BitcodeWriter.cpp revision 165dac08d1bb8428b32a5f39cdd3dbee2888987f 
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 CallInst &CI = cast<CallInst>(I);
1138    const PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1139    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1140
1141    Code = bitc::FUNC_CODE_INST_CALL;
1142
1143    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1144    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1145    PushValueAndType(CI.getCalledValue(), 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)));  // fixed param.
1150
1151    // Emit type/value pairs for varargs params.
1152    if (FTy->isVarArg()) {
1153      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-1;
1154           i != e; ++i)
1155        PushValueAndType(I.getOperand(i), InstID, Vals, VE);  // varargs
1156    }
1157    break;
1158  }
1159  case Instruction::VAArg:
1160    Code = bitc::FUNC_CODE_INST_VAARG;
1161    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1162    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1163    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1164    break;
1165  }
1166
1167  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1168  Vals.clear();
1169}
1170
1171// Emit names for globals/functions etc.
1172static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1173                                  const ValueEnumerator &VE,
1174                                  BitstreamWriter &Stream) {
1175  if (VST.empty()) return;
1176  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1177
1178  // FIXME: Set up the abbrev, we know how many values there are!
1179  // FIXME: We know if the type names can use 7-bit ascii.
1180  SmallVector<unsigned, 64> NameVals;
1181
1182  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1183       SI != SE; ++SI) {
1184
1185    const ValueName &Name = *SI;
1186
1187    // Figure out the encoding to use for the name.
1188    bool is7Bit = true;
1189    bool isChar6 = true;
1190    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1191         C != E; ++C) {
1192      if (isChar6)
1193        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1194      if ((unsigned char)*C & 128) {
1195        is7Bit = false;
1196        break;  // don't bother scanning the rest.
1197      }
1198    }
1199
1200    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1201
1202    // VST_ENTRY:   [valueid, namechar x N]
1203    // VST_BBENTRY: [bbid, namechar x N]
1204    unsigned Code;
1205    if (isa<BasicBlock>(SI->getValue())) {
1206      Code = bitc::VST_CODE_BBENTRY;
1207      if (isChar6)
1208        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1209    } else {
1210      Code = bitc::VST_CODE_ENTRY;
1211      if (isChar6)
1212        AbbrevToUse = VST_ENTRY_6_ABBREV;
1213      else if (is7Bit)
1214        AbbrevToUse = VST_ENTRY_7_ABBREV;
1215    }
1216
1217    NameVals.push_back(VE.getValueID(SI->getValue()));
1218    for (const char *P = Name.getKeyData(),
1219         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1220      NameVals.push_back((unsigned char)*P);
1221
1222    // Emit the finished record.
1223    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1224    NameVals.clear();
1225  }
1226  Stream.ExitBlock();
1227}
1228
1229/// WriteFunction - Emit a function body to the module stream.
1230static void WriteFunction(const Function &F, ValueEnumerator &VE,
1231                          BitstreamWriter &Stream) {
1232  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1233  VE.incorporateFunction(F);
1234
1235  SmallVector<unsigned, 64> Vals;
1236
1237  // Emit the number of basic blocks, so the reader can create them ahead of
1238  // time.
1239  Vals.push_back(VE.getBasicBlocks().size());
1240  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1241  Vals.clear();
1242
1243  // If there are function-local constants, emit them now.
1244  unsigned CstStart, CstEnd;
1245  VE.getFunctionConstantRange(CstStart, CstEnd);
1246  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1247
1248  // If there is function-local metadata, emit it now.
1249  WriteFunctionLocalMetadata(F, VE, Stream);
1250
1251  // Keep a running idea of what the instruction ID is.
1252  unsigned InstID = CstEnd;
1253
1254  bool NeedsMetadataAttachment = false;
1255
1256  DebugLoc LastDL;
1257
1258  // Finally, emit all the instructions, in order.
1259  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1260    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1261         I != E; ++I) {
1262      WriteInstruction(*I, InstID, VE, Stream, Vals);
1263
1264      if (!I->getType()->isVoidTy())
1265        ++InstID;
1266
1267      // If the instruction has metadata, write a metadata attachment later.
1268      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1269
1270      // If the instruction has a debug location, emit it.
1271      DebugLoc DL = I->getDebugLoc();
1272      if (DL.isUnknown()) {
1273        // nothing todo.
1274      } else if (DL == LastDL) {
1275        // Just repeat the same debug loc as last time.
1276        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1277      } else {
1278        MDNode *Scope, *IA;
1279        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1280
1281        Vals.push_back(DL.getLine());
1282        Vals.push_back(DL.getCol());
1283        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1284        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1285        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1286        Vals.clear();
1287
1288        LastDL = DL;
1289      }
1290    }
1291
1292  // Emit names for all the instructions etc.
1293  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1294
1295  if (NeedsMetadataAttachment)
1296    WriteMetadataAttachment(F, VE, Stream);
1297  VE.purgeFunction();
1298  Stream.ExitBlock();
1299}
1300
1301/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1302static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1303                                 const ValueEnumerator &VE,
1304                                 BitstreamWriter &Stream) {
1305  if (TST.empty()) return;
1306
1307  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1308
1309  // 7-bit fixed width VST_CODE_ENTRY strings.
1310  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1311  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1312  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1313                            Log2_32_Ceil(VE.getTypes().size()+1)));
1314  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1315  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1316  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1317
1318  SmallVector<unsigned, 64> NameVals;
1319
1320  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1321       TI != TE; ++TI) {
1322    // TST_ENTRY: [typeid, namechar x N]
1323    NameVals.push_back(VE.getTypeID(TI->second));
1324
1325    const std::string &Str = TI->first;
1326    bool is7Bit = true;
1327    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1328      NameVals.push_back((unsigned char)Str[i]);
1329      if (Str[i] & 128)
1330        is7Bit = false;
1331    }
1332
1333    // Emit the finished record.
1334    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1335    NameVals.clear();
1336  }
1337
1338  Stream.ExitBlock();
1339}
1340
1341// Emit blockinfo, which defines the standard abbreviations etc.
1342static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1343  // We only want to emit block info records for blocks that have multiple
1344  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1345  // blocks can defined their abbrevs inline.
1346  Stream.EnterBlockInfoBlock(2);
1347
1348  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1349    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1350    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1351    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1352    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1353    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1354    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1355                                   Abbv) != VST_ENTRY_8_ABBREV)
1356      llvm_unreachable("Unexpected abbrev ordering!");
1357  }
1358
1359  { // 7-bit fixed width VST_ENTRY strings.
1360    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1361    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1362    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1363    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1364    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1365    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1366                                   Abbv) != VST_ENTRY_7_ABBREV)
1367      llvm_unreachable("Unexpected abbrev ordering!");
1368  }
1369  { // 6-bit char6 VST_ENTRY strings.
1370    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1371    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1372    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1373    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1374    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1375    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1376                                   Abbv) != VST_ENTRY_6_ABBREV)
1377      llvm_unreachable("Unexpected abbrev ordering!");
1378  }
1379  { // 6-bit char6 VST_BBENTRY strings.
1380    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1381    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1382    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1383    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1384    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1385    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1386                                   Abbv) != VST_BBENTRY_6_ABBREV)
1387      llvm_unreachable("Unexpected abbrev ordering!");
1388  }
1389
1390
1391
1392  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1393    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1394    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1395    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1396                              Log2_32_Ceil(VE.getTypes().size()+1)));
1397    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1398                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1399      llvm_unreachable("Unexpected abbrev ordering!");
1400  }
1401
1402  { // INTEGER abbrev for CONSTANTS_BLOCK.
1403    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1404    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1405    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1406    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1407                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1408      llvm_unreachable("Unexpected abbrev ordering!");
1409  }
1410
1411  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1412    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1413    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1414    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1415    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1416                              Log2_32_Ceil(VE.getTypes().size()+1)));
1417    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1418
1419    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1420                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1421      llvm_unreachable("Unexpected abbrev ordering!");
1422  }
1423  { // NULL abbrev for CONSTANTS_BLOCK.
1424    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1425    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1426    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1427                                   Abbv) != CONSTANTS_NULL_Abbrev)
1428      llvm_unreachable("Unexpected abbrev ordering!");
1429  }
1430
1431  // FIXME: This should only use space for first class types!
1432
1433  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1434    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1435    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1436    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1437    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1438    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1439    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1440                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1441      llvm_unreachable("Unexpected abbrev ordering!");
1442  }
1443  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1444    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1445    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1446    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1447    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1448    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1449    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1450                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1451      llvm_unreachable("Unexpected abbrev ordering!");
1452  }
1453  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1454    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1455    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1456    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1457    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1458    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1459    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1460    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1461                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1462      llvm_unreachable("Unexpected abbrev ordering!");
1463  }
1464  { // INST_CAST abbrev for FUNCTION_BLOCK.
1465    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1466    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1467    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1468    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1469                              Log2_32_Ceil(VE.getTypes().size()+1)));
1470    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1471    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1472                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1473      llvm_unreachable("Unexpected abbrev ordering!");
1474  }
1475
1476  { // INST_RET abbrev for FUNCTION_BLOCK.
1477    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1478    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1479    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1480                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1481      llvm_unreachable("Unexpected abbrev ordering!");
1482  }
1483  { // INST_RET abbrev for FUNCTION_BLOCK.
1484    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1485    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1486    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1487    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1488                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1489      llvm_unreachable("Unexpected abbrev ordering!");
1490  }
1491  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1492    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1493    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1494    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1495                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1496      llvm_unreachable("Unexpected abbrev ordering!");
1497  }
1498
1499  Stream.ExitBlock();
1500}
1501
1502
1503/// WriteModule - Emit the specified module to the bitstream.
1504static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1505  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1506
1507  // Emit the version number if it is non-zero.
1508  if (CurVersion) {
1509    SmallVector<unsigned, 1> Vals;
1510    Vals.push_back(CurVersion);
1511    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1512  }
1513
1514  // Analyze the module, enumerating globals, functions, etc.
1515  ValueEnumerator VE(M);
1516
1517  // Emit blockinfo, which defines the standard abbreviations etc.
1518  WriteBlockInfo(VE, Stream);
1519
1520  // Emit information about parameter attributes.
1521  WriteAttributeTable(VE, Stream);
1522
1523  // Emit information describing all of the types in the module.
1524  WriteTypeTable(VE, Stream);
1525
1526  // Emit top-level description of module, including target triple, inline asm,
1527  // descriptors for global variables, and function prototype info.
1528  WriteModuleInfo(M, VE, Stream);
1529
1530  // Emit constants.
1531  WriteModuleConstants(VE, Stream);
1532
1533  // Emit metadata.
1534  WriteModuleMetadata(VE, Stream);
1535
1536  // Emit function bodies.
1537  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1538    if (!I->isDeclaration())
1539      WriteFunction(*I, VE, Stream);
1540
1541  // Emit metadata.
1542  WriteModuleMetadataStore(M, Stream);
1543
1544  // Emit the type symbol table information.
1545  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1546
1547  // Emit names for globals/functions etc.
1548  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1549
1550  Stream.ExitBlock();
1551}
1552
1553/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1554/// header and trailer to make it compatible with the system archiver.  To do
1555/// this we emit the following header, and then emit a trailer that pads the
1556/// file out to be a multiple of 16 bytes.
1557///
1558/// struct bc_header {
1559///   uint32_t Magic;         // 0x0B17C0DE
1560///   uint32_t Version;       // Version, currently always 0.
1561///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1562///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1563///   uint32_t CPUType;       // CPU specifier.
1564///   ... potentially more later ...
1565/// };
1566enum {
1567  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1568  DarwinBCHeaderSize = 5*4
1569};
1570
1571/// isARMTriplet - Return true if the triplet looks like:
1572/// arm-*, thumb-*, armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*.
1573static bool isARMTriplet(const std::string &TT) {
1574  size_t Pos = 0;
1575  size_t Size = TT.size();
1576  if (Size >= 6 &&
1577      TT[0] == 't' && TT[1] == 'h' && TT[2] == 'u' &&
1578      TT[3] == 'm' && TT[4] == 'b')
1579    Pos = 5;
1580  else if (Size >= 4 && TT[0] == 'a' && TT[1] == 'r' && TT[2] == 'm')
1581    Pos = 3;
1582  else
1583    return false;
1584
1585  if (TT[Pos] == '-')
1586    return true;
1587  else if (TT[Pos] == 'v') {
1588    if (Size >= Pos+4 &&
1589        TT[Pos+1] == '6' && TT[Pos+2] == 't' && TT[Pos+3] == '2')
1590      return true;
1591    else if (Size >= Pos+4 &&
1592             TT[Pos+1] == '5' && TT[Pos+2] == 't' && TT[Pos+3] == 'e')
1593      return true;
1594  } else
1595    return false;
1596  while (++Pos < Size && TT[Pos] != '-') {
1597    if (!isdigit(TT[Pos]))
1598      return false;
1599  }
1600  return true;
1601}
1602
1603static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1604                               const std::string &TT) {
1605  unsigned CPUType = ~0U;
1606
1607  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1608  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1609  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1610  // specific constants here because they are implicitly part of the Darwin ABI.
1611  enum {
1612    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1613    DARWIN_CPU_TYPE_X86        = 7,
1614    DARWIN_CPU_TYPE_ARM        = 12,
1615    DARWIN_CPU_TYPE_POWERPC    = 18
1616  };
1617
1618  if (TT.find("x86_64-") == 0)
1619    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1620  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1621           TT[4] == '-' && TT[1] - '3' < 6)
1622    CPUType = DARWIN_CPU_TYPE_X86;
1623  else if (TT.find("powerpc-") == 0)
1624    CPUType = DARWIN_CPU_TYPE_POWERPC;
1625  else if (TT.find("powerpc64-") == 0)
1626    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1627  else if (isARMTriplet(TT))
1628    CPUType = DARWIN_CPU_TYPE_ARM;
1629
1630  // Traditional Bitcode starts after header.
1631  unsigned BCOffset = DarwinBCHeaderSize;
1632
1633  Stream.Emit(0x0B17C0DE, 32);
1634  Stream.Emit(0         , 32);  // Version.
1635  Stream.Emit(BCOffset  , 32);
1636  Stream.Emit(0         , 32);  // Filled in later.
1637  Stream.Emit(CPUType   , 32);
1638}
1639
1640/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1641/// finalize the header.
1642static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1643  // Update the size field in the header.
1644  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1645
1646  // If the file is not a multiple of 16 bytes, insert dummy padding.
1647  while (BufferSize & 15) {
1648    Stream.Emit(0, 8);
1649    ++BufferSize;
1650  }
1651}
1652
1653
1654/// WriteBitcodeToFile - Write the specified module to the specified output
1655/// stream.
1656void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1657  std::vector<unsigned char> Buffer;
1658  BitstreamWriter Stream(Buffer);
1659
1660  Buffer.reserve(256*1024);
1661
1662  WriteBitcodeToStream( M, Stream );
1663
1664  // If writing to stdout, set binary mode.
1665  if (&llvm::outs() == &Out)
1666    sys::Program::ChangeStdoutToBinary();
1667
1668  // Write the generated bitstream to "Out".
1669  Out.write((char*)&Buffer.front(), Buffer.size());
1670
1671  // Make sure it hits disk now.
1672  Out.flush();
1673}
1674
1675/// WriteBitcodeToStream - Write the specified module to the specified output
1676/// stream.
1677void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1678  // If this is darwin, emit a file header and trailer if needed.
1679  bool isDarwin = M->getTargetTriple().find("-darwin") != std::string::npos;
1680  if (isDarwin)
1681    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1682
1683  // Emit the file header.
1684  Stream.Emit((unsigned)'B', 8);
1685  Stream.Emit((unsigned)'C', 8);
1686  Stream.Emit(0x0, 4);
1687  Stream.Emit(0xC, 4);
1688  Stream.Emit(0xE, 4);
1689  Stream.Emit(0xD, 4);
1690
1691  // Emit the module.
1692  WriteModule(M, Stream);
1693
1694  if (isDarwin)
1695    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1696}
1697