BitcodeWriter.cpp revision bb811a244567aa8a1522203f15588f4d001b7353 
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::X86_MMXTyID: Code = bitc::TYPE_CODE_X86_MMX; break;
215    case Type::IntegerTyID:
216      // INTEGER: [width]
217      Code = bitc::TYPE_CODE_INTEGER;
218      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
219      break;
220    case Type::PointerTyID: {
221      const PointerType *PTy = cast<PointerType>(T);
222      // POINTER: [pointee type, address space]
223      Code = bitc::TYPE_CODE_POINTER;
224      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
225      unsigned AddressSpace = PTy->getAddressSpace();
226      TypeVals.push_back(AddressSpace);
227      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
228      break;
229    }
230    case Type::FunctionTyID: {
231      const FunctionType *FT = cast<FunctionType>(T);
232      // FUNCTION: [isvararg, attrid, retty, paramty x N]
233      Code = bitc::TYPE_CODE_FUNCTION;
234      TypeVals.push_back(FT->isVarArg());
235      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
236      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
237      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
238        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
239      AbbrevToUse = FunctionAbbrev;
240      break;
241    }
242    case Type::StructTyID: {
243      const StructType *ST = cast<StructType>(T);
244      // STRUCT: [ispacked, eltty x N]
245      Code = bitc::TYPE_CODE_STRUCT;
246      TypeVals.push_back(ST->isPacked());
247      // Output all of the element types.
248      for (StructType::element_iterator I = ST->element_begin(),
249           E = ST->element_end(); I != E; ++I)
250        TypeVals.push_back(VE.getTypeID(*I));
251      AbbrevToUse = StructAbbrev;
252      break;
253    }
254    case Type::ArrayTyID: {
255      const ArrayType *AT = cast<ArrayType>(T);
256      // ARRAY: [numelts, eltty]
257      Code = bitc::TYPE_CODE_ARRAY;
258      TypeVals.push_back(AT->getNumElements());
259      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
260      AbbrevToUse = ArrayAbbrev;
261      break;
262    }
263    case Type::VectorTyID: {
264      const VectorType *VT = cast<VectorType>(T);
265      // VECTOR [numelts, eltty]
266      Code = bitc::TYPE_CODE_VECTOR;
267      TypeVals.push_back(VT->getNumElements());
268      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
269      break;
270    }
271    }
272
273    // Emit the finished record.
274    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
275    TypeVals.clear();
276  }
277
278  Stream.ExitBlock();
279}
280
281static unsigned getEncodedLinkage(const GlobalValue *GV) {
282  switch (GV->getLinkage()) {
283  default: llvm_unreachable("Invalid linkage!");
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  case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
299  case GlobalValue::LinkerPrivateWeakDefAutoLinkage: return 15;
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->getNumOperands(); i != e; ++i) {
481    if (N->getOperand(i)) {
482      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
483      Record.push_back(VE.getValueID(N->getOperand(i)));
484    } else {
485      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
486      Record.push_back(0);
487    }
488  }
489  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE2 :
490                                           bitc::METADATA_NODE2;
491  Stream.EmitRecord(MDCode, Record, 0);
492  Record.clear();
493}
494
495static void WriteModuleMetadata(const Module *M,
496                                const ValueEnumerator &VE,
497                                BitstreamWriter &Stream) {
498  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
499  bool StartedMetadataBlock = false;
500  unsigned MDSAbbrev = 0;
501  SmallVector<uint64_t, 64> Record;
502  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
503
504    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
505      if (!N->isFunctionLocal() || !N->getFunction()) {
506        if (!StartedMetadataBlock) {
507          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
508          StartedMetadataBlock = true;
509        }
510        WriteMDNode(N, VE, Stream, Record);
511      }
512    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
513      if (!StartedMetadataBlock)  {
514        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
515
516        // Abbrev for METADATA_STRING.
517        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
518        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
519        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
520        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
521        MDSAbbrev = Stream.EmitAbbrev(Abbv);
522        StartedMetadataBlock = true;
523      }
524
525      // Code: [strchar x N]
526      Record.append(MDS->begin(), MDS->end());
527
528      // Emit the finished record.
529      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
530      Record.clear();
531    }
532  }
533
534  // Write named metadata.
535  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
536       E = M->named_metadata_end(); I != E; ++I) {
537    const NamedMDNode *NMD = I;
538    if (!StartedMetadataBlock)  {
539      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
540      StartedMetadataBlock = true;
541    }
542
543    // Write name.
544    StringRef Str = NMD->getName();
545    for (unsigned i = 0, e = Str.size(); i != e; ++i)
546      Record.push_back(Str[i]);
547    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
548    Record.clear();
549
550    // Write named metadata operands.
551    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
552      Record.push_back(VE.getValueID(NMD->getOperand(i)));
553    Stream.EmitRecord(bitc::METADATA_NAMED_NODE2, Record, 0);
554    Record.clear();
555  }
556
557  if (StartedMetadataBlock)
558    Stream.ExitBlock();
559}
560
561static void WriteFunctionLocalMetadata(const Function &F,
562                                       const ValueEnumerator &VE,
563                                       BitstreamWriter &Stream) {
564  bool StartedMetadataBlock = false;
565  SmallVector<uint64_t, 64> Record;
566  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
567  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
568    if (const MDNode *N = Vals[i])
569      if (N->isFunctionLocal() && N->getFunction() == &F) {
570        if (!StartedMetadataBlock) {
571          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
572          StartedMetadataBlock = true;
573        }
574        WriteMDNode(N, VE, Stream, Record);
575      }
576
577  if (StartedMetadataBlock)
578    Stream.ExitBlock();
579}
580
581static void WriteMetadataAttachment(const Function &F,
582                                    const ValueEnumerator &VE,
583                                    BitstreamWriter &Stream) {
584  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
585
586  SmallVector<uint64_t, 64> Record;
587
588  // Write metadata attachments
589  // METADATA_ATTACHMENT2 - [m x [value, [n x [id, mdnode]]]
590  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
591
592  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
593    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
594         I != E; ++I) {
595      MDs.clear();
596      I->getAllMetadataOtherThanDebugLoc(MDs);
597
598      // If no metadata, ignore instruction.
599      if (MDs.empty()) continue;
600
601      Record.push_back(VE.getInstructionID(I));
602
603      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
604        Record.push_back(MDs[i].first);
605        Record.push_back(VE.getValueID(MDs[i].second));
606      }
607      Stream.EmitRecord(bitc::METADATA_ATTACHMENT2, Record, 0);
608      Record.clear();
609    }
610
611  Stream.ExitBlock();
612}
613
614static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
615  SmallVector<uint64_t, 64> Record;
616
617  // Write metadata kinds
618  // METADATA_KIND - [n x [id, name]]
619  SmallVector<StringRef, 4> Names;
620  M->getMDKindNames(Names);
621
622  if (Names.empty()) return;
623
624  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
625
626  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
627    Record.push_back(MDKindID);
628    StringRef KName = Names[MDKindID];
629    Record.append(KName.begin(), KName.end());
630
631    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
632    Record.clear();
633  }
634
635  Stream.ExitBlock();
636}
637
638static void WriteConstants(unsigned FirstVal, unsigned LastVal,
639                           const ValueEnumerator &VE,
640                           BitstreamWriter &Stream, bool isGlobal) {
641  if (FirstVal == LastVal) return;
642
643  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
644
645  unsigned AggregateAbbrev = 0;
646  unsigned String8Abbrev = 0;
647  unsigned CString7Abbrev = 0;
648  unsigned CString6Abbrev = 0;
649  // If this is a constant pool for the module, emit module-specific abbrevs.
650  if (isGlobal) {
651    // Abbrev for CST_CODE_AGGREGATE.
652    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
653    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
654    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
655    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
656    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
657
658    // Abbrev for CST_CODE_STRING.
659    Abbv = new BitCodeAbbrev();
660    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
661    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
662    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
663    String8Abbrev = Stream.EmitAbbrev(Abbv);
664    // Abbrev for CST_CODE_CSTRING.
665    Abbv = new BitCodeAbbrev();
666    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
667    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
668    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
669    CString7Abbrev = Stream.EmitAbbrev(Abbv);
670    // Abbrev for CST_CODE_CSTRING.
671    Abbv = new BitCodeAbbrev();
672    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
673    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
674    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
675    CString6Abbrev = Stream.EmitAbbrev(Abbv);
676  }
677
678  SmallVector<uint64_t, 64> Record;
679
680  const ValueEnumerator::ValueList &Vals = VE.getValues();
681  const Type *LastTy = 0;
682  for (unsigned i = FirstVal; i != LastVal; ++i) {
683    const Value *V = Vals[i].first;
684    // If we need to switch types, do so now.
685    if (V->getType() != LastTy) {
686      LastTy = V->getType();
687      Record.push_back(VE.getTypeID(LastTy));
688      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
689                        CONSTANTS_SETTYPE_ABBREV);
690      Record.clear();
691    }
692
693    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
694      Record.push_back(unsigned(IA->hasSideEffects()) |
695                       unsigned(IA->isAlignStack()) << 1);
696
697      // Add the asm string.
698      const std::string &AsmStr = IA->getAsmString();
699      Record.push_back(AsmStr.size());
700      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
701        Record.push_back(AsmStr[i]);
702
703      // Add the constraint string.
704      const std::string &ConstraintStr = IA->getConstraintString();
705      Record.push_back(ConstraintStr.size());
706      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
707        Record.push_back(ConstraintStr[i]);
708      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
709      Record.clear();
710      continue;
711    }
712    const Constant *C = cast<Constant>(V);
713    unsigned Code = -1U;
714    unsigned AbbrevToUse = 0;
715    if (C->isNullValue()) {
716      Code = bitc::CST_CODE_NULL;
717    } else if (isa<UndefValue>(C)) {
718      Code = bitc::CST_CODE_UNDEF;
719    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
720      if (IV->getBitWidth() <= 64) {
721        uint64_t V = IV->getSExtValue();
722        if ((int64_t)V >= 0)
723          Record.push_back(V << 1);
724        else
725          Record.push_back((-V << 1) | 1);
726        Code = bitc::CST_CODE_INTEGER;
727        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
728      } else {                             // Wide integers, > 64 bits in size.
729        // We have an arbitrary precision integer value to write whose
730        // bit width is > 64. However, in canonical unsigned integer
731        // format it is likely that the high bits are going to be zero.
732        // So, we only write the number of active words.
733        unsigned NWords = IV->getValue().getActiveWords();
734        const uint64_t *RawWords = IV->getValue().getRawData();
735        for (unsigned i = 0; i != NWords; ++i) {
736          int64_t V = RawWords[i];
737          if (V >= 0)
738            Record.push_back(V << 1);
739          else
740            Record.push_back((-V << 1) | 1);
741        }
742        Code = bitc::CST_CODE_WIDE_INTEGER;
743      }
744    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
745      Code = bitc::CST_CODE_FLOAT;
746      const Type *Ty = CFP->getType();
747      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
748        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
749      } else if (Ty->isX86_FP80Ty()) {
750        // api needed to prevent premature destruction
751        // bits are not in the same order as a normal i80 APInt, compensate.
752        APInt api = CFP->getValueAPF().bitcastToAPInt();
753        const uint64_t *p = api.getRawData();
754        Record.push_back((p[1] << 48) | (p[0] >> 16));
755        Record.push_back(p[0] & 0xffffLL);
756      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
757        APInt api = CFP->getValueAPF().bitcastToAPInt();
758        const uint64_t *p = api.getRawData();
759        Record.push_back(p[0]);
760        Record.push_back(p[1]);
761      } else {
762        assert (0 && "Unknown FP type!");
763      }
764    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
765      const ConstantArray *CA = cast<ConstantArray>(C);
766      // Emit constant strings specially.
767      unsigned NumOps = CA->getNumOperands();
768      // If this is a null-terminated string, use the denser CSTRING encoding.
769      if (CA->getOperand(NumOps-1)->isNullValue()) {
770        Code = bitc::CST_CODE_CSTRING;
771        --NumOps;  // Don't encode the null, which isn't allowed by char6.
772      } else {
773        Code = bitc::CST_CODE_STRING;
774        AbbrevToUse = String8Abbrev;
775      }
776      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
777      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
778      for (unsigned i = 0; i != NumOps; ++i) {
779        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
780        Record.push_back(V);
781        isCStr7 &= (V & 128) == 0;
782        if (isCStrChar6)
783          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
784      }
785
786      if (isCStrChar6)
787        AbbrevToUse = CString6Abbrev;
788      else if (isCStr7)
789        AbbrevToUse = CString7Abbrev;
790    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
791               isa<ConstantVector>(V)) {
792      Code = bitc::CST_CODE_AGGREGATE;
793      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
794        Record.push_back(VE.getValueID(C->getOperand(i)));
795      AbbrevToUse = AggregateAbbrev;
796    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
797      switch (CE->getOpcode()) {
798      default:
799        if (Instruction::isCast(CE->getOpcode())) {
800          Code = bitc::CST_CODE_CE_CAST;
801          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
802          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
803          Record.push_back(VE.getValueID(C->getOperand(0)));
804          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
805        } else {
806          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
807          Code = bitc::CST_CODE_CE_BINOP;
808          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
809          Record.push_back(VE.getValueID(C->getOperand(0)));
810          Record.push_back(VE.getValueID(C->getOperand(1)));
811          uint64_t Flags = GetOptimizationFlags(CE);
812          if (Flags != 0)
813            Record.push_back(Flags);
814        }
815        break;
816      case Instruction::GetElementPtr:
817        Code = bitc::CST_CODE_CE_GEP;
818        if (cast<GEPOperator>(C)->isInBounds())
819          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
820        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
821          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
822          Record.push_back(VE.getValueID(C->getOperand(i)));
823        }
824        break;
825      case Instruction::Select:
826        Code = bitc::CST_CODE_CE_SELECT;
827        Record.push_back(VE.getValueID(C->getOperand(0)));
828        Record.push_back(VE.getValueID(C->getOperand(1)));
829        Record.push_back(VE.getValueID(C->getOperand(2)));
830        break;
831      case Instruction::ExtractElement:
832        Code = bitc::CST_CODE_CE_EXTRACTELT;
833        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
834        Record.push_back(VE.getValueID(C->getOperand(0)));
835        Record.push_back(VE.getValueID(C->getOperand(1)));
836        break;
837      case Instruction::InsertElement:
838        Code = bitc::CST_CODE_CE_INSERTELT;
839        Record.push_back(VE.getValueID(C->getOperand(0)));
840        Record.push_back(VE.getValueID(C->getOperand(1)));
841        Record.push_back(VE.getValueID(C->getOperand(2)));
842        break;
843      case Instruction::ShuffleVector:
844        // If the return type and argument types are the same, this is a
845        // standard shufflevector instruction.  If the types are different,
846        // then the shuffle is widening or truncating the input vectors, and
847        // the argument type must also be encoded.
848        if (C->getType() == C->getOperand(0)->getType()) {
849          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
850        } else {
851          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
852          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
853        }
854        Record.push_back(VE.getValueID(C->getOperand(0)));
855        Record.push_back(VE.getValueID(C->getOperand(1)));
856        Record.push_back(VE.getValueID(C->getOperand(2)));
857        break;
858      case Instruction::ICmp:
859      case Instruction::FCmp:
860        Code = bitc::CST_CODE_CE_CMP;
861        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
862        Record.push_back(VE.getValueID(C->getOperand(0)));
863        Record.push_back(VE.getValueID(C->getOperand(1)));
864        Record.push_back(CE->getPredicate());
865        break;
866      }
867    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
868      assert(BA->getFunction() == BA->getBasicBlock()->getParent() &&
869             "Malformed blockaddress");
870      Code = bitc::CST_CODE_BLOCKADDRESS;
871      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
872      Record.push_back(VE.getValueID(BA->getFunction()));
873      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
874    } else {
875#ifndef NDEBUG
876      C->dump();
877#endif
878      llvm_unreachable("Unknown constant!");
879    }
880    Stream.EmitRecord(Code, Record, AbbrevToUse);
881    Record.clear();
882  }
883
884  Stream.ExitBlock();
885}
886
887static void WriteModuleConstants(const ValueEnumerator &VE,
888                                 BitstreamWriter &Stream) {
889  const ValueEnumerator::ValueList &Vals = VE.getValues();
890
891  // Find the first constant to emit, which is the first non-globalvalue value.
892  // We know globalvalues have been emitted by WriteModuleInfo.
893  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
894    if (!isa<GlobalValue>(Vals[i].first)) {
895      WriteConstants(i, Vals.size(), VE, Stream, true);
896      return;
897    }
898  }
899}
900
901/// PushValueAndType - The file has to encode both the value and type id for
902/// many values, because we need to know what type to create for forward
903/// references.  However, most operands are not forward references, so this type
904/// field is not needed.
905///
906/// This function adds V's value ID to Vals.  If the value ID is higher than the
907/// instruction ID, then it is a forward reference, and it also includes the
908/// type ID.
909static bool PushValueAndType(const Value *V, unsigned InstID,
910                             SmallVector<unsigned, 64> &Vals,
911                             ValueEnumerator &VE) {
912  unsigned ValID = VE.getValueID(V);
913  Vals.push_back(ValID);
914  if (ValID >= InstID) {
915    Vals.push_back(VE.getTypeID(V->getType()));
916    return true;
917  }
918  return false;
919}
920
921/// WriteInstruction - Emit an instruction to the specified stream.
922static void WriteInstruction(const Instruction &I, unsigned InstID,
923                             ValueEnumerator &VE, BitstreamWriter &Stream,
924                             SmallVector<unsigned, 64> &Vals) {
925  unsigned Code = 0;
926  unsigned AbbrevToUse = 0;
927  VE.setInstructionID(&I);
928  switch (I.getOpcode()) {
929  default:
930    if (Instruction::isCast(I.getOpcode())) {
931      Code = bitc::FUNC_CODE_INST_CAST;
932      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
933        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
934      Vals.push_back(VE.getTypeID(I.getType()));
935      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
936    } else {
937      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
938      Code = bitc::FUNC_CODE_INST_BINOP;
939      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
940        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
941      Vals.push_back(VE.getValueID(I.getOperand(1)));
942      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
943      uint64_t Flags = GetOptimizationFlags(&I);
944      if (Flags != 0) {
945        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
946          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
947        Vals.push_back(Flags);
948      }
949    }
950    break;
951
952  case Instruction::GetElementPtr:
953    Code = bitc::FUNC_CODE_INST_GEP;
954    if (cast<GEPOperator>(&I)->isInBounds())
955      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
956    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
957      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
958    break;
959  case Instruction::ExtractValue: {
960    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
961    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
962    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
963    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
964      Vals.push_back(*i);
965    break;
966  }
967  case Instruction::InsertValue: {
968    Code = bitc::FUNC_CODE_INST_INSERTVAL;
969    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
970    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
971    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
972    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
973      Vals.push_back(*i);
974    break;
975  }
976  case Instruction::Select:
977    Code = bitc::FUNC_CODE_INST_VSELECT;
978    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
979    Vals.push_back(VE.getValueID(I.getOperand(2)));
980    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
981    break;
982  case Instruction::ExtractElement:
983    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
984    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
985    Vals.push_back(VE.getValueID(I.getOperand(1)));
986    break;
987  case Instruction::InsertElement:
988    Code = bitc::FUNC_CODE_INST_INSERTELT;
989    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
990    Vals.push_back(VE.getValueID(I.getOperand(1)));
991    Vals.push_back(VE.getValueID(I.getOperand(2)));
992    break;
993  case Instruction::ShuffleVector:
994    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
995    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
996    Vals.push_back(VE.getValueID(I.getOperand(1)));
997    Vals.push_back(VE.getValueID(I.getOperand(2)));
998    break;
999  case Instruction::ICmp:
1000  case Instruction::FCmp:
1001    // compare returning Int1Ty or vector of Int1Ty
1002    Code = bitc::FUNC_CODE_INST_CMP2;
1003    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1004    Vals.push_back(VE.getValueID(I.getOperand(1)));
1005    Vals.push_back(cast<CmpInst>(I).getPredicate());
1006    break;
1007
1008  case Instruction::Ret:
1009    {
1010      Code = bitc::FUNC_CODE_INST_RET;
1011      unsigned NumOperands = I.getNumOperands();
1012      if (NumOperands == 0)
1013        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1014      else if (NumOperands == 1) {
1015        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1016          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1017      } else {
1018        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1019          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1020      }
1021    }
1022    break;
1023  case Instruction::Br:
1024    {
1025      Code = bitc::FUNC_CODE_INST_BR;
1026      BranchInst &II = cast<BranchInst>(I);
1027      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1028      if (II.isConditional()) {
1029        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1030        Vals.push_back(VE.getValueID(II.getCondition()));
1031      }
1032    }
1033    break;
1034  case Instruction::Switch:
1035    Code = bitc::FUNC_CODE_INST_SWITCH;
1036    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1037    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1038      Vals.push_back(VE.getValueID(I.getOperand(i)));
1039    break;
1040  case Instruction::IndirectBr:
1041    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1042    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1043    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1044      Vals.push_back(VE.getValueID(I.getOperand(i)));
1045    break;
1046
1047  case Instruction::Invoke: {
1048    const InvokeInst *II = cast<InvokeInst>(&I);
1049    const Value *Callee(II->getCalledValue());
1050    const PointerType *PTy = cast<PointerType>(Callee->getType());
1051    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1052    Code = bitc::FUNC_CODE_INST_INVOKE;
1053
1054    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1055    Vals.push_back(II->getCallingConv());
1056    Vals.push_back(VE.getValueID(II->getNormalDest()));
1057    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1058    PushValueAndType(Callee, InstID, Vals, VE);
1059
1060    // Emit value #'s for the fixed parameters.
1061    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1062      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1063
1064    // Emit type/value pairs for varargs params.
1065    if (FTy->isVarArg()) {
1066      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1067           i != e; ++i)
1068        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1069    }
1070    break;
1071  }
1072  case Instruction::Unwind:
1073    Code = bitc::FUNC_CODE_INST_UNWIND;
1074    break;
1075  case Instruction::Unreachable:
1076    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1077    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1078    break;
1079
1080  case Instruction::PHI:
1081    Code = bitc::FUNC_CODE_INST_PHI;
1082    Vals.push_back(VE.getTypeID(I.getType()));
1083    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1084      Vals.push_back(VE.getValueID(I.getOperand(i)));
1085    break;
1086
1087  case Instruction::Alloca:
1088    Code = bitc::FUNC_CODE_INST_ALLOCA;
1089    Vals.push_back(VE.getTypeID(I.getType()));
1090    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1091    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1092    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1093    break;
1094
1095  case Instruction::Load:
1096    Code = bitc::FUNC_CODE_INST_LOAD;
1097    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1098      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1099
1100    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1101    Vals.push_back(cast<LoadInst>(I).isVolatile());
1102    break;
1103  case Instruction::Store:
1104    Code = bitc::FUNC_CODE_INST_STORE2;
1105    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1106    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1107    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1108    Vals.push_back(cast<StoreInst>(I).isVolatile());
1109    break;
1110  case Instruction::Call: {
1111    const CallInst &CI = cast<CallInst>(I);
1112    const PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1113    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1114
1115    Code = bitc::FUNC_CODE_INST_CALL2;
1116
1117    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1118    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1119    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1120
1121    // Emit value #'s for the fixed parameters.
1122    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1123      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1124
1125    // Emit type/value pairs for varargs params.
1126    if (FTy->isVarArg()) {
1127      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1128           i != e; ++i)
1129        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1130    }
1131    break;
1132  }
1133  case Instruction::VAArg:
1134    Code = bitc::FUNC_CODE_INST_VAARG;
1135    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1136    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1137    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1138    break;
1139  }
1140
1141  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1142  Vals.clear();
1143}
1144
1145// Emit names for globals/functions etc.
1146static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1147                                  const ValueEnumerator &VE,
1148                                  BitstreamWriter &Stream) {
1149  if (VST.empty()) return;
1150  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1151
1152  // FIXME: Set up the abbrev, we know how many values there are!
1153  // FIXME: We know if the type names can use 7-bit ascii.
1154  SmallVector<unsigned, 64> NameVals;
1155
1156  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1157       SI != SE; ++SI) {
1158
1159    const ValueName &Name = *SI;
1160
1161    // Figure out the encoding to use for the name.
1162    bool is7Bit = true;
1163    bool isChar6 = true;
1164    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1165         C != E; ++C) {
1166      if (isChar6)
1167        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1168      if ((unsigned char)*C & 128) {
1169        is7Bit = false;
1170        break;  // don't bother scanning the rest.
1171      }
1172    }
1173
1174    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1175
1176    // VST_ENTRY:   [valueid, namechar x N]
1177    // VST_BBENTRY: [bbid, namechar x N]
1178    unsigned Code;
1179    if (isa<BasicBlock>(SI->getValue())) {
1180      Code = bitc::VST_CODE_BBENTRY;
1181      if (isChar6)
1182        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1183    } else {
1184      Code = bitc::VST_CODE_ENTRY;
1185      if (isChar6)
1186        AbbrevToUse = VST_ENTRY_6_ABBREV;
1187      else if (is7Bit)
1188        AbbrevToUse = VST_ENTRY_7_ABBREV;
1189    }
1190
1191    NameVals.push_back(VE.getValueID(SI->getValue()));
1192    for (const char *P = Name.getKeyData(),
1193         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1194      NameVals.push_back((unsigned char)*P);
1195
1196    // Emit the finished record.
1197    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1198    NameVals.clear();
1199  }
1200  Stream.ExitBlock();
1201}
1202
1203/// WriteFunction - Emit a function body to the module stream.
1204static void WriteFunction(const Function &F, ValueEnumerator &VE,
1205                          BitstreamWriter &Stream) {
1206  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1207  VE.incorporateFunction(F);
1208
1209  SmallVector<unsigned, 64> Vals;
1210
1211  // Emit the number of basic blocks, so the reader can create them ahead of
1212  // time.
1213  Vals.push_back(VE.getBasicBlocks().size());
1214  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1215  Vals.clear();
1216
1217  // If there are function-local constants, emit them now.
1218  unsigned CstStart, CstEnd;
1219  VE.getFunctionConstantRange(CstStart, CstEnd);
1220  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1221
1222  // If there is function-local metadata, emit it now.
1223  WriteFunctionLocalMetadata(F, VE, Stream);
1224
1225  // Keep a running idea of what the instruction ID is.
1226  unsigned InstID = CstEnd;
1227
1228  bool NeedsMetadataAttachment = false;
1229
1230  DebugLoc LastDL;
1231
1232  // Finally, emit all the instructions, in order.
1233  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1234    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1235         I != E; ++I) {
1236      WriteInstruction(*I, InstID, VE, Stream, Vals);
1237
1238      if (!I->getType()->isVoidTy())
1239        ++InstID;
1240
1241      // If the instruction has metadata, write a metadata attachment later.
1242      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1243
1244      // If the instruction has a debug location, emit it.
1245      DebugLoc DL = I->getDebugLoc();
1246      if (DL.isUnknown()) {
1247        // nothing todo.
1248      } else if (DL == LastDL) {
1249        // Just repeat the same debug loc as last time.
1250        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1251      } else {
1252        MDNode *Scope, *IA;
1253        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1254
1255        Vals.push_back(DL.getLine());
1256        Vals.push_back(DL.getCol());
1257        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1258        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1259        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC2, Vals);
1260        Vals.clear();
1261
1262        LastDL = DL;
1263      }
1264    }
1265
1266  // Emit names for all the instructions etc.
1267  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1268
1269  if (NeedsMetadataAttachment)
1270    WriteMetadataAttachment(F, VE, Stream);
1271  VE.purgeFunction();
1272  Stream.ExitBlock();
1273}
1274
1275/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1276static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1277                                 const ValueEnumerator &VE,
1278                                 BitstreamWriter &Stream) {
1279  if (TST.empty()) return;
1280
1281  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1282
1283  // 7-bit fixed width VST_CODE_ENTRY strings.
1284  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1285  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1286  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1287                            Log2_32_Ceil(VE.getTypes().size()+1)));
1288  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1289  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1290  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1291
1292  SmallVector<unsigned, 64> NameVals;
1293
1294  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1295       TI != TE; ++TI) {
1296    // TST_ENTRY: [typeid, namechar x N]
1297    NameVals.push_back(VE.getTypeID(TI->second));
1298
1299    const std::string &Str = TI->first;
1300    bool is7Bit = true;
1301    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1302      NameVals.push_back((unsigned char)Str[i]);
1303      if (Str[i] & 128)
1304        is7Bit = false;
1305    }
1306
1307    // Emit the finished record.
1308    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1309    NameVals.clear();
1310  }
1311
1312  Stream.ExitBlock();
1313}
1314
1315// Emit blockinfo, which defines the standard abbreviations etc.
1316static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1317  // We only want to emit block info records for blocks that have multiple
1318  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1319  // blocks can defined their abbrevs inline.
1320  Stream.EnterBlockInfoBlock(2);
1321
1322  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1323    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1324    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1325    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1326    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1327    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1328    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1329                                   Abbv) != VST_ENTRY_8_ABBREV)
1330      llvm_unreachable("Unexpected abbrev ordering!");
1331  }
1332
1333  { // 7-bit fixed width VST_ENTRY strings.
1334    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1335    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1336    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1337    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1338    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1339    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1340                                   Abbv) != VST_ENTRY_7_ABBREV)
1341      llvm_unreachable("Unexpected abbrev ordering!");
1342  }
1343  { // 6-bit char6 VST_ENTRY strings.
1344    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1345    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1346    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1347    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1348    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1349    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1350                                   Abbv) != VST_ENTRY_6_ABBREV)
1351      llvm_unreachable("Unexpected abbrev ordering!");
1352  }
1353  { // 6-bit char6 VST_BBENTRY strings.
1354    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1355    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1356    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1357    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1358    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1359    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1360                                   Abbv) != VST_BBENTRY_6_ABBREV)
1361      llvm_unreachable("Unexpected abbrev ordering!");
1362  }
1363
1364
1365
1366  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1367    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1368    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1369    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1370                              Log2_32_Ceil(VE.getTypes().size()+1)));
1371    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1372                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1373      llvm_unreachable("Unexpected abbrev ordering!");
1374  }
1375
1376  { // INTEGER abbrev for CONSTANTS_BLOCK.
1377    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1378    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1379    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1380    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1381                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1382      llvm_unreachable("Unexpected abbrev ordering!");
1383  }
1384
1385  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1386    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1387    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1388    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1389    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1390                              Log2_32_Ceil(VE.getTypes().size()+1)));
1391    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1392
1393    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1394                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1395      llvm_unreachable("Unexpected abbrev ordering!");
1396  }
1397  { // NULL abbrev for CONSTANTS_BLOCK.
1398    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1399    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1400    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1401                                   Abbv) != CONSTANTS_NULL_Abbrev)
1402      llvm_unreachable("Unexpected abbrev ordering!");
1403  }
1404
1405  // FIXME: This should only use space for first class types!
1406
1407  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1408    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1409    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1410    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1411    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1412    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1413    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1414                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1415      llvm_unreachable("Unexpected abbrev ordering!");
1416  }
1417  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1418    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1419    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1420    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1421    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1422    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1423    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1424                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1425      llvm_unreachable("Unexpected abbrev ordering!");
1426  }
1427  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1428    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1429    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1430    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1431    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1432    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1433    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1434    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1435                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1436      llvm_unreachable("Unexpected abbrev ordering!");
1437  }
1438  { // INST_CAST abbrev for FUNCTION_BLOCK.
1439    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1440    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1441    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1442    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1443                              Log2_32_Ceil(VE.getTypes().size()+1)));
1444    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1445    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1446                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1447      llvm_unreachable("Unexpected abbrev ordering!");
1448  }
1449
1450  { // INST_RET abbrev for FUNCTION_BLOCK.
1451    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1452    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1453    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1454                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1455      llvm_unreachable("Unexpected abbrev ordering!");
1456  }
1457  { // INST_RET abbrev for FUNCTION_BLOCK.
1458    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1459    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1460    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1461    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1462                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1463      llvm_unreachable("Unexpected abbrev ordering!");
1464  }
1465  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1466    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1467    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1468    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1469                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1470      llvm_unreachable("Unexpected abbrev ordering!");
1471  }
1472
1473  Stream.ExitBlock();
1474}
1475
1476
1477/// WriteModule - Emit the specified module to the bitstream.
1478static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1479  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1480
1481  // Emit the version number if it is non-zero.
1482  if (CurVersion) {
1483    SmallVector<unsigned, 1> Vals;
1484    Vals.push_back(CurVersion);
1485    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1486  }
1487
1488  // Analyze the module, enumerating globals, functions, etc.
1489  ValueEnumerator VE(M);
1490
1491  // Emit blockinfo, which defines the standard abbreviations etc.
1492  WriteBlockInfo(VE, Stream);
1493
1494  // Emit information about parameter attributes.
1495  WriteAttributeTable(VE, Stream);
1496
1497  // Emit information describing all of the types in the module.
1498  WriteTypeTable(VE, Stream);
1499
1500  // Emit top-level description of module, including target triple, inline asm,
1501  // descriptors for global variables, and function prototype info.
1502  WriteModuleInfo(M, VE, Stream);
1503
1504  // Emit constants.
1505  WriteModuleConstants(VE, Stream);
1506
1507  // Emit metadata.
1508  WriteModuleMetadata(M, VE, Stream);
1509
1510  // Emit function bodies.
1511  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1512    if (!I->isDeclaration())
1513      WriteFunction(*I, VE, Stream);
1514
1515  // Emit metadata.
1516  WriteModuleMetadataStore(M, Stream);
1517
1518  // Emit the type symbol table information.
1519  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1520
1521  // Emit names for globals/functions etc.
1522  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1523
1524  Stream.ExitBlock();
1525}
1526
1527/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1528/// header and trailer to make it compatible with the system archiver.  To do
1529/// this we emit the following header, and then emit a trailer that pads the
1530/// file out to be a multiple of 16 bytes.
1531///
1532/// struct bc_header {
1533///   uint32_t Magic;         // 0x0B17C0DE
1534///   uint32_t Version;       // Version, currently always 0.
1535///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1536///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1537///   uint32_t CPUType;       // CPU specifier.
1538///   ... potentially more later ...
1539/// };
1540enum {
1541  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1542  DarwinBCHeaderSize = 5*4
1543};
1544
1545/// isARMTriplet - Return true if the triplet looks like:
1546/// arm-*, thumb-*, armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*.
1547static bool isARMTriplet(const std::string &TT) {
1548  size_t Pos = 0;
1549  size_t Size = TT.size();
1550  if (Size >= 6 &&
1551      TT[0] == 't' && TT[1] == 'h' && TT[2] == 'u' &&
1552      TT[3] == 'm' && TT[4] == 'b')
1553    Pos = 5;
1554  else if (Size >= 4 && TT[0] == 'a' && TT[1] == 'r' && TT[2] == 'm')
1555    Pos = 3;
1556  else
1557    return false;
1558
1559  if (TT[Pos] == '-')
1560    return true;
1561  else if (TT[Pos] == 'v') {
1562    if (Size >= Pos+4 &&
1563        TT[Pos+1] == '6' && TT[Pos+2] == 't' && TT[Pos+3] == '2')
1564      return true;
1565    else if (Size >= Pos+4 &&
1566             TT[Pos+1] == '5' && TT[Pos+2] == 't' && TT[Pos+3] == 'e')
1567      return true;
1568  } else
1569    return false;
1570  while (++Pos < Size && TT[Pos] != '-') {
1571    if (!isdigit(TT[Pos]))
1572      return false;
1573  }
1574  return true;
1575}
1576
1577static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1578                               const std::string &TT) {
1579  unsigned CPUType = ~0U;
1580
1581  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1582  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1583  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1584  // specific constants here because they are implicitly part of the Darwin ABI.
1585  enum {
1586    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1587    DARWIN_CPU_TYPE_X86        = 7,
1588    DARWIN_CPU_TYPE_ARM        = 12,
1589    DARWIN_CPU_TYPE_POWERPC    = 18
1590  };
1591
1592  if (TT.find("x86_64-") == 0)
1593    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1594  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1595           TT[4] == '-' && TT[1] - '3' < 6)
1596    CPUType = DARWIN_CPU_TYPE_X86;
1597  else if (TT.find("powerpc-") == 0)
1598    CPUType = DARWIN_CPU_TYPE_POWERPC;
1599  else if (TT.find("powerpc64-") == 0)
1600    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1601  else if (isARMTriplet(TT))
1602    CPUType = DARWIN_CPU_TYPE_ARM;
1603
1604  // Traditional Bitcode starts after header.
1605  unsigned BCOffset = DarwinBCHeaderSize;
1606
1607  Stream.Emit(0x0B17C0DE, 32);
1608  Stream.Emit(0         , 32);  // Version.
1609  Stream.Emit(BCOffset  , 32);
1610  Stream.Emit(0         , 32);  // Filled in later.
1611  Stream.Emit(CPUType   , 32);
1612}
1613
1614/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1615/// finalize the header.
1616static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1617  // Update the size field in the header.
1618  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1619
1620  // If the file is not a multiple of 16 bytes, insert dummy padding.
1621  while (BufferSize & 15) {
1622    Stream.Emit(0, 8);
1623    ++BufferSize;
1624  }
1625}
1626
1627
1628/// WriteBitcodeToFile - Write the specified module to the specified output
1629/// stream.
1630void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1631  std::vector<unsigned char> Buffer;
1632  BitstreamWriter Stream(Buffer);
1633
1634  Buffer.reserve(256*1024);
1635
1636  WriteBitcodeToStream( M, Stream );
1637
1638  // Write the generated bitstream to "Out".
1639  Out.write((char*)&Buffer.front(), Buffer.size());
1640}
1641
1642/// WriteBitcodeToStream - Write the specified module to the specified output
1643/// stream.
1644void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1645  // If this is darwin, emit a file header and trailer if needed.
1646  bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1647  if (isDarwin)
1648    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1649
1650  // Emit the file header.
1651  Stream.Emit((unsigned)'B', 8);
1652  Stream.Emit((unsigned)'C', 8);
1653  Stream.Emit(0x0, 4);
1654  Stream.Emit(0xC, 4);
1655  Stream.Emit(0xE, 4);
1656  Stream.Emit(0xD, 4);
1657
1658  // Emit the module.
1659  WriteModule(M, Stream);
1660
1661  if (isDarwin)
1662    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1663}
1664