BitcodeWriter.cpp revision 202375 
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/Operator.h"
24#include "llvm/TypeSymbolTable.h"
25#include "llvm/ValueSymbolTable.h"
26#include "llvm/Support/ErrorHandling.h"
27#include "llvm/Support/MathExtras.h"
28#include "llvm/Support/raw_ostream.h"
29#include "llvm/System/Program.h"
30using namespace llvm;
31
32/// These are manifest constants used by the bitcode writer. They do not need to
33/// be kept in sync with the reader, but need to be consistent within this file.
34enum {
35  CurVersion = 0,
36
37  // VALUE_SYMTAB_BLOCK abbrev id's.
38  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
39  VST_ENTRY_7_ABBREV,
40  VST_ENTRY_6_ABBREV,
41  VST_BBENTRY_6_ABBREV,
42
43  // CONSTANTS_BLOCK abbrev id's.
44  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
45  CONSTANTS_INTEGER_ABBREV,
46  CONSTANTS_CE_CAST_Abbrev,
47  CONSTANTS_NULL_Abbrev,
48
49  // FUNCTION_BLOCK abbrev id's.
50  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
51  FUNCTION_INST_BINOP_ABBREV,
52  FUNCTION_INST_BINOP_FLAGS_ABBREV,
53  FUNCTION_INST_CAST_ABBREV,
54  FUNCTION_INST_RET_VOID_ABBREV,
55  FUNCTION_INST_RET_VAL_ABBREV,
56  FUNCTION_INST_UNREACHABLE_ABBREV
57};
58
59
60static unsigned GetEncodedCastOpcode(unsigned Opcode) {
61  switch (Opcode) {
62  default: llvm_unreachable("Unknown cast instruction!");
63  case Instruction::Trunc   : return bitc::CAST_TRUNC;
64  case Instruction::ZExt    : return bitc::CAST_ZEXT;
65  case Instruction::SExt    : return bitc::CAST_SEXT;
66  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
67  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
68  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
69  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
70  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
71  case Instruction::FPExt   : return bitc::CAST_FPEXT;
72  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
73  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
74  case Instruction::BitCast : return bitc::CAST_BITCAST;
75  }
76}
77
78static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
79  switch (Opcode) {
80  default: llvm_unreachable("Unknown binary instruction!");
81  case Instruction::Add:
82  case Instruction::FAdd: return bitc::BINOP_ADD;
83  case Instruction::Sub:
84  case Instruction::FSub: return bitc::BINOP_SUB;
85  case Instruction::Mul:
86  case Instruction::FMul: return bitc::BINOP_MUL;
87  case Instruction::UDiv: return bitc::BINOP_UDIV;
88  case Instruction::FDiv:
89  case Instruction::SDiv: return bitc::BINOP_SDIV;
90  case Instruction::URem: return bitc::BINOP_UREM;
91  case Instruction::FRem:
92  case Instruction::SRem: return bitc::BINOP_SREM;
93  case Instruction::Shl:  return bitc::BINOP_SHL;
94  case Instruction::LShr: return bitc::BINOP_LSHR;
95  case Instruction::AShr: return bitc::BINOP_ASHR;
96  case Instruction::And:  return bitc::BINOP_AND;
97  case Instruction::Or:   return bitc::BINOP_OR;
98  case Instruction::Xor:  return bitc::BINOP_XOR;
99  }
100}
101
102
103
104static void WriteStringRecord(unsigned Code, const std::string &Str,
105                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
106  SmallVector<unsigned, 64> Vals;
107
108  // Code: [strchar x N]
109  for (unsigned i = 0, e = Str.size(); i != e; ++i)
110    Vals.push_back(Str[i]);
111
112  // Emit the finished record.
113  Stream.EmitRecord(Code, Vals, AbbrevToUse);
114}
115
116// Emit information about parameter attributes.
117static void WriteAttributeTable(const ValueEnumerator &VE,
118                                BitstreamWriter &Stream) {
119  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
120  if (Attrs.empty()) return;
121
122  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
123
124  SmallVector<uint64_t, 64> Record;
125  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
126    const AttrListPtr &A = Attrs[i];
127    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
128      const AttributeWithIndex &PAWI = A.getSlot(i);
129      Record.push_back(PAWI.Index);
130
131      // FIXME: remove in LLVM 3.0
132      // Store the alignment in the bitcode as a 16-bit raw value instead of a
133      // 5-bit log2 encoded value. Shift the bits above the alignment up by
134      // 11 bits.
135      uint64_t FauxAttr = PAWI.Attrs & 0xffff;
136      if (PAWI.Attrs & Attribute::Alignment)
137        FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
138      FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
139
140      Record.push_back(FauxAttr);
141    }
142
143    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
144    Record.clear();
145  }
146
147  Stream.ExitBlock();
148}
149
150/// WriteTypeTable - Write out the type table for a module.
151static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
152  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
153
154  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
155  SmallVector<uint64_t, 64> TypeVals;
156
157  // Abbrev for TYPE_CODE_POINTER.
158  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
159  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
160  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
161                            Log2_32_Ceil(VE.getTypes().size()+1)));
162  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
163  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
164
165  // Abbrev for TYPE_CODE_FUNCTION.
166  Abbv = new BitCodeAbbrev();
167  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
168  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
169  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
170  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
171  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
172                            Log2_32_Ceil(VE.getTypes().size()+1)));
173  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
174
175  // Abbrev for TYPE_CODE_STRUCT.
176  Abbv = new BitCodeAbbrev();
177  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
178  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
179  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
180  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
181                            Log2_32_Ceil(VE.getTypes().size()+1)));
182  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
183
184  // Abbrev for TYPE_CODE_ARRAY.
185  Abbv = new BitCodeAbbrev();
186  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
187  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
188  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
189                            Log2_32_Ceil(VE.getTypes().size()+1)));
190  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
191
192  // Emit an entry count so the reader can reserve space.
193  TypeVals.push_back(TypeList.size());
194  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
195  TypeVals.clear();
196
197  // Loop over all of the types, emitting each in turn.
198  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
199    const Type *T = TypeList[i].first;
200    int AbbrevToUse = 0;
201    unsigned Code = 0;
202
203    switch (T->getTypeID()) {
204    default: llvm_unreachable("Unknown type!");
205    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
206    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
207    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
208    case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
209    case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
210    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
211    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
212    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
213    case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
214    case Type::IntegerTyID:
215      // INTEGER: [width]
216      Code = bitc::TYPE_CODE_INTEGER;
217      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
218      break;
219    case Type::PointerTyID: {
220      const PointerType *PTy = cast<PointerType>(T);
221      // POINTER: [pointee type, address space]
222      Code = bitc::TYPE_CODE_POINTER;
223      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
224      unsigned AddressSpace = PTy->getAddressSpace();
225      TypeVals.push_back(AddressSpace);
226      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
227      break;
228    }
229    case Type::FunctionTyID: {
230      const FunctionType *FT = cast<FunctionType>(T);
231      // FUNCTION: [isvararg, attrid, retty, paramty x N]
232      Code = bitc::TYPE_CODE_FUNCTION;
233      TypeVals.push_back(FT->isVarArg());
234      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
235      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
236      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
237        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
238      AbbrevToUse = FunctionAbbrev;
239      break;
240    }
241    case Type::StructTyID: {
242      const StructType *ST = cast<StructType>(T);
243      // STRUCT: [ispacked, eltty x N]
244      Code = bitc::TYPE_CODE_STRUCT;
245      TypeVals.push_back(ST->isPacked());
246      // Output all of the element types.
247      for (StructType::element_iterator I = ST->element_begin(),
248           E = ST->element_end(); I != E; ++I)
249        TypeVals.push_back(VE.getTypeID(*I));
250      AbbrevToUse = StructAbbrev;
251      break;
252    }
253    case Type::ArrayTyID: {
254      const ArrayType *AT = cast<ArrayType>(T);
255      // ARRAY: [numelts, eltty]
256      Code = bitc::TYPE_CODE_ARRAY;
257      TypeVals.push_back(AT->getNumElements());
258      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
259      AbbrevToUse = ArrayAbbrev;
260      break;
261    }
262    case Type::VectorTyID: {
263      const VectorType *VT = cast<VectorType>(T);
264      // VECTOR [numelts, eltty]
265      Code = bitc::TYPE_CODE_VECTOR;
266      TypeVals.push_back(VT->getNumElements());
267      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
268      break;
269    }
270    }
271
272    // Emit the finished record.
273    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
274    TypeVals.clear();
275  }
276
277  Stream.ExitBlock();
278}
279
280static unsigned getEncodedLinkage(const GlobalValue *GV) {
281  switch (GV->getLinkage()) {
282  default: llvm_unreachable("Invalid linkage!");
283  case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
284  case GlobalValue::ExternalLinkage:            return 0;
285  case GlobalValue::WeakAnyLinkage:             return 1;
286  case GlobalValue::AppendingLinkage:           return 2;
287  case GlobalValue::InternalLinkage:            return 3;
288  case GlobalValue::LinkOnceAnyLinkage:         return 4;
289  case GlobalValue::DLLImportLinkage:           return 5;
290  case GlobalValue::DLLExportLinkage:           return 6;
291  case GlobalValue::ExternalWeakLinkage:        return 7;
292  case GlobalValue::CommonLinkage:              return 8;
293  case GlobalValue::PrivateLinkage:             return 9;
294  case GlobalValue::WeakODRLinkage:             return 10;
295  case GlobalValue::LinkOnceODRLinkage:         return 11;
296  case GlobalValue::AvailableExternallyLinkage: return 12;
297  case GlobalValue::LinkerPrivateLinkage:       return 13;
298  }
299}
300
301static unsigned getEncodedVisibility(const GlobalValue *GV) {
302  switch (GV->getVisibility()) {
303  default: llvm_unreachable("Invalid visibility!");
304  case GlobalValue::DefaultVisibility:   return 0;
305  case GlobalValue::HiddenVisibility:    return 1;
306  case GlobalValue::ProtectedVisibility: return 2;
307  }
308}
309
310// Emit top-level description of module, including target triple, inline asm,
311// descriptors for global variables, and function prototype info.
312static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
313                            BitstreamWriter &Stream) {
314  // Emit the list of dependent libraries for the Module.
315  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
316    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
317
318  // Emit various pieces of data attached to a module.
319  if (!M->getTargetTriple().empty())
320    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
321                      0/*TODO*/, Stream);
322  if (!M->getDataLayout().empty())
323    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
324                      0/*TODO*/, Stream);
325  if (!M->getModuleInlineAsm().empty())
326    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
327                      0/*TODO*/, Stream);
328
329  // Emit information about sections and GC, computing how many there are. Also
330  // compute the maximum alignment value.
331  std::map<std::string, unsigned> SectionMap;
332  std::map<std::string, unsigned> GCMap;
333  unsigned MaxAlignment = 0;
334  unsigned MaxGlobalType = 0;
335  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
336       GV != E; ++GV) {
337    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
338    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
339
340    if (!GV->hasSection()) continue;
341    // Give section names unique ID's.
342    unsigned &Entry = SectionMap[GV->getSection()];
343    if (Entry != 0) continue;
344    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
345                      0/*TODO*/, Stream);
346    Entry = SectionMap.size();
347  }
348  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
349    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
350    if (F->hasSection()) {
351      // Give section names unique ID's.
352      unsigned &Entry = SectionMap[F->getSection()];
353      if (!Entry) {
354        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
355                          0/*TODO*/, Stream);
356        Entry = SectionMap.size();
357      }
358    }
359    if (F->hasGC()) {
360      // Same for GC names.
361      unsigned &Entry = GCMap[F->getGC()];
362      if (!Entry) {
363        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
364                          0/*TODO*/, Stream);
365        Entry = GCMap.size();
366      }
367    }
368  }
369
370  // Emit abbrev for globals, now that we know # sections and max alignment.
371  unsigned SimpleGVarAbbrev = 0;
372  if (!M->global_empty()) {
373    // Add an abbrev for common globals with no visibility or thread localness.
374    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
375    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
376    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
377                              Log2_32_Ceil(MaxGlobalType+1)));
378    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
379    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
380    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
381    if (MaxAlignment == 0)                                      // Alignment.
382      Abbv->Add(BitCodeAbbrevOp(0));
383    else {
384      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
385      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
386                               Log2_32_Ceil(MaxEncAlignment+1)));
387    }
388    if (SectionMap.empty())                                    // Section.
389      Abbv->Add(BitCodeAbbrevOp(0));
390    else
391      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
392                               Log2_32_Ceil(SectionMap.size()+1)));
393    // Don't bother emitting vis + thread local.
394    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
395  }
396
397  // Emit the global variable information.
398  SmallVector<unsigned, 64> Vals;
399  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
400       GV != E; ++GV) {
401    unsigned AbbrevToUse = 0;
402
403    // GLOBALVAR: [type, isconst, initid,
404    //             linkage, alignment, section, visibility, threadlocal]
405    Vals.push_back(VE.getTypeID(GV->getType()));
406    Vals.push_back(GV->isConstant());
407    Vals.push_back(GV->isDeclaration() ? 0 :
408                   (VE.getValueID(GV->getInitializer()) + 1));
409    Vals.push_back(getEncodedLinkage(GV));
410    Vals.push_back(Log2_32(GV->getAlignment())+1);
411    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
412    if (GV->isThreadLocal() ||
413        GV->getVisibility() != GlobalValue::DefaultVisibility) {
414      Vals.push_back(getEncodedVisibility(GV));
415      Vals.push_back(GV->isThreadLocal());
416    } else {
417      AbbrevToUse = SimpleGVarAbbrev;
418    }
419
420    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
421    Vals.clear();
422  }
423
424  // Emit the function proto information.
425  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
426    // FUNCTION:  [type, callingconv, isproto, paramattr,
427    //             linkage, alignment, section, visibility, gc]
428    Vals.push_back(VE.getTypeID(F->getType()));
429    Vals.push_back(F->getCallingConv());
430    Vals.push_back(F->isDeclaration());
431    Vals.push_back(getEncodedLinkage(F));
432    Vals.push_back(VE.getAttributeID(F->getAttributes()));
433    Vals.push_back(Log2_32(F->getAlignment())+1);
434    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
435    Vals.push_back(getEncodedVisibility(F));
436    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
437
438    unsigned AbbrevToUse = 0;
439    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
440    Vals.clear();
441  }
442
443
444  // Emit the alias information.
445  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
446       AI != E; ++AI) {
447    Vals.push_back(VE.getTypeID(AI->getType()));
448    Vals.push_back(VE.getValueID(AI->getAliasee()));
449    Vals.push_back(getEncodedLinkage(AI));
450    Vals.push_back(getEncodedVisibility(AI));
451    unsigned AbbrevToUse = 0;
452    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
453    Vals.clear();
454  }
455}
456
457static uint64_t GetOptimizationFlags(const Value *V) {
458  uint64_t Flags = 0;
459
460  if (const OverflowingBinaryOperator *OBO =
461        dyn_cast<OverflowingBinaryOperator>(V)) {
462    if (OBO->hasNoSignedWrap())
463      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
464    if (OBO->hasNoUnsignedWrap())
465      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
466  } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
467    if (Div->isExact())
468      Flags |= 1 << bitc::SDIV_EXACT;
469  }
470
471  return Flags;
472}
473
474static void WriteMDNode(const MDNode *N,
475                        const ValueEnumerator &VE,
476                        BitstreamWriter &Stream,
477                        SmallVector<uint64_t, 64> &Record) {
478  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
479    if (N->getOperand(i)) {
480      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
481      Record.push_back(VE.getValueID(N->getOperand(i)));
482    } else {
483      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
484      Record.push_back(0);
485    }
486  }
487  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
488                                           bitc::METADATA_NODE;
489  Stream.EmitRecord(MDCode, Record, 0);
490  Record.clear();
491}
492
493static void WriteModuleMetadata(const ValueEnumerator &VE,
494                                BitstreamWriter &Stream) {
495  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
496  bool StartedMetadataBlock = false;
497  unsigned MDSAbbrev = 0;
498  SmallVector<uint64_t, 64> Record;
499  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
500
501    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
502      if (!N->isFunctionLocal()) {
503        if (!StartedMetadataBlock) {
504          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
505          StartedMetadataBlock = true;
506        }
507        WriteMDNode(N, VE, Stream, Record);
508      }
509    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
510      if (!StartedMetadataBlock)  {
511        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
512
513        // Abbrev for METADATA_STRING.
514        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
515        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
516        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
517        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
518        MDSAbbrev = Stream.EmitAbbrev(Abbv);
519        StartedMetadataBlock = true;
520      }
521
522      // Code: [strchar x N]
523      Record.append(MDS->begin(), MDS->end());
524
525      // Emit the finished record.
526      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
527      Record.clear();
528    } else if (const NamedMDNode *NMD = dyn_cast<NamedMDNode>(Vals[i].first)) {
529      if (!StartedMetadataBlock)  {
530        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
531        StartedMetadataBlock = true;
532      }
533
534      // Write name.
535      StringRef Str = NMD->getName();
536      for (unsigned i = 0, e = Str.size(); i != e; ++i)
537        Record.push_back(Str[i]);
538      Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
539      Record.clear();
540
541      // Write named metadata operands.
542      for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
543        if (NMD->getOperand(i))
544          Record.push_back(VE.getValueID(NMD->getOperand(i)));
545        else
546          Record.push_back(~0U);
547      }
548      Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
549      Record.clear();
550    }
551  }
552
553  if (StartedMetadataBlock)
554    Stream.ExitBlock();
555}
556
557static void WriteFunctionLocalMetadata(const Function &F,
558                                       const ValueEnumerator &VE,
559                                       BitstreamWriter &Stream) {
560  bool StartedMetadataBlock = false;
561  SmallVector<uint64_t, 64> Record;
562  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
563
564  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
565    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first))
566      if (N->getFunction() == &F) {
567        if (!StartedMetadataBlock) {
568          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
569          StartedMetadataBlock = true;
570        }
571        WriteMDNode(N, VE, Stream, Record);
572      }
573
574  if (StartedMetadataBlock)
575    Stream.ExitBlock();
576}
577
578static void WriteMetadataAttachment(const Function &F,
579                                    const ValueEnumerator &VE,
580                                    BitstreamWriter &Stream) {
581  bool StartedMetadataBlock = false;
582  SmallVector<uint64_t, 64> Record;
583
584  // Write metadata attachments
585  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
586  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
587
588  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
589    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
590         I != E; ++I) {
591      MDs.clear();
592      I->getAllMetadata(MDs);
593
594      // If no metadata, ignore instruction.
595      if (MDs.empty()) continue;
596
597      Record.push_back(VE.getInstructionID(I));
598
599      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
600        Record.push_back(MDs[i].first);
601        Record.push_back(VE.getValueID(MDs[i].second));
602      }
603      if (!StartedMetadataBlock)  {
604        Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
605        StartedMetadataBlock = true;
606      }
607      Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
608      Record.clear();
609    }
610
611  if (StartedMetadataBlock)
612    Stream.ExitBlock();
613}
614
615static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
616  SmallVector<uint64_t, 64> Record;
617
618  // Write metadata kinds
619  // METADATA_KIND - [n x [id, name]]
620  SmallVector<StringRef, 4> Names;
621  M->getMDKindNames(Names);
622
623  assert(Names[0] == "" && "MDKind #0 is invalid");
624  if (Names.size() == 1) return;
625
626  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
627
628  for (unsigned MDKindID = 1, e = Names.size(); MDKindID != e; ++MDKindID) {
629    Record.push_back(MDKindID);
630    StringRef KName = Names[MDKindID];
631    Record.append(KName.begin(), KName.end());
632
633    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
634    Record.clear();
635  }
636
637  Stream.ExitBlock();
638}
639
640static void WriteConstants(unsigned FirstVal, unsigned LastVal,
641                           const ValueEnumerator &VE,
642                           BitstreamWriter &Stream, bool isGlobal) {
643  if (FirstVal == LastVal) return;
644
645  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
646
647  unsigned AggregateAbbrev = 0;
648  unsigned String8Abbrev = 0;
649  unsigned CString7Abbrev = 0;
650  unsigned CString6Abbrev = 0;
651  // If this is a constant pool for the module, emit module-specific abbrevs.
652  if (isGlobal) {
653    // Abbrev for CST_CODE_AGGREGATE.
654    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
655    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
656    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
657    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
658    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
659
660    // Abbrev for CST_CODE_STRING.
661    Abbv = new BitCodeAbbrev();
662    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
663    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
664    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
665    String8Abbrev = Stream.EmitAbbrev(Abbv);
666    // Abbrev for CST_CODE_CSTRING.
667    Abbv = new BitCodeAbbrev();
668    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
669    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
670    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
671    CString7Abbrev = Stream.EmitAbbrev(Abbv);
672    // Abbrev for CST_CODE_CSTRING.
673    Abbv = new BitCodeAbbrev();
674    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
675    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
676    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
677    CString6Abbrev = Stream.EmitAbbrev(Abbv);
678  }
679
680  SmallVector<uint64_t, 64> Record;
681
682  const ValueEnumerator::ValueList &Vals = VE.getValues();
683  const Type *LastTy = 0;
684  for (unsigned i = FirstVal; i != LastVal; ++i) {
685    const Value *V = Vals[i].first;
686    // If we need to switch types, do so now.
687    if (V->getType() != LastTy) {
688      LastTy = V->getType();
689      Record.push_back(VE.getTypeID(LastTy));
690      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
691                        CONSTANTS_SETTYPE_ABBREV);
692      Record.clear();
693    }
694
695    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
696      Record.push_back(unsigned(IA->hasSideEffects()) |
697                       unsigned(IA->isAlignStack()) << 1);
698
699      // Add the asm string.
700      const std::string &AsmStr = IA->getAsmString();
701      Record.push_back(AsmStr.size());
702      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
703        Record.push_back(AsmStr[i]);
704
705      // Add the constraint string.
706      const std::string &ConstraintStr = IA->getConstraintString();
707      Record.push_back(ConstraintStr.size());
708      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
709        Record.push_back(ConstraintStr[i]);
710      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
711      Record.clear();
712      continue;
713    }
714    const Constant *C = cast<Constant>(V);
715    unsigned Code = -1U;
716    unsigned AbbrevToUse = 0;
717    if (C->isNullValue()) {
718      Code = bitc::CST_CODE_NULL;
719    } else if (isa<UndefValue>(C)) {
720      Code = bitc::CST_CODE_UNDEF;
721    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
722      if (IV->getBitWidth() <= 64) {
723        int64_t V = IV->getSExtValue();
724        if (V >= 0)
725          Record.push_back(V << 1);
726        else
727          Record.push_back((-V << 1) | 1);
728        Code = bitc::CST_CODE_INTEGER;
729        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
730      } else {                             // Wide integers, > 64 bits in size.
731        // We have an arbitrary precision integer value to write whose
732        // bit width is > 64. However, in canonical unsigned integer
733        // format it is likely that the high bits are going to be zero.
734        // So, we only write the number of active words.
735        unsigned NWords = IV->getValue().getActiveWords();
736        const uint64_t *RawWords = IV->getValue().getRawData();
737        for (unsigned i = 0; i != NWords; ++i) {
738          int64_t V = RawWords[i];
739          if (V >= 0)
740            Record.push_back(V << 1);
741          else
742            Record.push_back((-V << 1) | 1);
743        }
744        Code = bitc::CST_CODE_WIDE_INTEGER;
745      }
746    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
747      Code = bitc::CST_CODE_FLOAT;
748      const Type *Ty = CFP->getType();
749      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
750        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
751      } else if (Ty->isX86_FP80Ty()) {
752        // api needed to prevent premature destruction
753        // bits are not in the same order as a normal i80 APInt, compensate.
754        APInt api = CFP->getValueAPF().bitcastToAPInt();
755        const uint64_t *p = api.getRawData();
756        Record.push_back((p[1] << 48) | (p[0] >> 16));
757        Record.push_back(p[0] & 0xffffLL);
758      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
759        APInt api = CFP->getValueAPF().bitcastToAPInt();
760        const uint64_t *p = api.getRawData();
761        Record.push_back(p[0]);
762        Record.push_back(p[1]);
763      } else {
764        assert (0 && "Unknown FP type!");
765      }
766    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
767      const ConstantArray *CA = cast<ConstantArray>(C);
768      // Emit constant strings specially.
769      unsigned NumOps = CA->getNumOperands();
770      // If this is a null-terminated string, use the denser CSTRING encoding.
771      if (CA->getOperand(NumOps-1)->isNullValue()) {
772        Code = bitc::CST_CODE_CSTRING;
773        --NumOps;  // Don't encode the null, which isn't allowed by char6.
774      } else {
775        Code = bitc::CST_CODE_STRING;
776        AbbrevToUse = String8Abbrev;
777      }
778      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
779      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
780      for (unsigned i = 0; i != NumOps; ++i) {
781        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
782        Record.push_back(V);
783        isCStr7 &= (V & 128) == 0;
784        if (isCStrChar6)
785          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
786      }
787
788      if (isCStrChar6)
789        AbbrevToUse = CString6Abbrev;
790      else if (isCStr7)
791        AbbrevToUse = CString7Abbrev;
792    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
793               isa<ConstantVector>(V)) {
794      Code = bitc::CST_CODE_AGGREGATE;
795      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
796        Record.push_back(VE.getValueID(C->getOperand(i)));
797      AbbrevToUse = AggregateAbbrev;
798    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
799      switch (CE->getOpcode()) {
800      default:
801        if (Instruction::isCast(CE->getOpcode())) {
802          Code = bitc::CST_CODE_CE_CAST;
803          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
804          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
805          Record.push_back(VE.getValueID(C->getOperand(0)));
806          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
807        } else {
808          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
809          Code = bitc::CST_CODE_CE_BINOP;
810          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
811          Record.push_back(VE.getValueID(C->getOperand(0)));
812          Record.push_back(VE.getValueID(C->getOperand(1)));
813          uint64_t Flags = GetOptimizationFlags(CE);
814          if (Flags != 0)
815            Record.push_back(Flags);
816        }
817        break;
818      case Instruction::GetElementPtr:
819        Code = bitc::CST_CODE_CE_GEP;
820        if (cast<GEPOperator>(C)->isInBounds())
821          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
822        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
823          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
824          Record.push_back(VE.getValueID(C->getOperand(i)));
825        }
826        break;
827      case Instruction::Select:
828        Code = bitc::CST_CODE_CE_SELECT;
829        Record.push_back(VE.getValueID(C->getOperand(0)));
830        Record.push_back(VE.getValueID(C->getOperand(1)));
831        Record.push_back(VE.getValueID(C->getOperand(2)));
832        break;
833      case Instruction::ExtractElement:
834        Code = bitc::CST_CODE_CE_EXTRACTELT;
835        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
836        Record.push_back(VE.getValueID(C->getOperand(0)));
837        Record.push_back(VE.getValueID(C->getOperand(1)));
838        break;
839      case Instruction::InsertElement:
840        Code = bitc::CST_CODE_CE_INSERTELT;
841        Record.push_back(VE.getValueID(C->getOperand(0)));
842        Record.push_back(VE.getValueID(C->getOperand(1)));
843        Record.push_back(VE.getValueID(C->getOperand(2)));
844        break;
845      case Instruction::ShuffleVector:
846        // If the return type and argument types are the same, this is a
847        // standard shufflevector instruction.  If the types are different,
848        // then the shuffle is widening or truncating the input vectors, and
849        // the argument type must also be encoded.
850        if (C->getType() == C->getOperand(0)->getType()) {
851          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
852        } else {
853          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
854          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
855        }
856        Record.push_back(VE.getValueID(C->getOperand(0)));
857        Record.push_back(VE.getValueID(C->getOperand(1)));
858        Record.push_back(VE.getValueID(C->getOperand(2)));
859        break;
860      case Instruction::ICmp:
861      case Instruction::FCmp:
862        Code = bitc::CST_CODE_CE_CMP;
863        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
864        Record.push_back(VE.getValueID(C->getOperand(0)));
865        Record.push_back(VE.getValueID(C->getOperand(1)));
866        Record.push_back(CE->getPredicate());
867        break;
868      }
869    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
870      assert(BA->getFunction() == BA->getBasicBlock()->getParent() &&
871             "Malformed blockaddress");
872      Code = bitc::CST_CODE_BLOCKADDRESS;
873      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
874      Record.push_back(VE.getValueID(BA->getFunction()));
875      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
876    } else {
877      llvm_unreachable("Unknown constant!");
878    }
879    Stream.EmitRecord(Code, Record, AbbrevToUse);
880    Record.clear();
881  }
882
883  Stream.ExitBlock();
884}
885
886static void WriteModuleConstants(const ValueEnumerator &VE,
887                                 BitstreamWriter &Stream) {
888  const ValueEnumerator::ValueList &Vals = VE.getValues();
889
890  // Find the first constant to emit, which is the first non-globalvalue value.
891  // We know globalvalues have been emitted by WriteModuleInfo.
892  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
893    if (!isa<GlobalValue>(Vals[i].first)) {
894      WriteConstants(i, Vals.size(), VE, Stream, true);
895      return;
896    }
897  }
898}
899
900/// PushValueAndType - The file has to encode both the value and type id for
901/// many values, because we need to know what type to create for forward
902/// references.  However, most operands are not forward references, so this type
903/// field is not needed.
904///
905/// This function adds V's value ID to Vals.  If the value ID is higher than the
906/// instruction ID, then it is a forward reference, and it also includes the
907/// type ID.
908static bool PushValueAndType(const Value *V, unsigned InstID,
909                             SmallVector<unsigned, 64> &Vals,
910                             ValueEnumerator &VE) {
911  unsigned ValID = VE.getValueID(V);
912  Vals.push_back(ValID);
913  if (ValID >= InstID) {
914    Vals.push_back(VE.getTypeID(V->getType()));
915    return true;
916  }
917  return false;
918}
919
920/// WriteInstruction - Emit an instruction to the specified stream.
921static void WriteInstruction(const Instruction &I, unsigned InstID,
922                             ValueEnumerator &VE, BitstreamWriter &Stream,
923                             SmallVector<unsigned, 64> &Vals) {
924  unsigned Code = 0;
925  unsigned AbbrevToUse = 0;
926  VE.setInstructionID(&I);
927  switch (I.getOpcode()) {
928  default:
929    if (Instruction::isCast(I.getOpcode())) {
930      Code = bitc::FUNC_CODE_INST_CAST;
931      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
932        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
933      Vals.push_back(VE.getTypeID(I.getType()));
934      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
935    } else {
936      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
937      Code = bitc::FUNC_CODE_INST_BINOP;
938      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
939        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
940      Vals.push_back(VE.getValueID(I.getOperand(1)));
941      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
942      uint64_t Flags = GetOptimizationFlags(&I);
943      if (Flags != 0) {
944        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
945          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
946        Vals.push_back(Flags);
947      }
948    }
949    break;
950
951  case Instruction::GetElementPtr:
952    Code = bitc::FUNC_CODE_INST_GEP;
953    if (cast<GEPOperator>(&I)->isInBounds())
954      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
955    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
956      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
957    break;
958  case Instruction::ExtractValue: {
959    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
960    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
961    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
962    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
963      Vals.push_back(*i);
964    break;
965  }
966  case Instruction::InsertValue: {
967    Code = bitc::FUNC_CODE_INST_INSERTVAL;
968    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
969    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
970    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
971    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
972      Vals.push_back(*i);
973    break;
974  }
975  case Instruction::Select:
976    Code = bitc::FUNC_CODE_INST_VSELECT;
977    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
978    Vals.push_back(VE.getValueID(I.getOperand(2)));
979    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
980    break;
981  case Instruction::ExtractElement:
982    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
983    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
984    Vals.push_back(VE.getValueID(I.getOperand(1)));
985    break;
986  case Instruction::InsertElement:
987    Code = bitc::FUNC_CODE_INST_INSERTELT;
988    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
989    Vals.push_back(VE.getValueID(I.getOperand(1)));
990    Vals.push_back(VE.getValueID(I.getOperand(2)));
991    break;
992  case Instruction::ShuffleVector:
993    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
994    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
995    Vals.push_back(VE.getValueID(I.getOperand(1)));
996    Vals.push_back(VE.getValueID(I.getOperand(2)));
997    break;
998  case Instruction::ICmp:
999  case Instruction::FCmp:
1000    // compare returning Int1Ty or vector of Int1Ty
1001    Code = bitc::FUNC_CODE_INST_CMP2;
1002    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1003    Vals.push_back(VE.getValueID(I.getOperand(1)));
1004    Vals.push_back(cast<CmpInst>(I).getPredicate());
1005    break;
1006
1007  case Instruction::Ret:
1008    {
1009      Code = bitc::FUNC_CODE_INST_RET;
1010      unsigned NumOperands = I.getNumOperands();
1011      if (NumOperands == 0)
1012        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1013      else if (NumOperands == 1) {
1014        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1015          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1016      } else {
1017        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1018          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1019      }
1020    }
1021    break;
1022  case Instruction::Br:
1023    {
1024      Code = bitc::FUNC_CODE_INST_BR;
1025      BranchInst &II = cast<BranchInst>(I);
1026      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1027      if (II.isConditional()) {
1028        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1029        Vals.push_back(VE.getValueID(II.getCondition()));
1030      }
1031    }
1032    break;
1033  case Instruction::Switch:
1034    Code = bitc::FUNC_CODE_INST_SWITCH;
1035    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1036    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1037      Vals.push_back(VE.getValueID(I.getOperand(i)));
1038    break;
1039  case Instruction::IndirectBr:
1040    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1041    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1042    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1043      Vals.push_back(VE.getValueID(I.getOperand(i)));
1044    break;
1045
1046  case Instruction::Invoke: {
1047    const InvokeInst *II = cast<InvokeInst>(&I);
1048    const Value *Callee(II->getCalledValue());
1049    const PointerType *PTy = cast<PointerType>(Callee->getType());
1050    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1051    Code = bitc::FUNC_CODE_INST_INVOKE;
1052
1053    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1054    Vals.push_back(II->getCallingConv());
1055    Vals.push_back(VE.getValueID(II->getNormalDest()));
1056    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1057    PushValueAndType(Callee, InstID, Vals, VE);
1058
1059    // Emit value #'s for the fixed parameters.
1060    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1061      Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
1062
1063    // Emit type/value pairs for varargs params.
1064    if (FTy->isVarArg()) {
1065      for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
1066           i != e; ++i)
1067        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1068    }
1069    break;
1070  }
1071  case Instruction::Unwind:
1072    Code = bitc::FUNC_CODE_INST_UNWIND;
1073    break;
1074  case Instruction::Unreachable:
1075    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1076    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1077    break;
1078
1079  case Instruction::PHI:
1080    Code = bitc::FUNC_CODE_INST_PHI;
1081    Vals.push_back(VE.getTypeID(I.getType()));
1082    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1083      Vals.push_back(VE.getValueID(I.getOperand(i)));
1084    break;
1085
1086  case Instruction::Alloca:
1087    Code = bitc::FUNC_CODE_INST_ALLOCA;
1088    Vals.push_back(VE.getTypeID(I.getType()));
1089    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1090    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1091    break;
1092
1093  case Instruction::Load:
1094    Code = bitc::FUNC_CODE_INST_LOAD;
1095    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1096      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1097
1098    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1099    Vals.push_back(cast<LoadInst>(I).isVolatile());
1100    break;
1101  case Instruction::Store:
1102    Code = bitc::FUNC_CODE_INST_STORE2;
1103    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1104    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1105    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1106    Vals.push_back(cast<StoreInst>(I).isVolatile());
1107    break;
1108  case Instruction::Call: {
1109    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
1110    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1111
1112    Code = bitc::FUNC_CODE_INST_CALL;
1113
1114    const CallInst *CI = cast<CallInst>(&I);
1115    Vals.push_back(VE.getAttributeID(CI->getAttributes()));
1116    Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
1117    PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
1118
1119    // Emit value #'s for the fixed parameters.
1120    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1121      Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
1122
1123    // Emit type/value pairs for varargs params.
1124    if (FTy->isVarArg()) {
1125      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
1126      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
1127           i != e; ++i)
1128        PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
1129    }
1130    break;
1131  }
1132  case Instruction::VAArg:
1133    Code = bitc::FUNC_CODE_INST_VAARG;
1134    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1135    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1136    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1137    break;
1138  }
1139
1140  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1141  Vals.clear();
1142}
1143
1144// Emit names for globals/functions etc.
1145static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1146                                  const ValueEnumerator &VE,
1147                                  BitstreamWriter &Stream) {
1148  if (VST.empty()) return;
1149  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1150
1151  // FIXME: Set up the abbrev, we know how many values there are!
1152  // FIXME: We know if the type names can use 7-bit ascii.
1153  SmallVector<unsigned, 64> NameVals;
1154
1155  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1156       SI != SE; ++SI) {
1157
1158    const ValueName &Name = *SI;
1159
1160    // Figure out the encoding to use for the name.
1161    bool is7Bit = true;
1162    bool isChar6 = true;
1163    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1164         C != E; ++C) {
1165      if (isChar6)
1166        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1167      if ((unsigned char)*C & 128) {
1168        is7Bit = false;
1169        break;  // don't bother scanning the rest.
1170      }
1171    }
1172
1173    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1174
1175    // VST_ENTRY:   [valueid, namechar x N]
1176    // VST_BBENTRY: [bbid, namechar x N]
1177    unsigned Code;
1178    if (isa<BasicBlock>(SI->getValue())) {
1179      Code = bitc::VST_CODE_BBENTRY;
1180      if (isChar6)
1181        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1182    } else {
1183      Code = bitc::VST_CODE_ENTRY;
1184      if (isChar6)
1185        AbbrevToUse = VST_ENTRY_6_ABBREV;
1186      else if (is7Bit)
1187        AbbrevToUse = VST_ENTRY_7_ABBREV;
1188    }
1189
1190    NameVals.push_back(VE.getValueID(SI->getValue()));
1191    for (const char *P = Name.getKeyData(),
1192         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1193      NameVals.push_back((unsigned char)*P);
1194
1195    // Emit the finished record.
1196    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1197    NameVals.clear();
1198  }
1199  Stream.ExitBlock();
1200}
1201
1202/// WriteFunction - Emit a function body to the module stream.
1203static void WriteFunction(const Function &F, ValueEnumerator &VE,
1204                          BitstreamWriter &Stream) {
1205  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1206  VE.incorporateFunction(F);
1207
1208  SmallVector<unsigned, 64> Vals;
1209
1210  // Emit the number of basic blocks, so the reader can create them ahead of
1211  // time.
1212  Vals.push_back(VE.getBasicBlocks().size());
1213  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1214  Vals.clear();
1215
1216  // If there are function-local constants, emit them now.
1217  unsigned CstStart, CstEnd;
1218  VE.getFunctionConstantRange(CstStart, CstEnd);
1219  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1220
1221  // If there is function-local metadata, emit it now.
1222  WriteFunctionLocalMetadata(F, VE, Stream);
1223
1224  // Keep a running idea of what the instruction ID is.
1225  unsigned InstID = CstEnd;
1226
1227  // Finally, emit all the instructions, in order.
1228  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1229    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1230         I != E; ++I) {
1231      WriteInstruction(*I, InstID, VE, Stream, Vals);
1232      if (!I->getType()->isVoidTy())
1233        ++InstID;
1234    }
1235
1236  // Emit names for all the instructions etc.
1237  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1238
1239  WriteMetadataAttachment(F, VE, Stream);
1240  VE.purgeFunction();
1241  Stream.ExitBlock();
1242}
1243
1244/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1245static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1246                                 const ValueEnumerator &VE,
1247                                 BitstreamWriter &Stream) {
1248  if (TST.empty()) return;
1249
1250  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1251
1252  // 7-bit fixed width VST_CODE_ENTRY strings.
1253  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1254  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1255  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1256                            Log2_32_Ceil(VE.getTypes().size()+1)));
1257  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1258  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1259  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1260
1261  SmallVector<unsigned, 64> NameVals;
1262
1263  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1264       TI != TE; ++TI) {
1265    // TST_ENTRY: [typeid, namechar x N]
1266    NameVals.push_back(VE.getTypeID(TI->second));
1267
1268    const std::string &Str = TI->first;
1269    bool is7Bit = true;
1270    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1271      NameVals.push_back((unsigned char)Str[i]);
1272      if (Str[i] & 128)
1273        is7Bit = false;
1274    }
1275
1276    // Emit the finished record.
1277    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1278    NameVals.clear();
1279  }
1280
1281  Stream.ExitBlock();
1282}
1283
1284// Emit blockinfo, which defines the standard abbreviations etc.
1285static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1286  // We only want to emit block info records for blocks that have multiple
1287  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1288  // blocks can defined their abbrevs inline.
1289  Stream.EnterBlockInfoBlock(2);
1290
1291  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1292    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1293    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1294    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1295    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1296    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1297    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1298                                   Abbv) != VST_ENTRY_8_ABBREV)
1299      llvm_unreachable("Unexpected abbrev ordering!");
1300  }
1301
1302  { // 7-bit fixed width VST_ENTRY strings.
1303    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1304    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1305    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1306    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1307    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1308    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1309                                   Abbv) != VST_ENTRY_7_ABBREV)
1310      llvm_unreachable("Unexpected abbrev ordering!");
1311  }
1312  { // 6-bit char6 VST_ENTRY strings.
1313    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1314    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1315    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1316    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1317    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1318    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1319                                   Abbv) != VST_ENTRY_6_ABBREV)
1320      llvm_unreachable("Unexpected abbrev ordering!");
1321  }
1322  { // 6-bit char6 VST_BBENTRY strings.
1323    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1324    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1325    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1326    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1327    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1328    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1329                                   Abbv) != VST_BBENTRY_6_ABBREV)
1330      llvm_unreachable("Unexpected abbrev ordering!");
1331  }
1332
1333
1334
1335  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1336    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1337    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1338    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1339                              Log2_32_Ceil(VE.getTypes().size()+1)));
1340    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1341                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1342      llvm_unreachable("Unexpected abbrev ordering!");
1343  }
1344
1345  { // INTEGER abbrev for CONSTANTS_BLOCK.
1346    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1347    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1348    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1349    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1350                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1351      llvm_unreachable("Unexpected abbrev ordering!");
1352  }
1353
1354  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1355    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1356    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1357    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1358    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1359                              Log2_32_Ceil(VE.getTypes().size()+1)));
1360    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1361
1362    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1363                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1364      llvm_unreachable("Unexpected abbrev ordering!");
1365  }
1366  { // NULL abbrev for CONSTANTS_BLOCK.
1367    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1368    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1369    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1370                                   Abbv) != CONSTANTS_NULL_Abbrev)
1371      llvm_unreachable("Unexpected abbrev ordering!");
1372  }
1373
1374  // FIXME: This should only use space for first class types!
1375
1376  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1377    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1378    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1379    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1380    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1381    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1382    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1383                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1384      llvm_unreachable("Unexpected abbrev ordering!");
1385  }
1386  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1387    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1388    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1389    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1390    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1391    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1392    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1393                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1394      llvm_unreachable("Unexpected abbrev ordering!");
1395  }
1396  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1397    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1398    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1399    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1400    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1401    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1402    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1403    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1404                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1405      llvm_unreachable("Unexpected abbrev ordering!");
1406  }
1407  { // INST_CAST abbrev for FUNCTION_BLOCK.
1408    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1409    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1410    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1411    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1412                              Log2_32_Ceil(VE.getTypes().size()+1)));
1413    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1414    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1415                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1416      llvm_unreachable("Unexpected abbrev ordering!");
1417  }
1418
1419  { // INST_RET abbrev for FUNCTION_BLOCK.
1420    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1421    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1422    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1423                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1424      llvm_unreachable("Unexpected abbrev ordering!");
1425  }
1426  { // INST_RET abbrev for FUNCTION_BLOCK.
1427    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1428    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1429    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1430    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1431                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1432      llvm_unreachable("Unexpected abbrev ordering!");
1433  }
1434  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1435    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1436    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1437    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1438                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1439      llvm_unreachable("Unexpected abbrev ordering!");
1440  }
1441
1442  Stream.ExitBlock();
1443}
1444
1445
1446/// WriteModule - Emit the specified module to the bitstream.
1447static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1448  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1449
1450  // Emit the version number if it is non-zero.
1451  if (CurVersion) {
1452    SmallVector<unsigned, 1> Vals;
1453    Vals.push_back(CurVersion);
1454    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1455  }
1456
1457  // Analyze the module, enumerating globals, functions, etc.
1458  ValueEnumerator VE(M);
1459
1460  // Emit blockinfo, which defines the standard abbreviations etc.
1461  WriteBlockInfo(VE, Stream);
1462
1463  // Emit information about parameter attributes.
1464  WriteAttributeTable(VE, Stream);
1465
1466  // Emit information describing all of the types in the module.
1467  WriteTypeTable(VE, Stream);
1468
1469  // Emit top-level description of module, including target triple, inline asm,
1470  // descriptors for global variables, and function prototype info.
1471  WriteModuleInfo(M, VE, Stream);
1472
1473  // Emit constants.
1474  WriteModuleConstants(VE, Stream);
1475
1476  // Emit metadata.
1477  WriteModuleMetadata(VE, Stream);
1478
1479  // Emit function bodies.
1480  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1481    if (!I->isDeclaration())
1482      WriteFunction(*I, VE, Stream);
1483
1484  // Emit metadata.
1485  WriteModuleMetadataStore(M, Stream);
1486
1487  // Emit the type symbol table information.
1488  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1489
1490  // Emit names for globals/functions etc.
1491  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1492
1493  Stream.ExitBlock();
1494}
1495
1496/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1497/// header and trailer to make it compatible with the system archiver.  To do
1498/// this we emit the following header, and then emit a trailer that pads the
1499/// file out to be a multiple of 16 bytes.
1500///
1501/// struct bc_header {
1502///   uint32_t Magic;         // 0x0B17C0DE
1503///   uint32_t Version;       // Version, currently always 0.
1504///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1505///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1506///   uint32_t CPUType;       // CPU specifier.
1507///   ... potentially more later ...
1508/// };
1509enum {
1510  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1511  DarwinBCHeaderSize = 5*4
1512};
1513
1514static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1515                               const std::string &TT) {
1516  unsigned CPUType = ~0U;
1517
1518  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*.  The CPUType is a
1519  // magic number from /usr/include/mach/machine.h.  It is ok to reproduce the
1520  // specific constants here because they are implicitly part of the Darwin ABI.
1521  enum {
1522    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1523    DARWIN_CPU_TYPE_X86        = 7,
1524    DARWIN_CPU_TYPE_POWERPC    = 18
1525  };
1526
1527  if (TT.find("x86_64-") == 0)
1528    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1529  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1530           TT[4] == '-' && TT[1] - '3' < 6)
1531    CPUType = DARWIN_CPU_TYPE_X86;
1532  else if (TT.find("powerpc-") == 0)
1533    CPUType = DARWIN_CPU_TYPE_POWERPC;
1534  else if (TT.find("powerpc64-") == 0)
1535    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1536
1537  // Traditional Bitcode starts after header.
1538  unsigned BCOffset = DarwinBCHeaderSize;
1539
1540  Stream.Emit(0x0B17C0DE, 32);
1541  Stream.Emit(0         , 32);  // Version.
1542  Stream.Emit(BCOffset  , 32);
1543  Stream.Emit(0         , 32);  // Filled in later.
1544  Stream.Emit(CPUType   , 32);
1545}
1546
1547/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1548/// finalize the header.
1549static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1550  // Update the size field in the header.
1551  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1552
1553  // If the file is not a multiple of 16 bytes, insert dummy padding.
1554  while (BufferSize & 15) {
1555    Stream.Emit(0, 8);
1556    ++BufferSize;
1557  }
1558}
1559
1560
1561/// WriteBitcodeToFile - Write the specified module to the specified output
1562/// stream.
1563void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1564  std::vector<unsigned char> Buffer;
1565  BitstreamWriter Stream(Buffer);
1566
1567  Buffer.reserve(256*1024);
1568
1569  WriteBitcodeToStream( M, Stream );
1570
1571  // If writing to stdout, set binary mode.
1572  if (&llvm::outs() == &Out)
1573    sys::Program::ChangeStdoutToBinary();
1574
1575  // Write the generated bitstream to "Out".
1576  Out.write((char*)&Buffer.front(), Buffer.size());
1577
1578  // Make sure it hits disk now.
1579  Out.flush();
1580}
1581
1582/// WriteBitcodeToStream - Write the specified module to the specified output
1583/// stream.
1584void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1585  // If this is darwin, emit a file header and trailer if needed.
1586  bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1587  if (isDarwin)
1588    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1589
1590  // Emit the file header.
1591  Stream.Emit((unsigned)'B', 8);
1592  Stream.Emit((unsigned)'C', 8);
1593  Stream.Emit(0x0, 4);
1594  Stream.Emit(0xC, 4);
1595  Stream.Emit(0xE, 4);
1596  Stream.Emit(0xD, 4);
1597
1598  // Emit the module.
1599  WriteModule(M, Stream);
1600
1601  if (isDarwin)
1602    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1603}
1604