BitcodeWriter.cpp revision 7111b02c734c992b8c97d9918118768026dad79e 
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/System/Program.h"
28using namespace llvm;
29
30/// These are manifest constants used by the bitcode writer. They do not need to
31/// be kept in sync with the reader, but need to be consistent within this file.
32enum {
33  CurVersion = 0,
34
35  // VALUE_SYMTAB_BLOCK abbrev id's.
36  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
37  VST_ENTRY_7_ABBREV,
38  VST_ENTRY_6_ABBREV,
39  VST_BBENTRY_6_ABBREV,
40
41  // CONSTANTS_BLOCK abbrev id's.
42  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
43  CONSTANTS_INTEGER_ABBREV,
44  CONSTANTS_CE_CAST_Abbrev,
45  CONSTANTS_NULL_Abbrev,
46
47  // FUNCTION_BLOCK abbrev id's.
48  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
49  FUNCTION_INST_BINOP_ABBREV,
50  FUNCTION_INST_CAST_ABBREV,
51  FUNCTION_INST_RET_VOID_ABBREV,
52  FUNCTION_INST_RET_VAL_ABBREV,
53  FUNCTION_INST_UNREACHABLE_ABBREV
54};
55
56
57static unsigned GetEncodedCastOpcode(unsigned Opcode) {
58  switch (Opcode) {
59  default: assert(0 && "Unknown cast instruction!");
60  case Instruction::Trunc   : return bitc::CAST_TRUNC;
61  case Instruction::ZExt    : return bitc::CAST_ZEXT;
62  case Instruction::SExt    : return bitc::CAST_SEXT;
63  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
64  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
65  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
66  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
67  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
68  case Instruction::FPExt   : return bitc::CAST_FPEXT;
69  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
70  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
71  case Instruction::BitCast : return bitc::CAST_BITCAST;
72  }
73}
74
75static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
76  switch (Opcode) {
77  default: assert(0 && "Unknown binary instruction!");
78  case Instruction::Add:  return bitc::BINOP_ADD;
79  case Instruction::Sub:  return bitc::BINOP_SUB;
80  case Instruction::Mul:  return bitc::BINOP_MUL;
81  case Instruction::UDiv: return bitc::BINOP_UDIV;
82  case Instruction::FDiv:
83  case Instruction::SDiv: return bitc::BINOP_SDIV;
84  case Instruction::URem: return bitc::BINOP_UREM;
85  case Instruction::FRem:
86  case Instruction::SRem: return bitc::BINOP_SREM;
87  case Instruction::Shl:  return bitc::BINOP_SHL;
88  case Instruction::LShr: return bitc::BINOP_LSHR;
89  case Instruction::AShr: return bitc::BINOP_ASHR;
90  case Instruction::And:  return bitc::BINOP_AND;
91  case Instruction::Or:   return bitc::BINOP_OR;
92  case Instruction::Xor:  return bitc::BINOP_XOR;
93  }
94}
95
96
97
98static void WriteStringRecord(unsigned Code, const std::string &Str,
99                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
100  SmallVector<unsigned, 64> Vals;
101
102  // Code: [strchar x N]
103  for (unsigned i = 0, e = Str.size(); i != e; ++i)
104    Vals.push_back(Str[i]);
105
106  // Emit the finished record.
107  Stream.EmitRecord(Code, Vals, AbbrevToUse);
108}
109
110// Emit information about parameter attributes.
111static void WriteAttributeTable(const ValueEnumerator &VE,
112                                BitstreamWriter &Stream) {
113  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
114  if (Attrs.empty()) return;
115
116  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
117
118  SmallVector<uint64_t, 64> Record;
119  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
120    const AttrListPtr &A = Attrs[i];
121    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
122      const AttributeWithIndex &PAWI = A.getSlot(i);
123      Record.push_back(PAWI.Index);
124      Record.push_back(PAWI.Attrs);
125    }
126
127    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
128    Record.clear();
129  }
130
131  Stream.ExitBlock();
132}
133
134/// WriteTypeTable - Write out the type table for a module.
135static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
136  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
137
138  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
139  SmallVector<uint64_t, 64> TypeVals;
140
141  // Abbrev for TYPE_CODE_POINTER.
142  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
143  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
144  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
145                            Log2_32_Ceil(VE.getTypes().size()+1)));
146  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
147  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
148
149  // Abbrev for TYPE_CODE_FUNCTION.
150  Abbv = new BitCodeAbbrev();
151  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
152  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
153  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
154  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
155  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
156                            Log2_32_Ceil(VE.getTypes().size()+1)));
157  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
158
159  // Abbrev for TYPE_CODE_STRUCT.
160  Abbv = new BitCodeAbbrev();
161  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
162  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
163  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
164  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
165                            Log2_32_Ceil(VE.getTypes().size()+1)));
166  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
167
168  // Abbrev for TYPE_CODE_ARRAY.
169  Abbv = new BitCodeAbbrev();
170  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
171  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
172  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
173                            Log2_32_Ceil(VE.getTypes().size()+1)));
174  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
175
176  // Emit an entry count so the reader can reserve space.
177  TypeVals.push_back(TypeList.size());
178  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
179  TypeVals.clear();
180
181  // Loop over all of the types, emitting each in turn.
182  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
183    const Type *T = TypeList[i].first;
184    int AbbrevToUse = 0;
185    unsigned Code = 0;
186
187    switch (T->getTypeID()) {
188    default: assert(0 && "Unknown type!");
189    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
190    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
191    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
192    case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
193    case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
194    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
195    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
196    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
197    case Type::IntegerTyID:
198      // INTEGER: [width]
199      Code = bitc::TYPE_CODE_INTEGER;
200      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
201      break;
202    case Type::PointerTyID: {
203      const PointerType *PTy = cast<PointerType>(T);
204      // POINTER: [pointee type, address space]
205      Code = bitc::TYPE_CODE_POINTER;
206      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
207      unsigned AddressSpace = PTy->getAddressSpace();
208      TypeVals.push_back(AddressSpace);
209      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
210      break;
211    }
212    case Type::FunctionTyID: {
213      const FunctionType *FT = cast<FunctionType>(T);
214      // FUNCTION: [isvararg, attrid, retty, paramty x N]
215      Code = bitc::TYPE_CODE_FUNCTION;
216      TypeVals.push_back(FT->isVarArg());
217      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
218      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
219      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
220        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
221      AbbrevToUse = FunctionAbbrev;
222      break;
223    }
224    case Type::StructTyID: {
225      const StructType *ST = cast<StructType>(T);
226      // STRUCT: [ispacked, eltty x N]
227      Code = bitc::TYPE_CODE_STRUCT;
228      TypeVals.push_back(ST->isPacked());
229      // Output all of the element types.
230      for (StructType::element_iterator I = ST->element_begin(),
231           E = ST->element_end(); I != E; ++I)
232        TypeVals.push_back(VE.getTypeID(*I));
233      AbbrevToUse = StructAbbrev;
234      break;
235    }
236    case Type::ArrayTyID: {
237      const ArrayType *AT = cast<ArrayType>(T);
238      // ARRAY: [numelts, eltty]
239      Code = bitc::TYPE_CODE_ARRAY;
240      TypeVals.push_back(AT->getNumElements());
241      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
242      AbbrevToUse = ArrayAbbrev;
243      break;
244    }
245    case Type::VectorTyID: {
246      const VectorType *VT = cast<VectorType>(T);
247      // VECTOR [numelts, eltty]
248      Code = bitc::TYPE_CODE_VECTOR;
249      TypeVals.push_back(VT->getNumElements());
250      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
251      break;
252    }
253    }
254
255    // Emit the finished record.
256    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
257    TypeVals.clear();
258  }
259
260  Stream.ExitBlock();
261}
262
263static unsigned getEncodedLinkage(const GlobalValue *GV) {
264  switch (GV->getLinkage()) {
265  default: assert(0 && "Invalid linkage!");
266  case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
267  case GlobalValue::ExternalLinkage:     return 0;
268  case GlobalValue::WeakLinkage:         return 1;
269  case GlobalValue::AppendingLinkage:    return 2;
270  case GlobalValue::InternalLinkage:     return 3;
271  case GlobalValue::LinkOnceLinkage:     return 4;
272  case GlobalValue::DLLImportLinkage:    return 5;
273  case GlobalValue::DLLExportLinkage:    return 6;
274  case GlobalValue::ExternalWeakLinkage: return 7;
275  case GlobalValue::CommonLinkage:       return 8;
276  }
277}
278
279static unsigned getEncodedVisibility(const GlobalValue *GV) {
280  switch (GV->getVisibility()) {
281  default: assert(0 && "Invalid visibility!");
282  case GlobalValue::DefaultVisibility:   return 0;
283  case GlobalValue::HiddenVisibility:    return 1;
284  case GlobalValue::ProtectedVisibility: return 2;
285  }
286}
287
288// Emit top-level description of module, including target triple, inline asm,
289// descriptors for global variables, and function prototype info.
290static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
291                            BitstreamWriter &Stream) {
292  // Emit the list of dependent libraries for the Module.
293  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
294    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
295
296  // Emit various pieces of data attached to a module.
297  if (!M->getTargetTriple().empty())
298    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
299                      0/*TODO*/, Stream);
300  if (!M->getDataLayout().empty())
301    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
302                      0/*TODO*/, Stream);
303  if (!M->getModuleInlineAsm().empty())
304    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
305                      0/*TODO*/, Stream);
306
307  // Emit information about sections and GC, computing how many there are. Also
308  // compute the maximum alignment value.
309  std::map<std::string, unsigned> SectionMap;
310  std::map<std::string, unsigned> GCMap;
311  unsigned MaxAlignment = 0;
312  unsigned MaxGlobalType = 0;
313  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
314       GV != E; ++GV) {
315    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
316    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
317
318    if (!GV->hasSection()) continue;
319    // Give section names unique ID's.
320    unsigned &Entry = SectionMap[GV->getSection()];
321    if (Entry != 0) continue;
322    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
323                      0/*TODO*/, Stream);
324    Entry = SectionMap.size();
325  }
326  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
327    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
328    if (F->hasSection()) {
329      // Give section names unique ID's.
330      unsigned &Entry = SectionMap[F->getSection()];
331      if (!Entry) {
332        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
333                          0/*TODO*/, Stream);
334        Entry = SectionMap.size();
335      }
336    }
337    if (F->hasGC()) {
338      // Same for GC names.
339      unsigned &Entry = GCMap[F->getGC()];
340      if (!Entry) {
341        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
342                          0/*TODO*/, Stream);
343        Entry = GCMap.size();
344      }
345    }
346  }
347
348  // Emit abbrev for globals, now that we know # sections and max alignment.
349  unsigned SimpleGVarAbbrev = 0;
350  if (!M->global_empty()) {
351    // Add an abbrev for common globals with no visibility or thread localness.
352    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
353    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
354    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
355                              Log2_32_Ceil(MaxGlobalType+1)));
356    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
357    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
358    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
359    if (MaxAlignment == 0)                                      // Alignment.
360      Abbv->Add(BitCodeAbbrevOp(0));
361    else {
362      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
363      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
364                               Log2_32_Ceil(MaxEncAlignment+1)));
365    }
366    if (SectionMap.empty())                                    // Section.
367      Abbv->Add(BitCodeAbbrevOp(0));
368    else
369      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
370                               Log2_32_Ceil(SectionMap.size()+1)));
371    // Don't bother emitting vis + thread local.
372    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
373  }
374
375  // Emit the global variable information.
376  SmallVector<unsigned, 64> Vals;
377  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
378       GV != E; ++GV) {
379    unsigned AbbrevToUse = 0;
380
381    // GLOBALVAR: [type, isconst, initid,
382    //             linkage, alignment, section, visibility, threadlocal]
383    Vals.push_back(VE.getTypeID(GV->getType()));
384    Vals.push_back(GV->isConstant());
385    Vals.push_back(GV->isDeclaration() ? 0 :
386                   (VE.getValueID(GV->getInitializer()) + 1));
387    Vals.push_back(getEncodedLinkage(GV));
388    Vals.push_back(Log2_32(GV->getAlignment())+1);
389    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
390    if (GV->isThreadLocal() ||
391        GV->getVisibility() != GlobalValue::DefaultVisibility) {
392      Vals.push_back(getEncodedVisibility(GV));
393      Vals.push_back(GV->isThreadLocal());
394    } else {
395      AbbrevToUse = SimpleGVarAbbrev;
396    }
397
398    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
399    Vals.clear();
400  }
401
402  // Emit the function proto information.
403  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
404    // FUNCTION:  [type, callingconv, isproto, paramattr,
405    //             linkage, alignment, section, visibility, gc]
406    Vals.push_back(VE.getTypeID(F->getType()));
407    Vals.push_back(F->getCallingConv());
408    Vals.push_back(F->isDeclaration());
409    Vals.push_back(getEncodedLinkage(F));
410    Vals.push_back(VE.getAttributeID(F->getAttributes()));
411    Vals.push_back(Log2_32(F->getAlignment())+1);
412    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
413    Vals.push_back(getEncodedVisibility(F));
414    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
415
416    unsigned AbbrevToUse = 0;
417    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
418    Vals.clear();
419  }
420
421
422  // Emit the alias information.
423  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
424       AI != E; ++AI) {
425    Vals.push_back(VE.getTypeID(AI->getType()));
426    Vals.push_back(VE.getValueID(AI->getAliasee()));
427    Vals.push_back(getEncodedLinkage(AI));
428    Vals.push_back(getEncodedVisibility(AI));
429    unsigned AbbrevToUse = 0;
430    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
431    Vals.clear();
432  }
433}
434
435
436static void WriteConstants(unsigned FirstVal, unsigned LastVal,
437                           const ValueEnumerator &VE,
438                           BitstreamWriter &Stream, bool isGlobal) {
439  if (FirstVal == LastVal) return;
440
441  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
442
443  unsigned AggregateAbbrev = 0;
444  unsigned String8Abbrev = 0;
445  unsigned CString7Abbrev = 0;
446  unsigned CString6Abbrev = 0;
447  // If this is a constant pool for the module, emit module-specific abbrevs.
448  if (isGlobal) {
449    // Abbrev for CST_CODE_AGGREGATE.
450    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
451    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
452    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
453    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
454    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
455
456    // Abbrev for CST_CODE_STRING.
457    Abbv = new BitCodeAbbrev();
458    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
459    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
460    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
461    String8Abbrev = Stream.EmitAbbrev(Abbv);
462    // Abbrev for CST_CODE_CSTRING.
463    Abbv = new BitCodeAbbrev();
464    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
465    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
466    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
467    CString7Abbrev = Stream.EmitAbbrev(Abbv);
468    // Abbrev for CST_CODE_CSTRING.
469    Abbv = new BitCodeAbbrev();
470    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
471    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
472    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
473    CString6Abbrev = Stream.EmitAbbrev(Abbv);
474  }
475
476  SmallVector<uint64_t, 64> Record;
477
478  const ValueEnumerator::ValueList &Vals = VE.getValues();
479  const Type *LastTy = 0;
480  for (unsigned i = FirstVal; i != LastVal; ++i) {
481    const Value *V = Vals[i].first;
482    // If we need to switch types, do so now.
483    if (V->getType() != LastTy) {
484      LastTy = V->getType();
485      Record.push_back(VE.getTypeID(LastTy));
486      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
487                        CONSTANTS_SETTYPE_ABBREV);
488      Record.clear();
489    }
490
491    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
492      Record.push_back(unsigned(IA->hasSideEffects()));
493
494      // Add the asm string.
495      const std::string &AsmStr = IA->getAsmString();
496      Record.push_back(AsmStr.size());
497      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
498        Record.push_back(AsmStr[i]);
499
500      // Add the constraint string.
501      const std::string &ConstraintStr = IA->getConstraintString();
502      Record.push_back(ConstraintStr.size());
503      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
504        Record.push_back(ConstraintStr[i]);
505      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
506      Record.clear();
507      continue;
508    }
509    const Constant *C = cast<Constant>(V);
510    unsigned Code = -1U;
511    unsigned AbbrevToUse = 0;
512    if (C->isNullValue()) {
513      Code = bitc::CST_CODE_NULL;
514    } else if (isa<UndefValue>(C)) {
515      Code = bitc::CST_CODE_UNDEF;
516    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
517      if (IV->getBitWidth() <= 64) {
518        int64_t V = IV->getSExtValue();
519        if (V >= 0)
520          Record.push_back(V << 1);
521        else
522          Record.push_back((-V << 1) | 1);
523        Code = bitc::CST_CODE_INTEGER;
524        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
525      } else {                             // Wide integers, > 64 bits in size.
526        // We have an arbitrary precision integer value to write whose
527        // bit width is > 64. However, in canonical unsigned integer
528        // format it is likely that the high bits are going to be zero.
529        // So, we only write the number of active words.
530        unsigned NWords = IV->getValue().getActiveWords();
531        const uint64_t *RawWords = IV->getValue().getRawData();
532        for (unsigned i = 0; i != NWords; ++i) {
533          int64_t V = RawWords[i];
534          if (V >= 0)
535            Record.push_back(V << 1);
536          else
537            Record.push_back((-V << 1) | 1);
538        }
539        Code = bitc::CST_CODE_WIDE_INTEGER;
540      }
541    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
542      Code = bitc::CST_CODE_FLOAT;
543      const Type *Ty = CFP->getType();
544      if (Ty == Type::FloatTy || Ty == Type::DoubleTy) {
545        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
546      } else if (Ty == Type::X86_FP80Ty) {
547        // api needed to prevent premature destruction
548        APInt api = CFP->getValueAPF().bitcastToAPInt();
549        const uint64_t *p = api.getRawData();
550        Record.push_back(p[0]);
551        Record.push_back((uint16_t)p[1]);
552      } else if (Ty == Type::FP128Ty || Ty == Type::PPC_FP128Ty) {
553        APInt api = CFP->getValueAPF().bitcastToAPInt();
554        const uint64_t *p = api.getRawData();
555        Record.push_back(p[0]);
556        Record.push_back(p[1]);
557      } else {
558        assert (0 && "Unknown FP type!");
559      }
560    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
561      // Emit constant strings specially.
562      unsigned NumOps = C->getNumOperands();
563      // If this is a null-terminated string, use the denser CSTRING encoding.
564      if (C->getOperand(NumOps-1)->isNullValue()) {
565        Code = bitc::CST_CODE_CSTRING;
566        --NumOps;  // Don't encode the null, which isn't allowed by char6.
567      } else {
568        Code = bitc::CST_CODE_STRING;
569        AbbrevToUse = String8Abbrev;
570      }
571      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
572      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
573      for (unsigned i = 0; i != NumOps; ++i) {
574        unsigned char V = cast<ConstantInt>(C->getOperand(i))->getZExtValue();
575        Record.push_back(V);
576        isCStr7 &= (V & 128) == 0;
577        if (isCStrChar6)
578          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
579      }
580
581      if (isCStrChar6)
582        AbbrevToUse = CString6Abbrev;
583      else if (isCStr7)
584        AbbrevToUse = CString7Abbrev;
585    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
586               isa<ConstantVector>(V)) {
587      Code = bitc::CST_CODE_AGGREGATE;
588      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
589        Record.push_back(VE.getValueID(C->getOperand(i)));
590      AbbrevToUse = AggregateAbbrev;
591    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
592      switch (CE->getOpcode()) {
593      default:
594        if (Instruction::isCast(CE->getOpcode())) {
595          Code = bitc::CST_CODE_CE_CAST;
596          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
597          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
598          Record.push_back(VE.getValueID(C->getOperand(0)));
599          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
600        } else {
601          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
602          Code = bitc::CST_CODE_CE_BINOP;
603          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
604          Record.push_back(VE.getValueID(C->getOperand(0)));
605          Record.push_back(VE.getValueID(C->getOperand(1)));
606        }
607        break;
608      case Instruction::GetElementPtr:
609        Code = bitc::CST_CODE_CE_GEP;
610        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
611          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
612          Record.push_back(VE.getValueID(C->getOperand(i)));
613        }
614        break;
615      case Instruction::Select:
616        Code = bitc::CST_CODE_CE_SELECT;
617        Record.push_back(VE.getValueID(C->getOperand(0)));
618        Record.push_back(VE.getValueID(C->getOperand(1)));
619        Record.push_back(VE.getValueID(C->getOperand(2)));
620        break;
621      case Instruction::ExtractElement:
622        Code = bitc::CST_CODE_CE_EXTRACTELT;
623        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
624        Record.push_back(VE.getValueID(C->getOperand(0)));
625        Record.push_back(VE.getValueID(C->getOperand(1)));
626        break;
627      case Instruction::InsertElement:
628        Code = bitc::CST_CODE_CE_INSERTELT;
629        Record.push_back(VE.getValueID(C->getOperand(0)));
630        Record.push_back(VE.getValueID(C->getOperand(1)));
631        Record.push_back(VE.getValueID(C->getOperand(2)));
632        break;
633      case Instruction::ShuffleVector:
634        Code = bitc::CST_CODE_CE_SHUFFLEVEC;
635        Record.push_back(VE.getValueID(C->getOperand(0)));
636        Record.push_back(VE.getValueID(C->getOperand(1)));
637        Record.push_back(VE.getValueID(C->getOperand(2)));
638        break;
639      case Instruction::ICmp:
640      case Instruction::FCmp:
641      case Instruction::VICmp:
642      case Instruction::VFCmp:
643        if (isa<VectorType>(C->getOperand(0)->getType())
644            && (CE->getOpcode() == Instruction::ICmp
645                || CE->getOpcode() == Instruction::FCmp)) {
646          // compare returning vector of Int1Ty
647          assert(0 && "Unsupported constant!");
648        } else {
649          Code = bitc::CST_CODE_CE_CMP;
650        }
651        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
652        Record.push_back(VE.getValueID(C->getOperand(0)));
653        Record.push_back(VE.getValueID(C->getOperand(1)));
654        Record.push_back(CE->getPredicate());
655        break;
656      }
657    } else {
658      assert(0 && "Unknown constant!");
659    }
660    Stream.EmitRecord(Code, Record, AbbrevToUse);
661    Record.clear();
662  }
663
664  Stream.ExitBlock();
665}
666
667static void WriteModuleConstants(const ValueEnumerator &VE,
668                                 BitstreamWriter &Stream) {
669  const ValueEnumerator::ValueList &Vals = VE.getValues();
670
671  // Find the first constant to emit, which is the first non-globalvalue value.
672  // We know globalvalues have been emitted by WriteModuleInfo.
673  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
674    if (!isa<GlobalValue>(Vals[i].first)) {
675      WriteConstants(i, Vals.size(), VE, Stream, true);
676      return;
677    }
678  }
679}
680
681/// PushValueAndType - The file has to encode both the value and type id for
682/// many values, because we need to know what type to create for forward
683/// references.  However, most operands are not forward references, so this type
684/// field is not needed.
685///
686/// This function adds V's value ID to Vals.  If the value ID is higher than the
687/// instruction ID, then it is a forward reference, and it also includes the
688/// type ID.
689static bool PushValueAndType(Value *V, unsigned InstID,
690                             SmallVector<unsigned, 64> &Vals,
691                             ValueEnumerator &VE) {
692  unsigned ValID = VE.getValueID(V);
693  Vals.push_back(ValID);
694  if (ValID >= InstID) {
695    Vals.push_back(VE.getTypeID(V->getType()));
696    return true;
697  }
698  return false;
699}
700
701/// WriteInstruction - Emit an instruction to the specified stream.
702static void WriteInstruction(const Instruction &I, unsigned InstID,
703                             ValueEnumerator &VE, BitstreamWriter &Stream,
704                             SmallVector<unsigned, 64> &Vals) {
705  unsigned Code = 0;
706  unsigned AbbrevToUse = 0;
707  switch (I.getOpcode()) {
708  default:
709    if (Instruction::isCast(I.getOpcode())) {
710      Code = bitc::FUNC_CODE_INST_CAST;
711      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
712        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
713      Vals.push_back(VE.getTypeID(I.getType()));
714      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
715    } else {
716      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
717      Code = bitc::FUNC_CODE_INST_BINOP;
718      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
719        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
720      Vals.push_back(VE.getValueID(I.getOperand(1)));
721      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
722    }
723    break;
724
725  case Instruction::GetElementPtr:
726    Code = bitc::FUNC_CODE_INST_GEP;
727    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
728      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
729    break;
730  case Instruction::ExtractValue: {
731    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
732    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
733    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
734    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
735      Vals.push_back(*i);
736    break;
737  }
738  case Instruction::InsertValue: {
739    Code = bitc::FUNC_CODE_INST_INSERTVAL;
740    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
741    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
742    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
743    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
744      Vals.push_back(*i);
745    break;
746  }
747  case Instruction::Select:
748    Code = bitc::FUNC_CODE_INST_VSELECT;
749    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
750    Vals.push_back(VE.getValueID(I.getOperand(2)));
751    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
752    break;
753  case Instruction::ExtractElement:
754    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
755    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
756    Vals.push_back(VE.getValueID(I.getOperand(1)));
757    break;
758  case Instruction::InsertElement:
759    Code = bitc::FUNC_CODE_INST_INSERTELT;
760    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
761    Vals.push_back(VE.getValueID(I.getOperand(1)));
762    Vals.push_back(VE.getValueID(I.getOperand(2)));
763    break;
764  case Instruction::ShuffleVector:
765    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
766    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
767    Vals.push_back(VE.getValueID(I.getOperand(1)));
768    Vals.push_back(VE.getValueID(I.getOperand(2)));
769    break;
770  case Instruction::ICmp:
771  case Instruction::FCmp:
772  case Instruction::VICmp:
773  case Instruction::VFCmp:
774    if (I.getOpcode() == Instruction::ICmp
775        || I.getOpcode() == Instruction::FCmp) {
776      // compare returning Int1Ty or vector of Int1Ty
777      Code = bitc::FUNC_CODE_INST_CMP2;
778    } else {
779      Code = bitc::FUNC_CODE_INST_CMP;
780    }
781    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
782    Vals.push_back(VE.getValueID(I.getOperand(1)));
783    Vals.push_back(cast<CmpInst>(I).getPredicate());
784    break;
785
786  case Instruction::Ret:
787    {
788      Code = bitc::FUNC_CODE_INST_RET;
789      unsigned NumOperands = I.getNumOperands();
790      if (NumOperands == 0)
791        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
792      else if (NumOperands == 1) {
793        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
794          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
795      } else {
796        for (unsigned i = 0, e = NumOperands; i != e; ++i)
797          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
798      }
799    }
800    break;
801  case Instruction::Br:
802    Code = bitc::FUNC_CODE_INST_BR;
803    Vals.push_back(VE.getValueID(I.getOperand(0)));
804    if (cast<BranchInst>(I).isConditional()) {
805      Vals.push_back(VE.getValueID(I.getOperand(1)));
806      Vals.push_back(VE.getValueID(I.getOperand(2)));
807    }
808    break;
809  case Instruction::Switch:
810    Code = bitc::FUNC_CODE_INST_SWITCH;
811    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
812    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
813      Vals.push_back(VE.getValueID(I.getOperand(i)));
814    break;
815  case Instruction::Invoke: {
816    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
817    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
818    Code = bitc::FUNC_CODE_INST_INVOKE;
819
820    const InvokeInst *II = cast<InvokeInst>(&I);
821    Vals.push_back(VE.getAttributeID(II->getAttributes()));
822    Vals.push_back(II->getCallingConv());
823    Vals.push_back(VE.getValueID(I.getOperand(1)));      // normal dest
824    Vals.push_back(VE.getValueID(I.getOperand(2)));      // unwind dest
825    PushValueAndType(I.getOperand(0), InstID, Vals, VE); // callee
826
827    // Emit value #'s for the fixed parameters.
828    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
829      Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
830
831    // Emit type/value pairs for varargs params.
832    if (FTy->isVarArg()) {
833      for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
834           i != e; ++i)
835        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
836    }
837    break;
838  }
839  case Instruction::Unwind:
840    Code = bitc::FUNC_CODE_INST_UNWIND;
841    break;
842  case Instruction::Unreachable:
843    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
844    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
845    break;
846
847  case Instruction::PHI:
848    Code = bitc::FUNC_CODE_INST_PHI;
849    Vals.push_back(VE.getTypeID(I.getType()));
850    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
851      Vals.push_back(VE.getValueID(I.getOperand(i)));
852    break;
853
854  case Instruction::Malloc:
855    Code = bitc::FUNC_CODE_INST_MALLOC;
856    Vals.push_back(VE.getTypeID(I.getType()));
857    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
858    Vals.push_back(Log2_32(cast<MallocInst>(I).getAlignment())+1);
859    break;
860
861  case Instruction::Free:
862    Code = bitc::FUNC_CODE_INST_FREE;
863    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
864    break;
865
866  case Instruction::Alloca:
867    Code = bitc::FUNC_CODE_INST_ALLOCA;
868    Vals.push_back(VE.getTypeID(I.getType()));
869    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
870    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
871    break;
872
873  case Instruction::Load:
874    Code = bitc::FUNC_CODE_INST_LOAD;
875    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
876      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
877
878    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
879    Vals.push_back(cast<LoadInst>(I).isVolatile());
880    break;
881  case Instruction::Store:
882    Code = bitc::FUNC_CODE_INST_STORE2;
883    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
884    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
885    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
886    Vals.push_back(cast<StoreInst>(I).isVolatile());
887    break;
888  case Instruction::Call: {
889    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
890    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
891
892    Code = bitc::FUNC_CODE_INST_CALL;
893
894    const CallInst *CI = cast<CallInst>(&I);
895    Vals.push_back(VE.getAttributeID(CI->getAttributes()));
896    Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
897    PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
898
899    // Emit value #'s for the fixed parameters.
900    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
901      Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
902
903    // Emit type/value pairs for varargs params.
904    if (FTy->isVarArg()) {
905      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
906      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
907           i != e; ++i)
908        PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
909    }
910    break;
911  }
912  case Instruction::VAArg:
913    Code = bitc::FUNC_CODE_INST_VAARG;
914    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
915    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
916    Vals.push_back(VE.getTypeID(I.getType())); // restype.
917    break;
918  }
919
920  Stream.EmitRecord(Code, Vals, AbbrevToUse);
921  Vals.clear();
922}
923
924// Emit names for globals/functions etc.
925static void WriteValueSymbolTable(const ValueSymbolTable &VST,
926                                  const ValueEnumerator &VE,
927                                  BitstreamWriter &Stream) {
928  if (VST.empty()) return;
929  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
930
931  // FIXME: Set up the abbrev, we know how many values there are!
932  // FIXME: We know if the type names can use 7-bit ascii.
933  SmallVector<unsigned, 64> NameVals;
934
935  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
936       SI != SE; ++SI) {
937
938    const ValueName &Name = *SI;
939
940    // Figure out the encoding to use for the name.
941    bool is7Bit = true;
942    bool isChar6 = true;
943    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
944         C != E; ++C) {
945      if (isChar6)
946        isChar6 = BitCodeAbbrevOp::isChar6(*C);
947      if ((unsigned char)*C & 128) {
948        is7Bit = false;
949        break;  // don't bother scanning the rest.
950      }
951    }
952
953    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
954
955    // VST_ENTRY:   [valueid, namechar x N]
956    // VST_BBENTRY: [bbid, namechar x N]
957    unsigned Code;
958    if (isa<BasicBlock>(SI->getValue())) {
959      Code = bitc::VST_CODE_BBENTRY;
960      if (isChar6)
961        AbbrevToUse = VST_BBENTRY_6_ABBREV;
962    } else {
963      Code = bitc::VST_CODE_ENTRY;
964      if (isChar6)
965        AbbrevToUse = VST_ENTRY_6_ABBREV;
966      else if (is7Bit)
967        AbbrevToUse = VST_ENTRY_7_ABBREV;
968    }
969
970    NameVals.push_back(VE.getValueID(SI->getValue()));
971    for (const char *P = Name.getKeyData(),
972         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
973      NameVals.push_back((unsigned char)*P);
974
975    // Emit the finished record.
976    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
977    NameVals.clear();
978  }
979  Stream.ExitBlock();
980}
981
982/// WriteFunction - Emit a function body to the module stream.
983static void WriteFunction(const Function &F, ValueEnumerator &VE,
984                          BitstreamWriter &Stream) {
985  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
986  VE.incorporateFunction(F);
987
988  SmallVector<unsigned, 64> Vals;
989
990  // Emit the number of basic blocks, so the reader can create them ahead of
991  // time.
992  Vals.push_back(VE.getBasicBlocks().size());
993  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
994  Vals.clear();
995
996  // If there are function-local constants, emit them now.
997  unsigned CstStart, CstEnd;
998  VE.getFunctionConstantRange(CstStart, CstEnd);
999  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1000
1001  // Keep a running idea of what the instruction ID is.
1002  unsigned InstID = CstEnd;
1003
1004  // Finally, emit all the instructions, in order.
1005  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1006    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1007         I != E; ++I) {
1008      WriteInstruction(*I, InstID, VE, Stream, Vals);
1009      if (I->getType() != Type::VoidTy)
1010        ++InstID;
1011    }
1012
1013  // Emit names for all the instructions etc.
1014  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1015
1016  VE.purgeFunction();
1017  Stream.ExitBlock();
1018}
1019
1020/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1021static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1022                                 const ValueEnumerator &VE,
1023                                 BitstreamWriter &Stream) {
1024  if (TST.empty()) return;
1025
1026  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1027
1028  // 7-bit fixed width VST_CODE_ENTRY strings.
1029  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1030  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1031  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1032                            Log2_32_Ceil(VE.getTypes().size()+1)));
1033  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1034  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1035  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1036
1037  SmallVector<unsigned, 64> NameVals;
1038
1039  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1040       TI != TE; ++TI) {
1041    // TST_ENTRY: [typeid, namechar x N]
1042    NameVals.push_back(VE.getTypeID(TI->second));
1043
1044    const std::string &Str = TI->first;
1045    bool is7Bit = true;
1046    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1047      NameVals.push_back((unsigned char)Str[i]);
1048      if (Str[i] & 128)
1049        is7Bit = false;
1050    }
1051
1052    // Emit the finished record.
1053    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1054    NameVals.clear();
1055  }
1056
1057  Stream.ExitBlock();
1058}
1059
1060// Emit blockinfo, which defines the standard abbreviations etc.
1061static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1062  // We only want to emit block info records for blocks that have multiple
1063  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1064  // blocks can defined their abbrevs inline.
1065  Stream.EnterBlockInfoBlock(2);
1066
1067  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1068    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1069    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1070    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1071    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1072    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1073    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1074                                   Abbv) != VST_ENTRY_8_ABBREV)
1075      assert(0 && "Unexpected abbrev ordering!");
1076  }
1077
1078  { // 7-bit fixed width VST_ENTRY strings.
1079    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1080    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1081    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1082    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1083    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1084    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1085                                   Abbv) != VST_ENTRY_7_ABBREV)
1086      assert(0 && "Unexpected abbrev ordering!");
1087  }
1088  { // 6-bit char6 VST_ENTRY strings.
1089    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1090    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1091    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1092    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1093    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1094    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1095                                   Abbv) != VST_ENTRY_6_ABBREV)
1096      assert(0 && "Unexpected abbrev ordering!");
1097  }
1098  { // 6-bit char6 VST_BBENTRY strings.
1099    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1100    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1101    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1102    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1103    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1104    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1105                                   Abbv) != VST_BBENTRY_6_ABBREV)
1106      assert(0 && "Unexpected abbrev ordering!");
1107  }
1108
1109
1110
1111  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1112    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1113    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1114    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1115                              Log2_32_Ceil(VE.getTypes().size()+1)));
1116    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1117                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1118      assert(0 && "Unexpected abbrev ordering!");
1119  }
1120
1121  { // INTEGER abbrev for CONSTANTS_BLOCK.
1122    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1123    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1124    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1125    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1126                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1127      assert(0 && "Unexpected abbrev ordering!");
1128  }
1129
1130  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1131    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1132    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1133    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1134    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1135                              Log2_32_Ceil(VE.getTypes().size()+1)));
1136    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1137
1138    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1139                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1140      assert(0 && "Unexpected abbrev ordering!");
1141  }
1142  { // NULL abbrev for CONSTANTS_BLOCK.
1143    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1144    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1145    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1146                                   Abbv) != CONSTANTS_NULL_Abbrev)
1147      assert(0 && "Unexpected abbrev ordering!");
1148  }
1149
1150  // FIXME: This should only use space for first class types!
1151
1152  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1153    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1154    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1155    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1156    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1157    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1158    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1159                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1160      assert(0 && "Unexpected abbrev ordering!");
1161  }
1162  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1163    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1164    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1165    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1166    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1167    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1168    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1169                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1170      assert(0 && "Unexpected abbrev ordering!");
1171  }
1172  { // INST_CAST abbrev for FUNCTION_BLOCK.
1173    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1174    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1175    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1176    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1177                              Log2_32_Ceil(VE.getTypes().size()+1)));
1178    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1179    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1180                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1181      assert(0 && "Unexpected abbrev ordering!");
1182  }
1183
1184  { // INST_RET abbrev for FUNCTION_BLOCK.
1185    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1186    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1187    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1188                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1189      assert(0 && "Unexpected abbrev ordering!");
1190  }
1191  { // INST_RET abbrev for FUNCTION_BLOCK.
1192    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1193    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1194    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1195    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1196                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1197      assert(0 && "Unexpected abbrev ordering!");
1198  }
1199  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1200    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1201    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1202    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1203                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1204      assert(0 && "Unexpected abbrev ordering!");
1205  }
1206
1207  Stream.ExitBlock();
1208}
1209
1210
1211/// WriteModule - Emit the specified module to the bitstream.
1212static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1213  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1214
1215  // Emit the version number if it is non-zero.
1216  if (CurVersion) {
1217    SmallVector<unsigned, 1> Vals;
1218    Vals.push_back(CurVersion);
1219    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1220  }
1221
1222  // Analyze the module, enumerating globals, functions, etc.
1223  ValueEnumerator VE(M);
1224
1225  // Emit blockinfo, which defines the standard abbreviations etc.
1226  WriteBlockInfo(VE, Stream);
1227
1228  // Emit information about parameter attributes.
1229  WriteAttributeTable(VE, Stream);
1230
1231  // Emit information describing all of the types in the module.
1232  WriteTypeTable(VE, Stream);
1233
1234  // Emit top-level description of module, including target triple, inline asm,
1235  // descriptors for global variables, and function prototype info.
1236  WriteModuleInfo(M, VE, Stream);
1237
1238  // Emit constants.
1239  WriteModuleConstants(VE, Stream);
1240
1241  // If we have any aggregate values in the value table, purge them - these can
1242  // only be used to initialize global variables.  Doing so makes the value
1243  // namespace smaller for code in functions.
1244  int NumNonAggregates = VE.PurgeAggregateValues();
1245  if (NumNonAggregates != -1) {
1246    SmallVector<unsigned, 1> Vals;
1247    Vals.push_back(NumNonAggregates);
1248    Stream.EmitRecord(bitc::MODULE_CODE_PURGEVALS, Vals);
1249  }
1250
1251  // Emit function bodies.
1252  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1253    if (!I->isDeclaration())
1254      WriteFunction(*I, VE, Stream);
1255
1256  // Emit the type symbol table information.
1257  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1258
1259  // Emit names for globals/functions etc.
1260  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1261
1262  Stream.ExitBlock();
1263}
1264
1265/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1266/// header and trailer to make it compatible with the system archiver.  To do
1267/// this we emit the following header, and then emit a trailer that pads the
1268/// file out to be a multiple of 16 bytes.
1269///
1270/// struct bc_header {
1271///   uint32_t Magic;         // 0x0B17C0DE
1272///   uint32_t Version;       // Version, currently always 0.
1273///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1274///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1275///   uint32_t CPUType;       // CPU specifier.
1276///   ... potentially more later ...
1277/// };
1278enum {
1279  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1280  DarwinBCHeaderSize = 5*4
1281};
1282
1283static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1284                               const std::string &TT) {
1285  unsigned CPUType = ~0U;
1286
1287  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*.  The CPUType is a
1288  // magic number from /usr/include/mach/machine.h.  It is ok to reproduce the
1289  // specific constants here because they are implicitly part of the Darwin ABI.
1290  enum {
1291    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1292    DARWIN_CPU_TYPE_X86        = 7,
1293    DARWIN_CPU_TYPE_POWERPC    = 18
1294  };
1295
1296  if (TT.find("x86_64-") == 0)
1297    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1298  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1299           TT[4] == '-' && TT[1] - '3' < 6)
1300    CPUType = DARWIN_CPU_TYPE_X86;
1301  else if (TT.find("powerpc-") == 0)
1302    CPUType = DARWIN_CPU_TYPE_POWERPC;
1303  else if (TT.find("powerpc64-") == 0)
1304    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1305
1306  // Traditional Bitcode starts after header.
1307  unsigned BCOffset = DarwinBCHeaderSize;
1308
1309  Stream.Emit(0x0B17C0DE, 32);
1310  Stream.Emit(0         , 32);  // Version.
1311  Stream.Emit(BCOffset  , 32);
1312  Stream.Emit(0         , 32);  // Filled in later.
1313  Stream.Emit(CPUType   , 32);
1314}
1315
1316/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1317/// finalize the header.
1318static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1319  // Update the size field in the header.
1320  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1321
1322  // If the file is not a multiple of 16 bytes, insert dummy padding.
1323  while (BufferSize & 15) {
1324    Stream.Emit(0, 8);
1325    ++BufferSize;
1326  }
1327}
1328
1329
1330/// WriteBitcodeToFile - Write the specified module to the specified output
1331/// stream.
1332void llvm::WriteBitcodeToFile(const Module *M, std::ostream &Out) {
1333  std::vector<unsigned char> Buffer;
1334  BitstreamWriter Stream(Buffer);
1335
1336  Buffer.reserve(256*1024);
1337
1338  // If this is darwin, emit a file header and trailer if needed.
1339  bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1340  if (isDarwin)
1341    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1342
1343  // Emit the file header.
1344  Stream.Emit((unsigned)'B', 8);
1345  Stream.Emit((unsigned)'C', 8);
1346  Stream.Emit(0x0, 4);
1347  Stream.Emit(0xC, 4);
1348  Stream.Emit(0xE, 4);
1349  Stream.Emit(0xD, 4);
1350
1351  // Emit the module.
1352  WriteModule(M, Stream);
1353
1354  if (isDarwin)
1355    EmitDarwinBCTrailer(Stream, Buffer.size());
1356
1357
1358  // If writing to stdout, set binary mode.
1359  if (llvm::cout == Out)
1360    sys::Program::ChangeStdoutToBinary();
1361
1362  // Write the generated bitstream to "Out".
1363  Out.write((char*)&Buffer.front(), Buffer.size());
1364
1365  // Make sure it hits disk now.
1366  Out.flush();
1367}
1368