BitcodeWriter.cpp revision d7bb295d223e028aa9ba7fbeafc8928db4a74972 
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  VST_LPADENTRY_6_ABBREV,
44
45  // CONSTANTS_BLOCK abbrev id's.
46  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
47  CONSTANTS_INTEGER_ABBREV,
48  CONSTANTS_CE_CAST_Abbrev,
49  CONSTANTS_NULL_Abbrev,
50
51  // FUNCTION_BLOCK abbrev id's.
52  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
53  FUNCTION_INST_BINOP_ABBREV,
54  FUNCTION_INST_BINOP_FLAGS_ABBREV,
55  FUNCTION_INST_CAST_ABBREV,
56  FUNCTION_INST_RET_VOID_ABBREV,
57  FUNCTION_INST_RET_VAL_ABBREV,
58  FUNCTION_INST_UNREACHABLE_ABBREV
59};
60
61
62static unsigned GetEncodedCastOpcode(unsigned Opcode) {
63  switch (Opcode) {
64  default: llvm_unreachable("Unknown cast instruction!");
65  case Instruction::Trunc   : return bitc::CAST_TRUNC;
66  case Instruction::ZExt    : return bitc::CAST_ZEXT;
67  case Instruction::SExt    : return bitc::CAST_SEXT;
68  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
69  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
70  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
71  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
72  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
73  case Instruction::FPExt   : return bitc::CAST_FPEXT;
74  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
75  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
76  case Instruction::BitCast : return bitc::CAST_BITCAST;
77  }
78}
79
80static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
81  switch (Opcode) {
82  default: llvm_unreachable("Unknown binary instruction!");
83  case Instruction::Add:
84  case Instruction::FAdd: return bitc::BINOP_ADD;
85  case Instruction::Sub:
86  case Instruction::FSub: return bitc::BINOP_SUB;
87  case Instruction::Mul:
88  case Instruction::FMul: return bitc::BINOP_MUL;
89  case Instruction::UDiv: return bitc::BINOP_UDIV;
90  case Instruction::FDiv:
91  case Instruction::SDiv: return bitc::BINOP_SDIV;
92  case Instruction::URem: return bitc::BINOP_UREM;
93  case Instruction::FRem:
94  case Instruction::SRem: return bitc::BINOP_SREM;
95  case Instruction::Shl:  return bitc::BINOP_SHL;
96  case Instruction::LShr: return bitc::BINOP_LSHR;
97  case Instruction::AShr: return bitc::BINOP_ASHR;
98  case Instruction::And:  return bitc::BINOP_AND;
99  case Instruction::Or:   return bitc::BINOP_OR;
100  case Instruction::Xor:  return bitc::BINOP_XOR;
101  }
102}
103
104
105
106static void WriteStringRecord(unsigned Code, const std::string &Str,
107                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
108  SmallVector<unsigned, 64> Vals;
109
110  // Code: [strchar x N]
111  for (unsigned i = 0, e = Str.size(); i != e; ++i)
112    Vals.push_back(Str[i]);
113
114  // Emit the finished record.
115  Stream.EmitRecord(Code, Vals, AbbrevToUse);
116}
117
118// Emit information about parameter attributes.
119static void WriteAttributeTable(const ValueEnumerator &VE,
120                                BitstreamWriter &Stream) {
121  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
122  if (Attrs.empty()) return;
123
124  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
125
126  SmallVector<uint64_t, 64> Record;
127  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
128    const AttrListPtr &A = Attrs[i];
129    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
130      const AttributeWithIndex &PAWI = A.getSlot(i);
131      Record.push_back(PAWI.Index);
132
133      // FIXME: remove in LLVM 3.0
134      // Store the alignment in the bitcode as a 16-bit raw value instead of a
135      // 5-bit log2 encoded value. Shift the bits above the alignment up by
136      // 11 bits.
137      uint64_t FauxAttr = PAWI.Attrs & 0xffff;
138      if (PAWI.Attrs & Attribute::Alignment)
139        FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
140      FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
141
142      Record.push_back(FauxAttr);
143    }
144
145    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
146    Record.clear();
147  }
148
149  Stream.ExitBlock();
150}
151
152/// WriteTypeTable - Write out the type table for a module.
153static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
154  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
155
156  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID, 4 /*count from # abbrevs */);
157  SmallVector<uint64_t, 64> TypeVals;
158
159  // Abbrev for TYPE_CODE_POINTER.
160  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
161  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
162  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
163                            Log2_32_Ceil(VE.getTypes().size()+1)));
164  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
165  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
166
167  // Abbrev for TYPE_CODE_FUNCTION.
168  Abbv = new BitCodeAbbrev();
169  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
170  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
171  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
172  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
173  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
174                            Log2_32_Ceil(VE.getTypes().size()+1)));
175  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
176
177  // Abbrev for TYPE_CODE_STRUCT.
178  Abbv = new BitCodeAbbrev();
179  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT));
180  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
181  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
182  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
183                            Log2_32_Ceil(VE.getTypes().size()+1)));
184  unsigned StructAbbrev = Stream.EmitAbbrev(Abbv);
185
186  // Abbrev for TYPE_CODE_ARRAY.
187  Abbv = new BitCodeAbbrev();
188  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
189  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
190  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
191                            Log2_32_Ceil(VE.getTypes().size()+1)));
192  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
193
194  // Emit an entry count so the reader can reserve space.
195  TypeVals.push_back(TypeList.size());
196  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
197  TypeVals.clear();
198
199  // Loop over all of the types, emitting each in turn.
200  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
201    const Type *T = TypeList[i];
202    int AbbrevToUse = 0;
203    unsigned Code = 0;
204
205    switch (T->getTypeID()) {
206    default: llvm_unreachable("Unknown type!");
207    case Type::VoidTyID:   Code = bitc::TYPE_CODE_VOID;   break;
208    case Type::FloatTyID:  Code = bitc::TYPE_CODE_FLOAT;  break;
209    case Type::DoubleTyID: Code = bitc::TYPE_CODE_DOUBLE; break;
210    case Type::X86_FP80TyID: Code = bitc::TYPE_CODE_X86_FP80; break;
211    case Type::FP128TyID: Code = bitc::TYPE_CODE_FP128; break;
212    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
213    case Type::LabelTyID:  Code = bitc::TYPE_CODE_LABEL;  break;
214    case Type::OpaqueTyID: Code = bitc::TYPE_CODE_OPAQUE; break;
215    case Type::MetadataTyID: Code = bitc::TYPE_CODE_METADATA; break;
216    case Type::X86_MMXTyID: Code = bitc::TYPE_CODE_X86_MMX; break;
217    case Type::IntegerTyID:
218      // INTEGER: [width]
219      Code = bitc::TYPE_CODE_INTEGER;
220      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
221      break;
222    case Type::PointerTyID: {
223      const PointerType *PTy = cast<PointerType>(T);
224      // POINTER: [pointee type, address space]
225      Code = bitc::TYPE_CODE_POINTER;
226      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
227      unsigned AddressSpace = PTy->getAddressSpace();
228      TypeVals.push_back(AddressSpace);
229      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
230      break;
231    }
232    case Type::FunctionTyID: {
233      const FunctionType *FT = cast<FunctionType>(T);
234      // FUNCTION: [isvararg, attrid, retty, paramty x N]
235      Code = bitc::TYPE_CODE_FUNCTION;
236      TypeVals.push_back(FT->isVarArg());
237      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
238      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
239      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
240        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
241      AbbrevToUse = FunctionAbbrev;
242      break;
243    }
244    case Type::StructTyID: {
245      const StructType *ST = cast<StructType>(T);
246      // STRUCT: [ispacked, eltty x N]
247      Code = bitc::TYPE_CODE_STRUCT;
248      TypeVals.push_back(ST->isPacked());
249      // Output all of the element types.
250      for (StructType::element_iterator I = ST->element_begin(),
251           E = ST->element_end(); I != E; ++I)
252        TypeVals.push_back(VE.getTypeID(*I));
253      AbbrevToUse = StructAbbrev;
254      break;
255    }
256    case Type::ArrayTyID: {
257      const ArrayType *AT = cast<ArrayType>(T);
258      // ARRAY: [numelts, eltty]
259      Code = bitc::TYPE_CODE_ARRAY;
260      TypeVals.push_back(AT->getNumElements());
261      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
262      AbbrevToUse = ArrayAbbrev;
263      break;
264    }
265    case Type::VectorTyID: {
266      const VectorType *VT = cast<VectorType>(T);
267      // VECTOR [numelts, eltty]
268      Code = bitc::TYPE_CODE_VECTOR;
269      TypeVals.push_back(VT->getNumElements());
270      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
271      break;
272    }
273    }
274
275    // Emit the finished record.
276    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
277    TypeVals.clear();
278  }
279
280  Stream.ExitBlock();
281}
282
283static unsigned getEncodedLinkage(const GlobalValue *GV) {
284  switch (GV->getLinkage()) {
285  default: llvm_unreachable("Invalid linkage!");
286  case GlobalValue::ExternalLinkage:                 return 0;
287  case GlobalValue::WeakAnyLinkage:                  return 1;
288  case GlobalValue::AppendingLinkage:                return 2;
289  case GlobalValue::InternalLinkage:                 return 3;
290  case GlobalValue::LinkOnceAnyLinkage:              return 4;
291  case GlobalValue::DLLImportLinkage:                return 5;
292  case GlobalValue::DLLExportLinkage:                return 6;
293  case GlobalValue::ExternalWeakLinkage:             return 7;
294  case GlobalValue::CommonLinkage:                   return 8;
295  case GlobalValue::PrivateLinkage:                  return 9;
296  case GlobalValue::WeakODRLinkage:                  return 10;
297  case GlobalValue::LinkOnceODRLinkage:              return 11;
298  case GlobalValue::AvailableExternallyLinkage:      return 12;
299  case GlobalValue::LinkerPrivateLinkage:            return 13;
300  case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
301  case GlobalValue::LinkerPrivateWeakDefAutoLinkage: return 15;
302  }
303}
304
305static unsigned getEncodedVisibility(const GlobalValue *GV) {
306  switch (GV->getVisibility()) {
307  default: llvm_unreachable("Invalid visibility!");
308  case GlobalValue::DefaultVisibility:   return 0;
309  case GlobalValue::HiddenVisibility:    return 1;
310  case GlobalValue::ProtectedVisibility: return 2;
311  }
312}
313
314// Emit top-level description of module, including target triple, inline asm,
315// descriptors for global variables, and function prototype info.
316static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
317                            BitstreamWriter &Stream) {
318  // Emit the list of dependent libraries for the Module.
319  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
320    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
321
322  // Emit various pieces of data attached to a module.
323  if (!M->getTargetTriple().empty())
324    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
325                      0/*TODO*/, Stream);
326  if (!M->getDataLayout().empty())
327    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
328                      0/*TODO*/, Stream);
329  if (!M->getModuleInlineAsm().empty())
330    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
331                      0/*TODO*/, Stream);
332
333  // Emit information about sections and GC, computing how many there are. Also
334  // compute the maximum alignment value.
335  std::map<std::string, unsigned> SectionMap;
336  std::map<std::string, unsigned> GCMap;
337  unsigned MaxAlignment = 0;
338  unsigned MaxGlobalType = 0;
339  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
340       GV != E; ++GV) {
341    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
342    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
343
344    if (!GV->hasSection()) continue;
345    // Give section names unique ID's.
346    unsigned &Entry = SectionMap[GV->getSection()];
347    if (Entry != 0) continue;
348    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
349                      0/*TODO*/, Stream);
350    Entry = SectionMap.size();
351  }
352  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
353    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
354    if (F->hasSection()) {
355      // Give section names unique ID's.
356      unsigned &Entry = SectionMap[F->getSection()];
357      if (!Entry) {
358        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
359                          0/*TODO*/, Stream);
360        Entry = SectionMap.size();
361      }
362    }
363    if (F->hasGC()) {
364      // Same for GC names.
365      unsigned &Entry = GCMap[F->getGC()];
366      if (!Entry) {
367        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
368                          0/*TODO*/, Stream);
369        Entry = GCMap.size();
370      }
371    }
372  }
373
374  // Emit abbrev for globals, now that we know # sections and max alignment.
375  unsigned SimpleGVarAbbrev = 0;
376  if (!M->global_empty()) {
377    // Add an abbrev for common globals with no visibility or thread localness.
378    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
379    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
380    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
381                              Log2_32_Ceil(MaxGlobalType+1)));
382    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
383    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
384    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
385    if (MaxAlignment == 0)                                      // Alignment.
386      Abbv->Add(BitCodeAbbrevOp(0));
387    else {
388      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
389      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
390                               Log2_32_Ceil(MaxEncAlignment+1)));
391    }
392    if (SectionMap.empty())                                    // Section.
393      Abbv->Add(BitCodeAbbrevOp(0));
394    else
395      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
396                               Log2_32_Ceil(SectionMap.size()+1)));
397    // Don't bother emitting vis + thread local.
398    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
399  }
400
401  // Emit the global variable information.
402  SmallVector<unsigned, 64> Vals;
403  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
404       GV != E; ++GV) {
405    unsigned AbbrevToUse = 0;
406
407    // GLOBALVAR: [type, isconst, initid,
408    //             linkage, alignment, section, visibility, threadlocal,
409    //             unnamed_addr]
410    Vals.push_back(VE.getTypeID(GV->getType()));
411    Vals.push_back(GV->isConstant());
412    Vals.push_back(GV->isDeclaration() ? 0 :
413                   (VE.getValueID(GV->getInitializer()) + 1));
414    Vals.push_back(getEncodedLinkage(GV));
415    Vals.push_back(Log2_32(GV->getAlignment())+1);
416    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
417    if (GV->isThreadLocal() ||
418        GV->getVisibility() != GlobalValue::DefaultVisibility ||
419        GV->hasUnnamedAddr()) {
420      Vals.push_back(getEncodedVisibility(GV));
421      Vals.push_back(GV->isThreadLocal());
422      Vals.push_back(GV->hasUnnamedAddr());
423    } else {
424      AbbrevToUse = SimpleGVarAbbrev;
425    }
426
427    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
428    Vals.clear();
429  }
430
431  // Emit the function proto information.
432  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
433    // FUNCTION:  [type, callingconv, isproto, paramattr,
434    //             linkage, alignment, section, visibility, gc, unnamed_addr]
435    Vals.push_back(VE.getTypeID(F->getType()));
436    Vals.push_back(F->getCallingConv());
437    Vals.push_back(F->isDeclaration());
438    Vals.push_back(getEncodedLinkage(F));
439    Vals.push_back(VE.getAttributeID(F->getAttributes()));
440    Vals.push_back(Log2_32(F->getAlignment())+1);
441    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
442    Vals.push_back(getEncodedVisibility(F));
443    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
444    Vals.push_back(F->hasUnnamedAddr());
445
446    unsigned AbbrevToUse = 0;
447    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
448    Vals.clear();
449  }
450
451
452  // Emit the alias information.
453  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
454       AI != E; ++AI) {
455    Vals.push_back(VE.getTypeID(AI->getType()));
456    Vals.push_back(VE.getValueID(AI->getAliasee()));
457    Vals.push_back(getEncodedLinkage(AI));
458    Vals.push_back(getEncodedVisibility(AI));
459    unsigned AbbrevToUse = 0;
460    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
461    Vals.clear();
462  }
463}
464
465static uint64_t GetOptimizationFlags(const Value *V) {
466  uint64_t Flags = 0;
467
468  if (const OverflowingBinaryOperator *OBO =
469        dyn_cast<OverflowingBinaryOperator>(V)) {
470    if (OBO->hasNoSignedWrap())
471      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
472    if (OBO->hasNoUnsignedWrap())
473      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
474  } else if (const PossiblyExactOperator *PEO =
475               dyn_cast<PossiblyExactOperator>(V)) {
476    if (PEO->isExact())
477      Flags |= 1 << bitc::PEO_EXACT;
478  }
479
480  return Flags;
481}
482
483static void WriteMDNode(const MDNode *N,
484                        const ValueEnumerator &VE,
485                        BitstreamWriter &Stream,
486                        SmallVector<uint64_t, 64> &Record) {
487  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
488    if (N->getOperand(i)) {
489      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
490      Record.push_back(VE.getValueID(N->getOperand(i)));
491    } else {
492      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
493      Record.push_back(0);
494    }
495  }
496  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE2 :
497                                           bitc::METADATA_NODE2;
498  Stream.EmitRecord(MDCode, Record, 0);
499  Record.clear();
500}
501
502static void WriteModuleMetadata(const Module *M,
503                                const ValueEnumerator &VE,
504                                BitstreamWriter &Stream) {
505  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
506  bool StartedMetadataBlock = false;
507  unsigned MDSAbbrev = 0;
508  SmallVector<uint64_t, 64> Record;
509  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
510
511    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
512      if (!N->isFunctionLocal() || !N->getFunction()) {
513        if (!StartedMetadataBlock) {
514          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
515          StartedMetadataBlock = true;
516        }
517        WriteMDNode(N, VE, Stream, Record);
518      }
519    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
520      if (!StartedMetadataBlock)  {
521        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
522
523        // Abbrev for METADATA_STRING.
524        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
525        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
526        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
527        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
528        MDSAbbrev = Stream.EmitAbbrev(Abbv);
529        StartedMetadataBlock = true;
530      }
531
532      // Code: [strchar x N]
533      Record.append(MDS->begin(), MDS->end());
534
535      // Emit the finished record.
536      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
537      Record.clear();
538    }
539  }
540
541  // Write named metadata.
542  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
543       E = M->named_metadata_end(); I != E; ++I) {
544    const NamedMDNode *NMD = I;
545    if (!StartedMetadataBlock)  {
546      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
547      StartedMetadataBlock = true;
548    }
549
550    // Write name.
551    StringRef Str = NMD->getName();
552    for (unsigned i = 0, e = Str.size(); i != e; ++i)
553      Record.push_back(Str[i]);
554    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
555    Record.clear();
556
557    // Write named metadata operands.
558    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
559      Record.push_back(VE.getValueID(NMD->getOperand(i)));
560    Stream.EmitRecord(bitc::METADATA_NAMED_NODE2, Record, 0);
561    Record.clear();
562  }
563
564  if (StartedMetadataBlock)
565    Stream.ExitBlock();
566}
567
568static void WriteFunctionLocalMetadata(const Function &F,
569                                       const ValueEnumerator &VE,
570                                       BitstreamWriter &Stream) {
571  bool StartedMetadataBlock = false;
572  SmallVector<uint64_t, 64> Record;
573  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
574  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
575    if (const MDNode *N = Vals[i])
576      if (N->isFunctionLocal() && N->getFunction() == &F) {
577        if (!StartedMetadataBlock) {
578          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
579          StartedMetadataBlock = true;
580        }
581        WriteMDNode(N, VE, Stream, Record);
582      }
583
584  if (StartedMetadataBlock)
585    Stream.ExitBlock();
586}
587
588static void WriteMetadataAttachment(const Function &F,
589                                    const ValueEnumerator &VE,
590                                    BitstreamWriter &Stream) {
591  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
592
593  SmallVector<uint64_t, 64> Record;
594
595  // Write metadata attachments
596  // METADATA_ATTACHMENT2 - [m x [value, [n x [id, mdnode]]]
597  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
598
599  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
600    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
601         I != E; ++I) {
602      MDs.clear();
603      I->getAllMetadataOtherThanDebugLoc(MDs);
604
605      // If no metadata, ignore instruction.
606      if (MDs.empty()) continue;
607
608      Record.push_back(VE.getInstructionID(I));
609
610      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
611        Record.push_back(MDs[i].first);
612        Record.push_back(VE.getValueID(MDs[i].second));
613      }
614      Stream.EmitRecord(bitc::METADATA_ATTACHMENT2, Record, 0);
615      Record.clear();
616    }
617
618  Stream.ExitBlock();
619}
620
621static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
622  SmallVector<uint64_t, 64> Record;
623
624  // Write metadata kinds
625  // METADATA_KIND - [n x [id, name]]
626  SmallVector<StringRef, 4> Names;
627  M->getMDKindNames(Names);
628
629  if (Names.empty()) return;
630
631  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
632
633  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
634    Record.push_back(MDKindID);
635    StringRef KName = Names[MDKindID];
636    Record.append(KName.begin(), KName.end());
637
638    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
639    Record.clear();
640  }
641
642  Stream.ExitBlock();
643}
644
645static void WriteConstants(unsigned FirstVal, unsigned LastVal,
646                           const ValueEnumerator &VE,
647                           BitstreamWriter &Stream, bool isGlobal) {
648  if (FirstVal == LastVal) return;
649
650  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
651
652  unsigned AggregateAbbrev = 0;
653  unsigned String8Abbrev = 0;
654  unsigned CString7Abbrev = 0;
655  unsigned CString6Abbrev = 0;
656  // If this is a constant pool for the module, emit module-specific abbrevs.
657  if (isGlobal) {
658    // Abbrev for CST_CODE_AGGREGATE.
659    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
660    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
661    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
662    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
663    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
664
665    // Abbrev for CST_CODE_STRING.
666    Abbv = new BitCodeAbbrev();
667    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
668    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
669    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
670    String8Abbrev = 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::Fixed, 7));
676    CString7Abbrev = Stream.EmitAbbrev(Abbv);
677    // Abbrev for CST_CODE_CSTRING.
678    Abbv = new BitCodeAbbrev();
679    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
680    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
681    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
682    CString6Abbrev = Stream.EmitAbbrev(Abbv);
683  }
684
685  SmallVector<uint64_t, 64> Record;
686
687  const ValueEnumerator::ValueList &Vals = VE.getValues();
688  const Type *LastTy = 0;
689  for (unsigned i = FirstVal; i != LastVal; ++i) {
690    const Value *V = Vals[i].first;
691    // If we need to switch types, do so now.
692    if (V->getType() != LastTy) {
693      LastTy = V->getType();
694      Record.push_back(VE.getTypeID(LastTy));
695      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
696                        CONSTANTS_SETTYPE_ABBREV);
697      Record.clear();
698    }
699
700    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
701      Record.push_back(unsigned(IA->hasSideEffects()) |
702                       unsigned(IA->isAlignStack()) << 1);
703
704      // Add the asm string.
705      const std::string &AsmStr = IA->getAsmString();
706      Record.push_back(AsmStr.size());
707      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
708        Record.push_back(AsmStr[i]);
709
710      // Add the constraint string.
711      const std::string &ConstraintStr = IA->getConstraintString();
712      Record.push_back(ConstraintStr.size());
713      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
714        Record.push_back(ConstraintStr[i]);
715      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
716      Record.clear();
717      continue;
718    }
719    const Constant *C = cast<Constant>(V);
720    unsigned Code = -1U;
721    unsigned AbbrevToUse = 0;
722    if (C->isNullValue()) {
723      Code = bitc::CST_CODE_NULL;
724    } else if (isa<UndefValue>(C)) {
725      Code = bitc::CST_CODE_UNDEF;
726    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
727      if (IV->getBitWidth() <= 64) {
728        uint64_t V = IV->getSExtValue();
729        if ((int64_t)V >= 0)
730          Record.push_back(V << 1);
731        else
732          Record.push_back((-V << 1) | 1);
733        Code = bitc::CST_CODE_INTEGER;
734        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
735      } else {                             // Wide integers, > 64 bits in size.
736        // We have an arbitrary precision integer value to write whose
737        // bit width is > 64. However, in canonical unsigned integer
738        // format it is likely that the high bits are going to be zero.
739        // So, we only write the number of active words.
740        unsigned NWords = IV->getValue().getActiveWords();
741        const uint64_t *RawWords = IV->getValue().getRawData();
742        for (unsigned i = 0; i != NWords; ++i) {
743          int64_t V = RawWords[i];
744          if (V >= 0)
745            Record.push_back(V << 1);
746          else
747            Record.push_back((-V << 1) | 1);
748        }
749        Code = bitc::CST_CODE_WIDE_INTEGER;
750      }
751    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
752      Code = bitc::CST_CODE_FLOAT;
753      const Type *Ty = CFP->getType();
754      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
755        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
756      } else if (Ty->isX86_FP80Ty()) {
757        // api needed to prevent premature destruction
758        // bits are not in the same order as a normal i80 APInt, compensate.
759        APInt api = CFP->getValueAPF().bitcastToAPInt();
760        const uint64_t *p = api.getRawData();
761        Record.push_back((p[1] << 48) | (p[0] >> 16));
762        Record.push_back(p[0] & 0xffffLL);
763      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
764        APInt api = CFP->getValueAPF().bitcastToAPInt();
765        const uint64_t *p = api.getRawData();
766        Record.push_back(p[0]);
767        Record.push_back(p[1]);
768      } else {
769        assert (0 && "Unknown FP type!");
770      }
771    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
772      const ConstantArray *CA = cast<ConstantArray>(C);
773      // Emit constant strings specially.
774      unsigned NumOps = CA->getNumOperands();
775      // If this is a null-terminated string, use the denser CSTRING encoding.
776      if (CA->getOperand(NumOps-1)->isNullValue()) {
777        Code = bitc::CST_CODE_CSTRING;
778        --NumOps;  // Don't encode the null, which isn't allowed by char6.
779      } else {
780        Code = bitc::CST_CODE_STRING;
781        AbbrevToUse = String8Abbrev;
782      }
783      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
784      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
785      for (unsigned i = 0; i != NumOps; ++i) {
786        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
787        Record.push_back(V);
788        isCStr7 &= (V & 128) == 0;
789        if (isCStrChar6)
790          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
791      }
792
793      if (isCStrChar6)
794        AbbrevToUse = CString6Abbrev;
795      else if (isCStr7)
796        AbbrevToUse = CString7Abbrev;
797    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
798               isa<ConstantVector>(V)) {
799      Code = bitc::CST_CODE_AGGREGATE;
800      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
801        Record.push_back(VE.getValueID(C->getOperand(i)));
802      AbbrevToUse = AggregateAbbrev;
803    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
804      switch (CE->getOpcode()) {
805      default:
806        if (Instruction::isCast(CE->getOpcode())) {
807          Code = bitc::CST_CODE_CE_CAST;
808          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
809          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
810          Record.push_back(VE.getValueID(C->getOperand(0)));
811          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
812        } else {
813          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
814          Code = bitc::CST_CODE_CE_BINOP;
815          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
816          Record.push_back(VE.getValueID(C->getOperand(0)));
817          Record.push_back(VE.getValueID(C->getOperand(1)));
818          uint64_t Flags = GetOptimizationFlags(CE);
819          if (Flags != 0)
820            Record.push_back(Flags);
821        }
822        break;
823      case Instruction::GetElementPtr:
824        Code = bitc::CST_CODE_CE_GEP;
825        if (cast<GEPOperator>(C)->isInBounds())
826          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
827        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
828          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
829          Record.push_back(VE.getValueID(C->getOperand(i)));
830        }
831        break;
832      case Instruction::Select:
833        Code = bitc::CST_CODE_CE_SELECT;
834        Record.push_back(VE.getValueID(C->getOperand(0)));
835        Record.push_back(VE.getValueID(C->getOperand(1)));
836        Record.push_back(VE.getValueID(C->getOperand(2)));
837        break;
838      case Instruction::ExtractElement:
839        Code = bitc::CST_CODE_CE_EXTRACTELT;
840        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
841        Record.push_back(VE.getValueID(C->getOperand(0)));
842        Record.push_back(VE.getValueID(C->getOperand(1)));
843        break;
844      case Instruction::InsertElement:
845        Code = bitc::CST_CODE_CE_INSERTELT;
846        Record.push_back(VE.getValueID(C->getOperand(0)));
847        Record.push_back(VE.getValueID(C->getOperand(1)));
848        Record.push_back(VE.getValueID(C->getOperand(2)));
849        break;
850      case Instruction::ShuffleVector:
851        // If the return type and argument types are the same, this is a
852        // standard shufflevector instruction.  If the types are different,
853        // then the shuffle is widening or truncating the input vectors, and
854        // the argument type must also be encoded.
855        if (C->getType() == C->getOperand(0)->getType()) {
856          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
857        } else {
858          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
859          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
860        }
861        Record.push_back(VE.getValueID(C->getOperand(0)));
862        Record.push_back(VE.getValueID(C->getOperand(1)));
863        Record.push_back(VE.getValueID(C->getOperand(2)));
864        break;
865      case Instruction::ICmp:
866      case Instruction::FCmp:
867        Code = bitc::CST_CODE_CE_CMP;
868        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
869        Record.push_back(VE.getValueID(C->getOperand(0)));
870        Record.push_back(VE.getValueID(C->getOperand(1)));
871        Record.push_back(CE->getPredicate());
872        break;
873      }
874    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
875      assert(BA->getFunction() == BA->getBasicBlock()->getParent() &&
876             "Malformed blockaddress");
877      Code = bitc::CST_CODE_BLOCKADDRESS;
878      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
879      Record.push_back(VE.getValueID(BA->getFunction()));
880      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
881    } else {
882#ifndef NDEBUG
883      C->dump();
884#endif
885      llvm_unreachable("Unknown constant!");
886    }
887    Stream.EmitRecord(Code, Record, AbbrevToUse);
888    Record.clear();
889  }
890
891  Stream.ExitBlock();
892}
893
894static void WriteModuleConstants(const ValueEnumerator &VE,
895                                 BitstreamWriter &Stream) {
896  const ValueEnumerator::ValueList &Vals = VE.getValues();
897
898  // Find the first constant to emit, which is the first non-globalvalue value.
899  // We know globalvalues have been emitted by WriteModuleInfo.
900  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
901    if (!isa<GlobalValue>(Vals[i].first)) {
902      WriteConstants(i, Vals.size(), VE, Stream, true);
903      return;
904    }
905  }
906}
907
908/// PushValueAndType - The file has to encode both the value and type id for
909/// many values, because we need to know what type to create for forward
910/// references.  However, most operands are not forward references, so this type
911/// field is not needed.
912///
913/// This function adds V's value ID to Vals.  If the value ID is higher than the
914/// instruction ID, then it is a forward reference, and it also includes the
915/// type ID.
916static bool PushValueAndType(const Value *V, unsigned InstID,
917                             SmallVector<unsigned, 64> &Vals,
918                             ValueEnumerator &VE) {
919  unsigned ValID = VE.getValueID(V);
920  Vals.push_back(ValID);
921  if (ValID >= InstID) {
922    Vals.push_back(VE.getTypeID(V->getType()));
923    return true;
924  }
925  return false;
926}
927
928/// WriteInstruction - Emit an instruction to the specified stream.
929static void WriteInstruction(const Instruction &I, unsigned InstID,
930                             ValueEnumerator &VE, BitstreamWriter &Stream,
931                             SmallVector<unsigned, 64> &Vals) {
932  unsigned Code = 0;
933  unsigned AbbrevToUse = 0;
934  VE.setInstructionID(&I);
935  switch (I.getOpcode()) {
936  default:
937    if (Instruction::isCast(I.getOpcode())) {
938      Code = bitc::FUNC_CODE_INST_CAST;
939      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
940        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
941      Vals.push_back(VE.getTypeID(I.getType()));
942      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
943    } else {
944      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
945      Code = bitc::FUNC_CODE_INST_BINOP;
946      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
947        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
948      Vals.push_back(VE.getValueID(I.getOperand(1)));
949      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
950      uint64_t Flags = GetOptimizationFlags(&I);
951      if (Flags != 0) {
952        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
953          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
954        Vals.push_back(Flags);
955      }
956    }
957    break;
958
959  case Instruction::GetElementPtr:
960    Code = bitc::FUNC_CODE_INST_GEP;
961    if (cast<GEPOperator>(&I)->isInBounds())
962      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
963    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
964      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
965    break;
966  case Instruction::ExtractValue: {
967    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
968    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
969    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
970    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
971      Vals.push_back(*i);
972    break;
973  }
974  case Instruction::InsertValue: {
975    Code = bitc::FUNC_CODE_INST_INSERTVAL;
976    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
977    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
978    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
979    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
980      Vals.push_back(*i);
981    break;
982  }
983  case Instruction::Select:
984    Code = bitc::FUNC_CODE_INST_VSELECT;
985    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
986    Vals.push_back(VE.getValueID(I.getOperand(2)));
987    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
988    break;
989  case Instruction::ExtractElement:
990    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
991    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
992    Vals.push_back(VE.getValueID(I.getOperand(1)));
993    break;
994  case Instruction::InsertElement:
995    Code = bitc::FUNC_CODE_INST_INSERTELT;
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::ShuffleVector:
1001    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1002    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1003    Vals.push_back(VE.getValueID(I.getOperand(1)));
1004    Vals.push_back(VE.getValueID(I.getOperand(2)));
1005    break;
1006  case Instruction::ICmp:
1007  case Instruction::FCmp:
1008    // compare returning Int1Ty or vector of Int1Ty
1009    Code = bitc::FUNC_CODE_INST_CMP2;
1010    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1011    Vals.push_back(VE.getValueID(I.getOperand(1)));
1012    Vals.push_back(cast<CmpInst>(I).getPredicate());
1013    break;
1014
1015  case Instruction::Ret:
1016    {
1017      Code = bitc::FUNC_CODE_INST_RET;
1018      unsigned NumOperands = I.getNumOperands();
1019      if (NumOperands == 0)
1020        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1021      else if (NumOperands == 1) {
1022        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1023          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1024      } else {
1025        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1026          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1027      }
1028    }
1029    break;
1030  case Instruction::Br:
1031    {
1032      Code = bitc::FUNC_CODE_INST_BR;
1033      BranchInst &II = cast<BranchInst>(I);
1034      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1035      if (II.isConditional()) {
1036        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1037        Vals.push_back(VE.getValueID(II.getCondition()));
1038      }
1039    }
1040    break;
1041  case Instruction::Switch:
1042    Code = bitc::FUNC_CODE_INST_SWITCH;
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  case Instruction::IndirectBr:
1048    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1049    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1050    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1051      Vals.push_back(VE.getValueID(I.getOperand(i)));
1052    break;
1053
1054  case Instruction::Invoke: {
1055    const InvokeInst *II = cast<InvokeInst>(&I);
1056    const Value *Callee(II->getCalledValue());
1057    const PointerType *PTy = cast<PointerType>(Callee->getType());
1058    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1059    Code = bitc::FUNC_CODE_INST_INVOKE;
1060
1061    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1062    Vals.push_back(II->getCallingConv());
1063    Vals.push_back(VE.getValueID(II->getNormalDest()));
1064    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1065    PushValueAndType(Callee, InstID, Vals, VE);
1066
1067    // Emit value #'s for the fixed parameters.
1068    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1069      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1070
1071    // Emit type/value pairs for varargs params.
1072    if (FTy->isVarArg()) {
1073      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1074           i != e; ++i)
1075        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1076    }
1077    break;
1078  }
1079  case Instruction::Unwind:
1080    Code = bitc::FUNC_CODE_INST_UNWIND;
1081    break;
1082  case Instruction::Unreachable:
1083    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1084    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1085    break;
1086
1087  case Instruction::PHI:
1088    Code = bitc::FUNC_CODE_INST_PHI;
1089    Vals.push_back(VE.getTypeID(I.getType()));
1090    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1091      Vals.push_back(VE.getValueID(I.getOperand(i)));
1092    break;
1093
1094  case Instruction::Alloca:
1095    Code = bitc::FUNC_CODE_INST_ALLOCA;
1096    Vals.push_back(VE.getTypeID(I.getType()));
1097    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1098    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1099    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1100    break;
1101
1102  case Instruction::Load:
1103    Code = bitc::FUNC_CODE_INST_LOAD;
1104    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1105      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1106
1107    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1108    Vals.push_back(cast<LoadInst>(I).isVolatile());
1109    break;
1110  case Instruction::Store:
1111    Code = bitc::FUNC_CODE_INST_STORE2;
1112    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1113    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1114    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1115    Vals.push_back(cast<StoreInst>(I).isVolatile());
1116    break;
1117  case Instruction::Call: {
1118    const CallInst &CI = cast<CallInst>(I);
1119    const PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1120    const FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1121
1122    Code = bitc::FUNC_CODE_INST_CALL2;
1123
1124    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1125    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1126    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1127
1128    // Emit value #'s for the fixed parameters.
1129    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1130      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1131
1132    // Emit type/value pairs for varargs params.
1133    if (FTy->isVarArg()) {
1134      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1135           i != e; ++i)
1136        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1137    }
1138    break;
1139  }
1140  case Instruction::VAArg:
1141    Code = bitc::FUNC_CODE_INST_VAARG;
1142    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1143    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1144    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1145    break;
1146  }
1147
1148  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1149  Vals.clear();
1150}
1151
1152// Emit names for globals/functions etc.
1153static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1154                                  const ValueEnumerator &VE,
1155                                  BitstreamWriter &Stream) {
1156  if (VST.empty()) return;
1157  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1158
1159  // FIXME: Set up the abbrev, we know how many values there are!
1160  // FIXME: We know if the type names can use 7-bit ascii.
1161  SmallVector<unsigned, 64> NameVals;
1162
1163  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1164       SI != SE; ++SI) {
1165
1166    const ValueName &Name = *SI;
1167
1168    // Figure out the encoding to use for the name.
1169    bool is7Bit = true;
1170    bool isChar6 = true;
1171    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1172         C != E; ++C) {
1173      if (isChar6)
1174        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1175      if ((unsigned char)*C & 128) {
1176        is7Bit = false;
1177        break;  // don't bother scanning the rest.
1178      }
1179    }
1180
1181    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1182
1183    // VST_ENTRY:     [valueid, namechar x N]
1184    // VST_BBENTRY:   [bbid, namechar x N]
1185    // VST_LPADENTRY: [lpadid, namechar x N]
1186    unsigned Code;
1187    if (const BasicBlock *BB = dyn_cast<BasicBlock>(SI->getValue())) {
1188      if (BB->isLandingPad()) {
1189        Code = bitc::VST_CODE_LPADENTRY;
1190        if (isChar6)
1191          AbbrevToUse = VST_LPADENTRY_6_ABBREV;
1192      } else {
1193        Code = bitc::VST_CODE_BBENTRY;
1194        if (isChar6)
1195          AbbrevToUse = VST_BBENTRY_6_ABBREV;
1196      }
1197    } else {
1198      Code = bitc::VST_CODE_ENTRY;
1199      if (isChar6)
1200        AbbrevToUse = VST_ENTRY_6_ABBREV;
1201      else if (is7Bit)
1202        AbbrevToUse = VST_ENTRY_7_ABBREV;
1203    }
1204
1205    NameVals.push_back(VE.getValueID(SI->getValue()));
1206    for (const char *P = Name.getKeyData(),
1207         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1208      NameVals.push_back((unsigned char)*P);
1209
1210    // Emit the finished record.
1211    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1212    NameVals.clear();
1213  }
1214  Stream.ExitBlock();
1215}
1216
1217/// WriteFunction - Emit a function body to the module stream.
1218static void WriteFunction(const Function &F, ValueEnumerator &VE,
1219                          BitstreamWriter &Stream) {
1220  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1221  VE.incorporateFunction(F);
1222
1223  SmallVector<unsigned, 64> Vals;
1224
1225  // Emit the number of basic blocks, so the reader can create them ahead of
1226  // time.
1227  Vals.push_back(VE.getBasicBlocks().size());
1228  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1229  Vals.clear();
1230
1231  // If there are function-local constants, emit them now.
1232  unsigned CstStart, CstEnd;
1233  VE.getFunctionConstantRange(CstStart, CstEnd);
1234  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1235
1236  // If there is function-local metadata, emit it now.
1237  WriteFunctionLocalMetadata(F, VE, Stream);
1238
1239  // Keep a running idea of what the instruction ID is.
1240  unsigned InstID = CstEnd;
1241
1242  bool NeedsMetadataAttachment = false;
1243
1244  DebugLoc LastDL;
1245
1246  // Finally, emit all the instructions, in order.
1247  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1248    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1249         I != E; ++I) {
1250      WriteInstruction(*I, InstID, VE, Stream, Vals);
1251
1252      if (!I->getType()->isVoidTy())
1253        ++InstID;
1254
1255      // If the instruction has metadata, write a metadata attachment later.
1256      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1257
1258      // If the instruction has a debug location, emit it.
1259      DebugLoc DL = I->getDebugLoc();
1260      if (DL.isUnknown()) {
1261        // nothing todo.
1262      } else if (DL == LastDL) {
1263        // Just repeat the same debug loc as last time.
1264        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1265      } else {
1266        MDNode *Scope, *IA;
1267        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1268
1269        Vals.push_back(DL.getLine());
1270        Vals.push_back(DL.getCol());
1271        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1272        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1273        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC2, Vals);
1274        Vals.clear();
1275
1276        LastDL = DL;
1277      }
1278    }
1279
1280  // Emit names for all the instructions etc.
1281  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1282
1283  if (NeedsMetadataAttachment)
1284    WriteMetadataAttachment(F, VE, Stream);
1285  VE.purgeFunction();
1286  Stream.ExitBlock();
1287}
1288
1289/// WriteTypeSymbolTable - Emit a block for the specified type symtab.
1290static void WriteTypeSymbolTable(const TypeSymbolTable &TST,
1291                                 const ValueEnumerator &VE,
1292                                 BitstreamWriter &Stream) {
1293  if (TST.empty()) return;
1294
1295  Stream.EnterSubblock(bitc::TYPE_SYMTAB_BLOCK_ID, 3);
1296
1297  // 7-bit fixed width VST_CODE_ENTRY strings.
1298  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1299  Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1300  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1301                            Log2_32_Ceil(VE.getTypes().size()+1)));
1302  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1303  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1304  unsigned V7Abbrev = Stream.EmitAbbrev(Abbv);
1305
1306  SmallVector<unsigned, 64> NameVals;
1307
1308  for (TypeSymbolTable::const_iterator TI = TST.begin(), TE = TST.end();
1309       TI != TE; ++TI) {
1310    // TST_ENTRY: [typeid, namechar x N]
1311    NameVals.push_back(VE.getTypeID(TI->second));
1312
1313    const std::string &Str = TI->first;
1314    bool is7Bit = true;
1315    for (unsigned i = 0, e = Str.size(); i != e; ++i) {
1316      NameVals.push_back((unsigned char)Str[i]);
1317      if (Str[i] & 128)
1318        is7Bit = false;
1319    }
1320
1321    // Emit the finished record.
1322    Stream.EmitRecord(bitc::VST_CODE_ENTRY, NameVals, is7Bit ? V7Abbrev : 0);
1323    NameVals.clear();
1324  }
1325
1326  Stream.ExitBlock();
1327}
1328
1329// Emit blockinfo, which defines the standard abbreviations etc.
1330static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1331  // We only want to emit block info records for blocks that have multiple
1332  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1333  // blocks can defined their abbrevs inline.
1334  Stream.EnterBlockInfoBlock(2);
1335
1336  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1337    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1338    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1339    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1340    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1341    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1342    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1343                                   Abbv) != VST_ENTRY_8_ABBREV)
1344      llvm_unreachable("Unexpected abbrev ordering!");
1345  }
1346
1347  { // 7-bit fixed width VST_ENTRY strings.
1348    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1349    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1350    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1351    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1352    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1353    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1354                                   Abbv) != VST_ENTRY_7_ABBREV)
1355      llvm_unreachable("Unexpected abbrev ordering!");
1356  }
1357  { // 6-bit char6 VST_ENTRY strings.
1358    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1359    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1360    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1361    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1362    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1363    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1364                                   Abbv) != VST_ENTRY_6_ABBREV)
1365      llvm_unreachable("Unexpected abbrev ordering!");
1366  }
1367  { // 6-bit char6 VST_BBENTRY strings.
1368    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1369    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1370    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1371    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1372    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1373    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1374                                   Abbv) != VST_BBENTRY_6_ABBREV)
1375      llvm_unreachable("Unexpected abbrev ordering!");
1376  }
1377  { // 6-bit char6 VST_LPADENTRY strings.
1378    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1379    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_LPADENTRY));
1380    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1381    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1382    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1383    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1384                                   Abbv) != VST_LPADENTRY_6_ABBREV)
1385      llvm_unreachable("Unexpected abbrev ordering!");
1386  }
1387
1388  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1389    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1390    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1391    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1392                              Log2_32_Ceil(VE.getTypes().size()+1)));
1393    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1394                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1395      llvm_unreachable("Unexpected abbrev ordering!");
1396  }
1397
1398  { // INTEGER abbrev for CONSTANTS_BLOCK.
1399    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1400    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1401    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1402    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1403                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1404      llvm_unreachable("Unexpected abbrev ordering!");
1405  }
1406
1407  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1408    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1409    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1410    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1411    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1412                              Log2_32_Ceil(VE.getTypes().size()+1)));
1413    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1414
1415    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1416                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1417      llvm_unreachable("Unexpected abbrev ordering!");
1418  }
1419  { // NULL abbrev for CONSTANTS_BLOCK.
1420    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1421    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1422    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1423                                   Abbv) != CONSTANTS_NULL_Abbrev)
1424      llvm_unreachable("Unexpected abbrev ordering!");
1425  }
1426
1427  // FIXME: This should only use space for first class types!
1428
1429  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1430    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1431    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1432    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1433    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1434    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1435    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1436                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1437      llvm_unreachable("Unexpected abbrev ordering!");
1438  }
1439  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1440    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1441    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1442    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1443    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1444    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1445    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1446                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1447      llvm_unreachable("Unexpected abbrev ordering!");
1448  }
1449  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1450    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1451    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1452    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1453    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1454    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1455    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1456    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1457                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1458      llvm_unreachable("Unexpected abbrev ordering!");
1459  }
1460  { // INST_CAST abbrev for FUNCTION_BLOCK.
1461    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1462    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1463    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1464    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1465                              Log2_32_Ceil(VE.getTypes().size()+1)));
1466    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1467    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1468                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1469      llvm_unreachable("Unexpected abbrev ordering!");
1470  }
1471
1472  { // INST_RET abbrev for FUNCTION_BLOCK.
1473    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1474    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1475    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1476                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1477      llvm_unreachable("Unexpected abbrev ordering!");
1478  }
1479  { // INST_RET abbrev for FUNCTION_BLOCK.
1480    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1481    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1482    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1483    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1484                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1485      llvm_unreachable("Unexpected abbrev ordering!");
1486  }
1487  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1488    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1489    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1490    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1491                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1492      llvm_unreachable("Unexpected abbrev ordering!");
1493  }
1494
1495  Stream.ExitBlock();
1496}
1497
1498
1499/// WriteModule - Emit the specified module to the bitstream.
1500static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1501  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1502
1503  // Emit the version number if it is non-zero.
1504  if (CurVersion) {
1505    SmallVector<unsigned, 1> Vals;
1506    Vals.push_back(CurVersion);
1507    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1508  }
1509
1510  // Analyze the module, enumerating globals, functions, etc.
1511  ValueEnumerator VE(M);
1512
1513  // Emit blockinfo, which defines the standard abbreviations etc.
1514  WriteBlockInfo(VE, Stream);
1515
1516  // Emit information about parameter attributes.
1517  WriteAttributeTable(VE, Stream);
1518
1519  // Emit information describing all of the types in the module.
1520  WriteTypeTable(VE, Stream);
1521
1522  // Emit top-level description of module, including target triple, inline asm,
1523  // descriptors for global variables, and function prototype info.
1524  WriteModuleInfo(M, VE, Stream);
1525
1526  // Emit constants.
1527  WriteModuleConstants(VE, Stream);
1528
1529  // Emit metadata.
1530  WriteModuleMetadata(M, VE, Stream);
1531
1532  // Emit function bodies.
1533  for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I)
1534    if (!I->isDeclaration())
1535      WriteFunction(*I, VE, Stream);
1536
1537  // Emit metadata.
1538  WriteModuleMetadataStore(M, Stream);
1539
1540  // Emit the type symbol table information.
1541  WriteTypeSymbolTable(M->getTypeSymbolTable(), VE, Stream);
1542
1543  // Emit names for globals/functions etc.
1544  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1545
1546  Stream.ExitBlock();
1547}
1548
1549/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1550/// header and trailer to make it compatible with the system archiver.  To do
1551/// this we emit the following header, and then emit a trailer that pads the
1552/// file out to be a multiple of 16 bytes.
1553///
1554/// struct bc_header {
1555///   uint32_t Magic;         // 0x0B17C0DE
1556///   uint32_t Version;       // Version, currently always 0.
1557///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1558///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1559///   uint32_t CPUType;       // CPU specifier.
1560///   ... potentially more later ...
1561/// };
1562enum {
1563  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1564  DarwinBCHeaderSize = 5*4
1565};
1566
1567/// isARMTriplet - Return true if the triplet looks like:
1568/// arm-*, thumb-*, armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*.
1569static bool isARMTriplet(const std::string &TT) {
1570  size_t Pos = 0;
1571  size_t Size = TT.size();
1572  if (Size >= 6 &&
1573      TT[0] == 't' && TT[1] == 'h' && TT[2] == 'u' &&
1574      TT[3] == 'm' && TT[4] == 'b')
1575    Pos = 5;
1576  else if (Size >= 4 && TT[0] == 'a' && TT[1] == 'r' && TT[2] == 'm')
1577    Pos = 3;
1578  else
1579    return false;
1580
1581  if (TT[Pos] == '-')
1582    return true;
1583  else if (TT[Pos] == 'v') {
1584    if (Size >= Pos+4 &&
1585        TT[Pos+1] == '6' && TT[Pos+2] == 't' && TT[Pos+3] == '2')
1586      return true;
1587    else if (Size >= Pos+4 &&
1588             TT[Pos+1] == '5' && TT[Pos+2] == 't' && TT[Pos+3] == 'e')
1589      return true;
1590  } else
1591    return false;
1592  while (++Pos < Size && TT[Pos] != '-') {
1593    if (!isdigit(TT[Pos]))
1594      return false;
1595  }
1596  return true;
1597}
1598
1599static void EmitDarwinBCHeader(BitstreamWriter &Stream,
1600                               const std::string &TT) {
1601  unsigned CPUType = ~0U;
1602
1603  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1604  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1605  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1606  // specific constants here because they are implicitly part of the Darwin ABI.
1607  enum {
1608    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1609    DARWIN_CPU_TYPE_X86        = 7,
1610    DARWIN_CPU_TYPE_ARM        = 12,
1611    DARWIN_CPU_TYPE_POWERPC    = 18
1612  };
1613
1614  if (TT.find("x86_64-") == 0)
1615    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1616  else if (TT.size() >= 5 && TT[0] == 'i' && TT[2] == '8' && TT[3] == '6' &&
1617           TT[4] == '-' && TT[1] - '3' < 6)
1618    CPUType = DARWIN_CPU_TYPE_X86;
1619  else if (TT.find("powerpc-") == 0)
1620    CPUType = DARWIN_CPU_TYPE_POWERPC;
1621  else if (TT.find("powerpc64-") == 0)
1622    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1623  else if (isARMTriplet(TT))
1624    CPUType = DARWIN_CPU_TYPE_ARM;
1625
1626  // Traditional Bitcode starts after header.
1627  unsigned BCOffset = DarwinBCHeaderSize;
1628
1629  Stream.Emit(0x0B17C0DE, 32);
1630  Stream.Emit(0         , 32);  // Version.
1631  Stream.Emit(BCOffset  , 32);
1632  Stream.Emit(0         , 32);  // Filled in later.
1633  Stream.Emit(CPUType   , 32);
1634}
1635
1636/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1637/// finalize the header.
1638static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1639  // Update the size field in the header.
1640  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1641
1642  // If the file is not a multiple of 16 bytes, insert dummy padding.
1643  while (BufferSize & 15) {
1644    Stream.Emit(0, 8);
1645    ++BufferSize;
1646  }
1647}
1648
1649
1650/// WriteBitcodeToFile - Write the specified module to the specified output
1651/// stream.
1652void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1653  std::vector<unsigned char> Buffer;
1654  BitstreamWriter Stream(Buffer);
1655
1656  Buffer.reserve(256*1024);
1657
1658  WriteBitcodeToStream( M, Stream );
1659
1660  // Write the generated bitstream to "Out".
1661  Out.write((char*)&Buffer.front(), Buffer.size());
1662}
1663
1664/// WriteBitcodeToStream - Write the specified module to the specified output
1665/// stream.
1666void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1667  // If this is darwin or another generic macho target, emit a file header and
1668  // trailer if needed.
1669  bool isMacho =
1670    M->getTargetTriple().find("-darwin") != std::string::npos ||
1671    M->getTargetTriple().find("-macho") != std::string::npos;
1672  if (isMacho)
1673    EmitDarwinBCHeader(Stream, M->getTargetTriple());
1674
1675  // Emit the file header.
1676  Stream.Emit((unsigned)'B', 8);
1677  Stream.Emit((unsigned)'C', 8);
1678  Stream.Emit(0x0, 4);
1679  Stream.Emit(0xC, 4);
1680  Stream.Emit(0xE, 4);
1681  Stream.Emit(0xD, 4);
1682
1683  // Emit the module.
1684  WriteModule(M, Stream);
1685
1686  if (isMacho)
1687    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1688}
1689