BitcodeWriter.cpp revision d928fb670fb3b0818fc23738e9c2418980bb141e 
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_UNION.
185  Abbv = new BitCodeAbbrev();
186  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_UNION));
187  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
188  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
189                            Log2_32_Ceil(VE.getTypes().size()+1)));
190  unsigned UnionAbbrev = Stream.EmitAbbrev(Abbv);
191
192  // Abbrev for TYPE_CODE_ARRAY.
193  Abbv = new BitCodeAbbrev();
194  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
195  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
196  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
197                            Log2_32_Ceil(VE.getTypes().size()+1)));
198  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
199
200  // Emit an entry count so the reader can reserve space.
201  TypeVals.push_back(TypeList.size());
202  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
203  TypeVals.clear();
204
205  // Loop over all of the types, emitting each in turn.
206  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
207    const Type *T = TypeList[i].first;
208    int AbbrevToUse = 0;
209    unsigned Code = 0;
210
211    switch (T->getTypeID()) {
212    default: llvm_unreachable("Unknown type!");
213    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
214    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
215    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
216    case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
217    case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
218    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
219    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
220    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
221    case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
222    case Type::IntegerTyID:
223      // INTEGER: [width]
224      Code = bitc::TYPE_CODE_INTEGER;
225      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
226      break;
227    case Type::PointerTyID: {
228      const PointerType *PTy = cast<PointerType>(T);
229      // POINTER: [pointee type, address space]
230      Code = bitc::TYPE_CODE_POINTER;
231      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
232      unsigned AddressSpace = PTy->getAddressSpace();
233      TypeVals.push_back(AddressSpace);
234      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
235      break;
236    }
237    case Type::FunctionTyID: {
238      const FunctionType *FT = cast<FunctionType>(T);
239      // FUNCTION: [isvararg, attrid, retty, paramty x N]
240      Code = bitc::TYPE_CODE_FUNCTION;
241      TypeVals.push_back(FT->isVarArg());
242      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
243      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
244      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
245        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
246      AbbrevToUse = FunctionAbbrev;
247      break;
248    }
249    case Type::StructTyID: {
250      const StructType *ST = cast<StructType>(T);
251      // STRUCT: [ispacked, eltty x N]
252      Code = bitc::TYPE_CODE_STRUCT;
253      TypeVals.push_back(ST->isPacked());
254      // Output all of the element types.
255      for (StructType::element_iterator I = ST->element_begin(),
256           E = ST->element_end(); I != E; ++I)
257        TypeVals.push_back(VE.getTypeID(*I));
258      AbbrevToUse = StructAbbrev;
259      break;
260    }
261    case Type::UnionTyID: {
262      const UnionType *UT = cast<UnionType>(T);
263      // UNION: [eltty x N]
264      Code = bitc::TYPE_CODE_UNION;
265      // Output all of the element types.
266      for (UnionType::element_iterator I = UT->element_begin(),
267           E = UT->element_end(); I != E; ++I)
268        TypeVals.push_back(VE.getTypeID(*I));
269      AbbrevToUse = UnionAbbrev;
270      break;
271    }
272    case Type::ArrayTyID: {
273      const ArrayType *AT = cast<ArrayType>(T);
274      // ARRAY: [numelts, eltty]
275      Code = bitc::TYPE_CODE_ARRAY;
276      TypeVals.push_back(AT->getNumElements());
277      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
278      AbbrevToUse = ArrayAbbrev;
279      break;
280    }
281    case Type::VectorTyID: {
282      const VectorType *VT = cast<VectorType>(T);
283      // VECTOR [numelts, eltty]
284      Code = bitc::TYPE_CODE_VECTOR;
285      TypeVals.push_back(VT->getNumElements());
286      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
287      break;
288    }
289    }
290
291    // Emit the finished record.
292    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
293    TypeVals.clear();
294  }
295
296  Stream.ExitBlock();
297}
298
299static unsigned getEncodedLinkage(const GlobalValue *GV) {
300  switch (GV->getLinkage()) {
301  default: llvm_unreachable("Invalid linkage!");
302  case GlobalValue::ExternalLinkage:            return 0;
303  case GlobalValue::WeakAnyLinkage:             return 1;
304  case GlobalValue::AppendingLinkage:           return 2;
305  case GlobalValue::InternalLinkage:            return 3;
306  case GlobalValue::LinkOnceAnyLinkage:         return 4;
307  case GlobalValue::DLLImportLinkage:           return 5;
308  case GlobalValue::DLLExportLinkage:           return 6;
309  case GlobalValue::ExternalWeakLinkage:        return 7;
310  case GlobalValue::CommonLinkage:              return 8;
311  case GlobalValue::PrivateLinkage:             return 9;
312  case GlobalValue::WeakODRLinkage:             return 10;
313  case GlobalValue::LinkOnceODRLinkage:         return 11;
314  case GlobalValue::AvailableExternallyLinkage: return 12;
315  case GlobalValue::LinkerPrivateLinkage:       return 13;
316  }
317}
318
319static unsigned getEncodedVisibility(const GlobalValue *GV) {
320  switch (GV->getVisibility()) {
321  default: llvm_unreachable("Invalid visibility!");
322  case GlobalValue::DefaultVisibility:   return 0;
323  case GlobalValue::HiddenVisibility:    return 1;
324  case GlobalValue::ProtectedVisibility: return 2;
325  }
326}
327
328// Emit top-level description of module, including target triple, inline asm,
329// descriptors for global variables, and function prototype info.
330static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
331                            BitstreamWriter &Stream) {
332  // Emit the list of dependent libraries for the Module.
333  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
334    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
335
336  // Emit various pieces of data attached to a module.
337  if (!M->getTargetTriple().empty())
338    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
339                      0/*TODO*/, Stream);
340  if (!M->getDataLayout().empty())
341    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
342                      0/*TODO*/, Stream);
343  if (!M->getModuleInlineAsm().empty())
344    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
345                      0/*TODO*/, Stream);
346
347  // Emit information about sections and GC, computing how many there are. Also
348  // compute the maximum alignment value.
349  std::map<std::string, unsigned> SectionMap;
350  std::map<std::string, unsigned> GCMap;
351  unsigned MaxAlignment = 0;
352  unsigned MaxGlobalType = 0;
353  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
354       GV != E; ++GV) {
355    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
356    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
357
358    if (!GV->hasSection()) continue;
359    // Give section names unique ID's.
360    unsigned &Entry = SectionMap[GV->getSection()];
361    if (Entry != 0) continue;
362    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
363                      0/*TODO*/, Stream);
364    Entry = SectionMap.size();
365  }
366  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
367    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
368    if (F->hasSection()) {
369      // Give section names unique ID's.
370      unsigned &Entry = SectionMap[F->getSection()];
371      if (!Entry) {
372        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
373                          0/*TODO*/, Stream);
374        Entry = SectionMap.size();
375      }
376    }
377    if (F->hasGC()) {
378      // Same for GC names.
379      unsigned &Entry = GCMap[F->getGC()];
380      if (!Entry) {
381        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
382                          0/*TODO*/, Stream);
383        Entry = GCMap.size();
384      }
385    }
386  }
387
388  // Emit abbrev for globals, now that we know # sections and max alignment.
389  unsigned SimpleGVarAbbrev = 0;
390  if (!M->global_empty()) {
391    // Add an abbrev for common globals with no visibility or thread localness.
392    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
393    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
394    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
395                              Log2_32_Ceil(MaxGlobalType+1)));
396    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
397    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
398    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
399    if (MaxAlignment == 0)                                      // Alignment.
400      Abbv->Add(BitCodeAbbrevOp(0));
401    else {
402      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
403      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
404                               Log2_32_Ceil(MaxEncAlignment+1)));
405    }
406    if (SectionMap.empty())                                    // Section.
407      Abbv->Add(BitCodeAbbrevOp(0));
408    else
409      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
410                               Log2_32_Ceil(SectionMap.size()+1)));
411    // Don't bother emitting vis + thread local.
412    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
413  }
414
415  // Emit the global variable information.
416  SmallVector<unsigned, 64> Vals;
417  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
418       GV != E; ++GV) {
419    unsigned AbbrevToUse = 0;
420
421    // GLOBALVAR: [type, isconst, initid,
422    //             linkage, alignment, section, visibility, threadlocal]
423    Vals.push_back(VE.getTypeID(GV->getType()));
424    Vals.push_back(GV->isConstant());
425    Vals.push_back(GV->isDeclaration() ? 0 :
426                   (VE.getValueID(GV->getInitializer()) + 1));
427    Vals.push_back(getEncodedLinkage(GV));
428    Vals.push_back(Log2_32(GV->getAlignment())+1);
429    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
430    if (GV->isThreadLocal() ||
431        GV->getVisibility() != GlobalValue::DefaultVisibility) {
432      Vals.push_back(getEncodedVisibility(GV));
433      Vals.push_back(GV->isThreadLocal());
434    } else {
435      AbbrevToUse = SimpleGVarAbbrev;
436    }
437
438    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
439    Vals.clear();
440  }
441
442  // Emit the function proto information.
443  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
444    // FUNCTION:  [type, callingconv, isproto, paramattr,
445    //             linkage, alignment, section, visibility, gc]
446    Vals.push_back(VE.getTypeID(F->getType()));
447    Vals.push_back(F->getCallingConv());
448    Vals.push_back(F->isDeclaration());
449    Vals.push_back(getEncodedLinkage(F));
450    Vals.push_back(VE.getAttributeID(F->getAttributes()));
451    Vals.push_back(Log2_32(F->getAlignment())+1);
452    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
453    Vals.push_back(getEncodedVisibility(F));
454    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
455
456    unsigned AbbrevToUse = 0;
457    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
458    Vals.clear();
459  }
460
461
462  // Emit the alias information.
463  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
464       AI != E; ++AI) {
465    Vals.push_back(VE.getTypeID(AI->getType()));
466    Vals.push_back(VE.getValueID(AI->getAliasee()));
467    Vals.push_back(getEncodedLinkage(AI));
468    Vals.push_back(getEncodedVisibility(AI));
469    unsigned AbbrevToUse = 0;
470    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
471    Vals.clear();
472  }
473}
474
475static uint64_t GetOptimizationFlags(const Value *V) {
476  uint64_t Flags = 0;
477
478  if (const OverflowingBinaryOperator *OBO =
479        dyn_cast<OverflowingBinaryOperator>(V)) {
480    if (OBO->hasNoSignedWrap())
481      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
482    if (OBO->hasNoUnsignedWrap())
483      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
484  } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
485    if (Div->isExact())
486      Flags |= 1 << bitc::SDIV_EXACT;
487  }
488
489  return Flags;
490}
491
492static void WriteMDNode(const MDNode *N,
493                        const ValueEnumerator &VE,
494                        BitstreamWriter &Stream,
495                        SmallVector<uint64_t, 64> &Record) {
496  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
497    if (N->getOperand(i)) {
498      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
499      Record.push_back(VE.getValueID(N->getOperand(i)));
500    } else {
501      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
502      Record.push_back(0);
503    }
504  }
505  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
506                                           bitc::METADATA_NODE;
507  Stream.EmitRecord(MDCode, Record, 0);
508  Record.clear();
509}
510
511static void WriteModuleMetadata(const ValueEnumerator &VE,
512                                BitstreamWriter &Stream) {
513  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
514  bool StartedMetadataBlock = false;
515  unsigned MDSAbbrev = 0;
516  SmallVector<uint64_t, 64> Record;
517  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
518
519    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
520      if (!N->isFunctionLocal() || !N->getFunction()) {
521        if (!StartedMetadataBlock) {
522          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
523          StartedMetadataBlock = true;
524        }
525        WriteMDNode(N, VE, Stream, Record);
526      }
527    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
528      if (!StartedMetadataBlock)  {
529        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
530
531        // Abbrev for METADATA_STRING.
532        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
533        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
534        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
535        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
536        MDSAbbrev = Stream.EmitAbbrev(Abbv);
537        StartedMetadataBlock = true;
538      }
539
540      // Code: [strchar x N]
541      Record.append(MDS->begin(), MDS->end());
542
543      // Emit the finished record.
544      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
545      Record.clear();
546    } else if (const NamedMDNode *NMD = dyn_cast<NamedMDNode>(Vals[i].first)) {
547      if (!StartedMetadataBlock)  {
548        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
549        StartedMetadataBlock = true;
550      }
551
552      // Write name.
553      StringRef Str = NMD->getName();
554      for (unsigned i = 0, e = Str.size(); i != e; ++i)
555        Record.push_back(Str[i]);
556      Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
557      Record.clear();
558
559      // Write named metadata operands.
560      for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i) {
561        if (NMD->getOperand(i))
562          Record.push_back(VE.getValueID(NMD->getOperand(i)));
563        else
564          Record.push_back(~0U);
565      }
566      Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
567      Record.clear();
568    }
569  }
570
571  if (StartedMetadataBlock)
572    Stream.ExitBlock();
573}
574
575static void WriteFunctionLocalMetadata(const Function &F,
576                                       const ValueEnumerator &VE,
577                                       BitstreamWriter &Stream) {
578  bool StartedMetadataBlock = false;
579  SmallVector<uint64_t, 64> Record;
580  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
581
582  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
583    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first))
584      if (N->isFunctionLocal() && N->getFunction() == &F) {
585        if (!StartedMetadataBlock) {
586          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
587          StartedMetadataBlock = true;
588        }
589        WriteMDNode(N, VE, Stream, Record);
590      }
591
592  if (StartedMetadataBlock)
593    Stream.ExitBlock();
594}
595
596static void WriteMetadataAttachment(const Function &F,
597                                    const ValueEnumerator &VE,
598                                    BitstreamWriter &Stream) {
599  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
600
601  SmallVector<uint64_t, 64> Record;
602
603  // Write metadata attachments
604  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
605  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
606
607  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
608    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
609         I != E; ++I) {
610      MDs.clear();
611      I->getAllMetadataOtherThanDebugLoc(MDs);
612
613      // If no metadata, ignore instruction.
614      if (MDs.empty()) continue;
615
616      Record.push_back(VE.getInstructionID(I));
617
618      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
619        Record.push_back(MDs[i].first);
620        Record.push_back(VE.getValueID(MDs[i].second));
621      }
622      Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
623      Record.clear();
624    }
625
626  Stream.ExitBlock();
627}
628
629static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
630  SmallVector<uint64_t, 64> Record;
631
632  // Write metadata kinds
633  // METADATA_KIND - [n x [id, name]]
634  SmallVector<StringRef, 4> Names;
635  M->getMDKindNames(Names);
636
637  assert(Names[0] == "" && "MDKind #0 is invalid");
638  if (Names.size() == 1) return;
639
640  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
641
642  for (unsigned MDKindID = 1, e = Names.size(); MDKindID != e; ++MDKindID) {
643    Record.push_back(MDKindID);
644    StringRef KName = Names[MDKindID];
645    Record.append(KName.begin(), KName.end());
646
647    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
648    Record.clear();
649  }
650
651  Stream.ExitBlock();
652}
653
654static void WriteConstants(unsigned FirstVal, unsigned LastVal,
655                           const ValueEnumerator &VE,
656                           BitstreamWriter &Stream, bool isGlobal) {
657  if (FirstVal == LastVal) return;
658
659  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
660
661  unsigned AggregateAbbrev = 0;
662  unsigned String8Abbrev = 0;
663  unsigned CString7Abbrev = 0;
664  unsigned CString6Abbrev = 0;
665  // If this is a constant pool for the module, emit module-specific abbrevs.
666  if (isGlobal) {
667    // Abbrev for CST_CODE_AGGREGATE.
668    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
669    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
670    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
671    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
672    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
673
674    // Abbrev for CST_CODE_STRING.
675    Abbv = new BitCodeAbbrev();
676    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
677    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
678    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
679    String8Abbrev = Stream.EmitAbbrev(Abbv);
680    // Abbrev for CST_CODE_CSTRING.
681    Abbv = new BitCodeAbbrev();
682    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
683    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
684    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
685    CString7Abbrev = Stream.EmitAbbrev(Abbv);
686    // Abbrev for CST_CODE_CSTRING.
687    Abbv = new BitCodeAbbrev();
688    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
689    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
690    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
691    CString6Abbrev = Stream.EmitAbbrev(Abbv);
692  }
693
694  SmallVector<uint64_t, 64> Record;
695
696  const ValueEnumerator::ValueList &Vals = VE.getValues();
697  const Type *LastTy = 0;
698  for (unsigned i = FirstVal; i != LastVal; ++i) {
699    const Value *V = Vals[i].first;
700    // If we need to switch types, do so now.
701    if (V->getType() != LastTy) {
702      LastTy = V->getType();
703      Record.push_back(VE.getTypeID(LastTy));
704      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
705                        CONSTANTS_SETTYPE_ABBREV);
706      Record.clear();
707    }
708
709    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
710      Record.push_back(unsigned(IA->hasSideEffects()) |
711                       unsigned(IA->isAlignStack()) << 1);
712
713      // Add the asm string.
714      const std::string &AsmStr = IA->getAsmString();
715      Record.push_back(AsmStr.size());
716      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
717        Record.push_back(AsmStr[i]);
718
719      // Add the constraint string.
720      const std::string &ConstraintStr = IA->getConstraintString();
721      Record.push_back(ConstraintStr.size());
722      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
723        Record.push_back(ConstraintStr[i]);
724      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
725      Record.clear();
726      continue;
727    }
728    const Constant *C = cast<Constant>(V);
729    unsigned Code = -1U;
730    unsigned AbbrevToUse = 0;
731    if (C->isNullValue()) {
732      Code = bitc::CST_CODE_NULL;
733    } else if (isa<UndefValue>(C)) {
734      Code = bitc::CST_CODE_UNDEF;
735    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
736      if (IV->getBitWidth() <= 64) {
737        int64_t V = IV->getSExtValue();
738        if (V >= 0)
739          Record.push_back(V << 1);
740        else
741          Record.push_back((-V << 1) | 1);
742        Code = bitc::CST_CODE_INTEGER;
743        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
744      } else {                             // Wide integers, > 64 bits in size.
745        // We have an arbitrary precision integer value to write whose
746        // bit width is > 64. However, in canonical unsigned integer
747        // format it is likely that the high bits are going to be zero.
748        // So, we only write the number of active words.
749        unsigned NWords = IV->getValue().getActiveWords();
750        const uint64_t *RawWords = IV->getValue().getRawData();
751        for (unsigned i = 0; i != NWords; ++i) {
752          int64_t V = RawWords[i];
753          if (V >= 0)
754            Record.push_back(V << 1);
755          else
756            Record.push_back((-V << 1) | 1);
757        }
758        Code = bitc::CST_CODE_WIDE_INTEGER;
759      }
760    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
761      Code = bitc::CST_CODE_FLOAT;
762      const Type *Ty = CFP->getType();
763      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
764        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
765      } else if (Ty->isX86_FP80Ty()) {
766        // api needed to prevent premature destruction
767        // bits are not in the same order as a normal i80 APInt, compensate.
768        APInt api = CFP->getValueAPF().bitcastToAPInt();
769        const uint64_t *p = api.getRawData();
770        Record.push_back((p[1] << 48) | (p[0] >> 16));
771        Record.push_back(p[0] & 0xffffLL);
772      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
773        APInt api = CFP->getValueAPF().bitcastToAPInt();
774        const uint64_t *p = api.getRawData();
775        Record.push_back(p[0]);
776        Record.push_back(p[1]);
777      } else {
778        assert (0 && "Unknown FP type!");
779      }
780    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
781      const ConstantArray *CA = cast<ConstantArray>(C);
782      // Emit constant strings specially.
783      unsigned NumOps = CA->getNumOperands();
784      // If this is a null-terminated string, use the denser CSTRING encoding.
785      if (CA->getOperand(NumOps-1)->isNullValue()) {
786        Code = bitc::CST_CODE_CSTRING;
787        --NumOps;  // Don't encode the null, which isn't allowed by char6.
788      } else {
789        Code = bitc::CST_CODE_STRING;
790        AbbrevToUse = String8Abbrev;
791      }
792      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
793      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
794      for (unsigned i = 0; i != NumOps; ++i) {
795        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
796        Record.push_back(V);
797        isCStr7 &= (V & 128) == 0;
798        if (isCStrChar6)
799          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
800      }
801
802      if (isCStrChar6)
803        AbbrevToUse = CString6Abbrev;
804      else if (isCStr7)
805        AbbrevToUse = CString7Abbrev;
806    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
807               isa<ConstantVector>(V)) {
808      Code = bitc::CST_CODE_AGGREGATE;
809      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
810        Record.push_back(VE.getValueID(C->getOperand(i)));
811      AbbrevToUse = AggregateAbbrev;
812    } else if (isa<ConstantUnion>(C)) {
813      Code = bitc::CST_CODE_AGGREGATE;
814
815      // Unions only have one entry but we must send type along with it.
816      const Type *EntryKind = C->getOperand(0)->getType();
817
818      const UnionType *UnTy = cast<UnionType>(C->getType());
819      int UnionIndex = UnTy->getElementTypeIndex(EntryKind);
820      assert(UnionIndex != -1 && "Constant union contains invalid entry");
821
822      Record.push_back(UnionIndex);
823      Record.push_back(VE.getValueID(C->getOperand(0)));
824
825      AbbrevToUse = AggregateAbbrev;
826    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
827      switch (CE->getOpcode()) {
828      default:
829        if (Instruction::isCast(CE->getOpcode())) {
830          Code = bitc::CST_CODE_CE_CAST;
831          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
832          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
833          Record.push_back(VE.getValueID(C->getOperand(0)));
834          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
835        } else {
836          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
837          Code = bitc::CST_CODE_CE_BINOP;
838          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
839          Record.push_back(VE.getValueID(C->getOperand(0)));
840          Record.push_back(VE.getValueID(C->getOperand(1)));
841          uint64_t Flags = GetOptimizationFlags(CE);
842          if (Flags != 0)
843            Record.push_back(Flags);
844        }
845        break;
846      case Instruction::GetElementPtr:
847        Code = bitc::CST_CODE_CE_GEP;
848        if (cast<GEPOperator>(C)->isInBounds())
849          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
850        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
851          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
852          Record.push_back(VE.getValueID(C->getOperand(i)));
853        }
854        break;
855      case Instruction::Select:
856        Code = bitc::CST_CODE_CE_SELECT;
857        Record.push_back(VE.getValueID(C->getOperand(0)));
858        Record.push_back(VE.getValueID(C->getOperand(1)));
859        Record.push_back(VE.getValueID(C->getOperand(2)));
860        break;
861      case Instruction::ExtractElement:
862        Code = bitc::CST_CODE_CE_EXTRACTELT;
863        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
864        Record.push_back(VE.getValueID(C->getOperand(0)));
865        Record.push_back(VE.getValueID(C->getOperand(1)));
866        break;
867      case Instruction::InsertElement:
868        Code = bitc::CST_CODE_CE_INSERTELT;
869        Record.push_back(VE.getValueID(C->getOperand(0)));
870        Record.push_back(VE.getValueID(C->getOperand(1)));
871        Record.push_back(VE.getValueID(C->getOperand(2)));
872        break;
873      case Instruction::ShuffleVector:
874        // If the return type and argument types are the same, this is a
875        // standard shufflevector instruction.  If the types are different,
876        // then the shuffle is widening or truncating the input vectors, and
877        // the argument type must also be encoded.
878        if (C->getType() == C->getOperand(0)->getType()) {
879          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
880        } else {
881          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
882          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
883        }
884        Record.push_back(VE.getValueID(C->getOperand(0)));
885        Record.push_back(VE.getValueID(C->getOperand(1)));
886        Record.push_back(VE.getValueID(C->getOperand(2)));
887        break;
888      case Instruction::ICmp:
889      case Instruction::FCmp:
890        Code = bitc::CST_CODE_CE_CMP;
891        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
892        Record.push_back(VE.getValueID(C->getOperand(0)));
893        Record.push_back(VE.getValueID(C->getOperand(1)));
894        Record.push_back(CE->getPredicate());
895        break;
896      }
897    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
898      assert(BA->getFunction() == BA->getBasicBlock()->getParent() &&
899             "Malformed blockaddress");
900      Code = bitc::CST_CODE_BLOCKADDRESS;
901      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
902      Record.push_back(VE.getValueID(BA->getFunction()));
903      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
904    } else {
905      llvm_unreachable("Unknown constant!");
906    }
907    Stream.EmitRecord(Code, Record, AbbrevToUse);
908    Record.clear();
909  }
910
911  Stream.ExitBlock();
912}
913
914static void WriteModuleConstants(const ValueEnumerator &VE,
915                                 BitstreamWriter &Stream) {
916  const ValueEnumerator::ValueList &Vals = VE.getValues();
917
918  // Find the first constant to emit, which is the first non-globalvalue value.
919  // We know globalvalues have been emitted by WriteModuleInfo.
920  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
921    if (!isa<GlobalValue>(Vals[i].first)) {
922      WriteConstants(i, Vals.size(), VE, Stream, true);
923      return;
924    }
925  }
926}
927
928/// PushValueAndType - The file has to encode both the value and type id for
929/// many values, because we need to know what type to create for forward
930/// references.  However, most operands are not forward references, so this type
931/// field is not needed.
932///
933/// This function adds V's value ID to Vals.  If the value ID is higher than the
934/// instruction ID, then it is a forward reference, and it also includes the
935/// type ID.
936static bool PushValueAndType(const Value *V, unsigned InstID,
937                             SmallVector<unsigned, 64> &Vals,
938                             ValueEnumerator &VE) {
939  unsigned ValID = VE.getValueID(V);
940  Vals.push_back(ValID);
941  if (ValID >= InstID) {
942    Vals.push_back(VE.getTypeID(V->getType()));
943    return true;
944  }
945  return false;
946}
947
948/// WriteInstruction - Emit an instruction to the specified stream.
949static void WriteInstruction(const Instruction &I, unsigned InstID,
950                             ValueEnumerator &VE, BitstreamWriter &Stream,
951                             SmallVector<unsigned, 64> &Vals) {
952  unsigned Code = 0;
953  unsigned AbbrevToUse = 0;
954  VE.setInstructionID(&I);
955  switch (I.getOpcode()) {
956  default:
957    if (Instruction::isCast(I.getOpcode())) {
958      Code = bitc::FUNC_CODE_INST_CAST;
959      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
960        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
961      Vals.push_back(VE.getTypeID(I.getType()));
962      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
963    } else {
964      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
965      Code = bitc::FUNC_CODE_INST_BINOP;
966      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
967        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
968      Vals.push_back(VE.getValueID(I.getOperand(1)));
969      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
970      uint64_t Flags = GetOptimizationFlags(&I);
971      if (Flags != 0) {
972        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
973          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
974        Vals.push_back(Flags);
975      }
976    }
977    break;
978
979  case Instruction::GetElementPtr:
980    Code = bitc::FUNC_CODE_INST_GEP;
981    if (cast<GEPOperator>(&I)->isInBounds())
982      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
983    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
984      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
985    break;
986  case Instruction::ExtractValue: {
987    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
988    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
989    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
990    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
991      Vals.push_back(*i);
992    break;
993  }
994  case Instruction::InsertValue: {
995    Code = bitc::FUNC_CODE_INST_INSERTVAL;
996    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
997    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
998    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
999    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1000      Vals.push_back(*i);
1001    break;
1002  }
1003  case Instruction::Select:
1004    Code = bitc::FUNC_CODE_INST_VSELECT;
1005    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1006    Vals.push_back(VE.getValueID(I.getOperand(2)));
1007    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1008    break;
1009  case Instruction::ExtractElement:
1010    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1011    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1012    Vals.push_back(VE.getValueID(I.getOperand(1)));
1013    break;
1014  case Instruction::InsertElement:
1015    Code = bitc::FUNC_CODE_INST_INSERTELT;
1016    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1017    Vals.push_back(VE.getValueID(I.getOperand(1)));
1018    Vals.push_back(VE.getValueID(I.getOperand(2)));
1019    break;
1020  case Instruction::ShuffleVector:
1021    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1022    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1023    Vals.push_back(VE.getValueID(I.getOperand(1)));
1024    Vals.push_back(VE.getValueID(I.getOperand(2)));
1025    break;
1026  case Instruction::ICmp:
1027  case Instruction::FCmp:
1028    // compare returning Int1Ty or vector of Int1Ty
1029    Code = bitc::FUNC_CODE_INST_CMP2;
1030    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1031    Vals.push_back(VE.getValueID(I.getOperand(1)));
1032    Vals.push_back(cast<CmpInst>(I).getPredicate());
1033    break;
1034
1035  case Instruction::Ret:
1036    {
1037      Code = bitc::FUNC_CODE_INST_RET;
1038      unsigned NumOperands = I.getNumOperands();
1039      if (NumOperands == 0)
1040        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1041      else if (NumOperands == 1) {
1042        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1043          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1044      } else {
1045        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1046          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1047      }
1048    }
1049    break;
1050  case Instruction::Br:
1051    {
1052      Code = bitc::FUNC_CODE_INST_BR;
1053      BranchInst &II = cast<BranchInst>(I);
1054      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1055      if (II.isConditional()) {
1056        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1057        Vals.push_back(VE.getValueID(II.getCondition()));
1058      }
1059    }
1060    break;
1061  case Instruction::Switch:
1062    Code = bitc::FUNC_CODE_INST_SWITCH;
1063    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1064    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1065      Vals.push_back(VE.getValueID(I.getOperand(i)));
1066    break;
1067  case Instruction::IndirectBr:
1068    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1069    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1070    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1071      Vals.push_back(VE.getValueID(I.getOperand(i)));
1072    break;
1073
1074  case Instruction::Invoke: {
1075    const InvokeInst *II = cast<InvokeInst>(&I);
1076    const Value *Callee(II->getCalledValue());
1077    const PointerType *PTy = cast<PointerType>(Callee->getType());
1078    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1079    Code = bitc::FUNC_CODE_INST_INVOKE;
1080
1081    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1082    Vals.push_back(II->getCallingConv());
1083    Vals.push_back(VE.getValueID(II->getNormalDest()));
1084    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1085    PushValueAndType(Callee, InstID, Vals, VE);
1086
1087    // Emit value #'s for the fixed parameters.
1088    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1089      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1090
1091    // Emit type/value pairs for varargs params.
1092    if (FTy->isVarArg()) {
1093      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1094           i != e; ++i)
1095        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1096    }
1097    break;
1098  }
1099  case Instruction::Unwind:
1100    Code = bitc::FUNC_CODE_INST_UNWIND;
1101    break;
1102  case Instruction::Unreachable:
1103    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1104    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1105    break;
1106
1107  case Instruction::PHI:
1108    Code = bitc::FUNC_CODE_INST_PHI;
1109    Vals.push_back(VE.getTypeID(I.getType()));
1110    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1111      Vals.push_back(VE.getValueID(I.getOperand(i)));
1112    break;
1113
1114  case Instruction::Alloca:
1115    Code = bitc::FUNC_CODE_INST_ALLOCA;
1116    Vals.push_back(VE.getTypeID(I.getType()));
1117    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1118    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1119    break;
1120
1121  case Instruction::Load:
1122    Code = bitc::FUNC_CODE_INST_LOAD;
1123    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1124      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1125
1126    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1127    Vals.push_back(cast<LoadInst>(I).isVolatile());
1128    break;
1129  case Instruction::Store:
1130    Code = bitc::FUNC_CODE_INST_STORE2;
1131    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1132    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1133    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1134    Vals.push_back(cast<StoreInst>(I).isVolatile());
1135    break;
1136  case Instruction::Call: {
1137    const PointerType *PTy = cast<PointerType>(I.getOperand(0)->getType());
1138    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1139
1140    Code = bitc::FUNC_CODE_INST_CALL;
1141
1142    const CallInst *CI = cast<CallInst>(&I);
1143    Vals.push_back(VE.getAttributeID(CI->getAttributes()));
1144    Vals.push_back((CI->getCallingConv() << 1) | unsigned(CI->isTailCall()));
1145    PushValueAndType(CI->getOperand(0), InstID, Vals, VE);  // Callee
1146
1147    // Emit value #'s for the fixed parameters.
1148    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1149      Vals.push_back(VE.getValueID(I.getOperand(i+1)));  // fixed param.
1150
1151    // Emit type/value pairs for varargs params.
1152    if (FTy->isVarArg()) {
1153      unsigned NumVarargs = I.getNumOperands()-1-FTy->getNumParams();
1154      for (unsigned i = I.getNumOperands()-NumVarargs, e = I.getNumOperands();
1155           i != e; ++i)
1156        PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
1157    }
1158    break;
1159  }
1160  case Instruction::VAArg:
1161    Code = bitc::FUNC_CODE_INST_VAARG;
1162    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1163    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1164    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1165    break;
1166  }
1167
1168  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1169  Vals.clear();
1170}
1171
1172// Emit names for globals/functions etc.
1173static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1174                                  const ValueEnumerator &VE,
1175                                  BitstreamWriter &Stream) {
1176  if (VST.empty()) return;
1177  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1178
1179  // FIXME: Set up the abbrev, we know how many values there are!
1180  // FIXME: We know if the type names can use 7-bit ascii.
1181  SmallVector<unsigned, 64> NameVals;
1182
1183  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1184       SI != SE; ++SI) {
1185
1186    const ValueName &Name = *SI;
1187
1188    // Figure out the encoding to use for the name.
1189    bool is7Bit = true;
1190    bool isChar6 = true;
1191    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1192         C != E; ++C) {
1193      if (isChar6)
1194        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1195      if ((unsigned char)*C & 128) {
1196        is7Bit = false;
1197        break;  // don't bother scanning the rest.
1198      }
1199    }
1200
1201    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1202
1203    // VST_ENTRY:   [valueid, namechar x N]
1204    // VST_BBENTRY: [bbid, namechar x N]
1205    unsigned Code;
1206    if (isa<BasicBlock>(SI->getValue())) {
1207      Code = bitc::VST_CODE_BBENTRY;
1208      if (isChar6)
1209        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1210    } else {
1211      Code = bitc::VST_CODE_ENTRY;
1212      if (isChar6)
1213        AbbrevToUse = VST_ENTRY_6_ABBREV;
1214      else if (is7Bit)
1215        AbbrevToUse = VST_ENTRY_7_ABBREV;
1216    }
1217
1218    NameVals.push_back(VE.getValueID(SI->getValue()));
1219    for (const char *P = Name.getKeyData(),
1220         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1221      NameVals.push_back((unsigned char)*P);
1222
1223    // Emit the finished record.
1224    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1225    NameVals.clear();
1226  }
1227  Stream.ExitBlock();
1228}
1229
1230/// WriteFunction - Emit a function body to the module stream.
1231static void WriteFunction(const Function &F, ValueEnumerator &VE,
1232                          BitstreamWriter &Stream) {
1233  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1234  VE.incorporateFunction(F);
1235
1236  SmallVector<unsigned, 64> Vals;
1237
1238  // Emit the number of basic blocks, so the reader can create them ahead of
1239  // time.
1240  Vals.push_back(VE.getBasicBlocks().size());
1241  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1242  Vals.clear();
1243
1244  // If there are function-local constants, emit them now.
1245  unsigned CstStart, CstEnd;
1246  VE.getFunctionConstantRange(CstStart, CstEnd);
1247  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1248
1249  // If there is function-local metadata, emit it now.
1250  WriteFunctionLocalMetadata(F, VE, Stream);
1251
1252  // Keep a running idea of what the instruction ID is.
1253  unsigned InstID = CstEnd;
1254
1255  bool NeedsMetadataAttachment = false;
1256
1257  DebugLoc LastDL;
1258
1259  // Finally, emit all the instructions, in order.
1260  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1261    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1262         I != E; ++I) {
1263      WriteInstruction(*I, InstID, VE, Stream, Vals);
1264
1265      if (!I->getType()->isVoidTy())
1266        ++InstID;
1267
1268      // If the instruction has metadata, write a metadata attachment later.
1269      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1270
1271      // If the instruction has a debug location, emit it.
1272      DebugLoc DL = I->getDebugLoc();
1273      if (DL.isUnknown()) {
1274        // nothing todo.
1275      } else if (DL == LastDL) {
1276        // Just repeat the same debug loc as last time.
1277        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1278      } else {
1279        MDNode *Scope, *IA;
1280        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1281
1282        Vals.push_back(DL.getLine());
1283        Vals.push_back(DL.getCol());
1284        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1285        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1286        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1287        Vals.clear();
1288
1289        LastDL = DL;
1290      }
1291    }
1292
1293  // Emit names for all the instructions etc.
1294  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1295
1296  if (NeedsMetadataAttachment)
1297    WriteMetadataAttachment(F, VE, Stream);
1298  VE.purgeFunction();
1299  Stream.ExitBlock();
1300}
1301
1302/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1303static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1304                                 const ValueEnumerator &VE,
1305                                 BitstreamWriter &Stream) {
1306  if (TST.empty()) return;
1307
1308  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1309
1310  // 7-bit fixed width VST_CODE_ENTRY strings.
1311  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1312  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1313  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1314                            Log2_32_Ceil(VE.getTypes().size()+1)));
1315  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1316  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1317  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1318
1319  SmallVector<unsigned, 64> NameVals;
1320
1321  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1322       TI != TE; ++TI) {
1323    // TST_ENTRY: [typeid, namechar x N]
1324    NameVals.push_back(VE.getTypeID(TI->second));
1325
1326    const std::string &Str = TI->first;
1327    bool is7Bit = true;
1328    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1329      NameVals.push_back((unsigned char)Str[i]);
1330      if (Str[i] & 128)
1331        is7Bit = false;
1332    }
1333
1334    // Emit the finished record.
1335    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1336    NameVals.clear();
1337  }
1338
1339  Stream.ExitBlock();
1340}
1341
1342// Emit blockinfo, which defines the standard abbreviations etc.
1343static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1344  // We only want to emit block info records for blocks that have multiple
1345  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1346  // blocks can defined their abbrevs inline.
1347  Stream.EnterBlockInfoBlock(2);
1348
1349  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1350    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1351    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1352    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1353    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1354    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1355    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1356                                   Abbv) != VST_ENTRY_8_ABBREV)
1357      llvm_unreachable("Unexpected abbrev ordering!");
1358  }
1359
1360  { // 7-bit fixed width VST_ENTRY strings.
1361    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1362    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1363    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1364    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1365    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1366    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1367                                   Abbv) != VST_ENTRY_7_ABBREV)
1368      llvm_unreachable("Unexpected abbrev ordering!");
1369  }
1370  { // 6-bit char6 VST_ENTRY strings.
1371    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1372    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1373    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1374    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1375    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1376    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1377                                   Abbv) != VST_ENTRY_6_ABBREV)
1378      llvm_unreachable("Unexpected abbrev ordering!");
1379  }
1380  { // 6-bit char6 VST_BBENTRY strings.
1381    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1382    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1383    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1384    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1385    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1386    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1387                                   Abbv) != VST_BBENTRY_6_ABBREV)
1388      llvm_unreachable("Unexpected abbrev ordering!");
1389  }
1390
1391
1392
1393  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1394    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1395    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1396    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1397                              Log2_32_Ceil(VE.getTypes().size()+1)));
1398    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1399                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1400      llvm_unreachable("Unexpected abbrev ordering!");
1401  }
1402
1403  { // INTEGER abbrev for CONSTANTS_BLOCK.
1404    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1405    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1406    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1407    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1408                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1409      llvm_unreachable("Unexpected abbrev ordering!");
1410  }
1411
1412  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1413    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1414    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1415    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1416    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1417                              Log2_32_Ceil(VE.getTypes().size()+1)));
1418    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1419
1420    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1421                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1422      llvm_unreachable("Unexpected abbrev ordering!");
1423  }
1424  { // NULL abbrev for CONSTANTS_BLOCK.
1425    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1426    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1427    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1428                                   Abbv) != CONSTANTS_NULL_Abbrev)
1429      llvm_unreachable("Unexpected abbrev ordering!");
1430  }
1431
1432  // FIXME: This should only use space for first class types!
1433
1434  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1435    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1436    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1437    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1438    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1439    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1440    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1441                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1442      llvm_unreachable("Unexpected abbrev ordering!");
1443  }
1444  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1445    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1446    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1447    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1448    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1449    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1450    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1451                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1452      llvm_unreachable("Unexpected abbrev ordering!");
1453  }
1454  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1455    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1456    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1457    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1458    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1459    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1460    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1461    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1462                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1463      llvm_unreachable("Unexpected abbrev ordering!");
1464  }
1465  { // INST_CAST abbrev for FUNCTION_BLOCK.
1466    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1467    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1468    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1469    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1470                              Log2_32_Ceil(VE.getTypes().size()+1)));
1471    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1472    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1473                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1474      llvm_unreachable("Unexpected abbrev ordering!");
1475  }
1476
1477  { // INST_RET abbrev for FUNCTION_BLOCK.
1478    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1479    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1480    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1481                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1482      llvm_unreachable("Unexpected abbrev ordering!");
1483  }
1484  { // INST_RET abbrev for FUNCTION_BLOCK.
1485    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1486    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1487    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1488    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1489                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1490      llvm_unreachable("Unexpected abbrev ordering!");
1491  }
1492  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1493    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1494    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1495    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1496                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1497      llvm_unreachable("Unexpected abbrev ordering!");
1498  }
1499
1500  Stream.ExitBlock();
1501}
1502
1503
1504/// WriteModule - Emit the specified module to the bitstream.
1505static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1506  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1507
1508  // Emit the version number if it is non-zero.
1509  if (CurVersion) {
1510    SmallVector<unsigned, 1> Vals;
1511    Vals.push_back(CurVersion);
1512    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1513  }
1514
1515  // Analyze the module, enumerating globals, functions, etc.
1516  ValueEnumerator VE(M);
1517
1518  // Emit blockinfo, which defines the standard abbreviations etc.
1519  WriteBlockInfo(VE, Stream);
1520
1521  // Emit information about parameter attributes.
1522  WriteAttributeTable(VE, Stream);
1523
1524  // Emit information describing all of the types in the module.
1525  WriteTypeTable(VE, Stream);
1526
1527  // Emit top-level description of module, including target triple, inline asm,
1528  // descriptors for global variables, and function prototype info.
1529  WriteModuleInfo(M, VE, Stream);
1530
1531  // Emit constants.
1532  WriteModuleConstants(VE, Stream);
1533
1534  // Emit metadata.
1535  WriteModuleMetadata(VE, Stream);
1536
1537  // Emit function bodies.
1538  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1539    if (!I->isDeclaration())
1540      WriteFunction(*I, VE, Stream);
1541
1542  // Emit metadata.
1543  WriteModuleMetadataStore(M, Stream);
1544
1545  // Emit the type symbol table information.
1546  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1547
1548  // Emit names for globals/functions etc.
1549  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1550
1551  Stream.ExitBlock();
1552}
1553
1554/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1555/// header and trailer to make it compatible with the system archiver.  To do
1556/// this we emit the following header, and then emit a trailer that pads the
1557/// file out to be a multiple of 16 bytes.
1558///
1559/// struct bc_header {
1560///   uint32_t Magic;         // 0x0B17C0DE
1561///   uint32_t Version;       // Version, currently always 0.
1562///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1563///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1564///   uint32_t CPUType;       // CPU specifier.
1565///   ... potentially more later ...
1566/// };
1567enum {
1568  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1569  DarwinBCHeaderSize = 5*4
1570};
1571
1572/// isARMTriplet - Return true if the triplet looks like:
1573/// arm-*, thumb-*, armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*.
1574static bool isARMTriplet(const std::string &TT) {
1575  size_t Pos = 0;
1576  size_t Size = TT.size();
1577  if (Size >= 6 &&
1578      TT[0] == 't' && TT[1] == 'h' && TT[2] == 'u' &&
1579      TT[3] == 'm' && TT[4] == 'b')
1580    Pos = 5;
1581  else if (Size >= 4 && TT[0] == 'a' && TT[1] == 'r' && TT[2] == 'm')
1582    Pos = 3;
1583  else
1584    return false;
1585
1586  if (TT[Pos] == '-')
1587    return true;
1588  else if (TT[Pos] == 'v') {
1589    if (Size >= Pos+4 &&
1590        TT[Pos+1] == '6' && TT[Pos+2] == 't' && TT[Pos+3] == '2')
1591      return true;
1592    else if (Size >= Pos+4 &&
1593             TT[Pos+1] == '5' && TT[Pos+2] == 't' && TT[Pos+3] == 'e')
1594      return true;
1595  } else
1596    return false;
1597  while (++Pos < Size && TT[Pos] != '-') {
1598    if (!isdigit(TT[Pos]))
1599      return false;
1600  }
1601  return true;
1602}
1603
1604static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1605                               const std::string &TT) {
1606  unsigned CPUType = ~0U;
1607
1608  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1609  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1610  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1611  // specific constants here because they are implicitly part of the Darwin ABI.
1612  enum {
1613    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1614    DARWIN_CPU_TYPE_X86        = 7,
1615    DARWIN_CPU_TYPE_ARM        = 12,
1616    DARWIN_CPU_TYPE_POWERPC    = 18
1617  };
1618
1619  if (TT.find("x86_64-") == 0)
1620    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1621  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1622           TT[4] == '-' && TT[1] - '3' < 6)
1623    CPUType = DARWIN_CPU_TYPE_X86;
1624  else if (TT.find("powerpc-") == 0)
1625    CPUType = DARWIN_CPU_TYPE_POWERPC;
1626  else if (TT.find("powerpc64-") == 0)
1627    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1628  else if (isARMTriplet(TT))
1629    CPUType = DARWIN_CPU_TYPE_ARM;
1630
1631  // Traditional Bitcode starts after header.
1632  unsigned BCOffset = DarwinBCHeaderSize;
1633
1634  Stream.Emit(0x0B17C0DE, 32);
1635  Stream.Emit(0         , 32);  // Version.
1636  Stream.Emit(BCOffset  , 32);
1637  Stream.Emit(0         , 32);  // Filled in later.
1638  Stream.Emit(CPUType   , 32);
1639}
1640
1641/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1642/// finalize the header.
1643static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1644  // Update the size field in the header.
1645  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1646
1647  // If the file is not a multiple of 16 bytes, insert dummy padding.
1648  while (BufferSize & 15) {
1649    Stream.Emit(0, 8);
1650    ++BufferSize;
1651  }
1652}
1653
1654
1655/// WriteBitcodeToFile - Write the specified module to the specified output
1656/// stream.
1657void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1658  std::vector<unsigned char> Buffer;
1659  BitstreamWriter Stream(Buffer);
1660
1661  Buffer.reserve(256*1024);
1662
1663  WriteBitcodeToStream( M, Stream );
1664
1665  // Write the generated bitstream to "Out".
1666  Out.write((char*)&Buffer.front(), Buffer.size());
1667
1668  // Make sure it hits disk now.
1669  Out.flush();
1670}
1671
1672/// WriteBitcodeToStream - Write the specified module to the specified output
1673/// stream.
1674void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1675  // If this is darwin, emit a file header and trailer if needed.
1676  bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1677  if (isDarwin)
1678    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1679
1680  // Emit the file header.
1681  Stream.Emit((unsigned)'B', 8);
1682  Stream.Emit((unsigned)'C', 8);
1683  Stream.Emit(0x0, 4);
1684  Stream.Emit(0xC, 4);
1685  Stream.Emit(0xE, 4);
1686  Stream.Emit(0xD, 4);
1687
1688  // Emit the module.
1689  WriteModule(M, Stream);
1690
1691  if (isDarwin)
1692    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1693}
1694