev ordering!");
1193  }
1194
1195  { // INST_RET abbrev for FUNCTION_BLOCK.
1196    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1197    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1198    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1199                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1200      assert(0 && "Unexpected abbrev ordering!");
1201  }
1202  { // INST_RET abbrev for FUNCTION_BLOCK.
1203    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1204    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1205    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1206    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1207                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1208      assert(0 && "Unexpected abbrev ordering!");
1209  }
1210  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1211    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1212    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1213    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1214                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1215      assert(0 && "Unexpected abbrev ordering!");
1216  }
1217
1218  Stream.ExitBlock();
1219}
1220
1221
1222/// WriteModule - Emit the specified module to the bitstream.
1223static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1224  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1225
1226  // Emit the version number if it is non-zero.
1227  if (CurVersion) {
1228    SmallVector<unsigned, 1> Vals;
1229    Vals.push_back(CurVersion);
1230    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1231  }
1232
1233  // Analyze the module, enumerating globals, functions, etc.
1234  ValueEnumerator VE(M);
1235
1236  // Emit blockinfo, which defines the standard abbreviations etc.
1237  WriteBlockInfo(VE, Stream);
1238
1239  // Emit information about parameter attributes.
1240  WriteAttributeTable(VE, Stream);
1241
1242  // Emit information describing all of the types in the module.
1243  WriteTypeTable(VE, Stream);
1244
1245  // Emit top-level description of module, including target triple, inline asm,
1246  // descriptors for global variables, and function prototype info.
1247  WriteModuleInfo(M, VE, Stream);
1248
1249  // Emit constants.
1250  WriteModuleConstants(VE, Stream);
1251
1252  // If we have any aggregate values in the value table, purge them - these can
1253  // only be used to initialize global variables.  Doing so makes the value
1254  // namespace smaller for code in functions.
1255  int NumNonAggregates = VE.PurgeAggregateValues();
1256  if (NumNonAggregates != -1) {
1257    SmallVector<unsigned, 1> Vals;
1258    Vals.push_back(NumNonAggregates);
1259    Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
1260  }
1261
1262  // Emit function bodies.
1263  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1264    if (!I->isDeclaration())
1265      WriteFunction(*I, VE, Stream);
1266
1267  // Emit the type symbol table information.
1268  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1269
1270  // Emit names for globals/functions etc.
1271  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1272
1273  Stream.ExitBlock();
1274}
1275
1276/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1277/// header and trailer to make it compatible with the system archiver.  To do
1278/// this we emit the following header, and then emit a trailer that pads the
1279/// file out to be a multiple of 16 bytes.
1280///
1281/// struct bc_header {
1282///   uint32_t Magic;         // 0x0B17C0DE
1283///   uint32_t Version;       // Version, currently always 0.
1284///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1285///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1286///   uint32_t CPUType;       // CPU specifier.
1287///   ... potentially more later ...
1288/// };
1289enum {
1290  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1291  DarwinBCHeaderSize = 5*4
1292};
1293
1294static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1295                               const std::string &TT) {
1296  unsigned CPUType = ~0U;
1297
1298  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*.  The CPUType is a
1299  // magic number from /usr/include/mach/machine.h.  It is ok to reproduce the
1300  // specific constants here because they are implicitly part of the Darwin ABI.
1301  enum {
1302    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1303    DARWIN_CPU_TYPE_X86        = 7,
1304    DARWIN_CPU_TYPE_POWERPC    = 18
1305  };
1306
1307  if (TT.find("x86_64-") == 0)
1308    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1309  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1310           TT[4] == '-' && TT[1] - '3' < 6)
1311    CPUType = DARWIN_CPU_TYPE_X86;
1312  else if (TT.find("powerpc-") == 0)
1313    CPUType = DARWIN_CPU_TYPE_POWERPC;
1314  else if (TT.find("powerpc64-") == 0)
1315    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1316
1317  // Traditional Bitcode starts after header.
1318  unsigned BCOffset = DarwinBCHeaderSize;
1319
1320  Stream.Emit(0x0B17C0DE, 32);
1321  Stream.Emit(0         , 32);  // Version.
1322  Stream.Emit(BCOffset  , 32);
1323  Stream.Emit(0         , 32);  // Filled in later.
1324  Stream.Emit(CPUType   , 32);
1325}
1326
1327/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1328/// finalize the header.
1329static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1330  // Update the size field in the header.
1331  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1332
1333  // If the file is not a multiple of 16 bytes, insert dummy padding.
1334  while (BufferSize & 15) {
1335    Stream.Emit(0, 8);
1336    ++BufferSize;
1337  }
1338}
1339
1340
1341/// WriteBitcodeToFile - Write the specified module to the specified output
1342/// stream.
1343void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
1344  raw_os_ostream RawOut(Out);
1345  // If writing to stdout, set binary mode.
1346  if (llvm::cout == Out)
1347    sys::Program::ChangeStdoutToBinary();
1348  WriteBitcodeToFile(M, RawOut);
1349}
1350
1351/// WriteBitcodeToFile - Write the specified module to the specified output
1352/// stream.
1353void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1354  std::vector<unsigned char> Buffer;
1355  BitstreamWriter Stream(Buffer);
1356
1357  Buffer.reserve(256*1024);
1358
1359  // If this is darwin, emit a file header and trailer if needed.
1360  bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1361  if (isDarwin)
1362    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1363
1364  // Emit the file header.
1365  Stream.Emit((unsigned)'B', 8);
1366  Stream.Emit((unsigned)'C', 8);
1367  Stream.Emit(0x0, 4);
1368  Stream.Emit(0xC, 4);
1369  Stream.Emit(0xE, 4);
1370  Stream.Emit(0xD, 4);
1371
1372  // Emit the module.
1373  WriteModule(M, Stream);
1374
1375  if (isDarwin)
1376    EmitDarwinBCTrailer(Stream, Buffer.size());
1377
1378
1379  // If writing to stdout, set binary mode.
1380  if (&llvm::outs() == &Out)
1381    sys::Program::ChangeStdoutToBinary();
1382
1383  // Write the generated bitstream to "Out".
1384  Out.write((char*)&Buffer.front(), Buffer.size());
1385
1386  // Make sure it hits disk now.
1387  Out.flush();
1388}
1389