BitcodeWriter.cpp revision bcb18538c26fd6fef942d9da8156b30febae5d7e 
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/LLVMContext.h"
23#include "llvm/Metadata.h"
24#include "llvm/Module.h"
25#include "llvm/Operator.h"
26#include "llvm/TypeSymbolTable.h"
27#include "llvm/ValueSymbolTable.h"
28#include "llvm/Support/ErrorHandling.h"
29#include "llvm/Support/MathExtras.h"
30#include "llvm/Support/raw_ostream.h"
31#include "llvm/System/Program.h"
32using namespace llvm;
33
34/// These are manifest constants used by the bitcode writer. They do not need to
35/// be kept in sync with the reader, but need to be consistent within this file.
36enum {
37  CurVersion = 0,
38
39  // VALUE_SYMTAB_BLOCK abbrev id's.
40  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
41  VST_ENTRY_7_ABBREV,
42  VST_ENTRY_6_ABBREV,
43  VST_BBENTRY_6_ABBREV,
44
45  // CONSTANTS_BLOCK abbrev id's.
46  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
47  CONSTANTS_INTEGER_ABBREV,
48  CONSTANTS_CE_CAST_Abbrev,
49  CONSTANTS_NULL_Abbrev,
50
51  // FUNCTION_BLOCK abbrev id's.
52  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
53  FUNCTION_INST_BINOP_ABBREV,
54  FUNCTION_INST_BINOP_FLAGS_ABBREV,
55  FUNCTION_INST_CAST_ABBREV,
56  FUNCTION_INST_RET_VOID_ABBREV,
57  FUNCTION_INST_RET_VAL_ABBREV,
58  FUNCTION_INST_UNREACHABLE_ABBREV
59};
60
61
62static unsigned GetEncodedCastOpcode(unsigned Opcode) {
63  switch (Opcode) {
64  default: llvm_unreachable("Unknown cast instruction!");
65  case Instruction::Trunc   : return bitc::CAST_TRUNC;
66  case Instruction::ZExt    : return bitc::CAST_ZEXT;
67  case Instruction::SExt    : return bitc::CAST_SEXT;
68  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
69  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
70  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
71  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
72  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
73  case Instruction::FPExt   : return bitc::CAST_FPEXT;
74  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
75  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
76  case Instruction::BitCast : return bitc::CAST_BITCAST;
77  }
78}
79
80static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
81  switch (Opcode) {
82  default: llvm_unreachable("Unknown binary instruction!");
83  case Instruction::Add:
84  case Instruction::FAdd: return bitc::BINOP_ADD;
85  case Instruction::Sub:
86  case Instruction::FSub: return bitc::BINOP_SUB;
87  case Instruction::Mul:
88  case Instruction::FMul: return bitc::BINOP_MUL;
89  case Instruction::UDiv: return bitc::BINOP_UDIV;
90  case Instruction::FDiv:
91  case Instruction::SDiv: return bitc::BINOP_SDIV;
92  case Instruction::URem: return bitc::BINOP_UREM;
93  case Instruction::FRem:
94  case Instruction::SRem: return bitc::BINOP_SREM;
95  case Instruction::Shl:  return bitc::BINOP_SHL;
96  case Instruction::LShr: return bitc::BINOP_LSHR;
97  case Instruction::AShr: return bitc::BINOP_ASHR;
98  case Instruction::And:  return bitc::BINOP_AND;
99  case Instruction::Or:   return bitc::BINOP_OR;
100  case Instruction::Xor:  return bitc::BINOP_XOR;
101  }
102}
103
104
105
106static void WriteStringRecord(unsigned Code, const std::string &Str,
107                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
108  SmallVector<unsigned, 64> Vals;
109
110  // Code: [strchar x N]
111  for (unsigned i = 0, e = Str.size(); i != e; ++i)
112    Vals.push_back(Str[i]);
113
114  // Emit the finished record.
115  Stream.EmitRecord(Code, Vals, AbbrevToUse);
116}
117
118// Emit information about parameter attributes.
119static void WriteAttributeTable(const ValueEnumerator &VE,
120                                BitstreamWriter &Stream) {
121  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
122  if (Attrs.empty()) return;
123
124  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
125
126  SmallVector<uint64_t, 64> Record;
127  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
128    const AttrListPtr &A = Attrs[i];
129    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
130      const AttributeWithIndex &PAWI = A.getSlot(i);
131      Record.push_back(PAWI.Index);
132
133      // FIXME: remove in LLVM 3.0
134      // Store the alignment in the bitcode as a 16-bit raw value instead of a
135      // 5-bit log2 encoded value. Shift the bits above the alignment up by
136      // 11 bits.
137      uint64_t FauxAttr = PAWI.Attrs & 0xffff;
138      if (PAWI.Attrs & Attribute::Alignment)
139        FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
140      FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
141
142      Record.push_back(FauxAttr);
143    }
144
145    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
146    Record.clear();
147  }
148
149  Stream.ExitBlock();
150}
151
152/// WriteTypeTable - Write out the type table for a module.
153static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
154  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
155
156  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
157  SmallVector<uint64_t, 64> TypeVals;
158
159  // Abbrev for TYPE_CODE_POINTER.
160  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
161  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
162  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
163                            Log2_32_Ceil(VE.getTypes().size()+1)));
164  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
165  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
166
167  // Abbrev for TYPE_CODE_FUNCTION.
168  Abbv = new BitCodeAbbrev();
169  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
170  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
171  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
172  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
173  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
174                            Log2_32_Ceil(VE.getTypes().size()+1)));
175  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
176
177  // Abbrev for TYPE_CODE_STRUCT.
178  Abbv = new BitCodeAbbrev();
179  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
180  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
181  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
182  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
183                            Log2_32_Ceil(VE.getTypes().size()+1)));
184  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
185
186  // Abbrev for TYPE_CODE_ARRAY.
187  Abbv = new BitCodeAbbrev();
188  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
189  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
190  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
191                            Log2_32_Ceil(VE.getTypes().size()+1)));
192  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
193
194  // Emit an entry count so the reader can reserve space.
195  TypeVals.push_back(TypeList.size());
196  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
197  TypeVals.clear();
198
199  // Loop over all of the types, emitting each in turn.
200  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
201    const Type *T = TypeList[i].first;
202    int AbbrevToUse = 0;
203    unsigned Code = 0;
204
205    switch (T->getTypeID()) {
206    default: llvm_unreachable("Unknown type!");
207    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
208    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
209    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
210    case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
211    case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
212    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
213    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
214    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
215    case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
216    case Type::IntegerTyID:
217      // INTEGER: [width]
218      Code = bitc::TYPE_CODE_INTEGER;
219      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
220      break;
221    case Type::PointerTyID: {
222      const PointerType *PTy = cast<PointerType>(T);
223      // POINTER: [pointee type, address space]
224      Code = bitc::TYPE_CODE_POINTER;
225      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
226      unsigned AddressSpace = PTy->getAddressSpace();
227      TypeVals.push_back(AddressSpace);
228      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
229      break;
230    }
231    case Type::FunctionTyID: {
232      const FunctionType *FT = cast<FunctionType>(T);
233      // FUNCTION: [isvararg, attrid, retty, paramty x N]
234      Code = bitc::TYPE_CODE_FUNCTION;
235      TypeVals.push_back(FT->isVarArg());
236      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
237      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
238      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
239        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
240      AbbrevToUse = FunctionAbbrev;
241      break;
242    }
243    case Type::StructTyID: {
244      const StructType *ST = cast<StructType>(T);
245      // STRUCT: [ispacked, eltty x N]
246      Code = bitc::TYPE_CODE_STRUCT;
247      TypeVals.push_back(ST->isPacked());
248      // Output all of the element types.
249      for (StructType::element_iterator I = ST->element_begin(),
250           E = ST->element_end(); I != E; ++I)
251        TypeVals.push_back(VE.getTypeID(*I));
252      AbbrevToUse = StructAbbrev;
253      break;
254    }
255    case Type::ArrayTyID: {
256      const ArrayType *AT = cast<ArrayType>(T);
257      // ARRAY: [numelts, eltty]
258      Code = bitc::TYPE_CODE_ARRAY;
259      TypeVals.push_back(AT->getNumElements());
260      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
261      AbbrevToUse = ArrayAbbrev;
262      break;
263    }
264    case Type::VectorTyID: {
265      const VectorType *VT = cast<VectorType>(T);
266      // VECTOR [numelts, eltty]
267      Code = bitc::TYPE_CODE_VECTOR;
268      TypeVals.push_back(VT->getNumElements());
269      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
270      break;
271    }
272    }
273
274    // Emit the finished record.
275    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
276    TypeVals.clear();
277  }
278
279  Stream.ExitBlock();
280}
281
282static unsigned getEncodedLinkage(const GlobalValue *GV) {
283  switch (GV->getLinkage()) {
284  default: llvm_unreachable("Invalid linkage!");
285  case GlobalValue::GhostLinkage:  // Map ghost linkage onto external.
286  case GlobalValue::ExternalLinkage:            return 0;
287  case GlobalValue::WeakAnyLinkage:             return 1;
288  case GlobalValue::AppendingLinkage:           return 2;
289  case GlobalValue::InternalLinkage:            return 3;
290  case GlobalValue::LinkOnceAnyLinkage:         return 4;
291  case GlobalValue::DLLImportLinkage:           return 5;
292  case GlobalValue::DLLExportLinkage:           return 6;
293  case GlobalValue::ExternalWeakLinkage:        return 7;
294  case GlobalValue::CommonLinkage:              return 8;
295  case GlobalValue::PrivateLinkage:             return 9;
296  case GlobalValue::WeakODRLinkage:             return 10;
297  case GlobalValue::LinkOnceODRLinkage:         return 11;
298  case GlobalValue::AvailableExternallyLinkage: return 12;
299  case GlobalValue::LinkerPrivateLinkage:       return 13;
300  }
301}
302
303static unsigned getEncodedVisibility(const GlobalValue *GV) {
304  switch (GV->getVisibility()) {
305  default: llvm_unreachable("Invalid visibility!");
306  case GlobalValue::DefaultVisibility:   return 0;
307  case GlobalValue::HiddenVisibility:    return 1;
308  case GlobalValue::ProtectedVisibility: return 2;
309  }
310}
311
312// Emit top-level description of module, including target triple, inline asm,
313// descriptors for global variables, and function prototype info.
314static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
315                            BitstreamWriter &Stream) {
316  // Emit the list of dependent libraries for the Module.
317  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
318    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
319
320  // Emit various pieces of data attached to a module.
321  if (!M->getTargetTriple().empty())
322    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
323                      0/*TODO*/, Stream);
324  if (!M->getDataLayout().empty())
325    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
326                      0/*TODO*/, Stream);
327  if (!M->getModuleInlineAsm().empty())
328    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
329                      0/*TODO*/, Stream);
330
331  // Emit information about sections and GC, computing how many there are. Also
332  // compute the maximum alignment value.
333  std::map<std::string, unsigned> SectionMap;
334  std::map<std::string, unsigned> GCMap;
335  unsigned MaxAlignment = 0;
336  unsigned MaxGlobalType = 0;
337  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
338       GV != E; ++GV) {
339    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
340    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
341
342    if (!GV->hasSection()) continue;
343    // Give section names unique ID's.
344    unsigned &Entry = SectionMap[GV->getSection()];
345    if (Entry != 0) continue;
346    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
347                      0/*TODO*/, Stream);
348    Entry = SectionMap.size();
349  }
350  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
351    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
352    if (F->hasSection()) {
353      // Give section names unique ID's.
354      unsigned &Entry = SectionMap[F->getSection()];
355      if (!Entry) {
356        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
357                          0/*TODO*/, Stream);
358        Entry = SectionMap.size();
359      }
360    }
361    if (F->hasGC()) {
362      // Same for GC names.
363      unsigned &Entry = GCMap[F->getGC()];
364      if (!Entry) {
365        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
366                          0/*TODO*/, Stream);
367        Entry = GCMap.size();
368      }
369    }
370  }
371
372  // Emit abbrev for globals, now that we know # sections and max alignment.
373  unsigned SimpleGVarAbbrev = 0;
374  if (!M->global_empty()) {
375    // Add an abbrev for common globals with no visibility or thread localness.
376    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
377    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
378    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
379                              Log2_32_Ceil(MaxGlobalType+1)));
380    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
381    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
382    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
383    if (MaxAlignment == 0)                                      // Alignment.
384      Abbv->Add(BitCodeAbbrevOp(0));
385    else {
386      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
387      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
388                               Log2_32_Ceil(MaxEncAlignment+1)));
389    }
390    if (SectionMap.empty())                                    // Section.
391      Abbv->Add(BitCodeAbbrevOp(0));
392    else
393      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
394                               Log2_32_Ceil(SectionMap.size()+1)));
395    // Don't bother emitting vis + thread local.
396    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
397  }
398
399  // Emit the global variable information.
400  SmallVector<unsigned, 64> Vals;
401  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
402       GV != E; ++GV) {
403    unsigned AbbrevToUse = 0;
404
405    // GLOBALVAR: [type, isconst, initid,
406    //             linkage, alignment, section, visibility, threadlocal]
407    Vals.push_back(VE.getTypeID(GV->getType()));
408    Vals.push_back(GV->isConstant());
409    Vals.push_back(GV->isDeclaration() ? 0 :
410                   (VE.getValueID(GV->getInitializer()) + 1));
411    Vals.push_back(getEncodedLinkage(GV));
412    Vals.push_back(Log2_32(GV->getAlignment())+1);
413    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
414    if (GV->isThreadLocal() ||
415        GV->getVisibility() != GlobalValue::DefaultVisibility) {
416      Vals.push_back(getEncodedVisibility(GV));
417      Vals.push_back(GV->isThreadLocal());
418    } else {
419      AbbrevToUse = SimpleGVarAbbrev;
420    }
421
422    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
423    Vals.clear();
424  }
425
426  // Emit the function proto information.
427  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
428    // FUNCTION:  [type, callingconv, isproto, paramattr,
429    //             linkage, alignment, section, visibility, gc]
430    Vals.push_back(VE.getTypeID(F->getType()));
431    Vals.push_back(F->getCallingConv());
432    Vals.push_back(F->isDeclaration());
433    Vals.push_back(getEncodedLinkage(F));
434    Vals.push_back(VE.getAttributeID(F->getAttributes()));
435    Vals.push_back(Log2_32(F->getAlignment())+1);
436    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
437    Vals.push_back(getEncodedVisibility(F));
438    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
439
440    unsigned AbbrevToUse = 0;
441    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
442    Vals.clear();
443  }
444
445
446  // Emit the alias information.
447  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
448       AI != E; ++AI) {
449    Vals.push_back(VE.getTypeID(AI->getType()));
450    Vals.push_back(VE.getValueID(AI->getAliasee()));
451    Vals.push_back(getEncodedLinkage(AI));
452    Vals.push_back(getEncodedVisibility(AI));
453    unsigned AbbrevToUse = 0;
454    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
455    Vals.clear();
456  }
457}
458
459static uint64_t GetOptimizationFlags(const Value *V) {
460  uint64_t Flags = 0;
461
462  if (const OverflowingBinaryOperator *OBO =
463        dyn_cast<OverflowingBinaryOperator>(V)) {
464    if (OBO->hasNoSignedWrap())
465      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
466    if (OBO->hasNoUnsignedWrap())
467      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
468  } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
469    if (Div->isExact())
470      Flags |= 1 << bitc::SDIV_EXACT;
471  }
472
473  return Flags;
474}
475
476static void WriteMDNode(const MDNode *N,
477                        const ValueEnumerator &VE,
478                        BitstreamWriter &Stream,
479                        SmallVector<uint64_t, 64> &Record) {
480  for (unsigned i = 0, e = N->getNumElements(); i != e; ++i) {
481    if (N->getElement(i)) {
482      Record.push_back(VE.getTypeID(N->getElement(i)->getType()));
483      Record.push_back(VE.getValueID(N->getElement(i)));
484    } else {
485      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
486      Record.push_back(0);
487    }
488  }
489  Stream.EmitRecord(bitc::METADATA_NODE, 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 (!StartedMetadataBlock) {
503        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
504        StartedMetadataBlock = true;
505      }
506      WriteMDNode(N, VE, Stream, Record);
507    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
508      if (!StartedMetadataBlock)  {
509        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
510
511        // Abbrev for METADATA_STRING.
512        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
513        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
514        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
515        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
516        MDSAbbrev = Stream.EmitAbbrev(Abbv);
517        StartedMetadataBlock = true;
518      }
519
520      // Code: [strchar x N]
521      Record.append(MDS->begin(), MDS->end());
522
523      // Emit the finished record.
524      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
525      Record.clear();
526    } else if (const NamedMDNode *NMD = dyn_cast<NamedMDNode>(Vals[i].first)) {
527      if (!StartedMetadataBlock)  {
528        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
529        StartedMetadataBlock = true;
530      }
531
532      // Write name.
533      std::string Str = NMD->getNameStr();
534      const char *StrBegin = Str.c_str();
535      for (unsigned i = 0, e = Str.length(); i != e; ++i)
536        Record.push_back(StrBegin[i]);
537      Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
538      Record.clear();
539
540      // Write named metadata elements.
541      for (unsigned i = 0, e = NMD->getNumElements(); i != e; ++i) {
542        if (NMD->getElement(i))
543          Record.push_back(VE.getValueID(NMD->getElement(i)));
544        else
545          Record.push_back(0);
546      }
547      Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
548      Record.clear();
549    }
550  }
551
552  if (StartedMetadataBlock)
553    Stream.ExitBlock();
554}
555
556static void WriteMetadataAttachment(const Function &F,
557                                    const ValueEnumerator &VE,
558                                    BitstreamWriter &Stream) {
559  bool StartedMetadataBlock = false;
560  SmallVector<uint64_t, 64> Record;
561
562  // Write metadata attachments
563  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
564  MetadataContext &TheMetadata = F.getContext().getMetadata();
565  typedef SmallVector<std::pair<unsigned, MDNode*>, 2> MDMapTy;
566  MDMapTy MDs;
567  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
568    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
569         I != E; ++I) {
570      MDs.clear();
571      TheMetadata.getMDs(I, MDs);
572      bool RecordedInstruction = false;
573      for (MDMapTy::const_iterator PI = MDs.begin(), PE = MDs.end();
574             PI != PE; ++PI) {
575        if (RecordedInstruction == false) {
576          Record.push_back(VE.getInstructionID(I));
577          RecordedInstruction = true;
578        }
579        Record.push_back(PI->first);
580        Record.push_back(VE.getValueID(PI->second));
581      }
582      if (!Record.empty()) {
583        if (!StartedMetadataBlock)  {
584          Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
585          StartedMetadataBlock = true;
586        }
587        Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
588        Record.clear();
589      }
590    }
591
592  if (StartedMetadataBlock)
593    Stream.ExitBlock();
594}
595
596static void WriteModuleMetadataStore(const Module *M,
597                                     const ValueEnumerator &VE,
598                                     BitstreamWriter &Stream) {
599
600  bool StartedMetadataBlock = false;
601  SmallVector<uint64_t, 64> Record;
602
603  // Write metadata kinds
604  // METADATA_KIND - [n x [id, name]]
605  MetadataContext &TheMetadata = M->getContext().getMetadata();
606  SmallVector<std::pair<unsigned, StringRef>, 4> Names;
607  TheMetadata.getHandlerNames(Names);
608  for (SmallVector<std::pair<unsigned, StringRef>, 4>::iterator
609         I = Names.begin(),
610         E = Names.end(); I != E; ++I) {
611    Record.push_back(I->first);
612    StringRef KName = I->second;
613    for (unsigned i = 0, e = KName.size(); i != e; ++i)
614      Record.push_back(KName[i]);
615    if (!StartedMetadataBlock)  {
616      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
617      StartedMetadataBlock = true;
618    }
619    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
620    Record.clear();
621  }
622
623  if (StartedMetadataBlock)
624    Stream.ExitBlock();
625}
626
627static void WriteConstants(unsigned FirstVal, unsigned LastVal,
628                           const ValueEnumerator &VE,
629                           BitstreamWriter &Stream, bool isGlobal) {
630  if (FirstVal == LastVal) return;
631
632  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
633
634  unsigned AggregateAbbrev = 0;
635  unsigned String8Abbrev = 0;
636  unsigned CString7Abbrev = 0;
637  unsigned CString6Abbrev = 0;
638  // If this is a constant pool for the module, emit module-specific abbrevs.
639  if (isGlobal) {
640    // Abbrev for CST_CODE_AGGREGATE.
641    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
642    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
643    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
644    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
645    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
646
647    // Abbrev for CST_CODE_STRING.
648    Abbv = new BitCodeAbbrev();
649    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
650    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
651    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
652    String8Abbrev = Stream.EmitAbbrev(Abbv);
653    // Abbrev for CST_CODE_CSTRING.
654    Abbv = new BitCodeAbbrev();
655    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
656    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
657    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
658    CString7Abbrev = Stream.EmitAbbrev(Abbv);
659    // Abbrev for CST_CODE_CSTRING.
660    Abbv = new BitCodeAbbrev();
661    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
662    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
663    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
664    CString6Abbrev = Stream.EmitAbbrev(Abbv);
665  }
666
667  SmallVector<uint64_t, 64> Record;
668
669  const ValueEnumerator::ValueList &Vals = VE.getValues();
670  const Type *LastTy = 0;
671  for (unsigned i = FirstVal; i != LastVal; ++i) {
672    const Value *V = Vals[i].first;
673    // If we need to switch types, do so now.
674    if (V->getType() != LastTy) {
675      LastTy = V->getType();
676      Record.push_back(VE.getTypeID(LastTy));
677      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
678                        CONSTANTS_SETTYPE_ABBREV);
679      Record.clear();
680    }
681
682    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
683      Record.push_back(unsigned(IA->hasSideEffects()) |
684                       unsigned(IA->isAlignStack()) << 1);
685
686      // Add the asm string.
687      const std::string &AsmStr = IA->getAsmString();
688      Record.push_back(AsmStr.size());
689      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
690        Record.push_back(AsmStr[i]);
691
692      // Add the constraint string.
693      const std::string &ConstraintStr = IA->getConstraintString();
694      Record.push_back(ConstraintStr.size());
695      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
696        Record.push_back(ConstraintStr[i]);
697      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
698      Record.clear();
699      continue;
700    }
701    const Constant *C = cast<Constant>(V);
702    unsigned Code = -1U;
703    unsigned AbbrevToUse = 0;
704    if (C->isNullValue()) {
705      Code = bitc::CST_CODE_NULL;
706    } else if (isa<UndefValue>(C)) {
707      Code = bitc::CST_CODE_UNDEF;
708    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
709      if (IV->getBitWidth() <= 64) {
710        int64_t V = IV->getSExtValue();
711        if (V >= 0)
712          Record.push_back(V << 1);
713        else
714          Record.push_back((-V << 1) | 1);
715        Code = bitc::CST_CODE_INTEGER;
716        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
717      } else {                             // Wide integers, > 64 bits in size.
718        // We have an arbitrary precision integer value to write whose
719        // bit width is > 64. However, in canonical unsigned integer
720        // format it is likely that the high bits are going to be zero.
721        // So, we only write the number of active words.
722        unsigned NWords = IV->getValue().getActiveWords();
723        const uint64_t *RawWords = IV->getValue().getRawData();
724        for (unsigned i = 0; i != NWords; ++i) {
725          int64_t V = RawWords[i];
726          if (V >= 0)
727            Record.push_back(V << 1);
728          else
729            Record.push_back((-V << 1) | 1);
730        }
731        Code = bitc::CST_CODE_WIDE_INTEGER;
732      }
733    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
734      Code = bitc::CST_CODE_FLOAT;
735      const Type *Ty = CFP->getType();
736      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
737        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
738      } else if (Ty->isX86_FP80Ty()) {
739        // api needed to prevent premature destruction
740        // bits are not in the same order as a normal i80 APInt, compensate.
741        APInt api = CFP->getValueAPF().bitcastToAPInt();
742        const uint64_t *p = api.getRawData();
743        Record.push_back((p[1] << 48) | (p[0] >> 16));
744        Record.push_back(p[0] & 0xffffLL);
745      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
746        APInt api = CFP->getValueAPF().bitcastToAPInt();
747        const uint64_t *p = api.getRawData();
748        Record.push_back(p[0]);
749        Record.push_back(p[1]);
750      } else {
751        assert (0 && "Unknown FP type!");
752      }
753    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
754      const ConstantArray *CA = cast<ConstantArray>(C);
755      // Emit constant strings specially.
756      unsigned NumOps = CA->getNumOperands();
757      // If this is a null-terminated string, use the denser CSTRING encoding.
758      if (CA->getOperand(NumOps-1)->isNullValue()) {
759        Code = bitc::CST_CODE_CSTRING;
760        --NumOps;  // Don't encode the null, which isn't allowed by char6.
761      } else {
762        Code = bitc::CST_CODE_STRING;
763        AbbrevToUse = String8Abbrev;
764      }
765      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
766      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
767      for (unsigned i = 0; i != NumOps; ++i) {
768        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
769        Record.push_back(V);
770        isCStr7 &= (V & 128) == 0;
771        if (isCStrChar6)
772          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
773      }
774
775      if (isCStrChar6)
776        AbbrevToUse = CString6Abbrev;
777      else if (isCStr7)
778        AbbrevToUse = CString7Abbrev;
779    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
780               isa<ConstantVector>(V)) {
781      Code = bitc::CST_CODE_AGGREGATE;
782      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
783        Record.push_back(VE.getValueID(C->getOperand(i)));
784      AbbrevToUse = AggregateAbbrev;
785    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
786      switch (CE->getOpcode()) {
787      default:
788        if (Instruction::isCast(CE->getOpcode())) {
789          Code = bitc::CST_CODE_CE_CAST;
790          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
791          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
792          Record.push_back(VE.getValueID(C->getOperand(0)));
793          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
794        } else {
795          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
796          Code = bitc::CST_CODE_CE_BINOP;
797          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
798          Record.push_back(VE.getValueID(C->getOperand(0)));
799          Record.push_back(VE.getValueID(C->getOperand(1)));
800          uint64_t Flags = GetOptimizationFlags(CE);
801          if (Flags != 0)
802            Record.push_back(Flags);
803        }
804        break;
805      case Instruction::GetElementPtr:
806        Code = bitc::CST_CODE_CE_GEP;
807        if (cast<GEPOperator>(C)->isInBounds())
808          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
809        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
810          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
811          Record.push_back(VE.getValueID(C->getOperand(i)));
812        }
813        break;
814      case Instruction::Select:
815        Code = bitc::CST_CODE_CE_SELECT;
816        Record.push_back(VE.getValueID(C->getOperand(0)));
817        Record.push_back(VE.getValueID(C->getOperand(1)));
818        Record.push_back(VE.getValueID(C->getOperand(2)));
819        break;
820      case Instruction::ExtractElement:
821        Code = bitc::CST_CODE_CE_EXTRACTELT;
822        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
823        Record.push_back(VE.getValueID(C->getOperand(0)));
824        Record.push_back(VE.getValueID(C->getOperand(1)));
825        break;
826      case Instruction::InsertElement:
827        Code = bitc::CST_CODE_CE_INSERTELT;
828        Record.push_back(VE.getValueID(C->getOperand(0)));
829        Record.push_back(VE.getValueID(C->getOperand(1)));
830        Record.push_back(VE.getValueID(C->getOperand(2)));
831        break;
832      case Instruction::ShuffleVector:
833        // If the return type and argument types are the same, this is a
834        // standard shufflevector instruction.  If the types are different,
835        // then the shuffle is widening or truncating the input vectors, and
836        // the argument type must also be encoded.
837        if (C->getType() == C->getOperand(0)->getType()) {
838          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
839        } else {
840          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
841          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
842        }
843        Record.push_back(VE.getValueID(C->getOperand(0)));
844        Record.push_back(VE.getValueID(C->getOperand(1)));
845        Record.push_back(VE.getValueID(C->getOperand(2)));
846        break;
847      case Instruction::ICmp:
848      case Instruction::FCmp:
849        Code = bitc::CST_CODE_CE_CMP;
850        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
851        Record.push_back(VE.getValueID(C->getOperand(0)));
852        Record.push_back(VE.getValueID(C->getOperand(1)));
853        Record.push_back(CE->getPredicate());
854        break;
855      }
856    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
857      assert(BA->getFunction() == BA->getBasicBlock()->getParent() &&
858             "Malformed blockaddress");
859      Code = bitc::CST_CODE_BLOCKADDRESS;
860      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
861      Record.push_back(VE.getValueID(BA->getFunction()));
862      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
863    } else {
864      llvm_unreachable("Unknown constant!");
865    }
866    Stream.EmitRecord(Code, Record, AbbrevToUse);
867    Record.clear();
868  }
869
870  Stream.ExitBlock();
871}
872
873static void WriteModuleConstants(const ValueEnumerator &VE,
874                                 BitstreamWriter &Stream) {
875  const ValueEnumerator::ValueList &Vals = VE.getValues();
876
877  // Find the first constant to emit, which is the first non-globalvalue value.
878  // We know globalvalues have been emitted by WriteModuleInfo.
879  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
880    if (!isa<GlobalValue>(Vals[i].first)) {
881      WriteConstants(i, Vals.size(), VE, Stream, true);
882      return;
883    }
884  }
885}
886
887/// PushValueAndType - The file has to encode both the value and type id for
888/// many values, because we need to know what type to create for forward
889/// references.  However, most operands are not forward references, so this type
890/// field is not needed.
891///
892/// This function adds V's value ID to Vals.  If the value ID is higher than the
893/// instruction ID, then it is a forward reference, and it also includes the
894/// type ID.
895static bool PushValueAndType(const Value *V, unsigned InstID,
896                             SmallVector<unsigned, 64> &Vals,
897                             ValueEnumerator &VE) {
898  unsigned ValID = VE.getValueID(V);
899  Vals.push_back(ValID);
900  if (ValID >= InstID) {
901    Vals.push_back(VE.getTypeID(V->getType()));
902    return true;
903  }
904  return false;
905}
906
907/// WriteInstruction - Emit an instruction to the specified stream.
908static void WriteInstruction(const Instruction &I, unsigned InstID,
909                             ValueEnumerator &VE, BitstreamWriter &Stream,
910                             SmallVector<unsigned, 64> &Vals) {
911  unsigned Code = 0;
912  unsigned AbbrevToUse = 0;
913  VE.setInstructionID(&I);
914  switch (I.getOpcode()) {
915  default:
916    if (Instruction::isCast(I.getOpcode())) {
917      Code = bitc::FUNC_CODE_INST_CAST;
918      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
919        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
920      Vals.push_back(VE.getTypeID(I.getType()));
921      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
922    } else {
923      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
924      Code = bitc::FUNC_CODE_INST_BINOP;
925      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
926        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
927      Vals.push_back(VE.getValueID(I.getOperand(1)));
928      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
929      uint64_t Flags = GetOptimizationFlags(&I);
930      if (Flags != 0) {
931        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
932          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
933        Vals.push_back(Flags);
934      }
935    }
936    break;
937
938  case Instruction::GetElementPtr:
939    Code = bitc::FUNC_CODE_INST_GEP;
940    if (cast<GEPOperator>(&I)->isInBounds())
941      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
942    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
943      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
944    break;
945  case Instruction::ExtractValue: {
946    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
947    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
948    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
949    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
950      Vals.push_back(*i);
951    break;
952  }
953  case Instruction::InsertValue: {
954    Code = bitc::FUNC_CODE_INST_INSERTVAL;
955    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
956    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
957    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
958    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
959      Vals.push_back(*i);
960    break;
961  }
962  case Instruction::Select:
963    Code = bitc::FUNC_CODE_INST_VSELECT;
964    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
965    Vals.push_back(VE.getValueID(I.getOperand(2)));
966    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
967    break;
968  case Instruction::ExtractElement:
969    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
970    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
971    Vals.push_back(VE.getValueID(I.getOperand(1)));
972    break;
973  case Instruction::InsertElement:
974    Code = bitc::FUNC_CODE_INST_INSERTELT;
975    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
976    Vals.push_back(VE.getValueID(I.getOperand(1)));
977    Vals.push_back(VE.getValueID(I.getOperand(2)));
978    break;
979  case Instruction::ShuffleVector:
980    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
981    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
982    Vals.push_back(VE.getValueID(I.getOperand(1)));
983    Vals.push_back(VE.getValueID(I.getOperand(2)));
984    break;
985  case Instruction::ICmp:
986  case Instruction::FCmp:
987    // compare returning Int1Ty or vector of Int1Ty
988    Code = bitc::FUNC_CODE_INST_CMP2;
989    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
990    Vals.push_back(VE.getValueID(I.getOperand(1)));
991    Vals.push_back(cast<CmpInst>(I).getPredicate());
992    break;
993
994  case Instruction::Ret:
995    {
996      Code = bitc::FUNC_CODE_INST_RET;
997      unsigned NumOperands = I.getNumOperands();
998      if (NumOperands == 0)
999        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1000      else if (NumOperands == 1) {
1001        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1002          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1003      } else {
1004        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1005          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1006      }
1007    }
1008    break;
1009  case Instruction::Br:
1010    {
1011      Code = bitc::FUNC_CODE_INST_BR;
1012      BranchInst &II = cast<BranchInst>(I);
1013      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1014      if (II.isConditional()) {
1015        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1016        Vals.push_back(VE.getValueID(II.getCondition()));
1017      }
1018    }
1019    break;
1020  case Instruction::Switch:
1021    Code = bitc::FUNC_CODE_INST_SWITCH;
1022    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1023    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1024      Vals.push_back(VE.getValueID(I.getOperand(i)));
1025    break;
1026  case Instruction::IndirectBr:
1027    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1028    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1029    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1030      Vals.push_back(VE.getValueID(I.getOperand(i)));
1031    break;
1032
1033  case Instruction::Invoke: {
1034    const InvokeInst *II = cast<InvokeInst>(&I);
1035    const Value *Callee(II->getCalledValue());
1036    const PointerType *PTy = cast<PointerType>(Callee->getType());
1037    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1038    Code = bitc::FUNC_CODE_INST_INVOKE;
1039
1040    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1041    Vals.push_back(II->getCallingConv());
1042    Vals.push_back(VE.getValueID(II->getNormalDest()));
1043    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1044    PushValueAndType(Callee, InstID, Vals, VE);
1045
1046    // Emit value #'s for the fixed parameters.
1047    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1048      Vals.push_back(VE.getValueID(I.getOperand(i+3)));  // fixed param.
1049
1050    // Emit type/value pairs for varargs params.
1051    if (FTy->isVarArg()) {
1052      for (unsigned i = 3+FTy->getNumParams(), e = I.getNumOperands();
1053           i != e; ++i)
1054        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1055    }
1056    break;
1057  }
1058  case Instruction::Unwind:
1059    Code = bitc::FUNC_CODE_INST_UNWIND;
1060    break;
1061  case Instruction::Unreachable:
1062    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1063    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1064    break;
1065
1066  case Instruction::PHI:
1067    Code = bitc::FUNC_CODE_INST_PHI;
1068    Vals.push_back(VE.getTypeID(I.getType()));
1069    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1070      Vals.push_back(VE.getValueID(I.getOperand(i)));
1071    break;
1072
1073  case Instruction::Alloca:
1074    Code = bitc::FUNC_CODE_INST_ALLOCA;
1075    Vals.push_back(VE.getTypeID(I.getType()));
1076    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1077    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1078    break;
1079
1080  case Instruction::Load:
1081    Code = bitc::FUNC_CODE_INST_LOAD;
1082    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1083      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1084
1085    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1086    Vals.push_back(cast<LoadInst>(I).isVolatile());
1087    break;
1088  case Instruction::Store:
1089    Code = bitc::FUNC_CODE_INST_STORE2;
1090    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1091    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1092    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1093    Vals.push_back(cast<StoreInst>(I).isVolatile());
1094    break;
1095  case Instruction::Call: {
1096    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
1097    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1098
1099    Code = bitc::FUNC_CODE_INST_CALL;
1100
1101    const CallInst *CI = cast<CallInst>(&I);
1102    Vals.push_back(VE.getAttributeID(CI->getAttributes()));
1103    Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
1104    PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
1105
1106    // Emit value #'s for the fixed parameters.
1107    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1108      Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
1109
1110    // Emit type/value pairs for varargs params.
1111    if (FTy->isVarArg()) {
1112      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
1113      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
1114           i != e; ++i)
1115        PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
1116    }
1117    break;
1118  }
1119  case Instruction::VAArg:
1120    Code = bitc::FUNC_CODE_INST_VAARG;
1121    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1122    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1123    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1124    break;
1125  }
1126
1127  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1128  Vals.clear();
1129}
1130
1131// Emit names for globals/functions etc.
1132static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1133                                  const ValueEnumerator &VE,
1134                                  BitstreamWriter &Stream) {
1135  if (VST.empty()) return;
1136  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1137
1138  // FIXME: Set up the abbrev, we know how many values there are!
1139  // FIXME: We know if the type names can use 7-bit ascii.
1140  SmallVector<unsigned, 64> NameVals;
1141
1142  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1143       SI != SE; ++SI) {
1144
1145    const ValueName &Name = *SI;
1146
1147    // Figure out the encoding to use for the name.
1148    bool is7Bit = true;
1149    bool isChar6 = true;
1150    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1151         C != E; ++C) {
1152      if (isChar6)
1153        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1154      if ((unsigned char)*C & 128) {
1155        is7Bit = false;
1156        break;  // don't bother scanning the rest.
1157      }
1158    }
1159
1160    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1161
1162    // VST_ENTRY:   [valueid, namechar x N]
1163    // VST_BBENTRY: [bbid, namechar x N]
1164    unsigned Code;
1165    if (isa<BasicBlock>(SI->getValue())) {
1166      Code = bitc::VST_CODE_BBENTRY;
1167      if (isChar6)
1168        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1169    } else {
1170      Code = bitc::VST_CODE_ENTRY;
1171      if (isChar6)
1172        AbbrevToUse = VST_ENTRY_6_ABBREV;
1173      else if (is7Bit)
1174        AbbrevToUse = VST_ENTRY_7_ABBREV;
1175    }
1176
1177    NameVals.push_back(VE.getValueID(SI->getValue()));
1178    for (const char *P = Name.getKeyData(),
1179         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1180      NameVals.push_back((unsigned char)*P);
1181
1182    // Emit the finished record.
1183    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1184    NameVals.clear();
1185  }
1186  Stream.ExitBlock();
1187}
1188
1189/// WriteFunction - Emit a function body to the module stream.
1190static void WriteFunction(const Function &F, ValueEnumerator &VE,
1191                          BitstreamWriter &Stream) {
1192  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1193  VE.incorporateFunction(F);
1194
1195  SmallVector<unsigned, 64> Vals;
1196
1197  // Emit the number of basic blocks, so the reader can create them ahead of
1198  // time.
1199  Vals.push_back(VE.getBasicBlocks().size());
1200  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1201  Vals.clear();
1202
1203  // If there are function-local constants, emit them now.
1204  unsigned CstStart, CstEnd;
1205  VE.getFunctionConstantRange(CstStart, CstEnd);
1206  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1207
1208  // Keep a running idea of what the instruction ID is.
1209  unsigned InstID = CstEnd;
1210
1211  // Finally, emit all the instructions, in order.
1212  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1213    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1214         I != E; ++I) {
1215      WriteInstruction(*I, InstID, VE, Stream, Vals);
1216      if (I->getType() != Type::getVoidTy(F.getContext()))
1217        ++InstID;
1218    }
1219
1220  // Emit names for all the instructions etc.
1221  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1222
1223  WriteMetadataAttachment(F, VE, Stream);
1224  VE.purgeFunction();
1225  Stream.ExitBlock();
1226}
1227
1228/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1229static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1230                                 const ValueEnumerator &VE,
1231                                 BitstreamWriter &Stream) {
1232  if (TST.empty()) return;
1233
1234  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1235
1236  // 7-bit fixed width VST_CODE_ENTRY strings.
1237  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1238  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1239  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1240                            Log2_32_Ceil(VE.getTypes().size()+1)));
1241  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1242  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1243  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1244
1245  SmallVector<unsigned, 64> NameVals;
1246
1247  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1248       TI != TE; ++TI) {
1249    // TST_ENTRY: [typeid, namechar x N]
1250    NameVals.push_back(VE.getTypeID(TI->second));
1251
1252    const std::string &Str = TI->first;
1253    bool is7Bit = true;
1254    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1255      NameVals.push_back((unsigned char)Str[i]);
1256      if (Str[i] & 128)
1257        is7Bit = false;
1258    }
1259
1260    // Emit the finished record.
1261    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1262    NameVals.clear();
1263  }
1264
1265  Stream.ExitBlock();
1266}
1267
1268// Emit blockinfo, which defines the standard abbreviations etc.
1269static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1270  // We only want to emit block info records for blocks that have multiple
1271  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1272  // blocks can defined their abbrevs inline.
1273  Stream.EnterBlockInfoBlock(2);
1274
1275  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1276    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1277    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1278    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1279    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1280    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1281    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1282                                   Abbv) != VST_ENTRY_8_ABBREV)
1283      llvm_unreachable("Unexpected abbrev ordering!");
1284  }
1285
1286  { // 7-bit fixed width VST_ENTRY strings.
1287    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1288    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1289    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1290    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1291    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1292    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1293                                   Abbv) != VST_ENTRY_7_ABBREV)
1294      llvm_unreachable("Unexpected abbrev ordering!");
1295  }
1296  { // 6-bit char6 VST_ENTRY strings.
1297    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1298    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1299    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1300    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1301    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1302    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1303                                   Abbv) != VST_ENTRY_6_ABBREV)
1304      llvm_unreachable("Unexpected abbrev ordering!");
1305  }
1306  { // 6-bit char6 VST_BBENTRY strings.
1307    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1308    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1309    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1310    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1311    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1312    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1313                                   Abbv) != VST_BBENTRY_6_ABBREV)
1314      llvm_unreachable("Unexpected abbrev ordering!");
1315  }
1316
1317
1318
1319  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1320    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1321    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1322    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1323                              Log2_32_Ceil(VE.getTypes().size()+1)));
1324    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1325                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1326      llvm_unreachable("Unexpected abbrev ordering!");
1327  }
1328
1329  { // INTEGER abbrev for CONSTANTS_BLOCK.
1330    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1331    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1332    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1333    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1334                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1335      llvm_unreachable("Unexpected abbrev ordering!");
1336  }
1337
1338  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1339    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1340    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1341    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1342    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1343                              Log2_32_Ceil(VE.getTypes().size()+1)));
1344    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1345
1346    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1347                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1348      llvm_unreachable("Unexpected abbrev ordering!");
1349  }
1350  { // NULL abbrev for CONSTANTS_BLOCK.
1351    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1352    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1353    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1354                                   Abbv) != CONSTANTS_NULL_Abbrev)
1355      llvm_unreachable("Unexpected abbrev ordering!");
1356  }
1357
1358  // FIXME: This should only use space for first class types!
1359
1360  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1361    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1362    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1363    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1364    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1365    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1366    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1367                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1368      llvm_unreachable("Unexpected abbrev ordering!");
1369  }
1370  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1371    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1372    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1373    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1374    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1375    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1376    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1377                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1378      llvm_unreachable("Unexpected abbrev ordering!");
1379  }
1380  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1381    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1382    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1383    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1384    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1385    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1386    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1387    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1388                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1389      llvm_unreachable("Unexpected abbrev ordering!");
1390  }
1391  { // INST_CAST abbrev for FUNCTION_BLOCK.
1392    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1393    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1394    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1395    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1396                              Log2_32_Ceil(VE.getTypes().size()+1)));
1397    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1398    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1399                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1400      llvm_unreachable("Unexpected abbrev ordering!");
1401  }
1402
1403  { // INST_RET abbrev for FUNCTION_BLOCK.
1404    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1405    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1406    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1407                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1408      llvm_unreachable("Unexpected abbrev ordering!");
1409  }
1410  { // INST_RET abbrev for FUNCTION_BLOCK.
1411    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1412    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1413    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1414    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1415                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1416      llvm_unreachable("Unexpected abbrev ordering!");
1417  }
1418  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1419    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1420    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1421    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1422                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1423      llvm_unreachable("Unexpected abbrev ordering!");
1424  }
1425
1426  Stream.ExitBlock();
1427}
1428
1429
1430/// WriteModule - Emit the specified module to the bitstream.
1431static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1432  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1433
1434  // Emit the version number if it is non-zero.
1435  if (CurVersion) {
1436    SmallVector<unsigned, 1> Vals;
1437    Vals.push_back(CurVersion);
1438    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1439  }
1440
1441  // Analyze the module, enumerating globals, functions, etc.
1442  ValueEnumerator VE(M);
1443
1444  // Emit blockinfo, which defines the standard abbreviations etc.
1445  WriteBlockInfo(VE, Stream);
1446
1447  // Emit information about parameter attributes.
1448  WriteAttributeTable(VE, Stream);
1449
1450  // Emit information describing all of the types in the module.
1451  WriteTypeTable(VE, Stream);
1452
1453  // Emit top-level description of module, including target triple, inline asm,
1454  // descriptors for global variables, and function prototype info.
1455  WriteModuleInfo(M, VE, Stream);
1456
1457  // Emit constants.
1458  WriteModuleConstants(VE, Stream);
1459
1460  // Emit metadata.
1461  WriteModuleMetadata(VE, Stream);
1462
1463  // Emit function bodies.
1464  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1465    if (!I->isDeclaration())
1466      WriteFunction(*I, VE, Stream);
1467
1468  // Emit metadata.
1469  WriteModuleMetadataStore(M, VE, Stream);
1470
1471  // Emit the type symbol table information.
1472  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1473
1474  // Emit names for globals/functions etc.
1475  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1476
1477  Stream.ExitBlock();
1478}
1479
1480/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1481/// header and trailer to make it compatible with the system archiver.  To do
1482/// this we emit the following header, and then emit a trailer that pads the
1483/// file out to be a multiple of 16 bytes.
1484///
1485/// struct bc_header {
1486///   uint32_t Magic;         // 0x0B17C0DE
1487///   uint32_t Version;       // Version, currently always 0.
1488///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1489///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1490///   uint32_t CPUType;       // CPU specifier.
1491///   ... potentially more later ...
1492/// };
1493enum {
1494  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1495  DarwinBCHeaderSize = 5*4
1496};
1497
1498static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1499                               const std::string &TT) {
1500  unsigned CPUType = ~0U;
1501
1502  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*.  The CPUType is a
1503  // magic number from /usr/include/mach/machine.h.  It is ok to reproduce the
1504  // specific constants here because they are implicitly part of the Darwin ABI.
1505  enum {
1506    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1507    DARWIN_CPU_TYPE_X86        = 7,
1508    DARWIN_CPU_TYPE_POWERPC    = 18
1509  };
1510
1511  if (TT.find("x86_64-") == 0)
1512    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1513  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1514           TT[4] == '-' && TT[1] - '3' < 6)
1515    CPUType = DARWIN_CPU_TYPE_X86;
1516  else if (TT.find("powerpc-") == 0)
1517    CPUType = DARWIN_CPU_TYPE_POWERPC;
1518  else if (TT.find("powerpc64-") == 0)
1519    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1520
1521  // Traditional Bitcode starts after header.
1522  unsigned BCOffset = DarwinBCHeaderSize;
1523
1524  Stream.Emit(0x0B17C0DE, 32);
1525  Stream.Emit(0         , 32);  // Version.
1526  Stream.Emit(BCOffset  , 32);
1527  Stream.Emit(0         , 32);  // Filled in later.
1528  Stream.Emit(CPUType   , 32);
1529}
1530
1531/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1532/// finalize the header.
1533static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1534  // Update the size field in the header.
1535  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1536
1537  // If the file is not a multiple of 16 bytes, insert dummy padding.
1538  while (BufferSize & 15) {
1539    Stream.Emit(0, 8);
1540    ++BufferSize;
1541  }
1542}
1543
1544
1545/// WriteBitcodeToFile - Write the specified module to the specified output
1546/// stream.
1547void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1548  std::vector<unsigned char> Buffer;
1549  BitstreamWriter Stream(Buffer);
1550
1551  Buffer.reserve(256*1024);
1552
1553  WriteBitcodeToStream( M, Stream );
1554
1555  // If writing to stdout, set binary mode.
1556  if (&llvm::outs() == &Out)
1557    sys::Program::ChangeStdoutToBinary();
1558
1559  // Write the generated bitstream to "Out".
1560  Out.write((char*)&Buffer.front(), Buffer.size());
1561
1562  // Make sure it hits disk now.
1563  Out.flush();
1564}
1565
1566/// WriteBitcodeToStream - Write the specified module to the specified output
1567/// stream.
1568void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1569  // If this is darwin, emit a file header and trailer if needed.
1570  bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1571  if (isDarwin)
1572    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1573
1574  // Emit the file header.
1575  Stream.Emit((unsigned)'B', 8);
1576  Stream.Emit((unsigned)'C', 8);
1577  Stream.Emit(0x0, 4);
1578  Stream.Emit(0xC, 4);
1579  Stream.Emit(0xE, 4);
1580  Stream.Emit(0xD, 4);
1581
1582  // Emit the module.
1583  WriteModule(M, Stream);
1584
1585  if (isDarwin)
1586    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1587}
1588