BitcodeWriter.cpp revision 476b242fe7a61e5f9ac6214b0bc5c680d24f152e 
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/Support/Program.h"
30#include <cctype>
31using namespace llvm;
32
33/// These are manifest constants used by the bitcode writer. They do not need to
34/// be kept in sync with the reader, but need to be consistent within this file.
35enum {
36  CurVersion = 0,
37
38  // VALUE_SYMTAB_BLOCK abbrev id's.
39  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
40  VST_ENTRY_7_ABBREV,
41  VST_ENTRY_6_ABBREV,
42  VST_BBENTRY_6_ABBREV,
43
44  // CONSTANTS_BLOCK abbrev id's.
45  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
46  CONSTANTS_INTEGER_ABBREV,
47  CONSTANTS_CE_CAST_Abbrev,
48  CONSTANTS_NULL_Abbrev,
49
50  // FUNCTION_BLOCK abbrev id's.
51  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
52  FUNCTION_INST_BINOP_ABBREV,
53  FUNCTION_INST_BINOP_FLAGS_ABBREV,
54  FUNCTION_INST_CAST_ABBREV,
55  FUNCTION_INST_RET_VOID_ABBREV,
56  FUNCTION_INST_RET_VAL_ABBREV,
57  FUNCTION_INST_UNREACHABLE_ABBREV
58};
59
60
61static unsigned GetEncodedCastOpcode(unsigned Opcode) {
62  switch (Opcode) {
63  default: llvm_unreachable("Unknown cast instruction!");
64  case Instruction::Trunc   : return bitc::CAST_TRUNC;
65  case Instruction::ZExt    : return bitc::CAST_ZEXT;
66  case Instruction::SExt    : return bitc::CAST_SEXT;
67  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
68  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
69  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
70  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
71  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
72  case Instruction::FPExt   : return bitc::CAST_FPEXT;
73  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
74  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
75  case Instruction::BitCast : return bitc::CAST_BITCAST;
76  }
77}
78
79static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
80  switch (Opcode) {
81  default: llvm_unreachable("Unknown binary instruction!");
82  case Instruction::Add:
83  case Instruction::FAdd: return bitc::BINOP_ADD;
84  case Instruction::Sub:
85  case Instruction::FSub: return bitc::BINOP_SUB;
86  case Instruction::Mul:
87  case Instruction::FMul: return bitc::BINOP_MUL;
88  case Instruction::UDiv: return bitc::BINOP_UDIV;
89  case Instruction::FDiv:
90  case Instruction::SDiv: return bitc::BINOP_SDIV;
91  case Instruction::URem: return bitc::BINOP_UREM;
92  case Instruction::FRem:
93  case Instruction::SRem: return bitc::BINOP_SREM;
94  case Instruction::Shl:  return bitc::BINOP_SHL;
95  case Instruction::LShr: return bitc::BINOP_LSHR;
96  case Instruction::AShr: return bitc::BINOP_ASHR;
97  case Instruction::And:  return bitc::BINOP_AND;
98  case Instruction::Or:   return bitc::BINOP_OR;
99  case Instruction::Xor:  return bitc::BINOP_XOR;
100  }
101}
102
103
104
105static void WriteStringRecord(unsigned Code, const std::string &Str,
106                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
107  SmallVector<unsigned, 64> Vals;
108
109  // Code: [strchar x N]
110  for (unsigned i = 0, e = Str.size(); i != e; ++i)
111    Vals.push_back(Str[i]);
112
113  // Emit the finished record.
114  Stream.EmitRecord(Code, Vals, AbbrevToUse);
115}
116
117// Emit information about parameter attributes.
118static void WriteAttributeTable(const ValueEnumerator &VE,
119                                BitstreamWriter &Stream) {
120  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
121  if (Attrs.empty()) return;
122
123  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
124
125  SmallVector<uint64_t, 64> Record;
126  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
127    const AttrListPtr &A = Attrs[i];
128    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
129      const AttributeWithIndex &PAWI = A.getSlot(i);
130      Record.push_back(PAWI.Index);
131
132      // FIXME: remove in LLVM 3.0
133      // Store the alignment in the bitcode as a 16-bit raw value instead of a
134      // 5-bit log2 encoded value. Shift the bits above the alignment up by
135      // 11 bits.
136      uint64_t FauxAttr = PAWI.Attrs & 0xffff;
137      if (PAWI.Attrs & Attribute::Alignment)
138        FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
139      FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
140
141      Record.push_back(FauxAttr);
142    }
143
144    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
145    Record.clear();
146  }
147
148  Stream.ExitBlock();
149}
150
151/// WriteTypeTable - Write out the type table for a module.
152static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
153  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
154
155  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
156  SmallVector<uint64_t, 64> TypeVals;
157
158  // Abbrev for TYPE_CODE_POINTER.
159  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
160  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
161  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
162                            Log2_32_Ceil(VE.getTypes().size()+1)));
163  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
164  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
165
166  // Abbrev for TYPE_CODE_FUNCTION.
167  Abbv = new BitCodeAbbrev();
168  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
169  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
170  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
171  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
172  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
173                            Log2_32_Ceil(VE.getTypes().size()+1)));
174  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
175
176  // Abbrev for TYPE_CODE_STRUCT.
177  Abbv = new BitCodeAbbrev();
178  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
179  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
180  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
181  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
182                            Log2_32_Ceil(VE.getTypes().size()+1)));
183  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
184
185  // Abbrev for TYPE_CODE_ARRAY.
186  Abbv = new BitCodeAbbrev();
187  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
188  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
189  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
190                            Log2_32_Ceil(VE.getTypes().size()+1)));
191  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
192
193  // Emit an entry count so the reader can reserve space.
194  TypeVals.push_back(TypeList.size());
195  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
196  TypeVals.clear();
197
198  // Loop over all of the types, emitting each in turn.
199  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
200    const Type *T = TypeList[i].first;
201    int AbbrevToUse = 0;
202    unsigned Code = 0;
203
204    switch (T->getTypeID()) {
205    default: llvm_unreachable("Unknown type!");
206    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
207    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
208    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
209    case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
210    case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
211    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
212    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
213    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
214    case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
215    case Type::X86_MMXTyID: Code = bitc::TYPE_CODE_X86_MMX; break;
216    case Type::IntegerTyID:
217      // INTEGER: [width]
218      Code = bitc::TYPE_CODE_INTEGER;
219      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
220      break;
221    case Type::PointerTyID: {
222      const PointerType *PTy = cast<PointerType>(T);
223      // POINTER: [pointee type, address space]
224      Code = bitc::TYPE_CODE_POINTER;
225      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
226      unsigned AddressSpace = PTy->getAddressSpace();
227      TypeVals.push_back(AddressSpace);
228      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
229      break;
230    }
231    case Type::FunctionTyID: {
232      const FunctionType *FT = cast<FunctionType>(T);
233      // FUNCTION: [isvararg, attrid, retty, paramty x N]
234      Code = bitc::TYPE_CODE_FUNCTION;
235      TypeVals.push_back(FT->isVarArg());
236      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
237      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
238      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
239        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
240      AbbrevToUse = FunctionAbbrev;
241      break;
242    }
243    case Type::StructTyID: {
244      const StructType *ST = cast<StructType>(T);
245      // STRUCT: [ispacked, eltty x N]
246      Code = bitc::TYPE_CODE_STRUCT;
247      TypeVals.push_back(ST->isPacked());
248      // Output all of the element types.
249      for (StructType::element_iterator I = ST->element_begin(),
250           E = ST->element_end(); I != E; ++I)
251        TypeVals.push_back(VE.getTypeID(*I));
252      AbbrevToUse = StructAbbrev;
253      break;
254    }
255    case Type::ArrayTyID: {
256      const ArrayType *AT = cast<ArrayType>(T);
257      // ARRAY: [numelts, eltty]
258      Code = bitc::TYPE_CODE_ARRAY;
259      TypeVals.push_back(AT->getNumElements());
260      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
261      AbbrevToUse = ArrayAbbrev;
262      break;
263    }
264    case Type::VectorTyID: {
265      const VectorType *VT = cast<VectorType>(T);
266      // VECTOR [numelts, eltty]
267      Code = bitc::TYPE_CODE_VECTOR;
268      TypeVals.push_back(VT->getNumElements());
269      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
270      break;
271    }
272    }
273
274    // Emit the finished record.
275    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
276    TypeVals.clear();
277  }
278
279  Stream.ExitBlock();
280}
281
282static unsigned getEncodedLinkage(const GlobalValue *GV) {
283  switch (GV->getLinkage()) {
284  default: llvm_unreachable("Invalid linkage!");
285  case GlobalValue::ExternalLinkage:                 return 0;
286  case GlobalValue::WeakAnyLinkage:                  return 1;
287  case GlobalValue::AppendingLinkage:                return 2;
288  case GlobalValue::InternalLinkage:                 return 3;
289  case GlobalValue::LinkOnceAnyLinkage:              return 4;
290  case GlobalValue::DLLImportLinkage:                return 5;
291  case GlobalValue::DLLExportLinkage:                return 6;
292  case GlobalValue::ExternalWeakLinkage:             return 7;
293  case GlobalValue::CommonLinkage:                   return 8;
294  case GlobalValue::PrivateLinkage:                  return 9;
295  case GlobalValue::WeakODRLinkage:                  return 10;
296  case GlobalValue::LinkOnceODRLinkage:              return 11;
297  case GlobalValue::AvailableExternallyLinkage:      return 12;
298  case GlobalValue::LinkerPrivateLinkage:            return 13;
299  case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
300  case GlobalValue::LinkerPrivateWeakDefAutoLinkage: return 15;
301  }
302}
303
304static unsigned getEncodedVisibility(const GlobalValue *GV) {
305  switch (GV->getVisibility()) {
306  default: llvm_unreachable("Invalid visibility!");
307  case GlobalValue::DefaultVisibility:   return 0;
308  case GlobalValue::HiddenVisibility:    return 1;
309  case GlobalValue::ProtectedVisibility: return 2;
310  }
311}
312
313// Emit top-level description of module, including target triple, inline asm,
314// descriptors for global variables, and function prototype info.
315static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
316                            BitstreamWriter &Stream) {
317  // Emit the list of dependent libraries for the Module.
318  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
319    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
320
321  // Emit various pieces of data attached to a module.
322  if (!M->getTargetTriple().empty())
323    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
324                      0/*TODO*/, Stream);
325  if (!M->getDataLayout().empty())
326    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
327                      0/*TODO*/, Stream);
328  if (!M->getModuleInlineAsm().empty())
329    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
330                      0/*TODO*/, Stream);
331
332  // Emit information about sections and GC, computing how many there are. Also
333  // compute the maximum alignment value.
334  std::map<std::string, unsigned> SectionMap;
335  std::map<std::string, unsigned> GCMap;
336  unsigned MaxAlignment = 0;
337  unsigned MaxGlobalType = 0;
338  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
339       GV != E; ++GV) {
340    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
341    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
342
343    if (!GV->hasSection()) continue;
344    // Give section names unique ID's.
345    unsigned &Entry = SectionMap[GV->getSection()];
346    if (Entry != 0) continue;
347    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
348                      0/*TODO*/, Stream);
349    Entry = SectionMap.size();
350  }
351  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
352    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
353    if (F->hasSection()) {
354      // Give section names unique ID's.
355      unsigned &Entry = SectionMap[F->getSection()];
356      if (!Entry) {
357        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
358                          0/*TODO*/, Stream);
359        Entry = SectionMap.size();
360      }
361    }
362    if (F->hasGC()) {
363      // Same for GC names.
364      unsigned &Entry = GCMap[F->getGC()];
365      if (!Entry) {
366        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
367                          0/*TODO*/, Stream);
368        Entry = GCMap.size();
369      }
370    }
371  }
372
373  // Emit abbrev for globals, now that we know # sections and max alignment.
374  unsigned SimpleGVarAbbrev = 0;
375  if (!M->global_empty()) {
376    // Add an abbrev for common globals with no visibility or thread localness.
377    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
378    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
379    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
380                              Log2_32_Ceil(MaxGlobalType+1)));
381    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
382    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
383    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
384    if (MaxAlignment == 0)                                      // Alignment.
385      Abbv->Add(BitCodeAbbrevOp(0));
386    else {
387      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
388      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
389                               Log2_32_Ceil(MaxEncAlignment+1)));
390    }
391    if (SectionMap.empty())                                    // Section.
392      Abbv->Add(BitCodeAbbrevOp(0));
393    else
394      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
395                               Log2_32_Ceil(SectionMap.size()+1)));
396    // Don't bother emitting vis + thread local.
397    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
398  }
399
400  // Emit the global variable information.
401  SmallVector<unsigned, 64> Vals;
402  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
403       GV != E; ++GV) {
404    unsigned AbbrevToUse = 0;
405
406    // GLOBALVAR: [type, isconst, initid,
407    //             linkage, alignment, section, visibility, threadlocal]
408    Vals.push_back(VE.getTypeID(GV->getType()));
409    Vals.push_back(GV->isConstant());
410    Vals.push_back(GV->isDeclaration() ? 0 :
411                   (VE.getValueID(GV->getInitializer()) + 1));
412    Vals.push_back(getEncodedLinkage(GV));
413    Vals.push_back(Log2_32(GV->getAlignment())+1);
414    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
415    if (GV->isThreadLocal() ||
416        GV->getVisibility() != GlobalValue::DefaultVisibility) {
417      Vals.push_back(getEncodedVisibility(GV));
418      Vals.push_back(GV->isThreadLocal());
419    } else {
420      AbbrevToUse = SimpleGVarAbbrev;
421    }
422
423    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
424    Vals.clear();
425  }
426
427  // Emit the function proto information.
428  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
429    // FUNCTION:  [type, callingconv, isproto, paramattr,
430    //             linkage, alignment, section, visibility, gc]
431    Vals.push_back(VE.getTypeID(F->getType()));
432    Vals.push_back(F->getCallingConv());
433    Vals.push_back(F->isDeclaration());
434    Vals.push_back(getEncodedLinkage(F));
435    Vals.push_back(VE.getAttributeID(F->getAttributes()));
436    Vals.push_back(Log2_32(F->getAlignment())+1);
437    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
438    Vals.push_back(getEncodedVisibility(F));
439    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
440
441    unsigned AbbrevToUse = 0;
442    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
443    Vals.clear();
444  }
445
446
447  // Emit the alias information.
448  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
449       AI != E; ++AI) {
450    Vals.push_back(VE.getTypeID(AI->getType()));
451    Vals.push_back(VE.getValueID(AI->getAliasee()));
452    Vals.push_back(getEncodedLinkage(AI));
453    Vals.push_back(getEncodedVisibility(AI));
454    unsigned AbbrevToUse = 0;
455    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
456    Vals.clear();
457  }
458}
459
460static uint64_t GetOptimizationFlags(const Value *V) {
461  uint64_t Flags = 0;
462
463  if (const OverflowingBinaryOperator *OBO =
464        dyn_cast<OverflowingBinaryOperator>(V)) {
465    if (OBO->hasNoSignedWrap())
466      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
467    if (OBO->hasNoUnsignedWrap())
468      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
469  } else if (const SDivOperator *Div = dyn_cast<SDivOperator>(V)) {
470    if (Div->isExact())
471      Flags |= 1 << bitc::SDIV_EXACT;
472  }
473
474  return Flags;
475}
476
477static void WriteMDNode(const MDNode *N,
478                        const ValueEnumerator &VE,
479                        BitstreamWriter &Stream,
480                        SmallVector<uint64_t, 64> &Record) {
481  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
482    if (N->getOperand(i)) {
483      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
484      Record.push_back(VE.getValueID(N->getOperand(i)));
485    } else {
486      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
487      Record.push_back(0);
488    }
489  }
490  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE2 :
491                                           bitc::METADATA_NODE2;
492  Stream.EmitRecord(MDCode, Record, 0);
493  Record.clear();
494}
495
496static void WriteModuleMetadata(const Module *M,
497                                const ValueEnumerator &VE,
498                                BitstreamWriter &Stream) {
499  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
500  bool StartedMetadataBlock = false;
501  unsigned MDSAbbrev = 0;
502  SmallVector<uint64_t, 64> Record;
503  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
504
505    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
506      if (!N->isFunctionLocal() || !N->getFunction()) {
507        if (!StartedMetadataBlock) {
508          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
509          StartedMetadataBlock = true;
510        }
511        WriteMDNode(N, VE, Stream, Record);
512      }
513    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
514      if (!StartedMetadataBlock)  {
515        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
516
517        // Abbrev for METADATA_STRING.
518        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
519        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
520        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
521        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
522        MDSAbbrev = Stream.EmitAbbrev(Abbv);
523        StartedMetadataBlock = true;
524      }
525
526      // Code: [strchar x N]
527      Record.append(MDS->begin(), MDS->end());
528
529      // Emit the finished record.
530      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
531      Record.clear();
532    }
533  }
534
535  // Write named metadata.
536  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
537       E = M->named_metadata_end(); I != E; ++I) {
538    const NamedMDNode *NMD = I;
539    if (!StartedMetadataBlock)  {
540      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
541      StartedMetadataBlock = true;
542    }
543
544    // Write name.
545    StringRef Str = NMD->getName();
546    for (unsigned i = 0, e = Str.size(); i != e; ++i)
547      Record.push_back(Str[i]);
548    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
549    Record.clear();
550
551    // Write named metadata operands.
552    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
553      Record.push_back(VE.getValueID(NMD->getOperand(i)));
554    Stream.EmitRecord(bitc::METADATA_NAMED_NODE2, Record, 0);
555    Record.clear();
556  }
557
558  if (StartedMetadataBlock)
559    Stream.ExitBlock();
560}
561
562static void WriteFunctionLocalMetadata(const Function &F,
563                                       const ValueEnumerator &VE,
564                                       BitstreamWriter &Stream) {
565  bool StartedMetadataBlock = false;
566  SmallVector<uint64_t, 64> Record;
567  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
568  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
569    if (const MDNode *N = Vals[i])
570      if (N->isFunctionLocal() && N->getFunction() == &F) {
571        if (!StartedMetadataBlock) {
572          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
573          StartedMetadataBlock = true;
574        }
575        WriteMDNode(N, VE, Stream, Record);
576      }
577
578  if (StartedMetadataBlock)
579    Stream.ExitBlock();
580}
581
582static void WriteMetadataAttachment(const Function &F,
583                                    const ValueEnumerator &VE,
584                                    BitstreamWriter &Stream) {
585  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
586
587  SmallVector<uint64_t, 64> Record;
588
589  // Write metadata attachments
590  // METADATA_ATTACHMENT2 - [m x [value, [n x [id, mdnode]]]
591  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
592
593  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
594    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
595         I != E; ++I) {
596      MDs.clear();
597      I->getAllMetadataOtherThanDebugLoc(MDs);
598
599      // If no metadata, ignore instruction.
600      if (MDs.empty()) continue;
601
602      Record.push_back(VE.getInstructionID(I));
603
604      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
605        Record.push_back(MDs[i].first);
606        Record.push_back(VE.getValueID(MDs[i].second));
607      }
608      Stream.EmitRecord(bitc::METADATA_ATTACHMENT2, Record, 0);
609      Record.clear();
610    }
611
612  Stream.ExitBlock();
613}
614
615static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
616  SmallVector<uint64_t, 64> Record;
617
618  // Write metadata kinds
619  // METADATA_KIND - [n x [id, name]]
620  SmallVector<StringRef, 4> Names;
621  M->getMDKindNames(Names);
622
623  if (Names.empty()) return;
624
625  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
626
627  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
628    Record.push_back(MDKindID);
629    StringRef KName = Names[MDKindID];
630    Record.append(KName.begin(), KName.end());
631
632    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
633    Record.clear();
634  }
635
636  Stream.ExitBlock();
637}
638
639static void WriteConstants(unsigned FirstVal, unsigned LastVal,
640                           const ValueEnumerator &VE,
641                           BitstreamWriter &Stream, bool isGlobal) {
642  if (FirstVal == LastVal) return;
643
644  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
645
646  unsigned AggregateAbbrev = 0;
647  unsigned String8Abbrev = 0;
648  unsigned CString7Abbrev = 0;
649  unsigned CString6Abbrev = 0;
650  // If this is a constant pool for the module, emit module-specific abbrevs.
651  if (isGlobal) {
652    // Abbrev for CST_CODE_AGGREGATE.
653    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
654    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
655    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
656    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
657    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
658
659    // Abbrev for CST_CODE_STRING.
660    Abbv = new BitCodeAbbrev();
661    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
662    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
663    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
664    String8Abbrev = Stream.EmitAbbrev(Abbv);
665    // Abbrev for CST_CODE_CSTRING.
666    Abbv = new BitCodeAbbrev();
667    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
668    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
669    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
670    CString7Abbrev = Stream.EmitAbbrev(Abbv);
671    // Abbrev for CST_CODE_CSTRING.
672    Abbv = new BitCodeAbbrev();
673    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
674    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
675    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
676    CString6Abbrev = Stream.EmitAbbrev(Abbv);
677  }
678
679  SmallVector<uint64_t, 64> Record;
680
681  const ValueEnumerator::ValueList &Vals = VE.getValues();
682  const Type *LastTy = 0;
683  for (unsigned i = FirstVal; i != LastVal; ++i) {
684    const Value *V = Vals[i].first;
685    // If we need to switch types, do so now.
686    if (V->getType() != LastTy) {
687      LastTy = V->getType();
688      Record.push_back(VE.getTypeID(LastTy));
689      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
690                        CONSTANTS_SETTYPE_ABBREV);
691      Record.clear();
692    }
693
694    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
695      Record.push_back(unsigned(IA->hasSideEffects()) |
696                       unsigned(IA->isAlignStack()) << 1);
697
698      // Add the asm string.
699      const std::string &AsmStr = IA->getAsmString();
700      Record.push_back(AsmStr.size());
701      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
702        Record.push_back(AsmStr[i]);
703
704      // Add the constraint string.
705      const std::string &ConstraintStr = IA->getConstraintString();
706      Record.push_back(ConstraintStr.size());
707      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
708        Record.push_back(ConstraintStr[i]);
709      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
710      Record.clear();
711      continue;
712    }
713    const Constant *C = cast<Constant>(V);
714    unsigned Code = -1U;
715    unsigned AbbrevToUse = 0;
716    if (C->isNullValue()) {
717      Code = bitc::CST_CODE_NULL;
718    } else if (isa<UndefValue>(C)) {
719      Code = bitc::CST_CODE_UNDEF;
720    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
721      if (IV->getBitWidth() <= 64) {
722        uint64_t V = IV->getSExtValue();
723        if ((int64_t)V >= 0)
724          Record.push_back(V << 1);
725        else
726          Record.push_back((-V << 1) | 1);
727        Code = bitc::CST_CODE_INTEGER;
728        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
729      } else {                             // Wide integers, > 64 bits in size.
730        // We have an arbitrary precision integer value to write whose
731        // bit width is > 64. However, in canonical unsigned integer
732        // format it is likely that the high bits are going to be zero.
733        // So, we only write the number of active words.
734        unsigned NWords = IV->getValue().getActiveWords();
735        const uint64_t *RawWords = IV->getValue().getRawData();
736        for (unsigned i = 0; i != NWords; ++i) {
737          int64_t V = RawWords[i];
738          if (V >= 0)
739            Record.push_back(V << 1);
740          else
741            Record.push_back((-V << 1) | 1);
742        }
743        Code = bitc::CST_CODE_WIDE_INTEGER;
744      }
745    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
746      Code = bitc::CST_CODE_FLOAT;
747      const Type *Ty = CFP->getType();
748      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
749        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
750      } else if (Ty->isX86_FP80Ty()) {
751        // api needed to prevent premature destruction
752        // bits are not in the same order as a normal i80 APInt, compensate.
753        APInt api = CFP->getValueAPF().bitcastToAPInt();
754        const uint64_t *p = api.getRawData();
755        Record.push_back((p[1] << 48) | (p[0] >> 16));
756        Record.push_back(p[0] & 0xffffLL);
757      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
758        APInt api = CFP->getValueAPF().bitcastToAPInt();
759        const uint64_t *p = api.getRawData();
760        Record.push_back(p[0]);
761        Record.push_back(p[1]);
762      } else {
763        assert (0 && "Unknown FP type!");
764      }
765    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
766      const ConstantArray *CA = cast<ConstantArray>(C);
767      // Emit constant strings specially.
768      unsigned NumOps = CA->getNumOperands();
769      // If this is a null-terminated string, use the denser CSTRING encoding.
770      if (CA->getOperand(NumOps-1)->isNullValue()) {
771        Code = bitc::CST_CODE_CSTRING;
772        --NumOps;  // Don't encode the null, which isn't allowed by char6.
773      } else {
774        Code = bitc::CST_CODE_STRING;
775        AbbrevToUse = String8Abbrev;
776      }
777      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
778      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
779      for (unsigned i = 0; i != NumOps; ++i) {
780        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
781        Record.push_back(V);
782        isCStr7 &= (V & 128) == 0;
783        if (isCStrChar6)
784          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
785      }
786
787      if (isCStrChar6)
788        AbbrevToUse = CString6Abbrev;
789      else if (isCStr7)
790        AbbrevToUse = CString7Abbrev;
791    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
792               isa<ConstantVector>(V)) {
793      Code = bitc::CST_CODE_AGGREGATE;
794      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
795        Record.push_back(VE.getValueID(C->getOperand(i)));
796      AbbrevToUse = AggregateAbbrev;
797    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
798      switch (CE->getOpcode()) {
799      default:
800        if (Instruction::isCast(CE->getOpcode())) {
801          Code = bitc::CST_CODE_CE_CAST;
802          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
803          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
804          Record.push_back(VE.getValueID(C->getOperand(0)));
805          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
806        } else {
807          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
808          Code = bitc::CST_CODE_CE_BINOP;
809          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
810          Record.push_back(VE.getValueID(C->getOperand(0)));
811          Record.push_back(VE.getValueID(C->getOperand(1)));
812          uint64_t Flags = GetOptimizationFlags(CE);
813          if (Flags != 0)
814            Record.push_back(Flags);
815        }
816        break;
817      case Instruction::GetElementPtr:
818        Code = bitc::CST_CODE_CE_GEP;
819        if (cast<GEPOperator>(C)->isInBounds())
820          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
821        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
822          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
823          Record.push_back(VE.getValueID(C->getOperand(i)));
824        }
825        break;
826      case Instruction::Select:
827        Code = bitc::CST_CODE_CE_SELECT;
828        Record.push_back(VE.getValueID(C->getOperand(0)));
829        Record.push_back(VE.getValueID(C->getOperand(1)));
830        Record.push_back(VE.getValueID(C->getOperand(2)));
831        break;
832      case Instruction::ExtractElement:
833        Code = bitc::CST_CODE_CE_EXTRACTELT;
834        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
835        Record.push_back(VE.getValueID(C->getOperand(0)));
836        Record.push_back(VE.getValueID(C->getOperand(1)));
837        break;
838      case Instruction::InsertElement:
839        Code = bitc::CST_CODE_CE_INSERTELT;
840        Record.push_back(VE.getValueID(C->getOperand(0)));
841        Record.push_back(VE.getValueID(C->getOperand(1)));
842        Record.push_back(VE.getValueID(C->getOperand(2)));
843        break;
844      case Instruction::ShuffleVector:
845        // If the return type and argument types are the same, this is a
846        // standard shufflevector instruction.  If the types are different,
847        // then the shuffle is widening or truncating the input vectors, and
848        // the argument type must also be encoded.
849        if (C->getType() == C->getOperand(0)->getType()) {
850          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
851        } else {
852          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
853          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
854        }
855        Record.push_back(VE.getValueID(C->getOperand(0)));
856        Record.push_back(VE.getValueID(C->getOperand(1)));
857        Record.push_back(VE.getValueID(C->getOperand(2)));
858        break;
859      case Instruction::ICmp:
860      case Instruction::FCmp:
861        Code = bitc::CST_CODE_CE_CMP;
862        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
863        Record.push_back(VE.getValueID(C->getOperand(0)));
864        Record.push_back(VE.getValueID(C->getOperand(1)));
865        Record.push_back(CE->getPredicate());
866        break;
867      }
868    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
869      assert(BA->getFunction() == BA->getBasicBlock()->getParent() &&
870             "Malformed blockaddress");
871      Code = bitc::CST_CODE_BLOCKADDRESS;
872      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
873      Record.push_back(VE.getValueID(BA->getFunction()));
874      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
875    } else {
876#ifndef NDEBUG
877      C->dump();
878#endif
879      llvm_unreachable("Unknown constant!");
880    }
881    Stream.EmitRecord(Code, Record, AbbrevToUse);
882    Record.clear();
883  }
884
885  Stream.ExitBlock();
886}
887
888static void WriteModuleConstants(const ValueEnumerator &VE,
889                                 BitstreamWriter &Stream) {
890  const ValueEnumerator::ValueList &Vals = VE.getValues();
891
892  // Find the first constant to emit, which is the first non-globalvalue value.
893  // We know globalvalues have been emitted by WriteModuleInfo.
894  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
895    if (!isa<GlobalValue>(Vals[i].first)) {
896      WriteConstants(i, Vals.size(), VE, Stream, true);
897      return;
898    }
899  }
900}
901
902/// PushValueAndType - The file has to encode both the value and type id for
903/// many values, because we need to know what type to create for forward
904/// references.  However, most operands are not forward references, so this type
905/// field is not needed.
906///
907/// This function adds V's value ID to Vals.  If the value ID is higher than the
908/// instruction ID, then it is a forward reference, and it also includes the
909/// type ID.
910static bool PushValueAndType(const Value *V, unsigned InstID,
911                             SmallVector<unsigned, 64> &Vals,
912                             ValueEnumerator &VE) {
913  unsigned ValID = VE.getValueID(V);
914  Vals.push_back(ValID);
915  if (ValID >= InstID) {
916    Vals.push_back(VE.getTypeID(V->getType()));
917    return true;
918  }
919  return false;
920}
921
922/// WriteInstruction - Emit an instruction to the specified stream.
923static void WriteInstruction(const Instruction &I, unsigned InstID,
924                             ValueEnumerator &VE, BitstreamWriter &Stream,
925                             SmallVector<unsigned, 64> &Vals) {
926  unsigned Code = 0;
927  unsigned AbbrevToUse = 0;
928  VE.setInstructionID(&I);
929  switch (I.getOpcode()) {
930  default:
931    if (Instruction::isCast(I.getOpcode())) {
932      Code = bitc::FUNC_CODE_INST_CAST;
933      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
934        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
935      Vals.push_back(VE.getTypeID(I.getType()));
936      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
937    } else {
938      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
939      Code = bitc::FUNC_CODE_INST_BINOP;
940      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
941        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
942      Vals.push_back(VE.getValueID(I.getOperand(1)));
943      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
944      uint64_t Flags = GetOptimizationFlags(&I);
945      if (Flags != 0) {
946        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
947          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
948        Vals.push_back(Flags);
949      }
950    }
951    break;
952
953  case Instruction::GetElementPtr:
954    Code = bitc::FUNC_CODE_INST_GEP;
955    if (cast<GEPOperator>(&I)->isInBounds())
956      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
957    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
958      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
959    break;
960  case Instruction::ExtractValue: {
961    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
962    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
963    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
964    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
965      Vals.push_back(*i);
966    break;
967  }
968  case Instruction::InsertValue: {
969    Code = bitc::FUNC_CODE_INST_INSERTVAL;
970    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
971    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
972    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
973    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
974      Vals.push_back(*i);
975    break;
976  }
977  case Instruction::Select:
978    Code = bitc::FUNC_CODE_INST_VSELECT;
979    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
980    Vals.push_back(VE.getValueID(I.getOperand(2)));
981    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
982    break;
983  case Instruction::ExtractElement:
984    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
985    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
986    Vals.push_back(VE.getValueID(I.getOperand(1)));
987    break;
988  case Instruction::InsertElement:
989    Code = bitc::FUNC_CODE_INST_INSERTELT;
990    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
991    Vals.push_back(VE.getValueID(I.getOperand(1)));
992    Vals.push_back(VE.getValueID(I.getOperand(2)));
993    break;
994  case Instruction::ShuffleVector:
995    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
996    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
997    Vals.push_back(VE.getValueID(I.getOperand(1)));
998    Vals.push_back(VE.getValueID(I.getOperand(2)));
999    break;
1000  case Instruction::ICmp:
1001  case Instruction::FCmp:
1002    // compare returning Int1Ty or vector of Int1Ty
1003    Code = bitc::FUNC_CODE_INST_CMP2;
1004    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1005    Vals.push_back(VE.getValueID(I.getOperand(1)));
1006    Vals.push_back(cast<CmpInst>(I).getPredicate());
1007    break;
1008
1009  case Instruction::Ret:
1010    {
1011      Code = bitc::FUNC_CODE_INST_RET;
1012      unsigned NumOperands = I.getNumOperands();
1013      if (NumOperands == 0)
1014        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1015      else if (NumOperands == 1) {
1016        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1017          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1018      } else {
1019        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1020          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1021      }
1022    }
1023    break;
1024  case Instruction::Br:
1025    {
1026      Code = bitc::FUNC_CODE_INST_BR;
1027      BranchInst &II = cast<BranchInst>(I);
1028      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1029      if (II.isConditional()) {
1030        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1031        Vals.push_back(VE.getValueID(II.getCondition()));
1032      }
1033    }
1034    break;
1035  case Instruction::Switch:
1036    Code = bitc::FUNC_CODE_INST_SWITCH;
1037    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1038    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1039      Vals.push_back(VE.getValueID(I.getOperand(i)));
1040    break;
1041  case Instruction::IndirectBr:
1042    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1043    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1044    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1045      Vals.push_back(VE.getValueID(I.getOperand(i)));
1046    break;
1047
1048  case Instruction::Invoke: {
1049    const InvokeInst *II = cast<InvokeInst>(&I);
1050    const Value *Callee(II->getCalledValue());
1051    const PointerType *PTy = cast<PointerType>(Callee->getType());
1052    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1053    Code = bitc::FUNC_CODE_INST_INVOKE;
1054
1055    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1056    Vals.push_back(II->getCallingConv());
1057    Vals.push_back(VE.getValueID(II->getNormalDest()));
1058    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1059    PushValueAndType(Callee, InstID, Vals, VE);
1060
1061    // Emit value #'s for the fixed parameters.
1062    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1063      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1064
1065    // Emit type/value pairs for varargs params.
1066    if (FTy->isVarArg()) {
1067      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1068           i != e; ++i)
1069        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1070    }
1071    break;
1072  }
1073  case Instruction::Unwind:
1074    Code = bitc::FUNC_CODE_INST_UNWIND;
1075    break;
1076  case Instruction::Unreachable:
1077    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1078    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1079    break;
1080
1081  case Instruction::PHI:
1082    Code = bitc::FUNC_CODE_INST_PHI;
1083    Vals.push_back(VE.getTypeID(I.getType()));
1084    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1085      Vals.push_back(VE.getValueID(I.getOperand(i)));
1086    break;
1087
1088  case Instruction::Alloca:
1089    Code = bitc::FUNC_CODE_INST_ALLOCA;
1090    Vals.push_back(VE.getTypeID(I.getType()));
1091    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1092    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1093    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1094    break;
1095
1096  case Instruction::Load:
1097    Code = bitc::FUNC_CODE_INST_LOAD;
1098    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1099      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1100
1101    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1102    Vals.push_back(cast<LoadInst>(I).isVolatile());
1103    break;
1104  case Instruction::Store:
1105    Code = bitc::FUNC_CODE_INST_STORE2;
1106    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1107    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1108    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1109    Vals.push_back(cast<StoreInst>(I).isVolatile());
1110    break;
1111  case Instruction::Call: {
1112    const CallInst &CI = cast<CallInst>(I);
1113    const PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1114    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1115
1116    Code = bitc::FUNC_CODE_INST_CALL2;
1117
1118    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1119    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1120    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1121
1122    // Emit value #'s for the fixed parameters.
1123    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1124      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1125
1126    // Emit type/value pairs for varargs params.
1127    if (FTy->isVarArg()) {
1128      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1129           i != e; ++i)
1130        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1131    }
1132    break;
1133  }
1134  case Instruction::VAArg:
1135    Code = bitc::FUNC_CODE_INST_VAARG;
1136    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1137    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1138    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1139    break;
1140  }
1141
1142  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1143  Vals.clear();
1144}
1145
1146// Emit names for globals/functions etc.
1147static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1148                                  const ValueEnumerator &VE,
1149                                  BitstreamWriter &Stream) {
1150  if (VST.empty()) return;
1151  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1152
1153  // FIXME: Set up the abbrev, we know how many values there are!
1154  // FIXME: We know if the type names can use 7-bit ascii.
1155  SmallVector<unsigned, 64> NameVals;
1156
1157  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1158       SI != SE; ++SI) {
1159
1160    const ValueName &Name = *SI;
1161
1162    // Figure out the encoding to use for the name.
1163    bool is7Bit = true;
1164    bool isChar6 = true;
1165    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1166         C != E; ++C) {
1167      if (isChar6)
1168        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1169      if ((unsigned char)*C & 128) {
1170        is7Bit = false;
1171        break;  // don't bother scanning the rest.
1172      }
1173    }
1174
1175    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1176
1177    // VST_ENTRY:   [valueid, namechar x N]
1178    // VST_BBENTRY: [bbid, namechar x N]
1179    unsigned Code;
1180    if (isa<BasicBlock>(SI->getValue())) {
1181      Code = bitc::VST_CODE_BBENTRY;
1182      if (isChar6)
1183        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1184    } else {
1185      Code = bitc::VST_CODE_ENTRY;
1186      if (isChar6)
1187        AbbrevToUse = VST_ENTRY_6_ABBREV;
1188      else if (is7Bit)
1189        AbbrevToUse = VST_ENTRY_7_ABBREV;
1190    }
1191
1192    NameVals.push_back(VE.getValueID(SI->getValue()));
1193    for (const char *P = Name.getKeyData(),
1194         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1195      NameVals.push_back((unsigned char)*P);
1196
1197    // Emit the finished record.
1198    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1199    NameVals.clear();
1200  }
1201  Stream.ExitBlock();
1202}
1203
1204/// WriteFunction - Emit a function body to the module stream.
1205static void WriteFunction(const Function &F, ValueEnumerator &VE,
1206                          BitstreamWriter &Stream) {
1207  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1208  VE.incorporateFunction(F);
1209
1210  SmallVector<unsigned, 64> Vals;
1211
1212  // Emit the number of basic blocks, so the reader can create them ahead of
1213  // time.
1214  Vals.push_back(VE.getBasicBlocks().size());
1215  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1216  Vals.clear();
1217
1218  // If there are function-local constants, emit them now.
1219  unsigned CstStart, CstEnd;
1220  VE.getFunctionConstantRange(CstStart, CstEnd);
1221  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1222
1223  // If there is function-local metadata, emit it now.
1224  WriteFunctionLocalMetadata(F, VE, Stream);
1225
1226  // Keep a running idea of what the instruction ID is.
1227  unsigned InstID = CstEnd;
1228
1229  bool NeedsMetadataAttachment = false;
1230
1231  DebugLoc LastDL;
1232
1233  // Finally, emit all the instructions, in order.
1234  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1235    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1236         I != E; ++I) {
1237      WriteInstruction(*I, InstID, VE, Stream, Vals);
1238
1239      if (!I->getType()->isVoidTy())
1240        ++InstID;
1241
1242      // If the instruction has metadata, write a metadata attachment later.
1243      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1244
1245      // If the instruction has a debug location, emit it.
1246      DebugLoc DL = I->getDebugLoc();
1247      if (DL.isUnknown()) {
1248        // nothing todo.
1249      } else if (DL == LastDL) {
1250        // Just repeat the same debug loc as last time.
1251        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1252      } else {
1253        MDNode *Scope, *IA;
1254        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1255
1256        Vals.push_back(DL.getLine());
1257        Vals.push_back(DL.getCol());
1258        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1259        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1260        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC2, Vals);
1261        Vals.clear();
1262
1263        LastDL = DL;
1264      }
1265    }
1266
1267  // Emit names for all the instructions etc.
1268  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1269
1270  if (NeedsMetadataAttachment)
1271    WriteMetadataAttachment(F, VE, Stream);
1272  VE.purgeFunction();
1273  Stream.ExitBlock();
1274}
1275
1276/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1277static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1278                                 const ValueEnumerator &VE,
1279                                 BitstreamWriter &Stream) {
1280  if (TST.empty()) return;
1281
1282  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1283
1284  // 7-bit fixed width VST_CODE_ENTRY strings.
1285  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1286  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1287  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1288                            Log2_32_Ceil(VE.getTypes().size()+1)));
1289  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1290  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1291  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1292
1293  SmallVector<unsigned, 64> NameVals;
1294
1295  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1296       TI != TE; ++TI) {
1297    // TST_ENTRY: [typeid, namechar x N]
1298    NameVals.push_back(VE.getTypeID(TI->second));
1299
1300    const std::string &Str = TI->first;
1301    bool is7Bit = true;
1302    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1303      NameVals.push_back((unsigned char)Str[i]);
1304      if (Str[i] & 128)
1305        is7Bit = false;
1306    }
1307
1308    // Emit the finished record.
1309    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1310    NameVals.clear();
1311  }
1312
1313  Stream.ExitBlock();
1314}
1315
1316// Emit blockinfo, which defines the standard abbreviations etc.
1317static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1318  // We only want to emit block info records for blocks that have multiple
1319  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1320  // blocks can defined their abbrevs inline.
1321  Stream.EnterBlockInfoBlock(2);
1322
1323  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1324    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1325    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1326    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1327    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1328    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1329    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1330                                   Abbv) != VST_ENTRY_8_ABBREV)
1331      llvm_unreachable("Unexpected abbrev ordering!");
1332  }
1333
1334  { // 7-bit fixed width VST_ENTRY strings.
1335    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1336    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1337    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1338    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1339    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1340    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1341                                   Abbv) != VST_ENTRY_7_ABBREV)
1342      llvm_unreachable("Unexpected abbrev ordering!");
1343  }
1344  { // 6-bit char6 VST_ENTRY strings.
1345    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1346    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1347    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1348    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1349    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1350    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1351                                   Abbv) != VST_ENTRY_6_ABBREV)
1352      llvm_unreachable("Unexpected abbrev ordering!");
1353  }
1354  { // 6-bit char6 VST_BBENTRY strings.
1355    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1356    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1357    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1358    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1359    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1360    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1361                                   Abbv) != VST_BBENTRY_6_ABBREV)
1362      llvm_unreachable("Unexpected abbrev ordering!");
1363  }
1364
1365
1366
1367  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1368    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1369    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1370    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1371                              Log2_32_Ceil(VE.getTypes().size()+1)));
1372    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1373                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1374      llvm_unreachable("Unexpected abbrev ordering!");
1375  }
1376
1377  { // INTEGER abbrev for CONSTANTS_BLOCK.
1378    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1379    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1380    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1381    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1382                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1383      llvm_unreachable("Unexpected abbrev ordering!");
1384  }
1385
1386  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1387    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1388    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1389    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1390    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1391                              Log2_32_Ceil(VE.getTypes().size()+1)));
1392    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1393
1394    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1395                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1396      llvm_unreachable("Unexpected abbrev ordering!");
1397  }
1398  { // NULL abbrev for CONSTANTS_BLOCK.
1399    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1400    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1401    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1402                                   Abbv) != CONSTANTS_NULL_Abbrev)
1403      llvm_unreachable("Unexpected abbrev ordering!");
1404  }
1405
1406  // FIXME: This should only use space for first class types!
1407
1408  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1409    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1410    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1411    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1412    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1413    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1414    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1415                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1416      llvm_unreachable("Unexpected abbrev ordering!");
1417  }
1418  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1419    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1420    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1421    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1422    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1423    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1424    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1425                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1426      llvm_unreachable("Unexpected abbrev ordering!");
1427  }
1428  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1429    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1430    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1431    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1432    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1433    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1434    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1435    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1436                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1437      llvm_unreachable("Unexpected abbrev ordering!");
1438  }
1439  { // INST_CAST abbrev for FUNCTION_BLOCK.
1440    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1441    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1442    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1443    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1444                              Log2_32_Ceil(VE.getTypes().size()+1)));
1445    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1446    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1447                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1448      llvm_unreachable("Unexpected abbrev ordering!");
1449  }
1450
1451  { // INST_RET abbrev for FUNCTION_BLOCK.
1452    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1453    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1454    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1455                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1456      llvm_unreachable("Unexpected abbrev ordering!");
1457  }
1458  { // INST_RET abbrev for FUNCTION_BLOCK.
1459    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1460    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1461    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1462    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1463                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1464      llvm_unreachable("Unexpected abbrev ordering!");
1465  }
1466  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1467    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1468    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1469    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1470                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1471      llvm_unreachable("Unexpected abbrev ordering!");
1472  }
1473
1474  Stream.ExitBlock();
1475}
1476
1477
1478/// WriteModule - Emit the specified module to the bitstream.
1479static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1480  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1481
1482  // Emit the version number if it is non-zero.
1483  if (CurVersion) {
1484    SmallVector<unsigned, 1> Vals;
1485    Vals.push_back(CurVersion);
1486    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1487  }
1488
1489  // Analyze the module, enumerating globals, functions, etc.
1490  ValueEnumerator VE(M);
1491
1492  // Emit blockinfo, which defines the standard abbreviations etc.
1493  WriteBlockInfo(VE, Stream);
1494
1495  // Emit information about parameter attributes.
1496  WriteAttributeTable(VE, Stream);
1497
1498  // Emit information describing all of the types in the module.
1499  WriteTypeTable(VE, Stream);
1500
1501  // Emit top-level description of module, including target triple, inline asm,
1502  // descriptors for global variables, and function prototype info.
1503  WriteModuleInfo(M, VE, Stream);
1504
1505  // Emit constants.
1506  WriteModuleConstants(VE, Stream);
1507
1508  // Emit metadata.
1509  WriteModuleMetadata(M, VE, Stream);
1510
1511  // Emit function bodies.
1512  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1513    if (!I->isDeclaration())
1514      WriteFunction(*I, VE, Stream);
1515
1516  // Emit metadata.
1517  WriteModuleMetadataStore(M, Stream);
1518
1519  // Emit the type symbol table information.
1520  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1521
1522  // Emit names for globals/functions etc.
1523  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1524
1525  Stream.ExitBlock();
1526}
1527
1528/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1529/// header and trailer to make it compatible with the system archiver.  To do
1530/// this we emit the following header, and then emit a trailer that pads the
1531/// file out to be a multiple of 16 bytes.
1532///
1533/// struct bc_header {
1534///   uint32_t Magic;         // 0x0B17C0DE
1535///   uint32_t Version;       // Version, currently always 0.
1536///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1537///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1538///   uint32_t CPUType;       // CPU specifier.
1539///   ... potentially more later ...
1540/// };
1541enum {
1542  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1543  DarwinBCHeaderSize = 5*4
1544};
1545
1546/// isARMTriplet - Return true if the triplet looks like:
1547/// arm-*, thumb-*, armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*.
1548static bool isARMTriplet(const std::string &TT) {
1549  size_t Pos = 0;
1550  size_t Size = TT.size();
1551  if (Size >= 6 &&
1552      TT[0] == 't' && TT[1] == 'h' && TT[2] == 'u' &&
1553      TT[3] == 'm' && TT[4] == 'b')
1554    Pos = 5;
1555  else if (Size >= 4 && TT[0] == 'a' && TT[1] == 'r' && TT[2] == 'm')
1556    Pos = 3;
1557  else
1558    return false;
1559
1560  if (TT[Pos] == '-')
1561    return true;
1562  else if (TT[Pos] == 'v') {
1563    if (Size >= Pos+4 &&
1564        TT[Pos+1] == '6' && TT[Pos+2] == 't' && TT[Pos+3] == '2')
1565      return true;
1566    else if (Size >= Pos+4 &&
1567             TT[Pos+1] == '5' && TT[Pos+2] == 't' && TT[Pos+3] == 'e')
1568      return true;
1569  } else
1570    return false;
1571  while (++Pos < Size && TT[Pos] != '-') {
1572    if (!isdigit(TT[Pos]))
1573      return false;
1574  }
1575  return true;
1576}
1577
1578static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1579                               const std::string &TT) {
1580  unsigned CPUType = ~0U;
1581
1582  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1583  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1584  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1585  // specific constants here because they are implicitly part of the Darwin ABI.
1586  enum {
1587    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1588    DARWIN_CPU_TYPE_X86        = 7,
1589    DARWIN_CPU_TYPE_ARM        = 12,
1590    DARWIN_CPU_TYPE_POWERPC    = 18
1591  };
1592
1593  if (TT.find("x86_64-") == 0)
1594    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1595  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1596           TT[4] == '-' && TT[1] - '3' < 6)
1597    CPUType = DARWIN_CPU_TYPE_X86;
1598  else if (TT.find("powerpc-") == 0)
1599    CPUType = DARWIN_CPU_TYPE_POWERPC;
1600  else if (TT.find("powerpc64-") == 0)
1601    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1602  else if (isARMTriplet(TT))
1603    CPUType = DARWIN_CPU_TYPE_ARM;
1604
1605  // Traditional Bitcode starts after header.
1606  unsigned BCOffset = DarwinBCHeaderSize;
1607
1608  Stream.Emit(0x0B17C0DE, 32);
1609  Stream.Emit(0         , 32);  // Version.
1610  Stream.Emit(BCOffset  , 32);
1611  Stream.Emit(0         , 32);  // Filled in later.
1612  Stream.Emit(CPUType   , 32);
1613}
1614
1615/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1616/// finalize the header.
1617static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1618  // Update the size field in the header.
1619  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1620
1621  // If the file is not a multiple of 16 bytes, insert dummy padding.
1622  while (BufferSize & 15) {
1623    Stream.Emit(0, 8);
1624    ++BufferSize;
1625  }
1626}
1627
1628
1629/// WriteBitcodeToFile - Write the specified module to the specified output
1630/// stream.
1631void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1632  std::vector<unsigned char> Buffer;
1633  BitstreamWriter Stream(Buffer);
1634
1635  Buffer.reserve(256*1024);
1636
1637  WriteBitcodeToStream( M, Stream );
1638
1639  // Write the generated bitstream to "Out".
1640  Out.write((char*)&Buffer.front(), Buffer.size());
1641}
1642
1643/// WriteBitcodeToStream - Write the specified module to the specified output
1644/// stream.
1645void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1646  // If this is darwin or another generic macho target, emit a file header and
1647  // trailer if needed.
1648  bool isMacho =
1649    M->getTargetTriple().find("-darwin") != std::string::npos ||
1650    M->getTargetTriple().find("-macho") != std::string::npos;
1651  if (isMacho)
1652    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1653
1654  // Emit the file header.
1655  Stream.Emit((unsigned)'B', 8);
1656  Stream.Emit((unsigned)'C', 8);
1657  Stream.Emit(0x0, 4);
1658  Stream.Emit(0xC, 4);
1659  Stream.Emit(0xE, 4);
1660  Stream.Emit(0xD, 4);
1661
1662  // Emit the module.
1663  WriteModule(M, Stream);
1664
1665  if (isMacho)
1666    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1667}
1668