BitcodeWriter.cpp revision 14d622dce651481c15e652e1595a9df01717ddd7 
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, linkage, paramattrs, alignment,
508    //             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    // ALIAS: [alias type, aliasee val#, linkage, visibility]
529    Vals.push_back(VE.getTypeID(AI->getType()));
530    Vals.push_back(VE.getValueID(AI->getAliasee()));
531    Vals.push_back(getEncodedLinkage(AI));
532    Vals.push_back(getEncodedVisibility(AI));
533    unsigned AbbrevToUse = 0;
534    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
535    Vals.clear();
536  }
537}
538
539static uint64_t GetOptimizationFlags(const Value *V) {
540  uint64_t Flags = 0;
541
542  if (const OverflowingBinaryOperator *OBO =
543        dyn_cast<OverflowingBinaryOperator>(V)) {
544    if (OBO->hasNoSignedWrap())
545      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
546    if (OBO->hasNoUnsignedWrap())
547      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
548  } else if (const PossiblyExactOperator *PEO =
549               dyn_cast<PossiblyExactOperator>(V)) {
550    if (PEO->isExact())
551      Flags |= 1 << bitc::PEO_EXACT;
552  }
553
554  return Flags;
555}
556
557static void WriteMDNode(const MDNode *N,
558                        const ValueEnumerator &VE,
559                        BitstreamWriter &Stream,
560                        SmallVector<uint64_t, 64> &Record) {
561  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
562    if (N->getOperand(i)) {
563      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
564      Record.push_back(VE.getValueID(N->getOperand(i)));
565    } else {
566      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
567      Record.push_back(0);
568    }
569  }
570  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
571                                           bitc::METADATA_NODE;
572  Stream.EmitRecord(MDCode, Record, 0);
573  Record.clear();
574}
575
576static void WriteModuleMetadata(const Module *M,
577                                const ValueEnumerator &VE,
578                                BitstreamWriter &Stream) {
579  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
580  bool StartedMetadataBlock = false;
581  unsigned MDSAbbrev = 0;
582  SmallVector<uint64_t, 64> Record;
583  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
584
585    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
586      if (!N->isFunctionLocal() || !N->getFunction()) {
587        if (!StartedMetadataBlock) {
588          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
589          StartedMetadataBlock = true;
590        }
591        WriteMDNode(N, VE, Stream, Record);
592      }
593    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
594      if (!StartedMetadataBlock)  {
595        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
596
597        // Abbrev for METADATA_STRING.
598        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
599        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
600        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
601        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
602        MDSAbbrev = Stream.EmitAbbrev(Abbv);
603        StartedMetadataBlock = true;
604      }
605
606      // Code: [strchar x N]
607      Record.append(MDS->begin(), MDS->end());
608
609      // Emit the finished record.
610      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
611      Record.clear();
612    }
613  }
614
615  // Write named metadata.
616  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
617       E = M->named_metadata_end(); I != E; ++I) {
618    const NamedMDNode *NMD = I;
619    if (!StartedMetadataBlock)  {
620      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
621      StartedMetadataBlock = true;
622    }
623
624    // Write name.
625    StringRef Str = NMD->getName();
626    for (unsigned i = 0, e = Str.size(); i != e; ++i)
627      Record.push_back(Str[i]);
628    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
629    Record.clear();
630
631    // Write named metadata operands.
632    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
633      Record.push_back(VE.getValueID(NMD->getOperand(i)));
634    Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
635    Record.clear();
636  }
637
638  if (StartedMetadataBlock)
639    Stream.ExitBlock();
640}
641
642static void WriteFunctionLocalMetadata(const Function &F,
643                                       const ValueEnumerator &VE,
644                                       BitstreamWriter &Stream) {
645  bool StartedMetadataBlock = false;
646  SmallVector<uint64_t, 64> Record;
647  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
648  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
649    if (const MDNode *N = Vals[i])
650      if (N->isFunctionLocal() && N->getFunction() == &F) {
651        if (!StartedMetadataBlock) {
652          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
653          StartedMetadataBlock = true;
654        }
655        WriteMDNode(N, VE, Stream, Record);
656      }
657
658  if (StartedMetadataBlock)
659    Stream.ExitBlock();
660}
661
662static void WriteMetadataAttachment(const Function &F,
663                                    const ValueEnumerator &VE,
664                                    BitstreamWriter &Stream) {
665  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
666
667  SmallVector<uint64_t, 64> Record;
668
669  // Write metadata attachments
670  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
671  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
672
673  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
674    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
675         I != E; ++I) {
676      MDs.clear();
677      I->getAllMetadataOtherThanDebugLoc(MDs);
678
679      // If no metadata, ignore instruction.
680      if (MDs.empty()) continue;
681
682      Record.push_back(VE.getInstructionID(I));
683
684      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
685        Record.push_back(MDs[i].first);
686        Record.push_back(VE.getValueID(MDs[i].second));
687      }
688      Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
689      Record.clear();
690    }
691
692  Stream.ExitBlock();
693}
694
695static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
696  SmallVector<uint64_t, 64> Record;
697
698  // Write metadata kinds
699  // METADATA_KIND - [n x [id, name]]
700  SmallVector<StringRef, 4> Names;
701  M->getMDKindNames(Names);
702
703  if (Names.empty()) return;
704
705  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
706
707  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
708    Record.push_back(MDKindID);
709    StringRef KName = Names[MDKindID];
710    Record.append(KName.begin(), KName.end());
711
712    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
713    Record.clear();
714  }
715
716  Stream.ExitBlock();
717}
718
719static void WriteConstants(unsigned FirstVal, unsigned LastVal,
720                           const ValueEnumerator &VE,
721                           BitstreamWriter &Stream, bool isGlobal) {
722  if (FirstVal == LastVal) return;
723
724  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
725
726  unsigned AggregateAbbrev = 0;
727  unsigned String8Abbrev = 0;
728  unsigned CString7Abbrev = 0;
729  unsigned CString6Abbrev = 0;
730  // If this is a constant pool for the module, emit module-specific abbrevs.
731  if (isGlobal) {
732    // Abbrev for CST_CODE_AGGREGATE.
733    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
734    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
735    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
736    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
737    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
738
739    // Abbrev for CST_CODE_STRING.
740    Abbv = new BitCodeAbbrev();
741    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
742    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
743    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
744    String8Abbrev = Stream.EmitAbbrev(Abbv);
745    // Abbrev for CST_CODE_CSTRING.
746    Abbv = new BitCodeAbbrev();
747    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
748    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
749    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
750    CString7Abbrev = Stream.EmitAbbrev(Abbv);
751    // Abbrev for CST_CODE_CSTRING.
752    Abbv = new BitCodeAbbrev();
753    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
754    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
755    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
756    CString6Abbrev = Stream.EmitAbbrev(Abbv);
757  }
758
759  SmallVector<uint64_t, 64> Record;
760
761  const ValueEnumerator::ValueList &Vals = VE.getValues();
762  Type *LastTy = 0;
763  for (unsigned i = FirstVal; i != LastVal; ++i) {
764    const Value *V = Vals[i].first;
765    // If we need to switch types, do so now.
766    if (V->getType() != LastTy) {
767      LastTy = V->getType();
768      Record.push_back(VE.getTypeID(LastTy));
769      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
770                        CONSTANTS_SETTYPE_ABBREV);
771      Record.clear();
772    }
773
774    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
775      Record.push_back(unsigned(IA->hasSideEffects()) |
776                       unsigned(IA->isAlignStack()) << 1);
777
778      // Add the asm string.
779      const std::string &AsmStr = IA->getAsmString();
780      Record.push_back(AsmStr.size());
781      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
782        Record.push_back(AsmStr[i]);
783
784      // Add the constraint string.
785      const std::string &ConstraintStr = IA->getConstraintString();
786      Record.push_back(ConstraintStr.size());
787      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
788        Record.push_back(ConstraintStr[i]);
789      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
790      Record.clear();
791      continue;
792    }
793    const Constant *C = cast<Constant>(V);
794    unsigned Code = -1U;
795    unsigned AbbrevToUse = 0;
796    if (C->isNullValue()) {
797      Code = bitc::CST_CODE_NULL;
798    } else if (isa<UndefValue>(C)) {
799      Code = bitc::CST_CODE_UNDEF;
800    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
801      if (IV->getBitWidth() <= 64) {
802        uint64_t V = IV->getSExtValue();
803        if ((int64_t)V >= 0)
804          Record.push_back(V << 1);
805        else
806          Record.push_back((-V << 1) | 1);
807        Code = bitc::CST_CODE_INTEGER;
808        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
809      } else {                             // Wide integers, > 64 bits in size.
810        // We have an arbitrary precision integer value to write whose
811        // bit width is > 64. However, in canonical unsigned integer
812        // format it is likely that the high bits are going to be zero.
813        // So, we only write the number of active words.
814        unsigned NWords = IV->getValue().getActiveWords();
815        const uint64_t *RawWords = IV->getValue().getRawData();
816        for (unsigned i = 0; i != NWords; ++i) {
817          int64_t V = RawWords[i];
818          if (V >= 0)
819            Record.push_back(V << 1);
820          else
821            Record.push_back((-V << 1) | 1);
822        }
823        Code = bitc::CST_CODE_WIDE_INTEGER;
824      }
825    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
826      Code = bitc::CST_CODE_FLOAT;
827      Type *Ty = CFP->getType();
828      if (Ty->isFloatTy() || Ty->isDoubleTy()) {
829        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
830      } else if (Ty->isX86_FP80Ty()) {
831        // api needed to prevent premature destruction
832        // bits are not in the same order as a normal i80 APInt, compensate.
833        APInt api = CFP->getValueAPF().bitcastToAPInt();
834        const uint64_t *p = api.getRawData();
835        Record.push_back((p[1] << 48) | (p[0] >> 16));
836        Record.push_back(p[0] & 0xffffLL);
837      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
838        APInt api = CFP->getValueAPF().bitcastToAPInt();
839        const uint64_t *p = api.getRawData();
840        Record.push_back(p[0]);
841        Record.push_back(p[1]);
842      } else {
843        assert (0 && "Unknown FP type!");
844      }
845    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
846      const ConstantArray *CA = cast<ConstantArray>(C);
847      // Emit constant strings specially.
848      unsigned NumOps = CA->getNumOperands();
849      // If this is a null-terminated string, use the denser CSTRING encoding.
850      if (CA->getOperand(NumOps-1)->isNullValue()) {
851        Code = bitc::CST_CODE_CSTRING;
852        --NumOps;  // Don't encode the null, which isn't allowed by char6.
853      } else {
854        Code = bitc::CST_CODE_STRING;
855        AbbrevToUse = String8Abbrev;
856      }
857      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
858      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
859      for (unsigned i = 0; i != NumOps; ++i) {
860        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
861        Record.push_back(V);
862        isCStr7 &= (V & 128) == 0;
863        if (isCStrChar6)
864          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
865      }
866
867      if (isCStrChar6)
868        AbbrevToUse = CString6Abbrev;
869      else if (isCStr7)
870        AbbrevToUse = CString7Abbrev;
871    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
872               isa<ConstantVector>(V)) {
873      Code = bitc::CST_CODE_AGGREGATE;
874      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
875        Record.push_back(VE.getValueID(C->getOperand(i)));
876      AbbrevToUse = AggregateAbbrev;
877    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
878      switch (CE->getOpcode()) {
879      default:
880        if (Instruction::isCast(CE->getOpcode())) {
881          Code = bitc::CST_CODE_CE_CAST;
882          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
883          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
884          Record.push_back(VE.getValueID(C->getOperand(0)));
885          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
886        } else {
887          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
888          Code = bitc::CST_CODE_CE_BINOP;
889          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
890          Record.push_back(VE.getValueID(C->getOperand(0)));
891          Record.push_back(VE.getValueID(C->getOperand(1)));
892          uint64_t Flags = GetOptimizationFlags(CE);
893          if (Flags != 0)
894            Record.push_back(Flags);
895        }
896        break;
897      case Instruction::GetElementPtr:
898        Code = bitc::CST_CODE_CE_GEP;
899        if (cast<GEPOperator>(C)->isInBounds())
900          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
901        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
902          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
903          Record.push_back(VE.getValueID(C->getOperand(i)));
904        }
905        break;
906      case Instruction::Select:
907        Code = bitc::CST_CODE_CE_SELECT;
908        Record.push_back(VE.getValueID(C->getOperand(0)));
909        Record.push_back(VE.getValueID(C->getOperand(1)));
910        Record.push_back(VE.getValueID(C->getOperand(2)));
911        break;
912      case Instruction::ExtractElement:
913        Code = bitc::CST_CODE_CE_EXTRACTELT;
914        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
915        Record.push_back(VE.getValueID(C->getOperand(0)));
916        Record.push_back(VE.getValueID(C->getOperand(1)));
917        break;
918      case Instruction::InsertElement:
919        Code = bitc::CST_CODE_CE_INSERTELT;
920        Record.push_back(VE.getValueID(C->getOperand(0)));
921        Record.push_back(VE.getValueID(C->getOperand(1)));
922        Record.push_back(VE.getValueID(C->getOperand(2)));
923        break;
924      case Instruction::ShuffleVector:
925        // If the return type and argument types are the same, this is a
926        // standard shufflevector instruction.  If the types are different,
927        // then the shuffle is widening or truncating the input vectors, and
928        // the argument type must also be encoded.
929        if (C->getType() == C->getOperand(0)->getType()) {
930          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
931        } else {
932          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
933          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
934        }
935        Record.push_back(VE.getValueID(C->getOperand(0)));
936        Record.push_back(VE.getValueID(C->getOperand(1)));
937        Record.push_back(VE.getValueID(C->getOperand(2)));
938        break;
939      case Instruction::ICmp:
940      case Instruction::FCmp:
941        Code = bitc::CST_CODE_CE_CMP;
942        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
943        Record.push_back(VE.getValueID(C->getOperand(0)));
944        Record.push_back(VE.getValueID(C->getOperand(1)));
945        Record.push_back(CE->getPredicate());
946        break;
947      }
948    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
949      Code = bitc::CST_CODE_BLOCKADDRESS;
950      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
951      Record.push_back(VE.getValueID(BA->getFunction()));
952      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
953    } else {
954#ifndef NDEBUG
955      C->dump();
956#endif
957      llvm_unreachable("Unknown constant!");
958    }
959    Stream.EmitRecord(Code, Record, AbbrevToUse);
960    Record.clear();
961  }
962
963  Stream.ExitBlock();
964}
965
966static void WriteModuleConstants(const ValueEnumerator &VE,
967                                 BitstreamWriter &Stream) {
968  const ValueEnumerator::ValueList &Vals = VE.getValues();
969
970  // Find the first constant to emit, which is the first non-globalvalue value.
971  // We know globalvalues have been emitted by WriteModuleInfo.
972  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
973    if (!isa<GlobalValue>(Vals[i].first)) {
974      WriteConstants(i, Vals.size(), VE, Stream, true);
975      return;
976    }
977  }
978}
979
980/// PushValueAndType - The file has to encode both the value and type id for
981/// many values, because we need to know what type to create for forward
982/// references.  However, most operands are not forward references, so this type
983/// field is not needed.
984///
985/// This function adds V's value ID to Vals.  If the value ID is higher than the
986/// instruction ID, then it is a forward reference, and it also includes the
987/// type ID.
988static bool PushValueAndType(const Value *V, unsigned InstID,
989                             SmallVector<unsigned, 64> &Vals,
990                             ValueEnumerator &VE) {
991  unsigned ValID = VE.getValueID(V);
992  Vals.push_back(ValID);
993  if (ValID >= InstID) {
994    Vals.push_back(VE.getTypeID(V->getType()));
995    return true;
996  }
997  return false;
998}
999
1000/// WriteInstruction - Emit an instruction to the specified stream.
1001static void WriteInstruction(const Instruction &I, unsigned InstID,
1002                             ValueEnumerator &VE, BitstreamWriter &Stream,
1003                             SmallVector<unsigned, 64> &Vals) {
1004  unsigned Code = 0;
1005  unsigned AbbrevToUse = 0;
1006  VE.setInstructionID(&I);
1007  switch (I.getOpcode()) {
1008  default:
1009    if (Instruction::isCast(I.getOpcode())) {
1010      Code = bitc::FUNC_CODE_INST_CAST;
1011      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1012        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1013      Vals.push_back(VE.getTypeID(I.getType()));
1014      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1015    } else {
1016      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1017      Code = bitc::FUNC_CODE_INST_BINOP;
1018      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1019        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1020      Vals.push_back(VE.getValueID(I.getOperand(1)));
1021      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1022      uint64_t Flags = GetOptimizationFlags(&I);
1023      if (Flags != 0) {
1024        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1025          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1026        Vals.push_back(Flags);
1027      }
1028    }
1029    break;
1030
1031  case Instruction::GetElementPtr:
1032    Code = bitc::FUNC_CODE_INST_GEP;
1033    if (cast<GEPOperator>(&I)->isInBounds())
1034      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
1035    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1036      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1037    break;
1038  case Instruction::ExtractValue: {
1039    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1040    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1041    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1042    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1043      Vals.push_back(*i);
1044    break;
1045  }
1046  case Instruction::InsertValue: {
1047    Code = bitc::FUNC_CODE_INST_INSERTVAL;
1048    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1049    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1050    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1051    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1052      Vals.push_back(*i);
1053    break;
1054  }
1055  case Instruction::Select:
1056    Code = bitc::FUNC_CODE_INST_VSELECT;
1057    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1058    Vals.push_back(VE.getValueID(I.getOperand(2)));
1059    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1060    break;
1061  case Instruction::ExtractElement:
1062    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1063    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1064    Vals.push_back(VE.getValueID(I.getOperand(1)));
1065    break;
1066  case Instruction::InsertElement:
1067    Code = bitc::FUNC_CODE_INST_INSERTELT;
1068    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1069    Vals.push_back(VE.getValueID(I.getOperand(1)));
1070    Vals.push_back(VE.getValueID(I.getOperand(2)));
1071    break;
1072  case Instruction::ShuffleVector:
1073    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1074    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1075    Vals.push_back(VE.getValueID(I.getOperand(1)));
1076    Vals.push_back(VE.getValueID(I.getOperand(2)));
1077    break;
1078  case Instruction::ICmp:
1079  case Instruction::FCmp:
1080    // compare returning Int1Ty or vector of Int1Ty
1081    Code = bitc::FUNC_CODE_INST_CMP2;
1082    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1083    Vals.push_back(VE.getValueID(I.getOperand(1)));
1084    Vals.push_back(cast<CmpInst>(I).getPredicate());
1085    break;
1086
1087  case Instruction::Ret:
1088    {
1089      Code = bitc::FUNC_CODE_INST_RET;
1090      unsigned NumOperands = I.getNumOperands();
1091      if (NumOperands == 0)
1092        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1093      else if (NumOperands == 1) {
1094        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1095          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1096      } else {
1097        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1098          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1099      }
1100    }
1101    break;
1102  case Instruction::Br:
1103    {
1104      Code = bitc::FUNC_CODE_INST_BR;
1105      BranchInst &II = cast<BranchInst>(I);
1106      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1107      if (II.isConditional()) {
1108        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1109        Vals.push_back(VE.getValueID(II.getCondition()));
1110      }
1111    }
1112    break;
1113  case Instruction::Switch:
1114    Code = bitc::FUNC_CODE_INST_SWITCH;
1115    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1116    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1117      Vals.push_back(VE.getValueID(I.getOperand(i)));
1118    break;
1119  case Instruction::IndirectBr:
1120    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1121    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1122    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1123      Vals.push_back(VE.getValueID(I.getOperand(i)));
1124    break;
1125
1126  case Instruction::Invoke: {
1127    const InvokeInst *II = cast<InvokeInst>(&I);
1128    const Value *Callee(II->getCalledValue());
1129    PointerType *PTy = cast<PointerType>(Callee->getType());
1130    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1131    Code = bitc::FUNC_CODE_INST_INVOKE;
1132
1133    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1134    Vals.push_back(II->getCallingConv());
1135    Vals.push_back(VE.getValueID(II->getNormalDest()));
1136    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1137    PushValueAndType(Callee, InstID, Vals, VE);
1138
1139    // Emit value #'s for the fixed parameters.
1140    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1141      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1142
1143    // Emit type/value pairs for varargs params.
1144    if (FTy->isVarArg()) {
1145      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1146           i != e; ++i)
1147        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1148    }
1149    break;
1150  }
1151  case Instruction::Resume:
1152    Code = bitc::FUNC_CODE_INST_RESUME;
1153    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1154    break;
1155  case Instruction::Unwind:
1156    Code = bitc::FUNC_CODE_INST_UNWIND;
1157    break;
1158  case Instruction::Unreachable:
1159    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1160    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1161    break;
1162
1163  case Instruction::PHI: {
1164    const PHINode &PN = cast<PHINode>(I);
1165    Code = bitc::FUNC_CODE_INST_PHI;
1166    Vals.push_back(VE.getTypeID(PN.getType()));
1167    for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1168      Vals.push_back(VE.getValueID(PN.getIncomingValue(i)));
1169      Vals.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1170    }
1171    break;
1172  }
1173
1174  case Instruction::LandingPad: {
1175    const LandingPadInst &LP = cast<LandingPadInst>(I);
1176    Code = bitc::FUNC_CODE_INST_LANDINGPAD;
1177    Vals.push_back(VE.getTypeID(LP.getType()));
1178    PushValueAndType(LP.getPersonalityFn(), InstID, Vals, VE);
1179    Vals.push_back(LP.isCleanup());
1180    Vals.push_back(LP.getNumClauses());
1181    for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1182      if (LP.isCatch(I))
1183        Vals.push_back(LandingPadInst::Catch);
1184      else
1185        Vals.push_back(LandingPadInst::Filter);
1186      PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1187    }
1188    break;
1189  }
1190
1191  case Instruction::Alloca:
1192    Code = bitc::FUNC_CODE_INST_ALLOCA;
1193    Vals.push_back(VE.getTypeID(I.getType()));
1194    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1195    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1196    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1197    break;
1198
1199  case Instruction::Load:
1200    if (cast<LoadInst>(I).isAtomic()) {
1201      Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1202      PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1203    } else {
1204      Code = bitc::FUNC_CODE_INST_LOAD;
1205      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1206        AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1207    }
1208    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1209    Vals.push_back(cast<LoadInst>(I).isVolatile());
1210    if (cast<LoadInst>(I).isAtomic()) {
1211      Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1212      Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1213    }
1214    break;
1215  case Instruction::Store:
1216    if (cast<StoreInst>(I).isAtomic())
1217      Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1218    else
1219      Code = bitc::FUNC_CODE_INST_STORE;
1220    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1221    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1222    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1223    Vals.push_back(cast<StoreInst>(I).isVolatile());
1224    if (cast<StoreInst>(I).isAtomic()) {
1225      Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1226      Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1227    }
1228    break;
1229  case Instruction::AtomicCmpXchg:
1230    Code = bitc::FUNC_CODE_INST_CMPXCHG;
1231    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1232    Vals.push_back(VE.getValueID(I.getOperand(1)));       // cmp.
1233    Vals.push_back(VE.getValueID(I.getOperand(2)));       // newval.
1234    Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1235    Vals.push_back(GetEncodedOrdering(
1236                     cast<AtomicCmpXchgInst>(I).getOrdering()));
1237    Vals.push_back(GetEncodedSynchScope(
1238                     cast<AtomicCmpXchgInst>(I).getSynchScope()));
1239    break;
1240  case Instruction::AtomicRMW:
1241    Code = bitc::FUNC_CODE_INST_ATOMICRMW;
1242    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1243    Vals.push_back(VE.getValueID(I.getOperand(1)));       // val.
1244    Vals.push_back(GetEncodedRMWOperation(
1245                     cast<AtomicRMWInst>(I).getOperation()));
1246    Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
1247    Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
1248    Vals.push_back(GetEncodedSynchScope(
1249                     cast<AtomicRMWInst>(I).getSynchScope()));
1250    break;
1251  case Instruction::Fence:
1252    Code = bitc::FUNC_CODE_INST_FENCE;
1253    Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
1254    Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
1255    break;
1256  case Instruction::Call: {
1257    const CallInst &CI = cast<CallInst>(I);
1258    PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1259    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1260
1261    Code = bitc::FUNC_CODE_INST_CALL;
1262
1263    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1264    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1265    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1266
1267    // Emit value #'s for the fixed parameters.
1268    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1269      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1270
1271    // Emit type/value pairs for varargs params.
1272    if (FTy->isVarArg()) {
1273      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1274           i != e; ++i)
1275        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1276    }
1277    break;
1278  }
1279  case Instruction::VAArg:
1280    Code = bitc::FUNC_CODE_INST_VAARG;
1281    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1282    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1283    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1284    break;
1285  }
1286
1287  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1288  Vals.clear();
1289}
1290
1291// Emit names for globals/functions etc.
1292static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1293                                  const ValueEnumerator &VE,
1294                                  BitstreamWriter &Stream) {
1295  if (VST.empty()) return;
1296  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1297
1298  // FIXME: Set up the abbrev, we know how many values there are!
1299  // FIXME: We know if the type names can use 7-bit ascii.
1300  SmallVector<unsigned, 64> NameVals;
1301
1302  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1303       SI != SE; ++SI) {
1304
1305    const ValueName &Name = *SI;
1306
1307    // Figure out the encoding to use for the name.
1308    bool is7Bit = true;
1309    bool isChar6 = true;
1310    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1311         C != E; ++C) {
1312      if (isChar6)
1313        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1314      if ((unsigned char)*C & 128) {
1315        is7Bit = false;
1316        break;  // don't bother scanning the rest.
1317      }
1318    }
1319
1320    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1321
1322    // VST_ENTRY:   [valueid, namechar x N]
1323    // VST_BBENTRY: [bbid, namechar x N]
1324    unsigned Code;
1325    if (isa<BasicBlock>(SI->getValue())) {
1326      Code = bitc::VST_CODE_BBENTRY;
1327      if (isChar6)
1328        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1329    } else {
1330      Code = bitc::VST_CODE_ENTRY;
1331      if (isChar6)
1332        AbbrevToUse = VST_ENTRY_6_ABBREV;
1333      else if (is7Bit)
1334        AbbrevToUse = VST_ENTRY_7_ABBREV;
1335    }
1336
1337    NameVals.push_back(VE.getValueID(SI->getValue()));
1338    for (const char *P = Name.getKeyData(),
1339         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1340      NameVals.push_back((unsigned char)*P);
1341
1342    // Emit the finished record.
1343    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1344    NameVals.clear();
1345  }
1346  Stream.ExitBlock();
1347}
1348
1349/// WriteFunction - Emit a function body to the module stream.
1350static void WriteFunction(const Function &F, ValueEnumerator &VE,
1351                          BitstreamWriter &Stream) {
1352  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1353  VE.incorporateFunction(F);
1354
1355  SmallVector<unsigned, 64> Vals;
1356
1357  // Emit the number of basic blocks, so the reader can create them ahead of
1358  // time.
1359  Vals.push_back(VE.getBasicBlocks().size());
1360  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1361  Vals.clear();
1362
1363  // If there are function-local constants, emit them now.
1364  unsigned CstStart, CstEnd;
1365  VE.getFunctionConstantRange(CstStart, CstEnd);
1366  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1367
1368  // If there is function-local metadata, emit it now.
1369  WriteFunctionLocalMetadata(F, VE, Stream);
1370
1371  // Keep a running idea of what the instruction ID is.
1372  unsigned InstID = CstEnd;
1373
1374  bool NeedsMetadataAttachment = false;
1375
1376  DebugLoc LastDL;
1377
1378  // Finally, emit all the instructions, in order.
1379  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1380    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1381         I != E; ++I) {
1382      WriteInstruction(*I, InstID, VE, Stream, Vals);
1383
1384      if (!I->getType()->isVoidTy())
1385        ++InstID;
1386
1387      // If the instruction has metadata, write a metadata attachment later.
1388      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1389
1390      // If the instruction has a debug location, emit it.
1391      DebugLoc DL = I->getDebugLoc();
1392      if (DL.isUnknown()) {
1393        // nothing todo.
1394      } else if (DL == LastDL) {
1395        // Just repeat the same debug loc as last time.
1396        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1397      } else {
1398        MDNode *Scope, *IA;
1399        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1400
1401        Vals.push_back(DL.getLine());
1402        Vals.push_back(DL.getCol());
1403        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1404        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1405        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1406        Vals.clear();
1407
1408        LastDL = DL;
1409      }
1410    }
1411
1412  // Emit names for all the instructions etc.
1413  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1414
1415  if (NeedsMetadataAttachment)
1416    WriteMetadataAttachment(F, VE, Stream);
1417  VE.purgeFunction();
1418  Stream.ExitBlock();
1419}
1420
1421// Emit blockinfo, which defines the standard abbreviations etc.
1422static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1423  // We only want to emit block info records for blocks that have multiple
1424  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1425  // blocks can defined their abbrevs inline.
1426  Stream.EnterBlockInfoBlock(2);
1427
1428  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1429    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1430    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1431    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1432    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1433    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1434    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1435                                   Abbv) != VST_ENTRY_8_ABBREV)
1436      llvm_unreachable("Unexpected abbrev ordering!");
1437  }
1438
1439  { // 7-bit fixed width VST_ENTRY strings.
1440    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1441    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1442    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1443    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1444    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1445    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1446                                   Abbv) != VST_ENTRY_7_ABBREV)
1447      llvm_unreachable("Unexpected abbrev ordering!");
1448  }
1449  { // 6-bit char6 VST_ENTRY strings.
1450    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1451    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1452    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1453    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1454    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1455    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1456                                   Abbv) != VST_ENTRY_6_ABBREV)
1457      llvm_unreachable("Unexpected abbrev ordering!");
1458  }
1459  { // 6-bit char6 VST_BBENTRY strings.
1460    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1461    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1462    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1463    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1464    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1465    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1466                                   Abbv) != VST_BBENTRY_6_ABBREV)
1467      llvm_unreachable("Unexpected abbrev ordering!");
1468  }
1469
1470
1471
1472  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1473    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1474    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1475    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1476                              Log2_32_Ceil(VE.getTypes().size()+1)));
1477    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1478                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1479      llvm_unreachable("Unexpected abbrev ordering!");
1480  }
1481
1482  { // INTEGER abbrev for CONSTANTS_BLOCK.
1483    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1484    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1485    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1486    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1487                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1488      llvm_unreachable("Unexpected abbrev ordering!");
1489  }
1490
1491  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1492    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1493    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1494    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1495    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1496                              Log2_32_Ceil(VE.getTypes().size()+1)));
1497    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1498
1499    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1500                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1501      llvm_unreachable("Unexpected abbrev ordering!");
1502  }
1503  { // NULL abbrev for CONSTANTS_BLOCK.
1504    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1505    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1506    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1507                                   Abbv) != CONSTANTS_NULL_Abbrev)
1508      llvm_unreachable("Unexpected abbrev ordering!");
1509  }
1510
1511  // FIXME: This should only use space for first class types!
1512
1513  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1514    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1515    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1516    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1517    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1518    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1519    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1520                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1521      llvm_unreachable("Unexpected abbrev ordering!");
1522  }
1523  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1524    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1525    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1526    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1527    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1528    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1529    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1530                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1531      llvm_unreachable("Unexpected abbrev ordering!");
1532  }
1533  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1534    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1535    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1536    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1537    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1538    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1539    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1540    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1541                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1542      llvm_unreachable("Unexpected abbrev ordering!");
1543  }
1544  { // INST_CAST abbrev for FUNCTION_BLOCK.
1545    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1546    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1547    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1548    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1549                              Log2_32_Ceil(VE.getTypes().size()+1)));
1550    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1551    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1552                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1553      llvm_unreachable("Unexpected abbrev ordering!");
1554  }
1555
1556  { // INST_RET abbrev for FUNCTION_BLOCK.
1557    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1558    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1559    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1560                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1561      llvm_unreachable("Unexpected abbrev ordering!");
1562  }
1563  { // INST_RET abbrev for FUNCTION_BLOCK.
1564    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1565    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1566    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1567    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1568                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1569      llvm_unreachable("Unexpected abbrev ordering!");
1570  }
1571  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1572    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1573    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1574    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1575                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1576      llvm_unreachable("Unexpected abbrev ordering!");
1577  }
1578
1579  Stream.ExitBlock();
1580}
1581
1582// Sort the Users based on the order in which the reader parses the bitcode
1583// file.
1584static bool bitcodereader_order(const User *lhs, const User *rhs) {
1585  // TODO: Implement.
1586  return true;
1587}
1588
1589static void WriteUseList(const Value *V, const ValueEnumerator &VE,
1590                         BitstreamWriter &Stream) {
1591
1592  // One or zero uses can't get out of order.
1593  if (V->use_empty() || V->hasNUses(1))
1594    return;
1595
1596  // Make a copy of the in-memory use-list for sorting.
1597  unsigned UseListSize = std::distance(V->use_begin(), V->use_end());
1598  SmallVector<const User*, 8> UseList;
1599  UseList.reserve(UseListSize);
1600  for (Value::const_use_iterator I = V->use_begin(), E = V->use_end();
1601       I != E; ++I) {
1602    const User *U = *I;
1603    UseList.push_back(U);
1604  }
1605
1606  // Sort the copy based on the order read by the BitcodeReader.
1607  std::sort(UseList.begin(), UseList.end(), bitcodereader_order);
1608
1609  // TODO: Generate a diff between the BitcodeWriter in-memory use-list and the
1610  // sorted list (i.e., the expected BitcodeReader in-memory use-list).
1611
1612  // TODO: Emit the USELIST_CODE_ENTRYs.
1613}
1614
1615static void WriteFunctionUseList(const Function *F, ValueEnumerator &VE,
1616                                 BitstreamWriter &Stream) {
1617  VE.incorporateFunction(*F);
1618
1619  for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
1620       AI != AE; ++AI)
1621    WriteUseList(AI, VE, Stream);
1622  for (Function::const_iterator BB = F->begin(), FE = F->end(); BB != FE;
1623       ++BB) {
1624    WriteUseList(BB, VE, Stream);
1625    for (BasicBlock::const_iterator II = BB->begin(), IE = BB->end(); II != IE;
1626         ++II) {
1627      WriteUseList(II, VE, Stream);
1628      for (User::const_op_iterator OI = II->op_begin(), E = II->op_end();
1629           OI != E; ++OI) {
1630        if ((isa<Constant>(*OI) && !isa<GlobalValue>(*OI)) ||
1631            isa<InlineAsm>(*OI))
1632          WriteUseList(*OI, VE, Stream);
1633      }
1634    }
1635  }
1636  VE.purgeFunction();
1637}
1638
1639// Emit use-lists.
1640static void WriteModuleUseLists(const Module *M, ValueEnumerator &VE,
1641                                BitstreamWriter &Stream) {
1642  Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
1643
1644  // XXX: this modifies the module, but in a way that should never change the
1645  // behavior of any pass or codegen in LLVM. The problem is that GVs may
1646  // contain entries in the use_list that do not exist in the Module and are
1647  // not stored in the .bc file.
1648  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
1649       I != E; ++I)
1650    I->removeDeadConstantUsers();
1651
1652  // Write the global variables.
1653  for (Module::const_global_iterator GI = M->global_begin(),
1654         GE = M->global_end(); GI != GE; ++GI) {
1655    WriteUseList(GI, VE, Stream);
1656
1657    // Write the global variable initializers.
1658    if (GI->hasInitializer())
1659      WriteUseList(GI->getInitializer(), VE, Stream);
1660  }
1661
1662  // Write the functions.
1663  for (Module::const_iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI) {
1664    WriteUseList(FI, VE, Stream);
1665    if (!FI->isDeclaration())
1666      WriteFunctionUseList(FI, VE, Stream);
1667  }
1668
1669  // Write the aliases.
1670  for (Module::const_alias_iterator AI = M->alias_begin(), AE = M->alias_end();
1671       AI != AE; ++AI) {
1672    WriteUseList(AI, VE, Stream);
1673    WriteUseList(AI->getAliasee(), VE, Stream);
1674  }
1675
1676  Stream.ExitBlock();
1677}
1678
1679/// WriteModule - Emit the specified module to the bitstream.
1680static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1681  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1682
1683  // Emit the version number if it is non-zero.
1684  if (CurVersion) {
1685    SmallVector<unsigned, 1> Vals;
1686    Vals.push_back(CurVersion);
1687    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1688  }
1689
1690  // Analyze the module, enumerating globals, functions, etc.
1691  ValueEnumerator VE(M);
1692
1693  // Emit blockinfo, which defines the standard abbreviations etc.
1694  WriteBlockInfo(VE, Stream);
1695
1696  // Emit information about parameter attributes.
1697  WriteAttributeTable(VE, Stream);
1698
1699  // Emit information describing all of the types in the module.
1700  WriteTypeTable(VE, Stream);
1701
1702  // Emit top-level description of module, including target triple, inline asm,
1703  // descriptors for global variables, and function prototype info.
1704  WriteModuleInfo(M, VE, Stream);
1705
1706  // Emit constants.
1707  WriteModuleConstants(VE, Stream);
1708
1709  // Emit metadata.
1710  WriteModuleMetadata(M, VE, Stream);
1711
1712  // Emit function bodies.
1713  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1714    if (!F->isDeclaration())
1715      WriteFunction(*F, VE, Stream);
1716
1717  // Emit metadata.
1718  WriteModuleMetadataStore(M, Stream);
1719
1720  // Emit names for globals/functions etc.
1721  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1722
1723  // Emit use-lists.
1724  if (EnablePreserveUseListOrdering)
1725    WriteModuleUseLists(M, VE, Stream);
1726
1727  Stream.ExitBlock();
1728}
1729
1730/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1731/// header and trailer to make it compatible with the system archiver.  To do
1732/// this we emit the following header, and then emit a trailer that pads the
1733/// file out to be a multiple of 16 bytes.
1734///
1735/// struct bc_header {
1736///   uint32_t Magic;         // 0x0B17C0DE
1737///   uint32_t Version;       // Version, currently always 0.
1738///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1739///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1740///   uint32_t CPUType;       // CPU specifier.
1741///   ... potentially more later ...
1742/// };
1743enum {
1744  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1745  DarwinBCHeaderSize = 5*4
1746};
1747
1748static void EmitDarwinBCHeader(BitstreamWriter &Stream, const Triple &TT) {
1749  unsigned CPUType = ~0U;
1750
1751  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1752  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1753  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1754  // specific constants here because they are implicitly part of the Darwin ABI.
1755  enum {
1756    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1757    DARWIN_CPU_TYPE_X86        = 7,
1758    DARWIN_CPU_TYPE_ARM        = 12,
1759    DARWIN_CPU_TYPE_POWERPC    = 18
1760  };
1761
1762  Triple::ArchType Arch = TT.getArch();
1763  if (Arch == Triple::x86_64)
1764    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1765  else if (Arch == Triple::x86)
1766    CPUType = DARWIN_CPU_TYPE_X86;
1767  else if (Arch == Triple::ppc)
1768    CPUType = DARWIN_CPU_TYPE_POWERPC;
1769  else if (Arch == Triple::ppc64)
1770    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1771  else if (Arch == Triple::arm || Arch == Triple::thumb)
1772    CPUType = DARWIN_CPU_TYPE_ARM;
1773
1774  // Traditional Bitcode starts after header.
1775  unsigned BCOffset = DarwinBCHeaderSize;
1776
1777  Stream.Emit(0x0B17C0DE, 32);
1778  Stream.Emit(0         , 32);  // Version.
1779  Stream.Emit(BCOffset  , 32);
1780  Stream.Emit(0         , 32);  // Filled in later.
1781  Stream.Emit(CPUType   , 32);
1782}
1783
1784/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1785/// finalize the header.
1786static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1787  // Update the size field in the header.
1788  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1789
1790  // If the file is not a multiple of 16 bytes, insert dummy padding.
1791  while (BufferSize & 15) {
1792    Stream.Emit(0, 8);
1793    ++BufferSize;
1794  }
1795}
1796
1797
1798/// WriteBitcodeToFile - Write the specified module to the specified output
1799/// stream.
1800void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1801  std::vector<unsigned char> Buffer;
1802  BitstreamWriter Stream(Buffer);
1803
1804  Buffer.reserve(256*1024);
1805
1806  WriteBitcodeToStream( M, Stream );
1807
1808  // Write the generated bitstream to "Out".
1809  Out.write((char*)&Buffer.front(), Buffer.size());
1810}
1811
1812/// WriteBitcodeToStream - Write the specified module to the specified output
1813/// stream.
1814void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1815  // If this is darwin or another generic macho target, emit a file header and
1816  // trailer if needed.
1817  Triple TT(M->getTargetTriple());
1818  if (TT.isOSDarwin())
1819    EmitDarwinBCHeader(Stream, TT);
1820
1821  // Emit the file header.
1822  Stream.Emit((unsigned)'B', 8);
1823  Stream.Emit((unsigned)'C', 8);
1824  Stream.Emit(0x0, 4);
1825  Stream.Emit(0xC, 4);
1826  Stream.Emit(0xE, 4);
1827  Stream.Emit(0xD, 4);
1828
1829  // Emit the module.
1830  WriteModule(M, Stream);
1831
1832  if (TT.isOSDarwin())
1833    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1834}
1835