BitcodeWriter.cpp revision cbbb09687f563fad96fd815a3a89920f436373e4 
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/CommandLine.h"
27#include "llvm/Support/ErrorHandling.h"
28#include "llvm/Support/MathExtras.h"
29#include "llvm/Support/raw_ostream.h"
30#include "llvm/Support/Program.h"
31#include <cctype>
32#include <map>
33using namespace llvm;
34
35static cl::opt<bool>
36EnablePreserveUseListOrdering("enable-bc-uselist-preserve",
37                              cl::desc("Turn on experimental support for "
38                                       "use-list order preservation."),
39                              cl::init(false), cl::Hidden);
40
41/// These are manifest constants used by the bitcode writer. They do not need to
42/// be kept in sync with the reader, but need to be consistent within this file.
43enum {
44  CurVersion = 0,
45
46  // VALUE_SYMTAB_BLOCK abbrev id's.
47  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
48  VST_ENTRY_7_ABBREV,
49  VST_ENTRY_6_ABBREV,
50  VST_BBENTRY_6_ABBREV,
51
52  // CONSTANTS_BLOCK abbrev id's.
53  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
54  CONSTANTS_INTEGER_ABBREV,
55  CONSTANTS_CE_CAST_Abbrev,
56  CONSTANTS_NULL_Abbrev,
57
58  // FUNCTION_BLOCK abbrev id's.
59  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
60  FUNCTION_INST_BINOP_ABBREV,
61  FUNCTION_INST_BINOP_FLAGS_ABBREV,
62  FUNCTION_INST_CAST_ABBREV,
63  FUNCTION_INST_RET_VOID_ABBREV,
64  FUNCTION_INST_RET_VAL_ABBREV,
65  FUNCTION_INST_UNREACHABLE_ABBREV
66};
67
68static unsigned GetEncodedCastOpcode(unsigned Opcode) {
69  switch (Opcode) {
70  default: llvm_unreachable("Unknown cast instruction!");
71  case Instruction::Trunc   : return bitc::CAST_TRUNC;
72  case Instruction::ZExt    : return bitc::CAST_ZEXT;
73  case Instruction::SExt    : return bitc::CAST_SEXT;
74  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
75  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
76  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
77  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
78  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
79  case Instruction::FPExt   : return bitc::CAST_FPEXT;
80  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
81  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
82  case Instruction::BitCast : return bitc::CAST_BITCAST;
83  }
84}
85
86static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
87  switch (Opcode) {
88  default: llvm_unreachable("Unknown binary instruction!");
89  case Instruction::Add:
90  case Instruction::FAdd: return bitc::BINOP_ADD;
91  case Instruction::Sub:
92  case Instruction::FSub: return bitc::BINOP_SUB;
93  case Instruction::Mul:
94  case Instruction::FMul: return bitc::BINOP_MUL;
95  case Instruction::UDiv: return bitc::BINOP_UDIV;
96  case Instruction::FDiv:
97  case Instruction::SDiv: return bitc::BINOP_SDIV;
98  case Instruction::URem: return bitc::BINOP_UREM;
99  case Instruction::FRem:
100  case Instruction::SRem: return bitc::BINOP_SREM;
101  case Instruction::Shl:  return bitc::BINOP_SHL;
102  case Instruction::LShr: return bitc::BINOP_LSHR;
103  case Instruction::AShr: return bitc::BINOP_ASHR;
104  case Instruction::And:  return bitc::BINOP_AND;
105  case Instruction::Or:   return bitc::BINOP_OR;
106  case Instruction::Xor:  return bitc::BINOP_XOR;
107  }
108}
109
110static unsigned GetEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
111  switch (Op) {
112  default: llvm_unreachable("Unknown RMW operation!");
113  case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
114  case AtomicRMWInst::Add: return bitc::RMW_ADD;
115  case AtomicRMWInst::Sub: return bitc::RMW_SUB;
116  case AtomicRMWInst::And: return bitc::RMW_AND;
117  case AtomicRMWInst::Nand: return bitc::RMW_NAND;
118  case AtomicRMWInst::Or: return bitc::RMW_OR;
119  case AtomicRMWInst::Xor: return bitc::RMW_XOR;
120  case AtomicRMWInst::Max: return bitc::RMW_MAX;
121  case AtomicRMWInst::Min: return bitc::RMW_MIN;
122  case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
123  case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
124  }
125}
126
127static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
128  switch (Ordering) {
129  default: llvm_unreachable("Unknown atomic ordering");
130  case NotAtomic: return bitc::ORDERING_NOTATOMIC;
131  case Unordered: return bitc::ORDERING_UNORDERED;
132  case Monotonic: return bitc::ORDERING_MONOTONIC;
133  case Acquire: return bitc::ORDERING_ACQUIRE;
134  case Release: return bitc::ORDERING_RELEASE;
135  case AcquireRelease: return bitc::ORDERING_ACQREL;
136  case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
137  }
138}
139
140static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
141  switch (SynchScope) {
142  default: llvm_unreachable("Unknown synchronization scope");
143  case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
144  case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
145  }
146}
147
148static void WriteStringRecord(unsigned Code, StringRef Str,
149                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
150  SmallVector<unsigned, 64> Vals;
151
152  // Code: [strchar x N]
153  for (unsigned i = 0, e = Str.size(); i != e; ++i) {
154    if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
155      AbbrevToUse = 0;
156    Vals.push_back(Str[i]);
157  }
158
159  // Emit the finished record.
160  Stream.EmitRecord(Code, Vals, AbbrevToUse);
161}
162
163// Emit information about parameter attributes.
164static void WriteAttributeTable(const ValueEnumerator &VE,
165                                BitstreamWriter &Stream) {
166  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
167  if (Attrs.empty()) return;
168
169  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
170
171  SmallVector<uint64_t, 64> Record;
172  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
173    const AttrListPtr &A = Attrs[i];
174    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
175      const AttributeWithIndex &PAWI = A.getSlot(i);
176      Record.push_back(PAWI.Index);
177
178      // FIXME: remove in LLVM 3.0
179      // Store the alignment in the bitcode as a 16-bit raw value instead of a
180      // 5-bit log2 encoded value. Shift the bits above the alignment up by
181      // 11 bits.
182      uint64_t FauxAttr = PAWI.Attrs & 0xffff;
183      if (PAWI.Attrs & Attribute::Alignment)
184        FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
185      FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
186
187      Record.push_back(FauxAttr);
188    }
189
190    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
191    Record.clear();
192  }
193
194  Stream.ExitBlock();
195}
196
197/// WriteTypeTable - Write out the type table for a module.
198static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
199  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
200
201  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
202  SmallVector<uint64_t, 64> TypeVals;
203
204  // Abbrev for TYPE_CODE_POINTER.
205  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
206  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
207  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
208                            Log2_32_Ceil(VE.getTypes().size()+1)));
209  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
210  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
211
212  // Abbrev for TYPE_CODE_FUNCTION.
213  Abbv = new BitCodeAbbrev();
214  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
215  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
216  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
217  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
218                            Log2_32_Ceil(VE.getTypes().size()+1)));
219  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
220
221  // Abbrev for TYPE_CODE_STRUCT_ANON.
222  Abbv = new BitCodeAbbrev();
223  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
224  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
225  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
226  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
227                            Log2_32_Ceil(VE.getTypes().size()+1)));
228  unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
229
230  // Abbrev for TYPE_CODE_STRUCT_NAME.
231  Abbv = new BitCodeAbbrev();
232  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
233  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
234  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
235  unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
236
237  // Abbrev for TYPE_CODE_STRUCT_NAMED.
238  Abbv = new BitCodeAbbrev();
239  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
240  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
241  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
242  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
243                            Log2_32_Ceil(VE.getTypes().size()+1)));
244  unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
245
246  // Abbrev for TYPE_CODE_ARRAY.
247  Abbv = new BitCodeAbbrev();
248  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
249  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
250  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
251                            Log2_32_Ceil(VE.getTypes().size()+1)));
252  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
253
254  // Emit an entry count so the reader can reserve space.
255  TypeVals.push_back(TypeList.size());
256  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
257  TypeVals.clear();
258
259  // Loop over all of the types, emitting each in turn.
260  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
261    Type *T = TypeList[i];
262    int AbbrevToUse = 0;
263    unsigned Code = 0;
264
265    switch (T->getTypeID()) {
266    default: llvm_unreachable("Unknown type!");
267    case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;   break;
268    case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;  break;
269    case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE; break;
270    case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80; break;
271    case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128; break;
272    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
273    case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;  break;
274    case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA; break;
275    case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX; break;
276    case Type::IntegerTyID:
277      // INTEGER: [width]
278      Code = bitc::TYPE_CODE_INTEGER;
279      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
280      break;
281    case Type::PointerTyID: {
282      PointerType *PTy = cast<PointerType>(T);
283      // POINTER: [pointee type, address space]
284      Code = bitc::TYPE_CODE_POINTER;
285      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
286      unsigned AddressSpace = PTy->getAddressSpace();
287      TypeVals.push_back(AddressSpace);
288      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
289      break;
290    }
291    case Type::FunctionTyID: {
292      FunctionType *FT = cast<FunctionType>(T);
293      // FUNCTION: [isvararg, retty, paramty x N]
294      Code = bitc::TYPE_CODE_FUNCTION;
295      TypeVals.push_back(FT->isVarArg());
296      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
297      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
298        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
299      AbbrevToUse = FunctionAbbrev;
300      break;
301    }
302    case Type::StructTyID: {
303      StructType *ST = cast<StructType>(T);
304      // STRUCT: [ispacked, eltty x N]
305      TypeVals.push_back(ST->isPacked());
306      // Output all of the element types.
307      for (StructType::element_iterator I = ST->element_begin(),
308           E = ST->element_end(); I != E; ++I)
309        TypeVals.push_back(VE.getTypeID(*I));
310
311      if (ST->isLiteral()) {
312        Code = bitc::TYPE_CODE_STRUCT_ANON;
313        AbbrevToUse = StructAnonAbbrev;
314      } else {
315        if (ST->isOpaque()) {
316          Code = bitc::TYPE_CODE_OPAQUE;
317        } else {
318          Code = bitc::TYPE_CODE_STRUCT_NAMED;
319          AbbrevToUse = StructNamedAbbrev;
320        }
321
322        // Emit the name if it is present.
323        if (!ST->getName().empty())
324          WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
325                            StructNameAbbrev, Stream);
326      }
327      break;
328    }
329    case Type::ArrayTyID: {
330      ArrayType *AT = cast<ArrayType>(T);
331      // ARRAY: [numelts, eltty]
332      Code = bitc::TYPE_CODE_ARRAY;
333      TypeVals.push_back(AT->getNumElements());
334      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
335      AbbrevToUse = ArrayAbbrev;
336      break;
337    }
338    case Type::VectorTyID: {
339      VectorType *VT = cast<VectorType>(T);
340      // VECTOR [numelts, eltty]
341      Code = bitc::TYPE_CODE_VECTOR;
342      TypeVals.push_back(VT->getNumElements());
343      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
344      break;
345    }
346    }
347
348    // Emit the finished record.
349    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
350    TypeVals.clear();
351  }
352
353  Stream.ExitBlock();
354}
355
356static unsigned getEncodedLinkage(const GlobalValue *GV) {
357  switch (GV->getLinkage()) {
358  default: llvm_unreachable("Invalid linkage!");
359  case GlobalValue::ExternalLinkage:                 return 0;
360  case GlobalValue::WeakAnyLinkage:                  return 1;
361  case GlobalValue::AppendingLinkage:                return 2;
362  case GlobalValue::InternalLinkage:                 return 3;
363  case GlobalValue::LinkOnceAnyLinkage:              return 4;
364  case GlobalValue::DLLImportLinkage:                return 5;
365  case GlobalValue::DLLExportLinkage:                return 6;
366  case GlobalValue::ExternalWeakLinkage:             return 7;
367  case GlobalValue::CommonLinkage:                   return 8;
368  case GlobalValue::PrivateLinkage:                  return 9;
369  case GlobalValue::WeakODRLinkage:                  return 10;
370  case GlobalValue::LinkOnceODRLinkage:              return 11;
371  case GlobalValue::AvailableExternallyLinkage:      return 12;
372  case GlobalValue::LinkerPrivateLinkage:            return 13;
373  case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
374  case GlobalValue::LinkerPrivateWeakDefAutoLinkage: return 15;
375  }
376}
377
378static unsigned getEncodedVisibility(const GlobalValue *GV) {
379  switch (GV->getVisibility()) {
380  default: llvm_unreachable("Invalid visibility!");
381  case GlobalValue::DefaultVisibility:   return 0;
382  case GlobalValue::HiddenVisibility:    return 1;
383  case GlobalValue::ProtectedVisibility: return 2;
384  }
385}
386
387// Emit top-level description of module, including target triple, inline asm,
388// descriptors for global variables, and function prototype info.
389static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
390                            BitstreamWriter &Stream) {
391  // Emit the list of dependent libraries for the Module.
392  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
393    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
394
395  // Emit various pieces of data attached to a module.
396  if (!M->getTargetTriple().empty())
397    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
398                      0/*TODO*/, Stream);
399  if (!M->getDataLayout().empty())
400    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
401                      0/*TODO*/, Stream);
402  if (!M->getModuleInlineAsm().empty())
403    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
404                      0/*TODO*/, Stream);
405
406  // Emit information about sections and GC, computing how many there are. Also
407  // compute the maximum alignment value.
408  std::map<std::string, unsigned> SectionMap;
409  std::map<std::string, unsigned> GCMap;
410  unsigned MaxAlignment = 0;
411  unsigned MaxGlobalType = 0;
412  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
413       GV != E; ++GV) {
414    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
415    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
416    if (GV->hasSection()) {
417      // Give section names unique ID's.
418      unsigned &Entry = SectionMap[GV->getSection()];
419      if (!Entry) {
420        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
421                          0/*TODO*/, Stream);
422        Entry = SectionMap.size();
423      }
424    }
425  }
426  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
427    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
428    if (F->hasSection()) {
429      // Give section names unique ID's.
430      unsigned &Entry = SectionMap[F->getSection()];
431      if (!Entry) {
432        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
433                          0/*TODO*/, Stream);
434        Entry = SectionMap.size();
435      }
436    }
437    if (F->hasGC()) {
438      // Same for GC names.
439      unsigned &Entry = GCMap[F->getGC()];
440      if (!Entry) {
441        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
442                          0/*TODO*/, Stream);
443        Entry = GCMap.size();
444      }
445    }
446  }
447
448  // Emit abbrev for globals, now that we know # sections and max alignment.
449  unsigned SimpleGVarAbbrev = 0;
450  if (!M->global_empty()) {
451    // Add an abbrev for common globals with no visibility or thread localness.
452    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
453    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
454    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
455                              Log2_32_Ceil(MaxGlobalType+1)));
456    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
457    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
458    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
459    if (MaxAlignment == 0)                                      // Alignment.
460      Abbv->Add(BitCodeAbbrevOp(0));
461    else {
462      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
463      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
464                               Log2_32_Ceil(MaxEncAlignment+1)));
465    }
466    if (SectionMap.empty())                                    // Section.
467      Abbv->Add(BitCodeAbbrevOp(0));
468    else
469      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
470                               Log2_32_Ceil(SectionMap.size()+1)));
471    // Don't bother emitting vis + thread local.
472    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
473  }
474
475  // Emit the global variable information.
476  SmallVector<unsigned, 64> Vals;
477  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
478       GV != E; ++GV) {
479    unsigned AbbrevToUse = 0;
480
481    // GLOBALVAR: [type, isconst, initid,
482    //             linkage, alignment, section, visibility, threadlocal,
483    //             unnamed_addr]
484    Vals.push_back(VE.getTypeID(GV->getType()));
485    Vals.push_back(GV->isConstant());
486    Vals.push_back(GV->isDeclaration() ? 0 :
487                   (VE.getValueID(GV->getInitializer()) + 1));
488    Vals.push_back(getEncodedLinkage(GV));
489    Vals.push_back(Log2_32(GV->getAlignment())+1);
490    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
491    if (GV->isThreadLocal() ||
492        GV->getVisibility() != GlobalValue::DefaultVisibility ||
493        GV->hasUnnamedAddr()) {
494      Vals.push_back(getEncodedVisibility(GV));
495      Vals.push_back(GV->isThreadLocal());
496      Vals.push_back(GV->hasUnnamedAddr());
497    } else {
498      AbbrevToUse = SimpleGVarAbbrev;
499    }
500
501    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
502    Vals.clear();
503  }
504
505  // Emit the function proto information.
506  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
507    // FUNCTION:  [type, callingconv, isproto, paramattr,
508    //             linkage, alignment, section, visibility, gc, unnamed_addr]
509    Vals.push_back(VE.getTypeID(F->getType()));
510    Vals.push_back(F->getCallingConv());
511    Vals.push_back(F->isDeclaration());
512    Vals.push_back(getEncodedLinkage(F));
513    Vals.push_back(VE.getAttributeID(F->getAttributes()));
514    Vals.push_back(Log2_32(F->getAlignment())+1);
515    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
516    Vals.push_back(getEncodedVisibility(F));
517    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
518    Vals.push_back(F->hasUnnamedAddr());
519
520    unsigned AbbrevToUse = 0;
521    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
522    Vals.clear();
523  }
524
525  // Emit the alias information.
526  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
527       AI != E; ++AI) {
528    Vals.push_back(VE.getTypeID(AI->getType()));
529    Vals.push_back(VE.getValueID(AI->getAliasee()));
530    Vals.push_back(getEncodedLinkage(AI));
531    Vals.push_back(getEncodedVisibility(AI));
532    unsigned AbbrevToUse = 0;
533    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
534    Vals.clear();
535  }
536}
537
538static uint64_t GetOptimizationFlags(const Value *V) {
539  uint64_t Flags = 0;
540
541  if (const OverflowingBinaryOperator *OBO =
542        dyn_cast<OverflowingBinaryOperator>(V)) {
543    if (OBO->hasNoSignedWrap())
544      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
545    if (OBO->hasNoUnsignedWrap())
546      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
547  } else if (const PossiblyExactOperator *PEO =
548               dyn_cast<PossiblyExactOperator>(V)) {
549    if (PEO->isExact())
550      Flags |= 1 << bitc::PEO_EXACT;
551  }
552
553  return Flags;
554}
555
556static void WriteMDNode(const MDNode *N,
557                        const ValueEnumerator &VE,
558                        BitstreamWriter &Stream,
559                        SmallVector<uint64_t, 64> &Record) {
560  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
561    if (N->getOperand(i)) {
562      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
563      Record.push_back(VE.getValueID(N->getOperand(i)));
564    } else {
565      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
566      Record.push_back(0);
567    }
568  }
569  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
570                                           bitc::METADATA_NODE;
571  Stream.EmitRecord(MDCode, Record, 0);
572  Record.clear();
573}
574
575static void WriteModuleMetadata(const Module *M,
576                                const ValueEnumerator &VE,
577                                BitstreamWriter &Stream) {
578  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
579  bool StartedMetadataBlock = false;
580  unsigned MDSAbbrev = 0;
581  SmallVector<uint64_t, 64> Record;
582  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
583
584    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
585      if (!N->isFunctionLocal() || !N->getFunction()) {
586        if (!StartedMetadataBlock) {
587          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
588          StartedMetadataBlock = true;
589        }
590        WriteMDNode(N, VE, Stream, Record);
591      }
592    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
593      if (!StartedMetadataBlock)  {
594        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
595
596        // Abbrev for METADATA_STRING.
597        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
598        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
599        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
600        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
601        MDSAbbrev = Stream.EmitAbbrev(Abbv);
602        StartedMetadataBlock = true;
603      }
604
605      // Code: [strchar x N]
606      Record.append(MDS->begin(), MDS->end());
607
608      // Emit the finished record.
609      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
610      Record.clear();
611    }
612  }
613
614  // Write named metadata.
615  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
616       E = M->named_metadata_end(); I != E; ++I) {
617    const NamedMDNode *NMD = I;
618    if (!StartedMetadataBlock)  {
619      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
620      StartedMetadataBlock = true;
621    }
622
623    // Write name.
624    StringRef Str = NMD->getName();
625    for (unsigned i = 0, e = Str.size(); i != e; ++i)
626      Record.push_back(Str[i]);
627    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
628    Record.clear();
629
630    // Write named metadata operands.
631    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
632      Record.push_back(VE.getValueID(NMD->getOperand(i)));
633    Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
634    Record.clear();
635  }
636
637  if (StartedMetadataBlock)
638    Stream.ExitBlock();
639}
640
641static void WriteFunctionLocalMetadata(const Function &F,
642                                       const ValueEnumerator &VE,
643                                       BitstreamWriter &Stream) {
644  bool StartedMetadataBlock = false;
645  SmallVector<uint64_t, 64> Record;
646  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
647  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
648    if (const MDNode *N = Vals[i])
649      if (N->isFunctionLocal() && N->getFunction() == &F) {
650        if (!StartedMetadataBlock) {
651          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
652          StartedMetadataBlock = true;
653        }
654        WriteMDNode(N, VE, Stream, Record);
655      }
656
657  if (StartedMetadataBlock)
658    Stream.ExitBlock();
659}
660
661static void WriteMetadataAttachment(const Function &F,
662                                    const ValueEnumerator &VE,
663                                    BitstreamWriter &Stream) {
664  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
665
666  SmallVector<uint64_t, 64> Record;
667
668  // Write metadata attachments
669  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
670  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
671
672  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
673    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
674         I != E; ++I) {
675      MDs.clear();
676      I->getAllMetadataOtherThanDebugLoc(MDs);
677
678      // If no metadata, ignore instruction.
679      if (MDs.empty()) continue;
680
681      Record.push_back(VE.getInstructionID(I));
682
683      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
684        Record.push_back(MDs[i].first);
685        Record.push_back(VE.getValueID(MDs[i].second));
686      }
687      Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
688      Record.clear();
689    }
690
691  Stream.ExitBlock();
692}
693
694static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
695  SmallVector<uint64_t, 64> Record;
696
697  // Write metadata kinds
698  // METADATA_KIND - [n x [id, name]]
699  SmallVector<StringRef, 4> Names;
700  M->getMDKindNames(Names);
701
702  if (Names.empty()) return;
703
704  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
705
706  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
707    Record.push_back(MDKindID);
708    StringRef KName = Names[MDKindID];
709    Record.append(KName.begin(), KName.end());
710
711    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
712    Record.clear();
713  }
714
715  Stream.ExitBlock();
716}
717
718static void WriteConstants(unsigned FirstVal, unsigned LastVal,
719                           const ValueEnumerator &VE,
720                           BitstreamWriter &Stream, bool isGlobal) {
721  if (FirstVal == LastVal) return;
722
723  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
724
725  unsigned AggregateAbbrev = 0;
726  unsigned String8Abbrev = 0;
727  unsigned CString7Abbrev = 0;
728  unsigned CString6Abbrev = 0;
729  // If this is a constant pool for the module, emit module-specific abbrevs.
730  if (isGlobal) {
731    // Abbrev for CST_CODE_AGGREGATE.
732    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
733    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
734    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
735    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
736    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
737
738    // Abbrev for CST_CODE_STRING.
739    Abbv = new BitCodeAbbrev();
740    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
741    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
742    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
743    String8Abbrev = Stream.EmitAbbrev(Abbv);
744    // Abbrev for CST_CODE_CSTRING.
745    Abbv = new BitCodeAbbrev();
746    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
747    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
748    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
749    CString7Abbrev = Stream.EmitAbbrev(Abbv);
750    // Abbrev for CST_CODE_CSTRING.
751    Abbv = new BitCodeAbbrev();
752    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
753    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
754    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
755    CString6Abbrev = Stream.EmitAbbrev(Abbv);
756  }
757
758  SmallVector<uint64_t, 64> Record;
759
760  const ValueEnumerator::ValueList &Vals = VE.getValues();
761  Type *LastTy = 0;
762  for (unsigned i = FirstVal; i != LastVal; ++i) {
763    const Value *V = Vals[i].first;
764    // If we need to switch types, do so now.
765    if (V->getType() != LastTy) {
766      LastTy = V->getType();
767      Record.push_back(VE.getTypeID(LastTy));
768      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
769                        CONSTANTS_SETTYPE_ABBREV);
770      Record.clear();
771    }
772
773    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
774      Record.push_back(unsigned(IA->hasSideEffects()) |
775                       unsigned(IA->isAlignStack()) << 1);
776
777      // Add the asm string.
778      const std::string &AsmStr = IA->getAsmString();
779      Record.push_back(AsmStr.size());
780      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
781        Record.push_back(AsmStr[i]);
782
783      // Add the constraint string.
784      const std::string &ConstraintStr = IA->getConstraintString();
785      Record.push_back(ConstraintStr.size());
786      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
787        Record.push_back(ConstraintStr[i]);
788      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
789      Record.clear();
790      continue;
791    }
792    const Constant *C = cast<Constant>(V);
793    unsigned Code = -1U;
794    unsigned AbbrevToUse = 0;
795    if (C->isNullValue()) {
796      Code = bitc::CST_CODE_NULL;
797    } else if (isa<UndefValue>(C)) {
798      Code = bitc::CST_CODE_UNDEF;
799    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
800      if (IV->getBitWidth() <= 64) {
801        uint64_t V = IV->getSExtValue();
802        if ((int64_t)V >= 0)
803          Record.push_back(V << 1);
804        else
805          Record.push_back((-V << 1) | 1);
806        Code = bitc::CST_CODE_INTEGER;
807        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
808      } else {                             // Wide integers, > 64 bits in size.
809        // We have an arbitrary precision integer value to write whose
810        // bit width is > 64. However, in canonical unsigned integer
811        // format it is likely that the high bits are going to be zero.
812        // So, we only write the number of active words.
813        unsigned NWords = IV->getValue().getActiveWords();
814        const uint64_t *RawWords = IV->getValue().getRawData();
815        for (unsigned i = 0; i != NWords; ++i) {
816          int64_t V = RawWords[i];
817          if (V >= 0)
818            Record.push_back(V << 1);
819          else
820            Record.push_back((-V << 1) | 1);
821        }
822        Code = bitc::CST_CODE_WIDE_INTEGER;
823      }
824    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
825      Code = bitc::CST_CODE_FLOAT;
826      Type *Ty = CFP->getType();
827      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
828        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
829      } else if (Ty->isX86_FP80Ty()) {
830        // api needed to prevent premature destruction
831        // bits are not in the same order as a normal i80 APInt, compensate.
832        APInt api = CFP->getValueAPF().bitcastToAPInt();
833        const uint64_t *p = api.getRawData();
834        Record.push_back((p[1] << 48) | (p[0] >> 16));
835        Record.push_back(p[0] & 0xffffLL);
836      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
837        APInt api = CFP->getValueAPF().bitcastToAPInt();
838        const uint64_t *p = api.getRawData();
839        Record.push_back(p[0]);
840        Record.push_back(p[1]);
841      } else {
842        assert (0 && "Unknown FP type!");
843      }
844    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
845      const ConstantArray *CA = cast<ConstantArray>(C);
846      // Emit constant strings specially.
847      unsigned NumOps = CA->getNumOperands();
848      // If this is a null-terminated string, use the denser CSTRING encoding.
849      if (CA->getOperand(NumOps-1)->isNullValue()) {
850        Code = bitc::CST_CODE_CSTRING;
851        --NumOps;  // Don't encode the null, which isn't allowed by char6.
852      } else {
853        Code = bitc::CST_CODE_STRING;
854        AbbrevToUse = String8Abbrev;
855      }
856      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
857      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
858      for (unsigned i = 0; i != NumOps; ++i) {
859        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
860        Record.push_back(V);
861        isCStr7 &= (V & 128) == 0;
862        if (isCStrChar6)
863          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
864      }
865
866      if (isCStrChar6)
867        AbbrevToUse = CString6Abbrev;
868      else if (isCStr7)
869        AbbrevToUse = CString7Abbrev;
870    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
871               isa<ConstantVector>(V)) {
872      Code = bitc::CST_CODE_AGGREGATE;
873      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
874        Record.push_back(VE.getValueID(C->getOperand(i)));
875      AbbrevToUse = AggregateAbbrev;
876    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
877      switch (CE->getOpcode()) {
878      default:
879        if (Instruction::isCast(CE->getOpcode())) {
880          Code = bitc::CST_CODE_CE_CAST;
881          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
882          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
883          Record.push_back(VE.getValueID(C->getOperand(0)));
884          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
885        } else {
886          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
887          Code = bitc::CST_CODE_CE_BINOP;
888          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
889          Record.push_back(VE.getValueID(C->getOperand(0)));
890          Record.push_back(VE.getValueID(C->getOperand(1)));
891          uint64_t Flags = GetOptimizationFlags(CE);
892          if (Flags != 0)
893            Record.push_back(Flags);
894        }
895        break;
896      case Instruction::GetElementPtr:
897        Code = bitc::CST_CODE_CE_GEP;
898        if (cast<GEPOperator>(C)->isInBounds())
899          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
900        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
901          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
902          Record.push_back(VE.getValueID(C->getOperand(i)));
903        }
904        break;
905      case Instruction::Select:
906        Code = bitc::CST_CODE_CE_SELECT;
907        Record.push_back(VE.getValueID(C->getOperand(0)));
908        Record.push_back(VE.getValueID(C->getOperand(1)));
909        Record.push_back(VE.getValueID(C->getOperand(2)));
910        break;
911      case Instruction::ExtractElement:
912        Code = bitc::CST_CODE_CE_EXTRACTELT;
913        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
914        Record.push_back(VE.getValueID(C->getOperand(0)));
915        Record.push_back(VE.getValueID(C->getOperand(1)));
916        break;
917      case Instruction::InsertElement:
918        Code = bitc::CST_CODE_CE_INSERTELT;
919        Record.push_back(VE.getValueID(C->getOperand(0)));
920        Record.push_back(VE.getValueID(C->getOperand(1)));
921        Record.push_back(VE.getValueID(C->getOperand(2)));
922        break;
923      case Instruction::ShuffleVector:
924        // If the return type and argument types are the same, this is a
925        // standard shufflevector instruction.  If the types are different,
926        // then the shuffle is widening or truncating the input vectors, and
927        // the argument type must also be encoded.
928        if (C->getType() == C->getOperand(0)->getType()) {
929          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
930        } else {
931          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
932          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
933        }
934        Record.push_back(VE.getValueID(C->getOperand(0)));
935        Record.push_back(VE.getValueID(C->getOperand(1)));
936        Record.push_back(VE.getValueID(C->getOperand(2)));
937        break;
938      case Instruction::ICmp:
939      case Instruction::FCmp:
940        Code = bitc::CST_CODE_CE_CMP;
941        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
942        Record.push_back(VE.getValueID(C->getOperand(0)));
943        Record.push_back(VE.getValueID(C->getOperand(1)));
944        Record.push_back(CE->getPredicate());
945        break;
946      }
947    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
948      Code = bitc::CST_CODE_BLOCKADDRESS;
949      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
950      Record.push_back(VE.getValueID(BA->getFunction()));
951      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
952    } else {
953#ifndef NDEBUG
954      C->dump();
955#endif
956      llvm_unreachable("Unknown constant!");
957    }
958    Stream.EmitRecord(Code, Record, AbbrevToUse);
959    Record.clear();
960  }
961
962  Stream.ExitBlock();
963}
964
965static void WriteModuleConstants(const ValueEnumerator &VE,
966                                 BitstreamWriter &Stream) {
967  const ValueEnumerator::ValueList &Vals = VE.getValues();
968
969  // Find the first constant to emit, which is the first non-globalvalue value.
970  // We know globalvalues have been emitted by WriteModuleInfo.
971  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
972    if (!isa<GlobalValue>(Vals[i].first)) {
973      WriteConstants(i, Vals.size(), VE, Stream, true);
974      return;
975    }
976  }
977}
978
979/// PushValueAndType - The file has to encode both the value and type id for
980/// many values, because we need to know what type to create for forward
981/// references.  However, most operands are not forward references, so this type
982/// field is not needed.
983///
984/// This function adds V's value ID to Vals.  If the value ID is higher than the
985/// instruction ID, then it is a forward reference, and it also includes the
986/// type ID.
987static bool PushValueAndType(const Value *V, unsigned InstID,
988                             SmallVector<unsigned, 64> &Vals,
989                             ValueEnumerator &VE) {
990  unsigned ValID = VE.getValueID(V);
991  Vals.push_back(ValID);
992  if (ValID >= InstID) {
993    Vals.push_back(VE.getTypeID(V->getType()));
994    return true;
995  }
996  return false;
997}
998
999/// WriteInstruction - Emit an instruction to the specified stream.
1000static void WriteInstruction(const Instruction &I, unsigned InstID,
1001                             ValueEnumerator &VE, BitstreamWriter &Stream,
1002                             SmallVector<unsigned, 64> &Vals) {
1003  unsigned Code = 0;
1004  unsigned AbbrevToUse = 0;
1005  VE.setInstructionID(&I);
1006  switch (I.getOpcode()) {
1007  default:
1008    if (Instruction::isCast(I.getOpcode())) {
1009      Code = bitc::FUNC_CODE_INST_CAST;
1010      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1011        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1012      Vals.push_back(VE.getTypeID(I.getType()));
1013      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1014    } else {
1015      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1016      Code = bitc::FUNC_CODE_INST_BINOP;
1017      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1018        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1019      Vals.push_back(VE.getValueID(I.getOperand(1)));
1020      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1021      uint64_t Flags = GetOptimizationFlags(&I);
1022      if (Flags != 0) {
1023        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1024          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1025        Vals.push_back(Flags);
1026      }
1027    }
1028    break;
1029
1030  case Instruction::GetElementPtr:
1031    Code = bitc::FUNC_CODE_INST_GEP;
1032    if (cast<GEPOperator>(&I)->isInBounds())
1033      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
1034    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1035      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1036    break;
1037  case Instruction::ExtractValue: {
1038    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1039    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1040    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1041    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1042      Vals.push_back(*i);
1043    break;
1044  }
1045  case Instruction::InsertValue: {
1046    Code = bitc::FUNC_CODE_INST_INSERTVAL;
1047    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1048    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1049    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1050    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1051      Vals.push_back(*i);
1052    break;
1053  }
1054  case Instruction::Select:
1055    Code = bitc::FUNC_CODE_INST_VSELECT;
1056    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1057    Vals.push_back(VE.getValueID(I.getOperand(2)));
1058    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1059    break;
1060  case Instruction::ExtractElement:
1061    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1062    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1063    Vals.push_back(VE.getValueID(I.getOperand(1)));
1064    break;
1065  case Instruction::InsertElement:
1066    Code = bitc::FUNC_CODE_INST_INSERTELT;
1067    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1068    Vals.push_back(VE.getValueID(I.getOperand(1)));
1069    Vals.push_back(VE.getValueID(I.getOperand(2)));
1070    break;
1071  case Instruction::ShuffleVector:
1072    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1073    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1074    Vals.push_back(VE.getValueID(I.getOperand(1)));
1075    Vals.push_back(VE.getValueID(I.getOperand(2)));
1076    break;
1077  case Instruction::ICmp:
1078  case Instruction::FCmp:
1079    // compare returning Int1Ty or vector of Int1Ty
1080    Code = bitc::FUNC_CODE_INST_CMP2;
1081    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1082    Vals.push_back(VE.getValueID(I.getOperand(1)));
1083    Vals.push_back(cast<CmpInst>(I).getPredicate());
1084    break;
1085
1086  case Instruction::Ret:
1087    {
1088      Code = bitc::FUNC_CODE_INST_RET;
1089      unsigned NumOperands = I.getNumOperands();
1090      if (NumOperands == 0)
1091        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1092      else if (NumOperands == 1) {
1093        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1094          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1095      } else {
1096        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1097          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1098      }
1099    }
1100    break;
1101  case Instruction::Br:
1102    {
1103      Code = bitc::FUNC_CODE_INST_BR;
1104      BranchInst &II = cast<BranchInst>(I);
1105      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1106      if (II.isConditional()) {
1107        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1108        Vals.push_back(VE.getValueID(II.getCondition()));
1109      }
1110    }
1111    break;
1112  case Instruction::Switch:
1113    Code = bitc::FUNC_CODE_INST_SWITCH;
1114    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1115    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1116      Vals.push_back(VE.getValueID(I.getOperand(i)));
1117    break;
1118  case Instruction::IndirectBr:
1119    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1120    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1121    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1122      Vals.push_back(VE.getValueID(I.getOperand(i)));
1123    break;
1124
1125  case Instruction::Invoke: {
1126    const InvokeInst *II = cast<InvokeInst>(&I);
1127    const Value *Callee(II->getCalledValue());
1128    PointerType *PTy = cast<PointerType>(Callee->getType());
1129    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1130    Code = bitc::FUNC_CODE_INST_INVOKE;
1131
1132    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1133    Vals.push_back(II->getCallingConv());
1134    Vals.push_back(VE.getValueID(II->getNormalDest()));
1135    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1136    PushValueAndType(Callee, InstID, Vals, VE);
1137
1138    // Emit value #'s for the fixed parameters.
1139    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1140      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1141
1142    // Emit type/value pairs for varargs params.
1143    if (FTy->isVarArg()) {
1144      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1145           i != e; ++i)
1146        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1147    }
1148    break;
1149  }
1150  case Instruction::Resume:
1151    Code = bitc::FUNC_CODE_INST_RESUME;
1152    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1153    break;
1154  case Instruction::Unwind:
1155    Code = bitc::FUNC_CODE_INST_UNWIND;
1156    break;
1157  case Instruction::Unreachable:
1158    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1159    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1160    break;
1161
1162  case Instruction::PHI: {
1163    const PHINode &PN = cast<PHINode>(I);
1164    Code = bitc::FUNC_CODE_INST_PHI;
1165    Vals.push_back(VE.getTypeID(PN.getType()));
1166    for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1167      Vals.push_back(VE.getValueID(PN.getIncomingValue(i)));
1168      Vals.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1169    }
1170    break;
1171  }
1172
1173  case Instruction::LandingPad: {
1174    const LandingPadInst &LP = cast<LandingPadInst>(I);
1175    Code = bitc::FUNC_CODE_INST_LANDINGPAD;
1176    Vals.push_back(VE.getTypeID(LP.getType()));
1177    PushValueAndType(LP.getPersonalityFn(), InstID, Vals, VE);
1178    Vals.push_back(LP.isCleanup());
1179    Vals.push_back(LP.getNumClauses());
1180    for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1181      if (LP.isCatch(I))
1182        Vals.push_back(LandingPadInst::Catch);
1183      else
1184        Vals.push_back(LandingPadInst::Filter);
1185      PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1186    }
1187    break;
1188  }
1189
1190  case Instruction::Alloca:
1191    Code = bitc::FUNC_CODE_INST_ALLOCA;
1192    Vals.push_back(VE.getTypeID(I.getType()));
1193    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1194    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1195    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1196    break;
1197
1198  case Instruction::Load:
1199    if (cast<LoadInst>(I).isAtomic()) {
1200      Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1201      PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1202    } else {
1203      Code = bitc::FUNC_CODE_INST_LOAD;
1204      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1205        AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1206    }
1207    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1208    Vals.push_back(cast<LoadInst>(I).isVolatile());
1209    if (cast<LoadInst>(I).isAtomic()) {
1210      Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1211      Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1212    }
1213    break;
1214  case Instruction::Store:
1215    if (cast<StoreInst>(I).isAtomic())
1216      Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1217    else
1218      Code = bitc::FUNC_CODE_INST_STORE;
1219    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1220    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1221    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1222    Vals.push_back(cast<StoreInst>(I).isVolatile());
1223    if (cast<StoreInst>(I).isAtomic()) {
1224      Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1225      Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1226    }
1227    break;
1228  case Instruction::AtomicCmpXchg:
1229    Code = bitc::FUNC_CODE_INST_CMPXCHG;
1230    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1231    Vals.push_back(VE.getValueID(I.getOperand(1)));       // cmp.
1232    Vals.push_back(VE.getValueID(I.getOperand(2)));       // newval.
1233    Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1234    Vals.push_back(GetEncodedOrdering(
1235                     cast<AtomicCmpXchgInst>(I).getOrdering()));
1236    Vals.push_back(GetEncodedSynchScope(
1237                     cast<AtomicCmpXchgInst>(I).getSynchScope()));
1238    break;
1239  case Instruction::AtomicRMW:
1240    Code = bitc::FUNC_CODE_INST_ATOMICRMW;
1241    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1242    Vals.push_back(VE.getValueID(I.getOperand(1)));       // val.
1243    Vals.push_back(GetEncodedRMWOperation(
1244                     cast<AtomicRMWInst>(I).getOperation()));
1245    Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
1246    Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
1247    Vals.push_back(GetEncodedSynchScope(
1248                     cast<AtomicRMWInst>(I).getSynchScope()));
1249    break;
1250  case Instruction::Fence:
1251    Code = bitc::FUNC_CODE_INST_FENCE;
1252    Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
1253    Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
1254    break;
1255  case Instruction::Call: {
1256    const CallInst &CI = cast<CallInst>(I);
1257    PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1258    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1259
1260    Code = bitc::FUNC_CODE_INST_CALL;
1261
1262    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1263    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1264    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1265
1266    // Emit value #'s for the fixed parameters.
1267    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1268      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1269
1270    // Emit type/value pairs for varargs params.
1271    if (FTy->isVarArg()) {
1272      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1273           i != e; ++i)
1274        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1275    }
1276    break;
1277  }
1278  case Instruction::VAArg:
1279    Code = bitc::FUNC_CODE_INST_VAARG;
1280    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1281    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1282    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1283    break;
1284  }
1285
1286  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1287  Vals.clear();
1288}
1289
1290// Emit names for globals/functions etc.
1291static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1292                                  const ValueEnumerator &VE,
1293                                  BitstreamWriter &Stream) {
1294  if (VST.empty()) return;
1295  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1296
1297  // FIXME: Set up the abbrev, we know how many values there are!
1298  // FIXME: We know if the type names can use 7-bit ascii.
1299  SmallVector<unsigned, 64> NameVals;
1300
1301  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1302       SI != SE; ++SI) {
1303
1304    const ValueName &Name = *SI;
1305
1306    // Figure out the encoding to use for the name.
1307    bool is7Bit = true;
1308    bool isChar6 = true;
1309    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1310         C != E; ++C) {
1311      if (isChar6)
1312        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1313      if ((unsigned char)*C & 128) {
1314        is7Bit = false;
1315        break;  // don't bother scanning the rest.
1316      }
1317    }
1318
1319    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1320
1321    // VST_ENTRY:   [valueid, namechar x N]
1322    // VST_BBENTRY: [bbid, namechar x N]
1323    unsigned Code;
1324    if (isa<BasicBlock>(SI->getValue())) {
1325      Code = bitc::VST_CODE_BBENTRY;
1326      if (isChar6)
1327        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1328    } else {
1329      Code = bitc::VST_CODE_ENTRY;
1330      if (isChar6)
1331        AbbrevToUse = VST_ENTRY_6_ABBREV;
1332      else if (is7Bit)
1333        AbbrevToUse = VST_ENTRY_7_ABBREV;
1334    }
1335
1336    NameVals.push_back(VE.getValueID(SI->getValue()));
1337    for (const char *P = Name.getKeyData(),
1338         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1339      NameVals.push_back((unsigned char)*P);
1340
1341    // Emit the finished record.
1342    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1343    NameVals.clear();
1344  }
1345  Stream.ExitBlock();
1346}
1347
1348/// WriteFunction - Emit a function body to the module stream.
1349static void WriteFunction(const Function &F, ValueEnumerator &VE,
1350                          BitstreamWriter &Stream) {
1351  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1352  VE.incorporateFunction(F);
1353
1354  SmallVector<unsigned, 64> Vals;
1355
1356  // Emit the number of basic blocks, so the reader can create them ahead of
1357  // time.
1358  Vals.push_back(VE.getBasicBlocks().size());
1359  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1360  Vals.clear();
1361
1362  // If there are function-local constants, emit them now.
1363  unsigned CstStart, CstEnd;
1364  VE.getFunctionConstantRange(CstStart, CstEnd);
1365  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1366
1367  // If there is function-local metadata, emit it now.
1368  WriteFunctionLocalMetadata(F, VE, Stream);
1369
1370  // Keep a running idea of what the instruction ID is.
1371  unsigned InstID = CstEnd;
1372
1373  bool NeedsMetadataAttachment = false;
1374
1375  DebugLoc LastDL;
1376
1377  // Finally, emit all the instructions, in order.
1378  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1379    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1380         I != E; ++I) {
1381      WriteInstruction(*I, InstID, VE, Stream, Vals);
1382
1383      if (!I->getType()->isVoidTy())
1384        ++InstID;
1385
1386      // If the instruction has metadata, write a metadata attachment later.
1387      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1388
1389      // If the instruction has a debug location, emit it.
1390      DebugLoc DL = I->getDebugLoc();
1391      if (DL.isUnknown()) {
1392        // nothing todo.
1393      } else if (DL == LastDL) {
1394        // Just repeat the same debug loc as last time.
1395        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1396      } else {
1397        MDNode *Scope, *IA;
1398        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1399
1400        Vals.push_back(DL.getLine());
1401        Vals.push_back(DL.getCol());
1402        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1403        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1404        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1405        Vals.clear();
1406
1407        LastDL = DL;
1408      }
1409    }
1410
1411  // Emit names for all the instructions etc.
1412  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1413
1414  if (NeedsMetadataAttachment)
1415    WriteMetadataAttachment(F, VE, Stream);
1416  VE.purgeFunction();
1417  Stream.ExitBlock();
1418}
1419
1420// Emit blockinfo, which defines the standard abbreviations etc.
1421static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1422  // We only want to emit block info records for blocks that have multiple
1423  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1424  // blocks can defined their abbrevs inline.
1425  Stream.EnterBlockInfoBlock(2);
1426
1427  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1428    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1429    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1430    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1431    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1432    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1433    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1434                                   Abbv) != VST_ENTRY_8_ABBREV)
1435      llvm_unreachable("Unexpected abbrev ordering!");
1436  }
1437
1438  { // 7-bit fixed width VST_ENTRY strings.
1439    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1440    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1441    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1442    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1443    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1444    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1445                                   Abbv) != VST_ENTRY_7_ABBREV)
1446      llvm_unreachable("Unexpected abbrev ordering!");
1447  }
1448  { // 6-bit char6 VST_ENTRY strings.
1449    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1450    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1451    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1452    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1453    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1454    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1455                                   Abbv) != VST_ENTRY_6_ABBREV)
1456      llvm_unreachable("Unexpected abbrev ordering!");
1457  }
1458  { // 6-bit char6 VST_BBENTRY strings.
1459    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1460    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1461    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1462    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1463    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1464    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1465                                   Abbv) != VST_BBENTRY_6_ABBREV)
1466      llvm_unreachable("Unexpected abbrev ordering!");
1467  }
1468
1469
1470
1471  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1472    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1473    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1474    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1475                              Log2_32_Ceil(VE.getTypes().size()+1)));
1476    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1477                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1478      llvm_unreachable("Unexpected abbrev ordering!");
1479  }
1480
1481  { // INTEGER abbrev for CONSTANTS_BLOCK.
1482    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1483    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1484    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1485    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1486                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1487      llvm_unreachable("Unexpected abbrev ordering!");
1488  }
1489
1490  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1491    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1492    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1493    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1494    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1495                              Log2_32_Ceil(VE.getTypes().size()+1)));
1496    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1497
1498    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1499                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1500      llvm_unreachable("Unexpected abbrev ordering!");
1501  }
1502  { // NULL abbrev for CONSTANTS_BLOCK.
1503    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1504    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1505    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1506                                   Abbv) != CONSTANTS_NULL_Abbrev)
1507      llvm_unreachable("Unexpected abbrev ordering!");
1508  }
1509
1510  // FIXME: This should only use space for first class types!
1511
1512  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1513    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1514    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1515    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1516    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1517    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1518    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1519                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1520      llvm_unreachable("Unexpected abbrev ordering!");
1521  }
1522  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1523    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1524    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1525    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1526    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1527    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1528    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1529                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1530      llvm_unreachable("Unexpected abbrev ordering!");
1531  }
1532  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1533    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1534    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1535    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1536    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1537    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1538    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1539    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1540                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1541      llvm_unreachable("Unexpected abbrev ordering!");
1542  }
1543  { // INST_CAST abbrev for FUNCTION_BLOCK.
1544    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1545    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1546    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1547    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1548                              Log2_32_Ceil(VE.getTypes().size()+1)));
1549    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1550    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1551                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1552      llvm_unreachable("Unexpected abbrev ordering!");
1553  }
1554
1555  { // INST_RET abbrev for FUNCTION_BLOCK.
1556    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1557    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1558    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1559                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1560      llvm_unreachable("Unexpected abbrev ordering!");
1561  }
1562  { // INST_RET abbrev for FUNCTION_BLOCK.
1563    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1564    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1565    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1566    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1567                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1568      llvm_unreachable("Unexpected abbrev ordering!");
1569  }
1570  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1571    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1572    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1573    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1574                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1575      llvm_unreachable("Unexpected abbrev ordering!");
1576  }
1577
1578  Stream.ExitBlock();
1579}
1580
1581// Emit use-lists.
1582static void WriteModuleUseLists(const Module *M, ValueEnumerator &VE,
1583                                BitstreamWriter &Stream) {
1584  Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
1585
1586  // Emit a bogus record for testing purposes.
1587  SmallVector<uint64_t, 64> Record;
1588  Record.push_back(0);
1589  Stream.EmitRecord(bitc::USELIST_CODE_ENTRY, Record);
1590
1591  // TODO: Tons.
1592
1593  Stream.ExitBlock();
1594}
1595
1596/// WriteModule - Emit the specified module to the bitstream.
1597static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1598  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1599
1600  // Emit the version number if it is non-zero.
1601  if (CurVersion) {
1602    SmallVector<unsigned, 1> Vals;
1603    Vals.push_back(CurVersion);
1604    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1605  }
1606
1607  // Analyze the module, enumerating globals, functions, etc.
1608  ValueEnumerator VE(M);
1609
1610  // Emit blockinfo, which defines the standard abbreviations etc.
1611  WriteBlockInfo(VE, Stream);
1612
1613  // Emit information about parameter attributes.
1614  WriteAttributeTable(VE, Stream);
1615
1616  // Emit information describing all of the types in the module.
1617  WriteTypeTable(VE, Stream);
1618
1619  // Emit top-level description of module, including target triple, inline asm,
1620  // descriptors for global variables, and function prototype info.
1621  WriteModuleInfo(M, VE, Stream);
1622
1623  // Emit constants.
1624  WriteModuleConstants(VE, Stream);
1625
1626  // Emit metadata.
1627  WriteModuleMetadata(M, VE, Stream);
1628
1629  // Emit function bodies.
1630  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1631    if (!F->isDeclaration())
1632      WriteFunction(*F, VE, Stream);
1633
1634  // Emit metadata.
1635  WriteModuleMetadataStore(M, Stream);
1636
1637  // Emit names for globals/functions etc.
1638  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1639
1640  // Emit use-lists.
1641  if (EnablePreserveUseListOrdering)
1642    WriteModuleUseLists(M, VE, Stream);
1643
1644  Stream.ExitBlock();
1645}
1646
1647/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1648/// header and trailer to make it compatible with the system archiver.  To do
1649/// this we emit the following header, and then emit a trailer that pads the
1650/// file out to be a multiple of 16 bytes.
1651///
1652/// struct bc_header {
1653///   uint32_t Magic;         // 0x0B17C0DE
1654///   uint32_t Version;       // Version, currently always 0.
1655///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1656///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1657///   uint32_t CPUType;       // CPU specifier.
1658///   ... potentially more later ...
1659/// };
1660enum {
1661  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1662  DarwinBCHeaderSize = 5*4
1663};
1664
1665static void EmitDarwinBCHeader(BitstreamWriter &Stream, const Triple &TT) {
1666  unsigned CPUType = ~0U;
1667
1668  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1669  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1670  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1671  // specific constants here because they are implicitly part of the Darwin ABI.
1672  enum {
1673    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1674    DARWIN_CPU_TYPE_X86        = 7,
1675    DARWIN_CPU_TYPE_ARM        = 12,
1676    DARWIN_CPU_TYPE_POWERPC    = 18
1677  };
1678
1679  Triple::ArchType Arch = TT.getArch();
1680  if (Arch == Triple::x86_64)
1681    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1682  else if (Arch == Triple::x86)
1683    CPUType = DARWIN_CPU_TYPE_X86;
1684  else if (Arch == Triple::ppc)
1685    CPUType = DARWIN_CPU_TYPE_POWERPC;
1686  else if (Arch == Triple::ppc64)
1687    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1688  else if (Arch == Triple::arm || Arch == Triple::thumb)
1689    CPUType = DARWIN_CPU_TYPE_ARM;
1690
1691  // Traditional Bitcode starts after header.
1692  unsigned BCOffset = DarwinBCHeaderSize;
1693
1694  Stream.Emit(0x0B17C0DE, 32);
1695  Stream.Emit(0         , 32);  // Version.
1696  Stream.Emit(BCOffset  , 32);
1697  Stream.Emit(0         , 32);  // Filled in later.
1698  Stream.Emit(CPUType   , 32);
1699}
1700
1701/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1702/// finalize the header.
1703static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1704  // Update the size field in the header.
1705  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1706
1707  // If the file is not a multiple of 16 bytes, insert dummy padding.
1708  while (BufferSize & 15) {
1709    Stream.Emit(0, 8);
1710    ++BufferSize;
1711  }
1712}
1713
1714
1715/// WriteBitcodeToFile - Write the specified module to the specified output
1716/// stream.
1717void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1718  std::vector<unsigned char> Buffer;
1719  BitstreamWriter Stream(Buffer);
1720
1721  Buffer.reserve(256*1024);
1722
1723  WriteBitcodeToStream( M, Stream );
1724
1725  // Write the generated bitstream to "Out".
1726  Out.write((char*)&Buffer.front(), Buffer.size());
1727}
1728
1729/// WriteBitcodeToStream - Write the specified module to the specified output
1730/// stream.
1731void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1732  // If this is darwin or another generic macho target, emit a file header and
1733  // trailer if needed.
1734  Triple TT(M->getTargetTriple());
1735  if (TT.isOSDarwin())
1736    EmitDarwinBCHeader(Stream, TT);
1737
1738  // Emit the file header.
1739  Stream.Emit((unsigned)'B', 8);
1740  Stream.Emit((unsigned)'C', 8);
1741  Stream.Emit(0x0, 4);
1742  Stream.Emit(0xC, 4);
1743  Stream.Emit(0xE, 4);
1744  Stream.Emit(0xD, 4);
1745
1746  // Emit the module.
1747  WriteModule(M, Stream);
1748
1749  if (TT.isOSDarwin())
1750    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1751}
1752