BitcodeWriter.cpp revision 4f6bab98c54a93276b8370d3f61f63bf765f7e1f 
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/ADT/Triple.h"
27#include "llvm/Support/ErrorHandling.h"
28#include "llvm/Support/MathExtras.h"
29#include "llvm/Support/raw_ostream.h"
30#include "llvm/Support/Program.h"
31#include <cctype>
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
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];
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    //             unnamed_addr]
408    Vals.push_back(VE.getTypeID(GV->getType()));
409    Vals.push_back(GV->isConstant());
410    Vals.push_back(GV->isDeclaration() ? 0 :
411                   (VE.getValueID(GV->getInitializer()) + 1));
412    Vals.push_back(getEncodedLinkage(GV));
413    Vals.push_back(Log2_32(GV->getAlignment())+1);
414    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
415    if (GV->isThreadLocal() ||
416        GV->getVisibility() != GlobalValue::DefaultVisibility ||
417        GV->hasUnnamedAddr()) {
418      Vals.push_back(getEncodedVisibility(GV));
419      Vals.push_back(GV->isThreadLocal());
420      Vals.push_back(GV->hasUnnamedAddr());
421    } else {
422      AbbrevToUse = SimpleGVarAbbrev;
423    }
424
425    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
426    Vals.clear();
427  }
428
429  // Emit the function proto information.
430  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
431    // FUNCTION:  [type, callingconv, isproto, paramattr,
432    //             linkage, alignment, section, visibility, gc, unnamed_addr]
433    Vals.push_back(VE.getTypeID(F->getType()));
434    Vals.push_back(F->getCallingConv());
435    Vals.push_back(F->isDeclaration());
436    Vals.push_back(getEncodedLinkage(F));
437    Vals.push_back(VE.getAttributeID(F->getAttributes()));
438    Vals.push_back(Log2_32(F->getAlignment())+1);
439    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
440    Vals.push_back(getEncodedVisibility(F));
441    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
442    Vals.push_back(F->hasUnnamedAddr());
443
444    unsigned AbbrevToUse = 0;
445    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
446    Vals.clear();
447  }
448
449  // Emit the alias information.
450  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
451       AI != E; ++AI) {
452    Vals.push_back(VE.getTypeID(AI->getType()));
453    Vals.push_back(VE.getValueID(AI->getAliasee()));
454    Vals.push_back(getEncodedLinkage(AI));
455    Vals.push_back(getEncodedVisibility(AI));
456    unsigned AbbrevToUse = 0;
457    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
458    Vals.clear();
459  }
460}
461
462static uint64_t GetOptimizationFlags(const Value *V) {
463  uint64_t Flags = 0;
464
465  if (const OverflowingBinaryOperator *OBO =
466        dyn_cast<OverflowingBinaryOperator>(V)) {
467    if (OBO->hasNoSignedWrap())
468      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
469    if (OBO->hasNoUnsignedWrap())
470      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
471  } else if (const PossiblyExactOperator *PEO =
472               dyn_cast<PossiblyExactOperator>(V)) {
473    if (PEO->isExact())
474      Flags |= 1 << bitc::PEO_EXACT;
475  }
476
477  return Flags;
478}
479
480static void WriteMDNode(const MDNode *N,
481                        const ValueEnumerator &VE,
482                        BitstreamWriter &Stream,
483                        SmallVector<uint64_t, 64> &Record) {
484  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
485    if (N->getOperand(i)) {
486      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
487      Record.push_back(VE.getValueID(N->getOperand(i)));
488    } else {
489      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
490      Record.push_back(0);
491    }
492  }
493  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
494                                           bitc::METADATA_NODE;
495  Stream.EmitRecord(MDCode, Record, 0);
496  Record.clear();
497}
498
499static void WriteModuleMetadata(const Module *M,
500                                const ValueEnumerator &VE,
501                                BitstreamWriter &Stream) {
502  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
503  bool StartedMetadataBlock = false;
504  unsigned MDSAbbrev = 0;
505  SmallVector<uint64_t, 64> Record;
506  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
507
508    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
509      if (!N->isFunctionLocal() || !N->getFunction()) {
510        if (!StartedMetadataBlock) {
511          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
512          StartedMetadataBlock = true;
513        }
514        WriteMDNode(N, VE, Stream, Record);
515      }
516    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
517      if (!StartedMetadataBlock)  {
518        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
519
520        // Abbrev for METADATA_STRING.
521        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
522        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
523        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
524        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
525        MDSAbbrev = Stream.EmitAbbrev(Abbv);
526        StartedMetadataBlock = true;
527      }
528
529      // Code: [strchar x N]
530      Record.append(MDS->begin(), MDS->end());
531
532      // Emit the finished record.
533      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
534      Record.clear();
535    }
536  }
537
538  // Write named metadata.
539  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
540       E = M->named_metadata_end(); I != E; ++I) {
541    const NamedMDNode *NMD = I;
542    if (!StartedMetadataBlock)  {
543      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
544      StartedMetadataBlock = true;
545    }
546
547    // Write name.
548    StringRef Str = NMD->getName();
549    for (unsigned i = 0, e = Str.size(); i != e; ++i)
550      Record.push_back(Str[i]);
551    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
552    Record.clear();
553
554    // Write named metadata operands.
555    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
556      Record.push_back(VE.getValueID(NMD->getOperand(i)));
557    Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
558    Record.clear();
559  }
560
561  if (StartedMetadataBlock)
562    Stream.ExitBlock();
563}
564
565static void WriteFunctionLocalMetadata(const Function &F,
566                                       const ValueEnumerator &VE,
567                                       BitstreamWriter &Stream) {
568  bool StartedMetadataBlock = false;
569  SmallVector<uint64_t, 64> Record;
570  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
571  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
572    if (const MDNode *N = Vals[i])
573      if (N->isFunctionLocal() && N->getFunction() == &F) {
574        if (!StartedMetadataBlock) {
575          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
576          StartedMetadataBlock = true;
577        }
578        WriteMDNode(N, VE, Stream, Record);
579      }
580
581  if (StartedMetadataBlock)
582    Stream.ExitBlock();
583}
584
585static void WriteMetadataAttachment(const Function &F,
586                                    const ValueEnumerator &VE,
587                                    BitstreamWriter &Stream) {
588  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
589
590  SmallVector<uint64_t, 64> Record;
591
592  // Write metadata attachments
593  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
594  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
595
596  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
597    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
598         I != E; ++I) {
599      MDs.clear();
600      I->getAllMetadataOtherThanDebugLoc(MDs);
601
602      // If no metadata, ignore instruction.
603      if (MDs.empty()) continue;
604
605      Record.push_back(VE.getInstructionID(I));
606
607      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
608        Record.push_back(MDs[i].first);
609        Record.push_back(VE.getValueID(MDs[i].second));
610      }
611      Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
612      Record.clear();
613    }
614
615  Stream.ExitBlock();
616}
617
618static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
619  SmallVector<uint64_t, 64> Record;
620
621  // Write metadata kinds
622  // METADATA_KIND - [n x [id, name]]
623  SmallVector<StringRef, 4> Names;
624  M->getMDKindNames(Names);
625
626  if (Names.empty()) return;
627
628  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
629
630  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
631    Record.push_back(MDKindID);
632    StringRef KName = Names[MDKindID];
633    Record.append(KName.begin(), KName.end());
634
635    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
636    Record.clear();
637  }
638
639  Stream.ExitBlock();
640}
641
642static void WriteConstants(unsigned FirstVal, unsigned LastVal,
643                           const ValueEnumerator &VE,
644                           BitstreamWriter &Stream, bool isGlobal) {
645  if (FirstVal == LastVal) return;
646
647  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
648
649  unsigned AggregateAbbrev = 0;
650  unsigned String8Abbrev = 0;
651  unsigned CString7Abbrev = 0;
652  unsigned CString6Abbrev = 0;
653  // If this is a constant pool for the module, emit module-specific abbrevs.
654  if (isGlobal) {
655    // Abbrev for CST_CODE_AGGREGATE.
656    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
657    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
658    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
659    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
660    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
661
662    // Abbrev for CST_CODE_STRING.
663    Abbv = new BitCodeAbbrev();
664    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
665    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
666    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
667    String8Abbrev = Stream.EmitAbbrev(Abbv);
668    // Abbrev for CST_CODE_CSTRING.
669    Abbv = new BitCodeAbbrev();
670    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
671    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
672    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
673    CString7Abbrev = Stream.EmitAbbrev(Abbv);
674    // Abbrev for CST_CODE_CSTRING.
675    Abbv = new BitCodeAbbrev();
676    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
677    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
678    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
679    CString6Abbrev = Stream.EmitAbbrev(Abbv);
680  }
681
682  SmallVector<uint64_t, 64> Record;
683
684  const ValueEnumerator::ValueList &Vals = VE.getValues();
685  const Type *LastTy = 0;
686  for (unsigned i = FirstVal; i != LastVal; ++i) {
687    const Value *V = Vals[i].first;
688    // If we need to switch types, do so now.
689    if (V->getType() != LastTy) {
690      LastTy = V->getType();
691      Record.push_back(VE.getTypeID(LastTy));
692      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
693                        CONSTANTS_SETTYPE_ABBREV);
694      Record.clear();
695    }
696
697    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
698      Record.push_back(unsigned(IA->hasSideEffects()) |
699                       unsigned(IA->isAlignStack()) << 1);
700
701      // Add the asm string.
702      const std::string &AsmStr = IA->getAsmString();
703      Record.push_back(AsmStr.size());
704      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
705        Record.push_back(AsmStr[i]);
706
707      // Add the constraint string.
708      const std::string &ConstraintStr = IA->getConstraintString();
709      Record.push_back(ConstraintStr.size());
710      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
711        Record.push_back(ConstraintStr[i]);
712      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
713      Record.clear();
714      continue;
715    }
716    const Constant *C = cast<Constant>(V);
717    unsigned Code = -1U;
718    unsigned AbbrevToUse = 0;
719    if (C->isNullValue()) {
720      Code = bitc::CST_CODE_NULL;
721    } else if (isa<UndefValue>(C)) {
722      Code = bitc::CST_CODE_UNDEF;
723    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
724      if (IV->getBitWidth() <= 64) {
725        uint64_t V = IV->getSExtValue();
726        if ((int64_t)V >= 0)
727          Record.push_back(V << 1);
728        else
729          Record.push_back((-V << 1) | 1);
730        Code = bitc::CST_CODE_INTEGER;
731        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
732      } else {                             // Wide integers, > 64 bits in size.
733        // We have an arbitrary precision integer value to write whose
734        // bit width is > 64. However, in canonical unsigned integer
735        // format it is likely that the high bits are going to be zero.
736        // So, we only write the number of active words.
737        unsigned NWords = IV->getValue().getActiveWords();
738        const uint64_t *RawWords = IV->getValue().getRawData();
739        for (unsigned i = 0; i != NWords; ++i) {
740          int64_t V = RawWords[i];
741          if (V >= 0)
742            Record.push_back(V << 1);
743          else
744            Record.push_back((-V << 1) | 1);
745        }
746        Code = bitc::CST_CODE_WIDE_INTEGER;
747      }
748    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
749      Code = bitc::CST_CODE_FLOAT;
750      const Type *Ty = CFP->getType();
751      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
752        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
753      } else if (Ty->isX86_FP80Ty()) {
754        // api needed to prevent premature destruction
755        // bits are not in the same order as a normal i80 APInt, compensate.
756        APInt api = CFP->getValueAPF().bitcastToAPInt();
757        const uint64_t *p = api.getRawData();
758        Record.push_back((p[1] << 48) | (p[0] >> 16));
759        Record.push_back(p[0] & 0xffffLL);
760      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
761        APInt api = CFP->getValueAPF().bitcastToAPInt();
762        const uint64_t *p = api.getRawData();
763        Record.push_back(p[0]);
764        Record.push_back(p[1]);
765      } else {
766        assert (0 && "Unknown FP type!");
767      }
768    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
769      const ConstantArray *CA = cast<ConstantArray>(C);
770      // Emit constant strings specially.
771      unsigned NumOps = CA->getNumOperands();
772      // If this is a null-terminated string, use the denser CSTRING encoding.
773      if (CA->getOperand(NumOps-1)->isNullValue()) {
774        Code = bitc::CST_CODE_CSTRING;
775        --NumOps;  // Don't encode the null, which isn't allowed by char6.
776      } else {
777        Code = bitc::CST_CODE_STRING;
778        AbbrevToUse = String8Abbrev;
779      }
780      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
781      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
782      for (unsigned i = 0; i != NumOps; ++i) {
783        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
784        Record.push_back(V);
785        isCStr7 &= (V & 128) == 0;
786        if (isCStrChar6)
787          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
788      }
789
790      if (isCStrChar6)
791        AbbrevToUse = CString6Abbrev;
792      else if (isCStr7)
793        AbbrevToUse = CString7Abbrev;
794    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
795               isa<ConstantVector>(V)) {
796      Code = bitc::CST_CODE_AGGREGATE;
797      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
798        Record.push_back(VE.getValueID(C->getOperand(i)));
799      AbbrevToUse = AggregateAbbrev;
800    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
801      switch (CE->getOpcode()) {
802      default:
803        if (Instruction::isCast(CE->getOpcode())) {
804          Code = bitc::CST_CODE_CE_CAST;
805          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
806          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
807          Record.push_back(VE.getValueID(C->getOperand(0)));
808          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
809        } else {
810          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
811          Code = bitc::CST_CODE_CE_BINOP;
812          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
813          Record.push_back(VE.getValueID(C->getOperand(0)));
814          Record.push_back(VE.getValueID(C->getOperand(1)));
815          uint64_t Flags = GetOptimizationFlags(CE);
816          if (Flags != 0)
817            Record.push_back(Flags);
818        }
819        break;
820      case Instruction::GetElementPtr:
821        Code = bitc::CST_CODE_CE_GEP;
822        if (cast<GEPOperator>(C)->isInBounds())
823          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
824        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
825          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
826          Record.push_back(VE.getValueID(C->getOperand(i)));
827        }
828        break;
829      case Instruction::Select:
830        Code = bitc::CST_CODE_CE_SELECT;
831        Record.push_back(VE.getValueID(C->getOperand(0)));
832        Record.push_back(VE.getValueID(C->getOperand(1)));
833        Record.push_back(VE.getValueID(C->getOperand(2)));
834        break;
835      case Instruction::ExtractElement:
836        Code = bitc::CST_CODE_CE_EXTRACTELT;
837        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
838        Record.push_back(VE.getValueID(C->getOperand(0)));
839        Record.push_back(VE.getValueID(C->getOperand(1)));
840        break;
841      case Instruction::InsertElement:
842        Code = bitc::CST_CODE_CE_INSERTELT;
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::ShuffleVector:
848        // If the return type and argument types are the same, this is a
849        // standard shufflevector instruction.  If the types are different,
850        // then the shuffle is widening or truncating the input vectors, and
851        // the argument type must also be encoded.
852        if (C->getType() == C->getOperand(0)->getType()) {
853          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
854        } else {
855          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
856          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
857        }
858        Record.push_back(VE.getValueID(C->getOperand(0)));
859        Record.push_back(VE.getValueID(C->getOperand(1)));
860        Record.push_back(VE.getValueID(C->getOperand(2)));
861        break;
862      case Instruction::ICmp:
863      case Instruction::FCmp:
864        Code = bitc::CST_CODE_CE_CMP;
865        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
866        Record.push_back(VE.getValueID(C->getOperand(0)));
867        Record.push_back(VE.getValueID(C->getOperand(1)));
868        Record.push_back(CE->getPredicate());
869        break;
870      }
871    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
872      Code = bitc::CST_CODE_BLOCKADDRESS;
873      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
874      Record.push_back(VE.getValueID(BA->getFunction()));
875      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
876    } else {
877#ifndef NDEBUG
878      C->dump();
879#endif
880      llvm_unreachable("Unknown constant!");
881    }
882    Stream.EmitRecord(Code, Record, AbbrevToUse);
883    Record.clear();
884  }
885
886  Stream.ExitBlock();
887}
888
889static void WriteModuleConstants(const ValueEnumerator &VE,
890                                 BitstreamWriter &Stream) {
891  const ValueEnumerator::ValueList &Vals = VE.getValues();
892
893  // Find the first constant to emit, which is the first non-globalvalue value.
894  // We know globalvalues have been emitted by WriteModuleInfo.
895  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
896    if (!isa<GlobalValue>(Vals[i].first)) {
897      WriteConstants(i, Vals.size(), VE, Stream, true);
898      return;
899    }
900  }
901}
902
903/// PushValueAndType - The file has to encode both the value and type id for
904/// many values, because we need to know what type to create for forward
905/// references.  However, most operands are not forward references, so this type
906/// field is not needed.
907///
908/// This function adds V's value ID to Vals.  If the value ID is higher than the
909/// instruction ID, then it is a forward reference, and it also includes the
910/// type ID.
911static bool PushValueAndType(const Value *V, unsigned InstID,
912                             SmallVector<unsigned, 64> &Vals,
913                             ValueEnumerator &VE) {
914  unsigned ValID = VE.getValueID(V);
915  Vals.push_back(ValID);
916  if (ValID >= InstID) {
917    Vals.push_back(VE.getTypeID(V->getType()));
918    return true;
919  }
920  return false;
921}
922
923/// WriteInstruction - Emit an instruction to the specified stream.
924static void WriteInstruction(const Instruction &I, unsigned InstID,
925                             ValueEnumerator &VE, BitstreamWriter &Stream,
926                             SmallVector<unsigned, 64> &Vals) {
927  unsigned Code = 0;
928  unsigned AbbrevToUse = 0;
929  VE.setInstructionID(&I);
930  switch (I.getOpcode()) {
931  default:
932    if (Instruction::isCast(I.getOpcode())) {
933      Code = bitc::FUNC_CODE_INST_CAST;
934      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
935        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
936      Vals.push_back(VE.getTypeID(I.getType()));
937      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
938    } else {
939      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
940      Code = bitc::FUNC_CODE_INST_BINOP;
941      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
942        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
943      Vals.push_back(VE.getValueID(I.getOperand(1)));
944      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
945      uint64_t Flags = GetOptimizationFlags(&I);
946      if (Flags != 0) {
947        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
948          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
949        Vals.push_back(Flags);
950      }
951    }
952    break;
953
954  case Instruction::GetElementPtr:
955    Code = bitc::FUNC_CODE_INST_GEP;
956    if (cast<GEPOperator>(&I)->isInBounds())
957      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
958    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
959      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
960    break;
961  case Instruction::ExtractValue: {
962    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
963    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
964    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
965    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
966      Vals.push_back(*i);
967    break;
968  }
969  case Instruction::InsertValue: {
970    Code = bitc::FUNC_CODE_INST_INSERTVAL;
971    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
972    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
973    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
974    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
975      Vals.push_back(*i);
976    break;
977  }
978  case Instruction::Select:
979    Code = bitc::FUNC_CODE_INST_VSELECT;
980    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
981    Vals.push_back(VE.getValueID(I.getOperand(2)));
982    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
983    break;
984  case Instruction::ExtractElement:
985    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
986    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
987    Vals.push_back(VE.getValueID(I.getOperand(1)));
988    break;
989  case Instruction::InsertElement:
990    Code = bitc::FUNC_CODE_INST_INSERTELT;
991    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
992    Vals.push_back(VE.getValueID(I.getOperand(1)));
993    Vals.push_back(VE.getValueID(I.getOperand(2)));
994    break;
995  case Instruction::ShuffleVector:
996    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
997    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
998    Vals.push_back(VE.getValueID(I.getOperand(1)));
999    Vals.push_back(VE.getValueID(I.getOperand(2)));
1000    break;
1001  case Instruction::ICmp:
1002  case Instruction::FCmp:
1003    // compare returning Int1Ty or vector of Int1Ty
1004    Code = bitc::FUNC_CODE_INST_CMP2;
1005    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1006    Vals.push_back(VE.getValueID(I.getOperand(1)));
1007    Vals.push_back(cast<CmpInst>(I).getPredicate());
1008    break;
1009
1010  case Instruction::Ret:
1011    {
1012      Code = bitc::FUNC_CODE_INST_RET;
1013      unsigned NumOperands = I.getNumOperands();
1014      if (NumOperands == 0)
1015        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1016      else if (NumOperands == 1) {
1017        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1018          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1019      } else {
1020        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1021          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1022      }
1023    }
1024    break;
1025  case Instruction::Br:
1026    {
1027      Code = bitc::FUNC_CODE_INST_BR;
1028      BranchInst &II = cast<BranchInst>(I);
1029      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1030      if (II.isConditional()) {
1031        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1032        Vals.push_back(VE.getValueID(II.getCondition()));
1033      }
1034    }
1035    break;
1036  case Instruction::Switch:
1037    Code = bitc::FUNC_CODE_INST_SWITCH;
1038    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1039    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1040      Vals.push_back(VE.getValueID(I.getOperand(i)));
1041    break;
1042  case Instruction::IndirectBr:
1043    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1044    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1045    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1046      Vals.push_back(VE.getValueID(I.getOperand(i)));
1047    break;
1048
1049  case Instruction::Invoke: {
1050    const InvokeInst *II = cast<InvokeInst>(&I);
1051    const Value *Callee(II->getCalledValue());
1052    const PointerType *PTy = cast<PointerType>(Callee->getType());
1053    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1054    Code = bitc::FUNC_CODE_INST_INVOKE;
1055
1056    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1057    Vals.push_back(II->getCallingConv());
1058    Vals.push_back(VE.getValueID(II->getNormalDest()));
1059    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1060    PushValueAndType(Callee, InstID, Vals, VE);
1061
1062    // Emit value #'s for the fixed parameters.
1063    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1064      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1065
1066    // Emit type/value pairs for varargs params.
1067    if (FTy->isVarArg()) {
1068      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1069           i != e; ++i)
1070        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1071    }
1072    break;
1073  }
1074  case Instruction::Unwind:
1075    Code = bitc::FUNC_CODE_INST_UNWIND;
1076    break;
1077  case Instruction::Unreachable:
1078    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1079    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1080    break;
1081
1082  case Instruction::PHI:
1083    Code = bitc::FUNC_CODE_INST_PHI;
1084    Vals.push_back(VE.getTypeID(I.getType()));
1085    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1086      Vals.push_back(VE.getValueID(I.getOperand(i)));
1087    break;
1088
1089  case Instruction::Alloca:
1090    Code = bitc::FUNC_CODE_INST_ALLOCA;
1091    Vals.push_back(VE.getTypeID(I.getType()));
1092    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1093    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1094    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1095    break;
1096
1097  case Instruction::Load:
1098    Code = bitc::FUNC_CODE_INST_LOAD;
1099    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1100      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1101
1102    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1103    Vals.push_back(cast<LoadInst>(I).isVolatile());
1104    break;
1105  case Instruction::Store:
1106    Code = bitc::FUNC_CODE_INST_STORE;
1107    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1108    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1109    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1110    Vals.push_back(cast<StoreInst>(I).isVolatile());
1111    break;
1112  case Instruction::Call: {
1113    const CallInst &CI = cast<CallInst>(I);
1114    const PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1115    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1116
1117    Code = bitc::FUNC_CODE_INST_CALL;
1118
1119    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1120    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1121    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1122
1123    // Emit value #'s for the fixed parameters.
1124    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1125      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1126
1127    // Emit type/value pairs for varargs params.
1128    if (FTy->isVarArg()) {
1129      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1130           i != e; ++i)
1131        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1132    }
1133    break;
1134  }
1135  case Instruction::VAArg:
1136    Code = bitc::FUNC_CODE_INST_VAARG;
1137    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1138    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1139    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1140    break;
1141  }
1142
1143  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1144  Vals.clear();
1145}
1146
1147// Emit names for globals/functions etc.
1148static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1149                                  const ValueEnumerator &VE,
1150                                  BitstreamWriter &Stream) {
1151  if (VST.empty()) return;
1152  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1153
1154  // FIXME: Set up the abbrev, we know how many values there are!
1155  // FIXME: We know if the type names can use 7-bit ascii.
1156  SmallVector<unsigned, 64> NameVals;
1157
1158  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1159       SI != SE; ++SI) {
1160
1161    const ValueName &Name = *SI;
1162
1163    // Figure out the encoding to use for the name.
1164    bool is7Bit = true;
1165    bool isChar6 = true;
1166    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1167         C != E; ++C) {
1168      if (isChar6)
1169        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1170      if ((unsigned char)*C & 128) {
1171        is7Bit = false;
1172        break;  // don't bother scanning the rest.
1173      }
1174    }
1175
1176    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1177
1178    // VST_ENTRY:   [valueid, namechar x N]
1179    // VST_BBENTRY: [bbid, namechar x N]
1180    unsigned Code;
1181    if (isa<BasicBlock>(SI->getValue())) {
1182      Code = bitc::VST_CODE_BBENTRY;
1183      if (isChar6)
1184        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1185    } else {
1186      Code = bitc::VST_CODE_ENTRY;
1187      if (isChar6)
1188        AbbrevToUse = VST_ENTRY_6_ABBREV;
1189      else if (is7Bit)
1190        AbbrevToUse = VST_ENTRY_7_ABBREV;
1191    }
1192
1193    NameVals.push_back(VE.getValueID(SI->getValue()));
1194    for (const char *P = Name.getKeyData(),
1195         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1196      NameVals.push_back((unsigned char)*P);
1197
1198    // Emit the finished record.
1199    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1200    NameVals.clear();
1201  }
1202  Stream.ExitBlock();
1203}
1204
1205/// WriteFunction - Emit a function body to the module stream.
1206static void WriteFunction(const Function &F, ValueEnumerator &VE,
1207                          BitstreamWriter &Stream) {
1208  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1209  VE.incorporateFunction(F);
1210
1211  SmallVector<unsigned, 64> Vals;
1212
1213  // Emit the number of basic blocks, so the reader can create them ahead of
1214  // time.
1215  Vals.push_back(VE.getBasicBlocks().size());
1216  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1217  Vals.clear();
1218
1219  // If there are function-local constants, emit them now.
1220  unsigned CstStart, CstEnd;
1221  VE.getFunctionConstantRange(CstStart, CstEnd);
1222  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1223
1224  // If there is function-local metadata, emit it now.
1225  WriteFunctionLocalMetadata(F, VE, Stream);
1226
1227  // Keep a running idea of what the instruction ID is.
1228  unsigned InstID = CstEnd;
1229
1230  bool NeedsMetadataAttachment = false;
1231
1232  DebugLoc LastDL;
1233
1234  // Finally, emit all the instructions, in order.
1235  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1236    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1237         I != E; ++I) {
1238      WriteInstruction(*I, InstID, VE, Stream, Vals);
1239
1240      if (!I->getType()->isVoidTy())
1241        ++InstID;
1242
1243      // If the instruction has metadata, write a metadata attachment later.
1244      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1245
1246      // If the instruction has a debug location, emit it.
1247      DebugLoc DL = I->getDebugLoc();
1248      if (DL.isUnknown()) {
1249        // nothing todo.
1250      } else if (DL == LastDL) {
1251        // Just repeat the same debug loc as last time.
1252        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1253      } else {
1254        MDNode *Scope, *IA;
1255        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1256
1257        Vals.push_back(DL.getLine());
1258        Vals.push_back(DL.getCol());
1259        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1260        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1261        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1262        Vals.clear();
1263
1264        LastDL = DL;
1265      }
1266    }
1267
1268  // Emit names for all the instructions etc.
1269  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1270
1271  if (NeedsMetadataAttachment)
1272    WriteMetadataAttachment(F, VE, Stream);
1273  VE.purgeFunction();
1274  Stream.ExitBlock();
1275}
1276
1277/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1278static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1279                                 const ValueEnumerator &VE,
1280                                 BitstreamWriter &Stream) {
1281  if (TST.empty()) return;
1282
1283  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1284
1285  // 7-bit fixed width VST_CODE_ENTRY strings.
1286  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1287  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1288  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1289                            Log2_32_Ceil(VE.getTypes().size()+1)));
1290  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1291  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1292  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1293
1294  SmallVector<unsigned, 64> NameVals;
1295
1296  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1297       TI != TE; ++TI) {
1298    // TST_ENTRY: [typeid, namechar x N]
1299    NameVals.push_back(VE.getTypeID(TI->second));
1300
1301    const std::string &Str = TI->first;
1302    bool is7Bit = true;
1303    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1304      NameVals.push_back((unsigned char)Str[i]);
1305      if (Str[i] & 128)
1306        is7Bit = false;
1307    }
1308
1309    // Emit the finished record.
1310    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1311    NameVals.clear();
1312  }
1313
1314  Stream.ExitBlock();
1315}
1316
1317// Emit blockinfo, which defines the standard abbreviations etc.
1318static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1319  // We only want to emit block info records for blocks that have multiple
1320  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1321  // blocks can defined their abbrevs inline.
1322  Stream.EnterBlockInfoBlock(2);
1323
1324  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1325    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1326    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1327    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1328    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1329    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1330    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1331                                   Abbv) != VST_ENTRY_8_ABBREV)
1332      llvm_unreachable("Unexpected abbrev ordering!");
1333  }
1334
1335  { // 7-bit fixed width VST_ENTRY strings.
1336    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1337    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1338    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1339    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1340    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1341    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1342                                   Abbv) != VST_ENTRY_7_ABBREV)
1343      llvm_unreachable("Unexpected abbrev ordering!");
1344  }
1345  { // 6-bit char6 VST_ENTRY strings.
1346    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1347    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1348    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1349    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1350    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1351    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1352                                   Abbv) != VST_ENTRY_6_ABBREV)
1353      llvm_unreachable("Unexpected abbrev ordering!");
1354  }
1355  { // 6-bit char6 VST_BBENTRY strings.
1356    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1357    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1358    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1359    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1360    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1361    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1362                                   Abbv) != VST_BBENTRY_6_ABBREV)
1363      llvm_unreachable("Unexpected abbrev ordering!");
1364  }
1365
1366
1367
1368  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1369    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1370    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1371    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1372                              Log2_32_Ceil(VE.getTypes().size()+1)));
1373    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1374                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1375      llvm_unreachable("Unexpected abbrev ordering!");
1376  }
1377
1378  { // INTEGER abbrev for CONSTANTS_BLOCK.
1379    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1380    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1381    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1382    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1383                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1384      llvm_unreachable("Unexpected abbrev ordering!");
1385  }
1386
1387  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1388    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1389    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1390    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1391    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1392                              Log2_32_Ceil(VE.getTypes().size()+1)));
1393    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1394
1395    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1396                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1397      llvm_unreachable("Unexpected abbrev ordering!");
1398  }
1399  { // NULL abbrev for CONSTANTS_BLOCK.
1400    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1401    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1402    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1403                                   Abbv) != CONSTANTS_NULL_Abbrev)
1404      llvm_unreachable("Unexpected abbrev ordering!");
1405  }
1406
1407  // FIXME: This should only use space for first class types!
1408
1409  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1410    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1411    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1412    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1413    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1414    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1415    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1416                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1417      llvm_unreachable("Unexpected abbrev ordering!");
1418  }
1419  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1420    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1421    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1422    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1423    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1424    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1425    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1426                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1427      llvm_unreachable("Unexpected abbrev ordering!");
1428  }
1429  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1430    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1431    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1432    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1433    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1434    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1435    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1436    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1437                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1438      llvm_unreachable("Unexpected abbrev ordering!");
1439  }
1440  { // INST_CAST abbrev for FUNCTION_BLOCK.
1441    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1442    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1443    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1444    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1445                              Log2_32_Ceil(VE.getTypes().size()+1)));
1446    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1447    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1448                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1449      llvm_unreachable("Unexpected abbrev ordering!");
1450  }
1451
1452  { // INST_RET abbrev for FUNCTION_BLOCK.
1453    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1454    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1455    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1456                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1457      llvm_unreachable("Unexpected abbrev ordering!");
1458  }
1459  { // INST_RET abbrev for FUNCTION_BLOCK.
1460    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1461    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1462    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1463    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1464                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1465      llvm_unreachable("Unexpected abbrev ordering!");
1466  }
1467  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1468    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1469    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1470    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1471                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1472      llvm_unreachable("Unexpected abbrev ordering!");
1473  }
1474
1475  Stream.ExitBlock();
1476}
1477
1478
1479/// WriteModule - Emit the specified module to the bitstream.
1480static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1481  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1482
1483  // Emit the version number if it is non-zero.
1484  if (CurVersion) {
1485    SmallVector<unsigned, 1> Vals;
1486    Vals.push_back(CurVersion);
1487    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1488  }
1489
1490  // Analyze the module, enumerating globals, functions, etc.
1491  ValueEnumerator VE(M);
1492
1493  // Emit blockinfo, which defines the standard abbreviations etc.
1494  WriteBlockInfo(VE, Stream);
1495
1496  // Emit information about parameter attributes.
1497  WriteAttributeTable(VE, Stream);
1498
1499  // Emit information describing all of the types in the module.
1500  WriteTypeTable(VE, Stream);
1501
1502  // Emit top-level description of module, including target triple, inline asm,
1503  // descriptors for global variables, and function prototype info.
1504  WriteModuleInfo(M, VE, Stream);
1505
1506  // Emit constants.
1507  WriteModuleConstants(VE, Stream);
1508
1509  // Emit metadata.
1510  WriteModuleMetadata(M, VE, Stream);
1511
1512  // Emit function bodies.
1513  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1514    if (!F->isDeclaration())
1515      WriteFunction(*F, VE, Stream);
1516
1517  // Emit metadata.
1518  WriteModuleMetadataStore(M, Stream);
1519
1520  // Emit the type symbol table information.
1521  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1522
1523  // Emit names for globals/functions etc.
1524  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1525
1526  Stream.ExitBlock();
1527}
1528
1529/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1530/// header and trailer to make it compatible with the system archiver.  To do
1531/// this we emit the following header, and then emit a trailer that pads the
1532/// file out to be a multiple of 16 bytes.
1533///
1534/// struct bc_header {
1535///   uint32_t Magic;         // 0x0B17C0DE
1536///   uint32_t Version;       // Version, currently always 0.
1537///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1538///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1539///   uint32_t CPUType;       // CPU specifier.
1540///   ... potentially more later ...
1541/// };
1542enum {
1543  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1544  DarwinBCHeaderSize = 5*4
1545};
1546
1547static void EmitDarwinBCHeader(BitstreamWriter &Stream, const Triple &TT) {
1548  unsigned CPUType = ~0U;
1549
1550  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1551  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1552  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1553  // specific constants here because they are implicitly part of the Darwin ABI.
1554  enum {
1555    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1556    DARWIN_CPU_TYPE_X86        = 7,
1557    DARWIN_CPU_TYPE_ARM        = 12,
1558    DARWIN_CPU_TYPE_POWERPC    = 18
1559  };
1560
1561  Triple::ArchType Arch = TT.getArch();
1562  if (Arch == Triple::x86_64)
1563    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1564  else if (Arch == Triple::x86)
1565    CPUType = DARWIN_CPU_TYPE_X86;
1566  else if (Arch == Triple::ppc)
1567    CPUType = DARWIN_CPU_TYPE_POWERPC;
1568  else if (Arch == Triple::ppc64)
1569    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1570  else if (Arch == Triple::arm || Arch == Triple::thumb)
1571    CPUType = DARWIN_CPU_TYPE_ARM;
1572
1573  // Traditional Bitcode starts after header.
1574  unsigned BCOffset = DarwinBCHeaderSize;
1575
1576  Stream.Emit(0x0B17C0DE, 32);
1577  Stream.Emit(0         , 32);  // Version.
1578  Stream.Emit(BCOffset  , 32);
1579  Stream.Emit(0         , 32);  // Filled in later.
1580  Stream.Emit(CPUType   , 32);
1581}
1582
1583/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1584/// finalize the header.
1585static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1586  // Update the size field in the header.
1587  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1588
1589  // If the file is not a multiple of 16 bytes, insert dummy padding.
1590  while (BufferSize & 15) {
1591    Stream.Emit(0, 8);
1592    ++BufferSize;
1593  }
1594}
1595
1596
1597/// WriteBitcodeToFile - Write the specified module to the specified output
1598/// stream.
1599void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1600  std::vector<unsigned char> Buffer;
1601  BitstreamWriter Stream(Buffer);
1602
1603  Buffer.reserve(256*1024);
1604
1605  WriteBitcodeToStream( M, Stream );
1606
1607  // Write the generated bitstream to "Out".
1608  Out.write((char*)&Buffer.front(), Buffer.size());
1609}
1610
1611/// WriteBitcodeToStream - Write the specified module to the specified output
1612/// stream.
1613void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1614  // If this is darwin or another generic macho target, emit a file header and
1615  // trailer if needed.
1616  Triple TT(M->getTargetTriple());
1617  if (TT.isOSDarwin())
1618    EmitDarwinBCHeader(Stream, TT);
1619
1620  // Emit the file header.
1621  Stream.Emit((unsigned)'B', 8);
1622  Stream.Emit((unsigned)'C', 8);
1623  Stream.Emit(0x0, 4);
1624  Stream.Emit(0xC, 4);
1625  Stream.Emit(0xE, 4);
1626  Stream.Emit(0xD, 4);
1627
1628  // Emit the module.
1629  WriteModule(M, Stream);
1630
1631  if (TT.isOSDarwin())
1632    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1633}
1634