BitcodeWriter.cpp revision 10c6d12a9fd4dab411091f64db4db69670b88850 
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/ValueSymbolTable.h"
25#include "llvm/ADT/Triple.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>
31#include <map>
32using namespace llvm;
33
34/// These are manifest constants used by the bitcode writer. They do not need to
35/// be kept in sync with the reader, but need to be consistent within this file.
36enum {
37  CurVersion = 0,
38
39  // VALUE_SYMTAB_BLOCK abbrev id's.
40  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
41  VST_ENTRY_7_ABBREV,
42  VST_ENTRY_6_ABBREV,
43  VST_BBENTRY_6_ABBREV,
44
45  // CONSTANTS_BLOCK abbrev id's.
46  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
47  CONSTANTS_INTEGER_ABBREV,
48  CONSTANTS_CE_CAST_Abbrev,
49  CONSTANTS_NULL_Abbrev,
50
51  // FUNCTION_BLOCK abbrev id's.
52  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
53  FUNCTION_INST_BINOP_ABBREV,
54  FUNCTION_INST_BINOP_FLAGS_ABBREV,
55  FUNCTION_INST_CAST_ABBREV,
56  FUNCTION_INST_RET_VOID_ABBREV,
57  FUNCTION_INST_RET_VAL_ABBREV,
58  FUNCTION_INST_UNREACHABLE_ABBREV
59};
60
61
62static unsigned GetEncodedCastOpcode(unsigned Opcode) {
63  switch (Opcode) {
64  default: llvm_unreachable("Unknown cast instruction!");
65  case Instruction::Trunc   : return bitc::CAST_TRUNC;
66  case Instruction::ZExt    : return bitc::CAST_ZEXT;
67  case Instruction::SExt    : return bitc::CAST_SEXT;
68  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
69  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
70  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
71  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
72  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
73  case Instruction::FPExt   : return bitc::CAST_FPEXT;
74  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
75  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
76  case Instruction::BitCast : return bitc::CAST_BITCAST;
77  }
78}
79
80static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
81  switch (Opcode) {
82  default: llvm_unreachable("Unknown binary instruction!");
83  case Instruction::Add:
84  case Instruction::FAdd: return bitc::BINOP_ADD;
85  case Instruction::Sub:
86  case Instruction::FSub: return bitc::BINOP_SUB;
87  case Instruction::Mul:
88  case Instruction::FMul: return bitc::BINOP_MUL;
89  case Instruction::UDiv: return bitc::BINOP_UDIV;
90  case Instruction::FDiv:
91  case Instruction::SDiv: return bitc::BINOP_SDIV;
92  case Instruction::URem: return bitc::BINOP_UREM;
93  case Instruction::FRem:
94  case Instruction::SRem: return bitc::BINOP_SREM;
95  case Instruction::Shl:  return bitc::BINOP_SHL;
96  case Instruction::LShr: return bitc::BINOP_LSHR;
97  case Instruction::AShr: return bitc::BINOP_ASHR;
98  case Instruction::And:  return bitc::BINOP_AND;
99  case Instruction::Or:   return bitc::BINOP_OR;
100  case Instruction::Xor:  return bitc::BINOP_XOR;
101  }
102}
103
104static unsigned GetEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
105  switch (Op) {
106  default: llvm_unreachable("Unknown RMW operation!");
107  case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
108  case AtomicRMWInst::Add: return bitc::RMW_ADD;
109  case AtomicRMWInst::Sub: return bitc::RMW_SUB;
110  case AtomicRMWInst::And: return bitc::RMW_AND;
111  case AtomicRMWInst::Nand: return bitc::RMW_NAND;
112  case AtomicRMWInst::Or: return bitc::RMW_OR;
113  case AtomicRMWInst::Xor: return bitc::RMW_XOR;
114  case AtomicRMWInst::Max: return bitc::RMW_MAX;
115  case AtomicRMWInst::Min: return bitc::RMW_MIN;
116  case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
117  case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
118  }
119}
120
121static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
122  switch (Ordering) {
123  default: llvm_unreachable("Unknown atomic ordering");
124  case NotAtomic: return bitc::ORDERING_NOTATOMIC;
125  case Unordered: return bitc::ORDERING_UNORDERED;
126  case Monotonic: return bitc::ORDERING_MONOTONIC;
127  case Acquire: return bitc::ORDERING_ACQUIRE;
128  case Release: return bitc::ORDERING_RELEASE;
129  case AcquireRelease: return bitc::ORDERING_ACQREL;
130  case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
131  }
132}
133
134static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
135  switch (SynchScope) {
136  default: llvm_unreachable("Unknown synchronization scope");
137  case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
138  case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
139  }
140}
141
142static void WriteStringRecord(unsigned Code, StringRef Str,
143                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
144  SmallVector<unsigned, 64> Vals;
145
146  // Code: [strchar x N]
147  for (unsigned i = 0, e = Str.size(); i != e; ++i) {
148    if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
149      AbbrevToUse = 0;
150    Vals.push_back(Str[i]);
151  }
152
153  // Emit the finished record.
154  Stream.EmitRecord(Code, Vals, AbbrevToUse);
155}
156
157// Emit information about parameter attributes.
158static void WriteAttributeTable(const ValueEnumerator &VE,
159                                BitstreamWriter &Stream) {
160  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
161  if (Attrs.empty()) return;
162
163  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
164
165  SmallVector<uint64_t, 64> Record;
166  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
167    const AttrListPtr &A = Attrs[i];
168    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
169      const AttributeWithIndex &PAWI = A.getSlot(i);
170      Record.push_back(PAWI.Index);
171
172      // FIXME: remove in LLVM 3.0
173      // Store the alignment in the bitcode as a 16-bit raw value instead of a
174      // 5-bit log2 encoded value. Shift the bits above the alignment up by
175      // 11 bits.
176      uint64_t FauxAttr = PAWI.Attrs & 0xffff;
177      if (PAWI.Attrs & Attribute::Alignment)
178        FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
179      FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
180
181      Record.push_back(FauxAttr);
182    }
183
184    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
185    Record.clear();
186  }
187
188  Stream.ExitBlock();
189}
190
191/// WriteTypeTable - Write out the type table for a module.
192static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
193  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
194
195  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
196  SmallVector<uint64_t, 64> TypeVals;
197
198  // Abbrev for TYPE_CODE_POINTER.
199  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
200  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
201  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
202                            Log2_32_Ceil(VE.getTypes().size()+1)));
203  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
204  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
205
206  // Abbrev for TYPE_CODE_FUNCTION.
207  Abbv = new BitCodeAbbrev();
208  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
209  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
210  Abbv->Add(BitCodeAbbrevOp(0));  // FIXME: DEAD value, remove in LLVM 3.0
211  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
212  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
213                            Log2_32_Ceil(VE.getTypes().size()+1)));
214  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
215
216  // Abbrev for TYPE_CODE_STRUCT_ANON.
217  Abbv = new BitCodeAbbrev();
218  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
219  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
220  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
221  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
222                            Log2_32_Ceil(VE.getTypes().size()+1)));
223  unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
224
225  // Abbrev for TYPE_CODE_STRUCT_NAME.
226  Abbv = new BitCodeAbbrev();
227  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
228  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
229  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
230  unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
231
232  // Abbrev for TYPE_CODE_STRUCT_NAMED.
233  Abbv = new BitCodeAbbrev();
234  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
235  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
236  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
237  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
238                            Log2_32_Ceil(VE.getTypes().size()+1)));
239  unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
240
241
242  // Abbrev for TYPE_CODE_ARRAY.
243  Abbv = new BitCodeAbbrev();
244  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
245  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
246  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
247                            Log2_32_Ceil(VE.getTypes().size()+1)));
248  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
249
250  // Emit an entry count so the reader can reserve space.
251  TypeVals.push_back(TypeList.size());
252  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
253  TypeVals.clear();
254
255  // Loop over all of the types, emitting each in turn.
256  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
257    Type *T = TypeList[i];
258    int AbbrevToUse = 0;
259    unsigned Code = 0;
260
261    switch (T->getTypeID()) {
262    default: llvm_unreachable("Unknown type!");
263    case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;   break;
264    case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;  break;
265    case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE; break;
266    case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80; break;
267    case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128; break;
268    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
269    case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;  break;
270    case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA; break;
271    case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX; break;
272    case Type::IntegerTyID:
273      // INTEGER: [width]
274      Code = bitc::TYPE_CODE_INTEGER;
275      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
276      break;
277    case Type::PointerTyID: {
278      PointerType *PTy = cast<PointerType>(T);
279      // POINTER: [pointee type, address space]
280      Code = bitc::TYPE_CODE_POINTER;
281      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
282      unsigned AddressSpace = PTy->getAddressSpace();
283      TypeVals.push_back(AddressSpace);
284      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
285      break;
286    }
287    case Type::FunctionTyID: {
288      FunctionType *FT = cast<FunctionType>(T);
289      // FUNCTION: [isvararg, attrid, retty, paramty x N]
290      Code = bitc::TYPE_CODE_FUNCTION;
291      TypeVals.push_back(FT->isVarArg());
292      TypeVals.push_back(0);  // FIXME: DEAD: remove in llvm 3.0
293      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
294      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
295        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
296      AbbrevToUse = FunctionAbbrev;
297      break;
298    }
299    case Type::StructTyID: {
300      StructType *ST = cast<StructType>(T);
301      // STRUCT: [ispacked, eltty x N]
302      TypeVals.push_back(ST->isPacked());
303      // Output all of the element types.
304      for (StructType::element_iterator I = ST->element_begin(),
305           E = ST->element_end(); I != E; ++I)
306        TypeVals.push_back(VE.getTypeID(*I));
307
308      if (ST->isAnonymous()) {
309        Code = bitc::TYPE_CODE_STRUCT_ANON;
310        AbbrevToUse = StructAnonAbbrev;
311      } else {
312        if (ST->isOpaque()) {
313          Code = bitc::TYPE_CODE_OPAQUE;
314        } else {
315          Code = bitc::TYPE_CODE_STRUCT_NAMED;
316          AbbrevToUse = StructNamedAbbrev;
317        }
318
319        // Emit the name if it is present.
320        if (!ST->getName().empty())
321          WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
322                            StructNameAbbrev, Stream);
323      }
324      break;
325    }
326    case Type::ArrayTyID: {
327      ArrayType *AT = cast<ArrayType>(T);
328      // ARRAY: [numelts, eltty]
329      Code = bitc::TYPE_CODE_ARRAY;
330      TypeVals.push_back(AT->getNumElements());
331      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
332      AbbrevToUse = ArrayAbbrev;
333      break;
334    }
335    case Type::VectorTyID: {
336      VectorType *VT = cast<VectorType>(T);
337      // VECTOR [numelts, eltty]
338      Code = bitc::TYPE_CODE_VECTOR;
339      TypeVals.push_back(VT->getNumElements());
340      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
341      break;
342    }
343    }
344
345    // Emit the finished record.
346    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
347    TypeVals.clear();
348  }
349
350  Stream.ExitBlock();
351}
352
353static unsigned getEncodedLinkage(const GlobalValue *GV) {
354  switch (GV->getLinkage()) {
355  default: llvm_unreachable("Invalid linkage!");
356  case GlobalValue::ExternalLinkage:                 return 0;
357  case GlobalValue::WeakAnyLinkage:                  return 1;
358  case GlobalValue::AppendingLinkage:                return 2;
359  case GlobalValue::InternalLinkage:                 return 3;
360  case GlobalValue::LinkOnceAnyLinkage:              return 4;
361  case GlobalValue::DLLImportLinkage:                return 5;
362  case GlobalValue::DLLExportLinkage:                return 6;
363  case GlobalValue::ExternalWeakLinkage:             return 7;
364  case GlobalValue::CommonLinkage:                   return 8;
365  case GlobalValue::PrivateLinkage:                  return 9;
366  case GlobalValue::WeakODRLinkage:                  return 10;
367  case GlobalValue::LinkOnceODRLinkage:              return 11;
368  case GlobalValue::AvailableExternallyLinkage:      return 12;
369  case GlobalValue::LinkerPrivateLinkage:            return 13;
370  case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
371  case GlobalValue::LinkerPrivateWeakDefAutoLinkage: return 15;
372  }
373}
374
375static unsigned getEncodedVisibility(const GlobalValue *GV) {
376  switch (GV->getVisibility()) {
377  default: llvm_unreachable("Invalid visibility!");
378  case GlobalValue::DefaultVisibility:   return 0;
379  case GlobalValue::HiddenVisibility:    return 1;
380  case GlobalValue::ProtectedVisibility: return 2;
381  }
382}
383
384// Emit top-level description of module, including target triple, inline asm,
385// descriptors for global variables, and function prototype info.
386static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
387                            BitstreamWriter &Stream) {
388  // Emit the list of dependent libraries for the Module.
389  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
390    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
391
392  // Emit various pieces of data attached to a module.
393  if (!M->getTargetTriple().empty())
394    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
395                      0/*TODO*/, Stream);
396  if (!M->getDataLayout().empty())
397    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
398                      0/*TODO*/, Stream);
399  if (!M->getModuleInlineAsm().empty())
400    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
401                      0/*TODO*/, Stream);
402
403  // Emit information about sections and GC, computing how many there are. Also
404  // compute the maximum alignment value.
405  std::map<std::string, unsigned> SectionMap;
406  std::map<std::string, unsigned> GCMap;
407  unsigned MaxAlignment = 0;
408  unsigned MaxGlobalType = 0;
409  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
410       GV != E; ++GV) {
411    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
412    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
413
414    if (!GV->hasSection()) continue;
415    // Give section names unique ID's.
416    unsigned &Entry = SectionMap[GV->getSection()];
417    if (Entry != 0) continue;
418    WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
419                      0/*TODO*/, Stream);
420    Entry = SectionMap.size();
421  }
422  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
423    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
424    if (F->hasSection()) {
425      // Give section names unique ID's.
426      unsigned &Entry = SectionMap[F->getSection()];
427      if (!Entry) {
428        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
429                          0/*TODO*/, Stream);
430        Entry = SectionMap.size();
431      }
432    }
433    if (F->hasGC()) {
434      // Same for GC names.
435      unsigned &Entry = GCMap[F->getGC()];
436      if (!Entry) {
437        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
438                          0/*TODO*/, Stream);
439        Entry = GCMap.size();
440      }
441    }
442  }
443
444  // Emit abbrev for globals, now that we know # sections and max alignment.
445  unsigned SimpleGVarAbbrev = 0;
446  if (!M->global_empty()) {
447    // Add an abbrev for common globals with no visibility or thread localness.
448    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
449    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
450    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
451                              Log2_32_Ceil(MaxGlobalType+1)));
452    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
453    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
454    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
455    if (MaxAlignment == 0)                                      // Alignment.
456      Abbv->Add(BitCodeAbbrevOp(0));
457    else {
458      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
459      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
460                               Log2_32_Ceil(MaxEncAlignment+1)));
461    }
462    if (SectionMap.empty())                                    // Section.
463      Abbv->Add(BitCodeAbbrevOp(0));
464    else
465      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
466                               Log2_32_Ceil(SectionMap.size()+1)));
467    // Don't bother emitting vis + thread local.
468    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
469  }
470
471  // Emit the global variable information.
472  SmallVector<unsigned, 64> Vals;
473  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
474       GV != E; ++GV) {
475    unsigned AbbrevToUse = 0;
476
477    // GLOBALVAR: [type, isconst, initid,
478    //             linkage, alignment, section, visibility, threadlocal,
479    //             unnamed_addr]
480    Vals.push_back(VE.getTypeID(GV->getType()));
481    Vals.push_back(GV->isConstant());
482    Vals.push_back(GV->isDeclaration() ? 0 :
483                   (VE.getValueID(GV->getInitializer()) + 1));
484    Vals.push_back(getEncodedLinkage(GV));
485    Vals.push_back(Log2_32(GV->getAlignment())+1);
486    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
487    if (GV->isThreadLocal() ||
488        GV->getVisibility() != GlobalValue::DefaultVisibility ||
489        GV->hasUnnamedAddr()) {
490      Vals.push_back(getEncodedVisibility(GV));
491      Vals.push_back(GV->isThreadLocal());
492      Vals.push_back(GV->hasUnnamedAddr());
493    } else {
494      AbbrevToUse = SimpleGVarAbbrev;
495    }
496
497    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
498    Vals.clear();
499  }
500
501  // Emit the function proto information.
502  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
503    // FUNCTION:  [type, callingconv, isproto, paramattr,
504    //             linkage, alignment, section, visibility, gc, unnamed_addr]
505    Vals.push_back(VE.getTypeID(F->getType()));
506    Vals.push_back(F->getCallingConv());
507    Vals.push_back(F->isDeclaration());
508    Vals.push_back(getEncodedLinkage(F));
509    Vals.push_back(VE.getAttributeID(F->getAttributes()));
510    Vals.push_back(Log2_32(F->getAlignment())+1);
511    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
512    Vals.push_back(getEncodedVisibility(F));
513    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
514    Vals.push_back(F->hasUnnamedAddr());
515
516    unsigned AbbrevToUse = 0;
517    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
518    Vals.clear();
519  }
520
521  // Emit the alias information.
522  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
523       AI != E; ++AI) {
524    Vals.push_back(VE.getTypeID(AI->getType()));
525    Vals.push_back(VE.getValueID(AI->getAliasee()));
526    Vals.push_back(getEncodedLinkage(AI));
527    Vals.push_back(getEncodedVisibility(AI));
528    unsigned AbbrevToUse = 0;
529    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
530    Vals.clear();
531  }
532}
533
534static uint64_t GetOptimizationFlags(const Value *V) {
535  uint64_t Flags = 0;
536
537  if (const OverflowingBinaryOperator *OBO =
538        dyn_cast<OverflowingBinaryOperator>(V)) {
539    if (OBO->hasNoSignedWrap())
540      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
541    if (OBO->hasNoUnsignedWrap())
542      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
543  } else if (const PossiblyExactOperator *PEO =
544               dyn_cast<PossiblyExactOperator>(V)) {
545    if (PEO->isExact())
546      Flags |= 1 << bitc::PEO_EXACT;
547  }
548
549  return Flags;
550}
551
552static void WriteMDNode(const MDNode *N,
553                        const ValueEnumerator &VE,
554                        BitstreamWriter &Stream,
555                        SmallVector<uint64_t, 64> &Record) {
556  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
557    if (N->getOperand(i)) {
558      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
559      Record.push_back(VE.getValueID(N->getOperand(i)));
560    } else {
561      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
562      Record.push_back(0);
563    }
564  }
565  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
566                                           bitc::METADATA_NODE;
567  Stream.EmitRecord(MDCode, Record, 0);
568  Record.clear();
569}
570
571static void WriteModuleMetadata(const Module *M,
572                                const ValueEnumerator &VE,
573                                BitstreamWriter &Stream) {
574  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
575  bool StartedMetadataBlock = false;
576  unsigned MDSAbbrev = 0;
577  SmallVector<uint64_t, 64> Record;
578  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
579
580    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
581      if (!N->isFunctionLocal() || !N->getFunction()) {
582        if (!StartedMetadataBlock) {
583          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
584          StartedMetadataBlock = true;
585        }
586        WriteMDNode(N, VE, Stream, Record);
587      }
588    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
589      if (!StartedMetadataBlock)  {
590        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
591
592        // Abbrev for METADATA_STRING.
593        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
594        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
595        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
596        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
597        MDSAbbrev = Stream.EmitAbbrev(Abbv);
598        StartedMetadataBlock = true;
599      }
600
601      // Code: [strchar x N]
602      Record.append(MDS->begin(), MDS->end());
603
604      // Emit the finished record.
605      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
606      Record.clear();
607    }
608  }
609
610  // Write named metadata.
611  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
612       E = M->named_metadata_end(); I != E; ++I) {
613    const NamedMDNode *NMD = I;
614    if (!StartedMetadataBlock)  {
615      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
616      StartedMetadataBlock = true;
617    }
618
619    // Write name.
620    StringRef Str = NMD->getName();
621    for (unsigned i = 0, e = Str.size(); i != e; ++i)
622      Record.push_back(Str[i]);
623    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
624    Record.clear();
625
626    // Write named metadata operands.
627    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
628      Record.push_back(VE.getValueID(NMD->getOperand(i)));
629    Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
630    Record.clear();
631  }
632
633  if (StartedMetadataBlock)
634    Stream.ExitBlock();
635}
636
637static void WriteFunctionLocalMetadata(const Function &F,
638                                       const ValueEnumerator &VE,
639                                       BitstreamWriter &Stream) {
640  bool StartedMetadataBlock = false;
641  SmallVector<uint64_t, 64> Record;
642  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
643  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
644    if (const MDNode *N = Vals[i])
645      if (N->isFunctionLocal() && N->getFunction() == &F) {
646        if (!StartedMetadataBlock) {
647          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
648          StartedMetadataBlock = true;
649        }
650        WriteMDNode(N, VE, Stream, Record);
651      }
652
653  if (StartedMetadataBlock)
654    Stream.ExitBlock();
655}
656
657static void WriteMetadataAttachment(const Function &F,
658                                    const ValueEnumerator &VE,
659                                    BitstreamWriter &Stream) {
660  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
661
662  SmallVector<uint64_t, 64> Record;
663
664  // Write metadata attachments
665  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
666  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
667
668  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
669    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
670         I != E; ++I) {
671      MDs.clear();
672      I->getAllMetadataOtherThanDebugLoc(MDs);
673
674      // If no metadata, ignore instruction.
675      if (MDs.empty()) continue;
676
677      Record.push_back(VE.getInstructionID(I));
678
679      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
680        Record.push_back(MDs[i].first);
681        Record.push_back(VE.getValueID(MDs[i].second));
682      }
683      Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
684      Record.clear();
685    }
686
687  Stream.ExitBlock();
688}
689
690static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
691  SmallVector<uint64_t, 64> Record;
692
693  // Write metadata kinds
694  // METADATA_KIND - [n x [id, name]]
695  SmallVector<StringRef, 4> Names;
696  M->getMDKindNames(Names);
697
698  if (Names.empty()) return;
699
700  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
701
702  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
703    Record.push_back(MDKindID);
704    StringRef KName = Names[MDKindID];
705    Record.append(KName.begin(), KName.end());
706
707    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
708    Record.clear();
709  }
710
711  Stream.ExitBlock();
712}
713
714static void WriteConstants(unsigned FirstVal, unsigned LastVal,
715                           const ValueEnumerator &VE,
716                           BitstreamWriter &Stream, bool isGlobal) {
717  if (FirstVal == LastVal) return;
718
719  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
720
721  unsigned AggregateAbbrev = 0;
722  unsigned String8Abbrev = 0;
723  unsigned CString7Abbrev = 0;
724  unsigned CString6Abbrev = 0;
725  // If this is a constant pool for the module, emit module-specific abbrevs.
726  if (isGlobal) {
727    // Abbrev for CST_CODE_AGGREGATE.
728    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
729    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
730    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
731    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
732    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
733
734    // Abbrev for CST_CODE_STRING.
735    Abbv = new BitCodeAbbrev();
736    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
737    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
738    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
739    String8Abbrev = Stream.EmitAbbrev(Abbv);
740    // Abbrev for CST_CODE_CSTRING.
741    Abbv = new BitCodeAbbrev();
742    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
743    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
744    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
745    CString7Abbrev = Stream.EmitAbbrev(Abbv);
746    // Abbrev for CST_CODE_CSTRING.
747    Abbv = new BitCodeAbbrev();
748    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
749    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
750    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
751    CString6Abbrev = Stream.EmitAbbrev(Abbv);
752  }
753
754  SmallVector<uint64_t, 64> Record;
755
756  const ValueEnumerator::ValueList &Vals = VE.getValues();
757  Type *LastTy = 0;
758  for (unsigned i = FirstVal; i != LastVal; ++i) {
759    const Value *V = Vals[i].first;
760    // If we need to switch types, do so now.
761    if (V->getType() != LastTy) {
762      LastTy = V->getType();
763      Record.push_back(VE.getTypeID(LastTy));
764      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
765                        CONSTANTS_SETTYPE_ABBREV);
766      Record.clear();
767    }
768
769    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
770      Record.push_back(unsigned(IA->hasSideEffects()) |
771                       unsigned(IA->isAlignStack()) << 1);
772
773      // Add the asm string.
774      const std::string &AsmStr = IA->getAsmString();
775      Record.push_back(AsmStr.size());
776      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
777        Record.push_back(AsmStr[i]);
778
779      // Add the constraint string.
780      const std::string &ConstraintStr = IA->getConstraintString();
781      Record.push_back(ConstraintStr.size());
782      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
783        Record.push_back(ConstraintStr[i]);
784      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
785      Record.clear();
786      continue;
787    }
788    const Constant *C = cast<Constant>(V);
789    unsigned Code = -1U;
790    unsigned AbbrevToUse = 0;
791    if (C->isNullValue()) {
792      Code = bitc::CST_CODE_NULL;
793    } else if (isa<UndefValue>(C)) {
794      Code = bitc::CST_CODE_UNDEF;
795    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
796      if (IV->getBitWidth() <= 64) {
797        uint64_t V = IV->getSExtValue();
798        if ((int64_t)V >= 0)
799          Record.push_back(V << 1);
800        else
801          Record.push_back((-V << 1) | 1);
802        Code = bitc::CST_CODE_INTEGER;
803        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
804      } else {                             // Wide integers, > 64 bits in size.
805        // We have an arbitrary precision integer value to write whose
806        // bit width is > 64. However, in canonical unsigned integer
807        // format it is likely that the high bits are going to be zero.
808        // So, we only write the number of active words.
809        unsigned NWords = IV->getValue().getActiveWords();
810        const uint64_t *RawWords = IV->getValue().getRawData();
811        for (unsigned i = 0; i != NWords; ++i) {
812          int64_t V = RawWords[i];
813          if (V >= 0)
814            Record.push_back(V << 1);
815          else
816            Record.push_back((-V << 1) | 1);
817        }
818        Code = bitc::CST_CODE_WIDE_INTEGER;
819      }
820    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
821      Code = bitc::CST_CODE_FLOAT;
822      Type *Ty = CFP->getType();
823      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
824        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
825      } else if (Ty->isX86_FP80Ty()) {
826        // api needed to prevent premature destruction
827        // bits are not in the same order as a normal i80 APInt, compensate.
828        APInt api = CFP->getValueAPF().bitcastToAPInt();
829        const uint64_t *p = api.getRawData();
830        Record.push_back((p[1] << 48) | (p[0] >> 16));
831        Record.push_back(p[0] & 0xffffLL);
832      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
833        APInt api = CFP->getValueAPF().bitcastToAPInt();
834        const uint64_t *p = api.getRawData();
835        Record.push_back(p[0]);
836        Record.push_back(p[1]);
837      } else {
838        assert (0 && "Unknown FP type!");
839      }
840    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
841      const ConstantArray *CA = cast<ConstantArray>(C);
842      // Emit constant strings specially.
843      unsigned NumOps = CA->getNumOperands();
844      // If this is a null-terminated string, use the denser CSTRING encoding.
845      if (CA->getOperand(NumOps-1)->isNullValue()) {
846        Code = bitc::CST_CODE_CSTRING;
847        --NumOps;  // Don't encode the null, which isn't allowed by char6.
848      } else {
849        Code = bitc::CST_CODE_STRING;
850        AbbrevToUse = String8Abbrev;
851      }
852      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
853      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
854      for (unsigned i = 0; i != NumOps; ++i) {
855        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
856        Record.push_back(V);
857        isCStr7 &= (V & 128) == 0;
858        if (isCStrChar6)
859          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
860      }
861
862      if (isCStrChar6)
863        AbbrevToUse = CString6Abbrev;
864      else if (isCStr7)
865        AbbrevToUse = CString7Abbrev;
866    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
867               isa<ConstantVector>(V)) {
868      Code = bitc::CST_CODE_AGGREGATE;
869      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
870        Record.push_back(VE.getValueID(C->getOperand(i)));
871      AbbrevToUse = AggregateAbbrev;
872    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
873      switch (CE->getOpcode()) {
874      default:
875        if (Instruction::isCast(CE->getOpcode())) {
876          Code = bitc::CST_CODE_CE_CAST;
877          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
878          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
879          Record.push_back(VE.getValueID(C->getOperand(0)));
880          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
881        } else {
882          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
883          Code = bitc::CST_CODE_CE_BINOP;
884          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
885          Record.push_back(VE.getValueID(C->getOperand(0)));
886          Record.push_back(VE.getValueID(C->getOperand(1)));
887          uint64_t Flags = GetOptimizationFlags(CE);
888          if (Flags != 0)
889            Record.push_back(Flags);
890        }
891        break;
892      case Instruction::GetElementPtr:
893        Code = bitc::CST_CODE_CE_GEP;
894        if (cast<GEPOperator>(C)->isInBounds())
895          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
896        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
897          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
898          Record.push_back(VE.getValueID(C->getOperand(i)));
899        }
900        break;
901      case Instruction::Select:
902        Code = bitc::CST_CODE_CE_SELECT;
903        Record.push_back(VE.getValueID(C->getOperand(0)));
904        Record.push_back(VE.getValueID(C->getOperand(1)));
905        Record.push_back(VE.getValueID(C->getOperand(2)));
906        break;
907      case Instruction::ExtractElement:
908        Code = bitc::CST_CODE_CE_EXTRACTELT;
909        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
910        Record.push_back(VE.getValueID(C->getOperand(0)));
911        Record.push_back(VE.getValueID(C->getOperand(1)));
912        break;
913      case Instruction::InsertElement:
914        Code = bitc::CST_CODE_CE_INSERTELT;
915        Record.push_back(VE.getValueID(C->getOperand(0)));
916        Record.push_back(VE.getValueID(C->getOperand(1)));
917        Record.push_back(VE.getValueID(C->getOperand(2)));
918        break;
919      case Instruction::ShuffleVector:
920        // If the return type and argument types are the same, this is a
921        // standard shufflevector instruction.  If the types are different,
922        // then the shuffle is widening or truncating the input vectors, and
923        // the argument type must also be encoded.
924        if (C->getType() == C->getOperand(0)->getType()) {
925          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
926        } else {
927          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
928          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
929        }
930        Record.push_back(VE.getValueID(C->getOperand(0)));
931        Record.push_back(VE.getValueID(C->getOperand(1)));
932        Record.push_back(VE.getValueID(C->getOperand(2)));
933        break;
934      case Instruction::ICmp:
935      case Instruction::FCmp:
936        Code = bitc::CST_CODE_CE_CMP;
937        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
938        Record.push_back(VE.getValueID(C->getOperand(0)));
939        Record.push_back(VE.getValueID(C->getOperand(1)));
940        Record.push_back(CE->getPredicate());
941        break;
942      }
943    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
944      Code = bitc::CST_CODE_BLOCKADDRESS;
945      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
946      Record.push_back(VE.getValueID(BA->getFunction()));
947      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
948    } else {
949#ifndef NDEBUG
950      C->dump();
951#endif
952      llvm_unreachable("Unknown constant!");
953    }
954    Stream.EmitRecord(Code, Record, AbbrevToUse);
955    Record.clear();
956  }
957
958  Stream.ExitBlock();
959}
960
961static void WriteModuleConstants(const ValueEnumerator &VE,
962                                 BitstreamWriter &Stream) {
963  const ValueEnumerator::ValueList &Vals = VE.getValues();
964
965  // Find the first constant to emit, which is the first non-globalvalue value.
966  // We know globalvalues have been emitted by WriteModuleInfo.
967  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
968    if (!isa<GlobalValue>(Vals[i].first)) {
969      WriteConstants(i, Vals.size(), VE, Stream, true);
970      return;
971    }
972  }
973}
974
975/// PushValueAndType - The file has to encode both the value and type id for
976/// many values, because we need to know what type to create for forward
977/// references.  However, most operands are not forward references, so this type
978/// field is not needed.
979///
980/// This function adds V's value ID to Vals.  If the value ID is higher than the
981/// instruction ID, then it is a forward reference, and it also includes the
982/// type ID.
983static bool PushValueAndType(const Value *V, unsigned InstID,
984                             SmallVector<unsigned, 64> &Vals,
985                             ValueEnumerator &VE) {
986  unsigned ValID = VE.getValueID(V);
987  Vals.push_back(ValID);
988  if (ValID >= InstID) {
989    Vals.push_back(VE.getTypeID(V->getType()));
990    return true;
991  }
992  return false;
993}
994
995/// WriteInstruction - Emit an instruction to the specified stream.
996static void WriteInstruction(const Instruction &I, unsigned InstID,
997                             ValueEnumerator &VE, BitstreamWriter &Stream,
998                             SmallVector<unsigned, 64> &Vals) {
999  unsigned Code = 0;
1000  unsigned AbbrevToUse = 0;
1001  VE.setInstructionID(&I);
1002  switch (I.getOpcode()) {
1003  default:
1004    if (Instruction::isCast(I.getOpcode())) {
1005      Code = bitc::FUNC_CODE_INST_CAST;
1006      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1007        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1008      Vals.push_back(VE.getTypeID(I.getType()));
1009      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1010    } else {
1011      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1012      Code = bitc::FUNC_CODE_INST_BINOP;
1013      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1014        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1015      Vals.push_back(VE.getValueID(I.getOperand(1)));
1016      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1017      uint64_t Flags = GetOptimizationFlags(&I);
1018      if (Flags != 0) {
1019        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1020          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1021        Vals.push_back(Flags);
1022      }
1023    }
1024    break;
1025
1026  case Instruction::GetElementPtr:
1027    Code = bitc::FUNC_CODE_INST_GEP;
1028    if (cast<GEPOperator>(&I)->isInBounds())
1029      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
1030    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1031      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1032    break;
1033  case Instruction::ExtractValue: {
1034    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1035    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1036    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1037    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1038      Vals.push_back(*i);
1039    break;
1040  }
1041  case Instruction::InsertValue: {
1042    Code = bitc::FUNC_CODE_INST_INSERTVAL;
1043    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1044    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1045    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1046    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1047      Vals.push_back(*i);
1048    break;
1049  }
1050  case Instruction::Select:
1051    Code = bitc::FUNC_CODE_INST_VSELECT;
1052    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1053    Vals.push_back(VE.getValueID(I.getOperand(2)));
1054    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1055    break;
1056  case Instruction::ExtractElement:
1057    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1058    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1059    Vals.push_back(VE.getValueID(I.getOperand(1)));
1060    break;
1061  case Instruction::InsertElement:
1062    Code = bitc::FUNC_CODE_INST_INSERTELT;
1063    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1064    Vals.push_back(VE.getValueID(I.getOperand(1)));
1065    Vals.push_back(VE.getValueID(I.getOperand(2)));
1066    break;
1067  case Instruction::ShuffleVector:
1068    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1069    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1070    Vals.push_back(VE.getValueID(I.getOperand(1)));
1071    Vals.push_back(VE.getValueID(I.getOperand(2)));
1072    break;
1073  case Instruction::ICmp:
1074  case Instruction::FCmp:
1075    // compare returning Int1Ty or vector of Int1Ty
1076    Code = bitc::FUNC_CODE_INST_CMP2;
1077    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1078    Vals.push_back(VE.getValueID(I.getOperand(1)));
1079    Vals.push_back(cast<CmpInst>(I).getPredicate());
1080    break;
1081
1082  case Instruction::Ret:
1083    {
1084      Code = bitc::FUNC_CODE_INST_RET;
1085      unsigned NumOperands = I.getNumOperands();
1086      if (NumOperands == 0)
1087        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1088      else if (NumOperands == 1) {
1089        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1090          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1091      } else {
1092        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1093          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1094      }
1095    }
1096    break;
1097  case Instruction::Br:
1098    {
1099      Code = bitc::FUNC_CODE_INST_BR;
1100      BranchInst &II = cast<BranchInst>(I);
1101      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1102      if (II.isConditional()) {
1103        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1104        Vals.push_back(VE.getValueID(II.getCondition()));
1105      }
1106    }
1107    break;
1108  case Instruction::Switch:
1109    Code = bitc::FUNC_CODE_INST_SWITCH;
1110    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1111    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1112      Vals.push_back(VE.getValueID(I.getOperand(i)));
1113    break;
1114  case Instruction::IndirectBr:
1115    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1116    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1117    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1118      Vals.push_back(VE.getValueID(I.getOperand(i)));
1119    break;
1120
1121  case Instruction::Invoke: {
1122    const InvokeInst *II = cast<InvokeInst>(&I);
1123    const Value *Callee(II->getCalledValue());
1124    PointerType *PTy = cast<PointerType>(Callee->getType());
1125    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1126    Code = bitc::FUNC_CODE_INST_INVOKE;
1127
1128    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1129    Vals.push_back(II->getCallingConv());
1130    Vals.push_back(VE.getValueID(II->getNormalDest()));
1131    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1132    PushValueAndType(Callee, InstID, Vals, VE);
1133
1134    // Emit value #'s for the fixed parameters.
1135    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1136      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1137
1138    // Emit type/value pairs for varargs params.
1139    if (FTy->isVarArg()) {
1140      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1141           i != e; ++i)
1142        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1143    }
1144    break;
1145  }
1146  case Instruction::Unwind:
1147    Code = bitc::FUNC_CODE_INST_UNWIND;
1148    break;
1149  case Instruction::Unreachable:
1150    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1151    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1152    break;
1153
1154  case Instruction::PHI: {
1155    const PHINode &PN = cast<PHINode>(I);
1156    Code = bitc::FUNC_CODE_INST_PHI;
1157    Vals.push_back(VE.getTypeID(PN.getType()));
1158    for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1159      Vals.push_back(VE.getValueID(PN.getIncomingValue(i)));
1160      Vals.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1161    }
1162    break;
1163  }
1164
1165  case Instruction::Alloca:
1166    Code = bitc::FUNC_CODE_INST_ALLOCA;
1167    Vals.push_back(VE.getTypeID(I.getType()));
1168    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1169    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1170    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1171    break;
1172
1173  case Instruction::Load:
1174    Code = bitc::FUNC_CODE_INST_LOAD;
1175    if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1176      AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1177
1178    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1179    Vals.push_back(cast<LoadInst>(I).isVolatile());
1180    break;
1181  case Instruction::Store:
1182    Code = bitc::FUNC_CODE_INST_STORE;
1183    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1184    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1185    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1186    Vals.push_back(cast<StoreInst>(I).isVolatile());
1187    break;
1188  case Instruction::AtomicCmpXchg:
1189    Code = bitc::FUNC_CODE_INST_CMPXCHG;
1190    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1191    Vals.push_back(VE.getValueID(I.getOperand(1)));       // cmp.
1192    Vals.push_back(VE.getValueID(I.getOperand(2)));       // newval.
1193    Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1194    Vals.push_back(GetEncodedOrdering(
1195                     cast<AtomicCmpXchgInst>(I).getOrdering()));
1196    Vals.push_back(GetEncodedSynchScope(
1197                     cast<AtomicCmpXchgInst>(I).getSynchScope()));
1198    break;
1199  case Instruction::AtomicRMW:
1200    Code = bitc::FUNC_CODE_INST_ATOMICRMW;
1201    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1202    Vals.push_back(VE.getValueID(I.getOperand(1)));       // val.
1203    Vals.push_back(GetEncodedRMWOperation(
1204                     cast<AtomicRMWInst>(I).getOperation()));
1205    Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
1206    Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
1207    Vals.push_back(GetEncodedSynchScope(
1208                     cast<AtomicRMWInst>(I).getSynchScope()));
1209    break;
1210  case Instruction::Fence:
1211    Code = bitc::FUNC_CODE_INST_FENCE;
1212    Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
1213    Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
1214    break;
1215  case Instruction::Call: {
1216    const CallInst &CI = cast<CallInst>(I);
1217    PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1218    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1219
1220    Code = bitc::FUNC_CODE_INST_CALL;
1221
1222    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1223    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1224    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1225
1226    // Emit value #'s for the fixed parameters.
1227    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1228      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1229
1230    // Emit type/value pairs for varargs params.
1231    if (FTy->isVarArg()) {
1232      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1233           i != e; ++i)
1234        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1235    }
1236    break;
1237  }
1238  case Instruction::VAArg:
1239    Code = bitc::FUNC_CODE_INST_VAARG;
1240    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1241    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1242    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1243    break;
1244  }
1245
1246  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1247  Vals.clear();
1248}
1249
1250// Emit names for globals/functions etc.
1251static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1252                                  const ValueEnumerator &VE,
1253                                  BitstreamWriter &Stream) {
1254  if (VST.empty()) return;
1255  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1256
1257  // FIXME: Set up the abbrev, we know how many values there are!
1258  // FIXME: We know if the type names can use 7-bit ascii.
1259  SmallVector<unsigned, 64> NameVals;
1260
1261  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1262       SI != SE; ++SI) {
1263
1264    const ValueName &Name = *SI;
1265
1266    // Figure out the encoding to use for the name.
1267    bool is7Bit = true;
1268    bool isChar6 = true;
1269    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1270         C != E; ++C) {
1271      if (isChar6)
1272        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1273      if ((unsigned char)*C & 128) {
1274        is7Bit = false;
1275        break;  // don't bother scanning the rest.
1276      }
1277    }
1278
1279    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1280
1281    // VST_ENTRY:   [valueid, namechar x N]
1282    // VST_BBENTRY: [bbid, namechar x N]
1283    unsigned Code;
1284    if (isa<BasicBlock>(SI->getValue())) {
1285      Code = bitc::VST_CODE_BBENTRY;
1286      if (isChar6)
1287        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1288    } else {
1289      Code = bitc::VST_CODE_ENTRY;
1290      if (isChar6)
1291        AbbrevToUse = VST_ENTRY_6_ABBREV;
1292      else if (is7Bit)
1293        AbbrevToUse = VST_ENTRY_7_ABBREV;
1294    }
1295
1296    NameVals.push_back(VE.getValueID(SI->getValue()));
1297    for (const char *P = Name.getKeyData(),
1298         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1299      NameVals.push_back((unsigned char)*P);
1300
1301    // Emit the finished record.
1302    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1303    NameVals.clear();
1304  }
1305  Stream.ExitBlock();
1306}
1307
1308/// WriteFunction - Emit a function body to the module stream.
1309static void WriteFunction(const Function &F, ValueEnumerator &VE,
1310                          BitstreamWriter &Stream) {
1311  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1312  VE.incorporateFunction(F);
1313
1314  SmallVector<unsigned, 64> Vals;
1315
1316  // Emit the number of basic blocks, so the reader can create them ahead of
1317  // time.
1318  Vals.push_back(VE.getBasicBlocks().size());
1319  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1320  Vals.clear();
1321
1322  // If there are function-local constants, emit them now.
1323  unsigned CstStart, CstEnd;
1324  VE.getFunctionConstantRange(CstStart, CstEnd);
1325  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1326
1327  // If there is function-local metadata, emit it now.
1328  WriteFunctionLocalMetadata(F, VE, Stream);
1329
1330  // Keep a running idea of what the instruction ID is.
1331  unsigned InstID = CstEnd;
1332
1333  bool NeedsMetadataAttachment = false;
1334
1335  DebugLoc LastDL;
1336
1337  // Finally, emit all the instructions, in order.
1338  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1339    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1340         I != E; ++I) {
1341      WriteInstruction(*I, InstID, VE, Stream, Vals);
1342
1343      if (!I->getType()->isVoidTy())
1344        ++InstID;
1345
1346      // If the instruction has metadata, write a metadata attachment later.
1347      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1348
1349      // If the instruction has a debug location, emit it.
1350      DebugLoc DL = I->getDebugLoc();
1351      if (DL.isUnknown()) {
1352        // nothing todo.
1353      } else if (DL == LastDL) {
1354        // Just repeat the same debug loc as last time.
1355        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1356      } else {
1357        MDNode *Scope, *IA;
1358        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1359
1360        Vals.push_back(DL.getLine());
1361        Vals.push_back(DL.getCol());
1362        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1363        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1364        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1365        Vals.clear();
1366
1367        LastDL = DL;
1368      }
1369    }
1370
1371  // Emit names for all the instructions etc.
1372  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1373
1374  if (NeedsMetadataAttachment)
1375    WriteMetadataAttachment(F, VE, Stream);
1376  VE.purgeFunction();
1377  Stream.ExitBlock();
1378}
1379
1380// Emit blockinfo, which defines the standard abbreviations etc.
1381static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1382  // We only want to emit block info records for blocks that have multiple
1383  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1384  // blocks can defined their abbrevs inline.
1385  Stream.EnterBlockInfoBlock(2);
1386
1387  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1388    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1389    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1390    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1391    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1392    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1393    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1394                                   Abbv) != VST_ENTRY_8_ABBREV)
1395      llvm_unreachable("Unexpected abbrev ordering!");
1396  }
1397
1398  { // 7-bit fixed width VST_ENTRY strings.
1399    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1400    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1401    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1402    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1403    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1404    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1405                                   Abbv) != VST_ENTRY_7_ABBREV)
1406      llvm_unreachable("Unexpected abbrev ordering!");
1407  }
1408  { // 6-bit char6 VST_ENTRY strings.
1409    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1410    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1411    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1412    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1413    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1414    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1415                                   Abbv) != VST_ENTRY_6_ABBREV)
1416      llvm_unreachable("Unexpected abbrev ordering!");
1417  }
1418  { // 6-bit char6 VST_BBENTRY strings.
1419    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1420    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1421    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1422    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1423    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1424    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1425                                   Abbv) != VST_BBENTRY_6_ABBREV)
1426      llvm_unreachable("Unexpected abbrev ordering!");
1427  }
1428
1429
1430
1431  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1432    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1433    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1434    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1435                              Log2_32_Ceil(VE.getTypes().size()+1)));
1436    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1437                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1438      llvm_unreachable("Unexpected abbrev ordering!");
1439  }
1440
1441  { // INTEGER abbrev for CONSTANTS_BLOCK.
1442    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1443    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1444    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1445    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1446                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1447      llvm_unreachable("Unexpected abbrev ordering!");
1448  }
1449
1450  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1451    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1452    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1453    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1454    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1455                              Log2_32_Ceil(VE.getTypes().size()+1)));
1456    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1457
1458    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1459                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1460      llvm_unreachable("Unexpected abbrev ordering!");
1461  }
1462  { // NULL abbrev for CONSTANTS_BLOCK.
1463    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1464    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1465    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1466                                   Abbv) != CONSTANTS_NULL_Abbrev)
1467      llvm_unreachable("Unexpected abbrev ordering!");
1468  }
1469
1470  // FIXME: This should only use space for first class types!
1471
1472  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1473    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1474    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1475    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1476    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1477    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1478    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1479                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1480      llvm_unreachable("Unexpected abbrev ordering!");
1481  }
1482  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1483    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1484    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1485    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1486    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1487    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1488    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1489                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1490      llvm_unreachable("Unexpected abbrev ordering!");
1491  }
1492  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1493    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1494    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1495    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1496    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1497    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1498    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1499    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1500                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1501      llvm_unreachable("Unexpected abbrev ordering!");
1502  }
1503  { // INST_CAST abbrev for FUNCTION_BLOCK.
1504    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1505    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1506    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1507    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1508                              Log2_32_Ceil(VE.getTypes().size()+1)));
1509    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1510    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1511                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1512      llvm_unreachable("Unexpected abbrev ordering!");
1513  }
1514
1515  { // INST_RET abbrev for FUNCTION_BLOCK.
1516    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1517    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1518    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1519                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1520      llvm_unreachable("Unexpected abbrev ordering!");
1521  }
1522  { // INST_RET abbrev for FUNCTION_BLOCK.
1523    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1524    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1525    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1526    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1527                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1528      llvm_unreachable("Unexpected abbrev ordering!");
1529  }
1530  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1531    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1532    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1533    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1534                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1535      llvm_unreachable("Unexpected abbrev ordering!");
1536  }
1537
1538  Stream.ExitBlock();
1539}
1540
1541
1542/// WriteModule - Emit the specified module to the bitstream.
1543static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1544  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1545
1546  // Emit the version number if it is non-zero.
1547  if (CurVersion) {
1548    SmallVector<unsigned, 1> Vals;
1549    Vals.push_back(CurVersion);
1550    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1551  }
1552
1553  // Analyze the module, enumerating globals, functions, etc.
1554  ValueEnumerator VE(M);
1555
1556  // Emit blockinfo, which defines the standard abbreviations etc.
1557  WriteBlockInfo(VE, Stream);
1558
1559  // Emit information about parameter attributes.
1560  WriteAttributeTable(VE, Stream);
1561
1562  // Emit information describing all of the types in the module.
1563  WriteTypeTable(VE, Stream);
1564
1565  // Emit top-level description of module, including target triple, inline asm,
1566  // descriptors for global variables, and function prototype info.
1567  WriteModuleInfo(M, VE, Stream);
1568
1569  // Emit constants.
1570  WriteModuleConstants(VE, Stream);
1571
1572  // Emit metadata.
1573  WriteModuleMetadata(M, VE, Stream);
1574
1575  // Emit function bodies.
1576  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1577    if (!F->isDeclaration())
1578      WriteFunction(*F, VE, Stream);
1579
1580  // Emit metadata.
1581  WriteModuleMetadataStore(M, Stream);
1582
1583  // Emit names for globals/functions etc.
1584  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1585
1586  Stream.ExitBlock();
1587}
1588
1589/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1590/// header and trailer to make it compatible with the system archiver.  To do
1591/// this we emit the following header, and then emit a trailer that pads the
1592/// file out to be a multiple of 16 bytes.
1593///
1594/// struct bc_header {
1595///   uint32_t Magic;         // 0x0B17C0DE
1596///   uint32_t Version;       // Version, currently always 0.
1597///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1598///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1599///   uint32_t CPUType;       // CPU specifier.
1600///   ... potentially more later ...
1601/// };
1602enum {
1603  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1604  DarwinBCHeaderSize = 5*4
1605};
1606
1607static void EmitDarwinBCHeader(BitstreamWriter &Stream, const Triple &TT) {
1608  unsigned CPUType = ~0U;
1609
1610  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1611  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1612  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1613  // specific constants here because they are implicitly part of the Darwin ABI.
1614  enum {
1615    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1616    DARWIN_CPU_TYPE_X86        = 7,
1617    DARWIN_CPU_TYPE_ARM        = 12,
1618    DARWIN_CPU_TYPE_POWERPC    = 18
1619  };
1620
1621  Triple::ArchType Arch = TT.getArch();
1622  if (Arch == Triple::x86_64)
1623    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1624  else if (Arch == Triple::x86)
1625    CPUType = DARWIN_CPU_TYPE_X86;
1626  else if (Arch == Triple::ppc)
1627    CPUType = DARWIN_CPU_TYPE_POWERPC;
1628  else if (Arch == Triple::ppc64)
1629    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1630  else if (Arch == Triple::arm || Arch == Triple::thumb)
1631    CPUType = DARWIN_CPU_TYPE_ARM;
1632
1633  // Traditional Bitcode starts after header.
1634  unsigned BCOffset = DarwinBCHeaderSize;
1635
1636  Stream.Emit(0x0B17C0DE, 32);
1637  Stream.Emit(0         , 32);  // Version.
1638  Stream.Emit(BCOffset  , 32);
1639  Stream.Emit(0         , 32);  // Filled in later.
1640  Stream.Emit(CPUType   , 32);
1641}
1642
1643/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1644/// finalize the header.
1645static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1646  // Update the size field in the header.
1647  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1648
1649  // If the file is not a multiple of 16 bytes, insert dummy padding.
1650  while (BufferSize & 15) {
1651    Stream.Emit(0, 8);
1652    ++BufferSize;
1653  }
1654}
1655
1656
1657/// WriteBitcodeToFile - Write the specified module to the specified output
1658/// stream.
1659void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1660  std::vector<unsigned char> Buffer;
1661  BitstreamWriter Stream(Buffer);
1662
1663  Buffer.reserve(256*1024);
1664
1665  WriteBitcodeToStream( M, Stream );
1666
1667  // Write the generated bitstream to "Out".
1668  Out.write((char*)&Buffer.front(), Buffer.size());
1669}
1670
1671/// WriteBitcodeToStream - Write the specified module to the specified output
1672/// stream.
1673void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1674  // If this is darwin or another generic macho target, emit a file header and
1675  // trailer if needed.
1676  Triple TT(M->getTargetTriple());
1677  if (TT.isOSDarwin())
1678    EmitDarwinBCHeader(Stream, TT);
1679
1680  // Emit the file header.
1681  Stream.Emit((unsigned)'B', 8);
1682  Stream.Emit((unsigned)'C', 8);
1683  Stream.Emit(0x0, 4);
1684  Stream.Emit(0xC, 4);
1685  Stream.Emit(0xE, 4);
1686  Stream.Emit(0xD, 4);
1687
1688  // Emit the module.
1689  WriteModule(M, Stream);
1690
1691  if (TT.isOSDarwin())
1692    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1693}
1694