BitcodeWriter.cpp revision 18c7f80b3e83ab584bd8572695a3cde8bafd9d3c 
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  case NotAtomic: return bitc::ORDERING_NOTATOMIC;
130  case Unordered: return bitc::ORDERING_UNORDERED;
131  case Monotonic: return bitc::ORDERING_MONOTONIC;
132  case Acquire: return bitc::ORDERING_ACQUIRE;
133  case Release: return bitc::ORDERING_RELEASE;
134  case AcquireRelease: return bitc::ORDERING_ACQREL;
135  case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
136  }
137  llvm_unreachable("Invalid ordering");
138}
139
140static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
141  switch (SynchScope) {
142  case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
143  case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
144  }
145  llvm_unreachable("Invalid synch scope");
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.Raw() & 0xffff;
183      if (PAWI.Attrs & Attribute::Alignment)
184        FauxAttr |= (1ull<<16)<<
185            (((PAWI.Attrs & Attribute::Alignment).Raw()-1) >> 16);
186      FauxAttr |= (PAWI.Attrs.Raw() & (0x3FFull << 21)) << 11;
187
188      Record.push_back(FauxAttr);
189    }
190
191    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
192    Record.clear();
193  }
194
195  Stream.ExitBlock();
196}
197
198/// WriteTypeTable - Write out the type table for a module.
199static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
200  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
201
202  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
203  SmallVector<uint64_t, 64> TypeVals;
204
205  uint64_t NumBits = Log2_32_Ceil(VE.getTypes().size()+1);
206
207  // Abbrev for TYPE_CODE_POINTER.
208  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
209  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
210  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
211  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
212  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
213
214  // Abbrev for TYPE_CODE_FUNCTION.
215  Abbv = new BitCodeAbbrev();
216  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
217  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
218  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
219  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
220
221  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
222
223  // Abbrev for TYPE_CODE_STRUCT_ANON.
224  Abbv = new BitCodeAbbrev();
225  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
226  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
227  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
228  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
229
230  unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
231
232  // Abbrev for TYPE_CODE_STRUCT_NAME.
233  Abbv = new BitCodeAbbrev();
234  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
235  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
236  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
237  unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
238
239  // Abbrev for TYPE_CODE_STRUCT_NAMED.
240  Abbv = new BitCodeAbbrev();
241  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
242  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
243  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
244  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
245
246  unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
247
248  // Abbrev for TYPE_CODE_ARRAY.
249  Abbv = new BitCodeAbbrev();
250  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
251  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
252  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
253
254  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
255
256  // Emit an entry count so the reader can reserve space.
257  TypeVals.push_back(TypeList.size());
258  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
259  TypeVals.clear();
260
261  // Loop over all of the types, emitting each in turn.
262  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
263    Type *T = TypeList[i];
264    int AbbrevToUse = 0;
265    unsigned Code = 0;
266
267    switch (T->getTypeID()) {
268    default: llvm_unreachable("Unknown type!");
269    case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;   break;
270    case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;   break;
271    case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;  break;
272    case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE; break;
273    case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80; break;
274    case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128; break;
275    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
276    case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;  break;
277    case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA; break;
278    case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX; break;
279    case Type::IntegerTyID:
280      // INTEGER: [width]
281      Code = bitc::TYPE_CODE_INTEGER;
282      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
283      break;
284    case Type::PointerTyID: {
285      PointerType *PTy = cast<PointerType>(T);
286      // POINTER: [pointee type, address space]
287      Code = bitc::TYPE_CODE_POINTER;
288      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
289      unsigned AddressSpace = PTy->getAddressSpace();
290      TypeVals.push_back(AddressSpace);
291      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
292      break;
293    }
294    case Type::FunctionTyID: {
295      FunctionType *FT = cast<FunctionType>(T);
296      // FUNCTION: [isvararg, retty, paramty x N]
297      Code = bitc::TYPE_CODE_FUNCTION;
298      TypeVals.push_back(FT->isVarArg());
299      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
300      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
301        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
302      AbbrevToUse = FunctionAbbrev;
303      break;
304    }
305    case Type::StructTyID: {
306      StructType *ST = cast<StructType>(T);
307      // STRUCT: [ispacked, eltty x N]
308      TypeVals.push_back(ST->isPacked());
309      // Output all of the element types.
310      for (StructType::element_iterator I = ST->element_begin(),
311           E = ST->element_end(); I != E; ++I)
312        TypeVals.push_back(VE.getTypeID(*I));
313
314      if (ST->isLiteral()) {
315        Code = bitc::TYPE_CODE_STRUCT_ANON;
316        AbbrevToUse = StructAnonAbbrev;
317      } else {
318        if (ST->isOpaque()) {
319          Code = bitc::TYPE_CODE_OPAQUE;
320        } else {
321          Code = bitc::TYPE_CODE_STRUCT_NAMED;
322          AbbrevToUse = StructNamedAbbrev;
323        }
324
325        // Emit the name if it is present.
326        if (!ST->getName().empty())
327          WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
328                            StructNameAbbrev, Stream);
329      }
330      break;
331    }
332    case Type::ArrayTyID: {
333      ArrayType *AT = cast<ArrayType>(T);
334      // ARRAY: [numelts, eltty]
335      Code = bitc::TYPE_CODE_ARRAY;
336      TypeVals.push_back(AT->getNumElements());
337      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
338      AbbrevToUse = ArrayAbbrev;
339      break;
340    }
341    case Type::VectorTyID: {
342      VectorType *VT = cast<VectorType>(T);
343      // VECTOR [numelts, eltty]
344      Code = bitc::TYPE_CODE_VECTOR;
345      TypeVals.push_back(VT->getNumElements());
346      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
347      break;
348    }
349    }
350
351    // Emit the finished record.
352    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
353    TypeVals.clear();
354  }
355
356  Stream.ExitBlock();
357}
358
359static unsigned getEncodedLinkage(const GlobalValue *GV) {
360  switch (GV->getLinkage()) {
361  case GlobalValue::ExternalLinkage:                 return 0;
362  case GlobalValue::WeakAnyLinkage:                  return 1;
363  case GlobalValue::AppendingLinkage:                return 2;
364  case GlobalValue::InternalLinkage:                 return 3;
365  case GlobalValue::LinkOnceAnyLinkage:              return 4;
366  case GlobalValue::DLLImportLinkage:                return 5;
367  case GlobalValue::DLLExportLinkage:                return 6;
368  case GlobalValue::ExternalWeakLinkage:             return 7;
369  case GlobalValue::CommonLinkage:                   return 8;
370  case GlobalValue::PrivateLinkage:                  return 9;
371  case GlobalValue::WeakODRLinkage:                  return 10;
372  case GlobalValue::LinkOnceODRLinkage:              return 11;
373  case GlobalValue::AvailableExternallyLinkage:      return 12;
374  case GlobalValue::LinkerPrivateLinkage:            return 13;
375  case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
376  case GlobalValue::LinkerPrivateWeakDefAutoLinkage: return 15;
377  }
378  llvm_unreachable("Invalid linkage");
379}
380
381static unsigned getEncodedVisibility(const GlobalValue *GV) {
382  switch (GV->getVisibility()) {
383  case GlobalValue::DefaultVisibility:   return 0;
384  case GlobalValue::HiddenVisibility:    return 1;
385  case GlobalValue::ProtectedVisibility: return 2;
386  }
387  llvm_unreachable("Invalid visibility");
388}
389
390// Emit top-level description of module, including target triple, inline asm,
391// descriptors for global variables, and function prototype info.
392static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
393                            BitstreamWriter &Stream) {
394  // Emit the list of dependent libraries for the Module.
395  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
396    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
397
398  // Emit various pieces of data attached to a module.
399  if (!M->getTargetTriple().empty())
400    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
401                      0/*TODO*/, Stream);
402  if (!M->getDataLayout().empty())
403    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
404                      0/*TODO*/, Stream);
405  if (!M->getModuleInlineAsm().empty())
406    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
407                      0/*TODO*/, Stream);
408
409  // Emit information about sections and GC, computing how many there are. Also
410  // compute the maximum alignment value.
411  std::map<std::string, unsigned> SectionMap;
412  std::map<std::string, unsigned> GCMap;
413  unsigned MaxAlignment = 0;
414  unsigned MaxGlobalType = 0;
415  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
416       GV != E; ++GV) {
417    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
418    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
419    if (GV->hasSection()) {
420      // Give section names unique ID's.
421      unsigned &Entry = SectionMap[GV->getSection()];
422      if (!Entry) {
423        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
424                          0/*TODO*/, Stream);
425        Entry = SectionMap.size();
426      }
427    }
428  }
429  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
430    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
431    if (F->hasSection()) {
432      // Give section names unique ID's.
433      unsigned &Entry = SectionMap[F->getSection()];
434      if (!Entry) {
435        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
436                          0/*TODO*/, Stream);
437        Entry = SectionMap.size();
438      }
439    }
440    if (F->hasGC()) {
441      // Same for GC names.
442      unsigned &Entry = GCMap[F->getGC()];
443      if (!Entry) {
444        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
445                          0/*TODO*/, Stream);
446        Entry = GCMap.size();
447      }
448    }
449  }
450
451  // Emit abbrev for globals, now that we know # sections and max alignment.
452  unsigned SimpleGVarAbbrev = 0;
453  if (!M->global_empty()) {
454    // Add an abbrev for common globals with no visibility or thread localness.
455    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
456    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
457    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
458                              Log2_32_Ceil(MaxGlobalType+1)));
459    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
460    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
461    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
462    if (MaxAlignment == 0)                                      // Alignment.
463      Abbv->Add(BitCodeAbbrevOp(0));
464    else {
465      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
466      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
467                               Log2_32_Ceil(MaxEncAlignment+1)));
468    }
469    if (SectionMap.empty())                                    // Section.
470      Abbv->Add(BitCodeAbbrevOp(0));
471    else
472      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
473                               Log2_32_Ceil(SectionMap.size()+1)));
474    // Don't bother emitting vis + thread local.
475    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
476  }
477
478  // Emit the global variable information.
479  SmallVector<unsigned, 64> Vals;
480  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
481       GV != E; ++GV) {
482    unsigned AbbrevToUse = 0;
483
484    // GLOBALVAR: [type, isconst, initid,
485    //             linkage, alignment, section, visibility, threadlocal,
486    //             unnamed_addr]
487    Vals.push_back(VE.getTypeID(GV->getType()));
488    Vals.push_back(GV->isConstant());
489    Vals.push_back(GV->isDeclaration() ? 0 :
490                   (VE.getValueID(GV->getInitializer()) + 1));
491    Vals.push_back(getEncodedLinkage(GV));
492    Vals.push_back(Log2_32(GV->getAlignment())+1);
493    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
494    if (GV->isThreadLocal() ||
495        GV->getVisibility() != GlobalValue::DefaultVisibility ||
496        GV->hasUnnamedAddr()) {
497      Vals.push_back(getEncodedVisibility(GV));
498      Vals.push_back(GV->isThreadLocal());
499      Vals.push_back(GV->hasUnnamedAddr());
500    } else {
501      AbbrevToUse = SimpleGVarAbbrev;
502    }
503
504    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
505    Vals.clear();
506  }
507
508  // Emit the function proto information.
509  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
510    // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
511    //             section, visibility, gc, unnamed_addr]
512    Vals.push_back(VE.getTypeID(F->getType()));
513    Vals.push_back(F->getCallingConv());
514    Vals.push_back(F->isDeclaration());
515    Vals.push_back(getEncodedLinkage(F));
516    Vals.push_back(VE.getAttributeID(F->getAttributes()));
517    Vals.push_back(Log2_32(F->getAlignment())+1);
518    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
519    Vals.push_back(getEncodedVisibility(F));
520    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
521    Vals.push_back(F->hasUnnamedAddr());
522
523    unsigned AbbrevToUse = 0;
524    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
525    Vals.clear();
526  }
527
528  // Emit the alias information.
529  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
530       AI != E; ++AI) {
531    // ALIAS: [alias type, aliasee val#, linkage, visibility]
532    Vals.push_back(VE.getTypeID(AI->getType()));
533    Vals.push_back(VE.getValueID(AI->getAliasee()));
534    Vals.push_back(getEncodedLinkage(AI));
535    Vals.push_back(getEncodedVisibility(AI));
536    unsigned AbbrevToUse = 0;
537    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
538    Vals.clear();
539  }
540}
541
542static uint64_t GetOptimizationFlags(const Value *V) {
543  uint64_t Flags = 0;
544
545  if (const OverflowingBinaryOperator *OBO =
546        dyn_cast<OverflowingBinaryOperator>(V)) {
547    if (OBO->hasNoSignedWrap())
548      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
549    if (OBO->hasNoUnsignedWrap())
550      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
551  } else if (const PossiblyExactOperator *PEO =
552               dyn_cast<PossiblyExactOperator>(V)) {
553    if (PEO->isExact())
554      Flags |= 1 << bitc::PEO_EXACT;
555  }
556
557  return Flags;
558}
559
560static void WriteMDNode(const MDNode *N,
561                        const ValueEnumerator &VE,
562                        BitstreamWriter &Stream,
563                        SmallVector<uint64_t, 64> &Record) {
564  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
565    if (N->getOperand(i)) {
566      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
567      Record.push_back(VE.getValueID(N->getOperand(i)));
568    } else {
569      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
570      Record.push_back(0);
571    }
572  }
573  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
574                                           bitc::METADATA_NODE;
575  Stream.EmitRecord(MDCode, Record, 0);
576  Record.clear();
577}
578
579static void WriteModuleMetadata(const Module *M,
580                                const ValueEnumerator &VE,
581                                BitstreamWriter &Stream) {
582  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
583  bool StartedMetadataBlock = false;
584  unsigned MDSAbbrev = 0;
585  SmallVector<uint64_t, 64> Record;
586  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
587
588    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
589      if (!N->isFunctionLocal() || !N->getFunction()) {
590        if (!StartedMetadataBlock) {
591          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
592          StartedMetadataBlock = true;
593        }
594        WriteMDNode(N, VE, Stream, Record);
595      }
596    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
597      if (!StartedMetadataBlock)  {
598        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
599
600        // Abbrev for METADATA_STRING.
601        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
602        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
603        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
604        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
605        MDSAbbrev = Stream.EmitAbbrev(Abbv);
606        StartedMetadataBlock = true;
607      }
608
609      // Code: [strchar x N]
610      Record.append(MDS->begin(), MDS->end());
611
612      // Emit the finished record.
613      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
614      Record.clear();
615    }
616  }
617
618  // Write named metadata.
619  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
620       E = M->named_metadata_end(); I != E; ++I) {
621    const NamedMDNode *NMD = I;
622    if (!StartedMetadataBlock)  {
623      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
624      StartedMetadataBlock = true;
625    }
626
627    // Write name.
628    StringRef Str = NMD->getName();
629    for (unsigned i = 0, e = Str.size(); i != e; ++i)
630      Record.push_back(Str[i]);
631    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
632    Record.clear();
633
634    // Write named metadata operands.
635    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
636      Record.push_back(VE.getValueID(NMD->getOperand(i)));
637    Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
638    Record.clear();
639  }
640
641  if (StartedMetadataBlock)
642    Stream.ExitBlock();
643}
644
645static void WriteFunctionLocalMetadata(const Function &F,
646                                       const ValueEnumerator &VE,
647                                       BitstreamWriter &Stream) {
648  bool StartedMetadataBlock = false;
649  SmallVector<uint64_t, 64> Record;
650  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
651  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
652    if (const MDNode *N = Vals[i])
653      if (N->isFunctionLocal() && N->getFunction() == &F) {
654        if (!StartedMetadataBlock) {
655          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
656          StartedMetadataBlock = true;
657        }
658        WriteMDNode(N, VE, Stream, Record);
659      }
660
661  if (StartedMetadataBlock)
662    Stream.ExitBlock();
663}
664
665static void WriteMetadataAttachment(const Function &F,
666                                    const ValueEnumerator &VE,
667                                    BitstreamWriter &Stream) {
668  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
669
670  SmallVector<uint64_t, 64> Record;
671
672  // Write metadata attachments
673  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
674  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
675
676  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
677    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
678         I != E; ++I) {
679      MDs.clear();
680      I->getAllMetadataOtherThanDebugLoc(MDs);
681
682      // If no metadata, ignore instruction.
683      if (MDs.empty()) continue;
684
685      Record.push_back(VE.getInstructionID(I));
686
687      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
688        Record.push_back(MDs[i].first);
689        Record.push_back(VE.getValueID(MDs[i].second));
690      }
691      Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
692      Record.clear();
693    }
694
695  Stream.ExitBlock();
696}
697
698static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
699  SmallVector<uint64_t, 64> Record;
700
701  // Write metadata kinds
702  // METADATA_KIND - [n x [id, name]]
703  SmallVector<StringRef, 4> Names;
704  M->getMDKindNames(Names);
705
706  if (Names.empty()) return;
707
708  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
709
710  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
711    Record.push_back(MDKindID);
712    StringRef KName = Names[MDKindID];
713    Record.append(KName.begin(), KName.end());
714
715    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
716    Record.clear();
717  }
718
719  Stream.ExitBlock();
720}
721
722static void WriteConstants(unsigned FirstVal, unsigned LastVal,
723                           const ValueEnumerator &VE,
724                           BitstreamWriter &Stream, bool isGlobal) {
725  if (FirstVal == LastVal) return;
726
727  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
728
729  unsigned AggregateAbbrev = 0;
730  unsigned String8Abbrev = 0;
731  unsigned CString7Abbrev = 0;
732  unsigned CString6Abbrev = 0;
733  // If this is a constant pool for the module, emit module-specific abbrevs.
734  if (isGlobal) {
735    // Abbrev for CST_CODE_AGGREGATE.
736    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
737    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
738    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
739    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
740    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
741
742    // Abbrev for CST_CODE_STRING.
743    Abbv = new BitCodeAbbrev();
744    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
745    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
746    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
747    String8Abbrev = Stream.EmitAbbrev(Abbv);
748    // Abbrev for CST_CODE_CSTRING.
749    Abbv = new BitCodeAbbrev();
750    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
751    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
752    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
753    CString7Abbrev = Stream.EmitAbbrev(Abbv);
754    // Abbrev for CST_CODE_CSTRING.
755    Abbv = new BitCodeAbbrev();
756    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
757    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
758    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
759    CString6Abbrev = Stream.EmitAbbrev(Abbv);
760  }
761
762  SmallVector<uint64_t, 64> Record;
763
764  const ValueEnumerator::ValueList &Vals = VE.getValues();
765  Type *LastTy = 0;
766  for (unsigned i = FirstVal; i != LastVal; ++i) {
767    const Value *V = Vals[i].first;
768    // If we need to switch types, do so now.
769    if (V->getType() != LastTy) {
770      LastTy = V->getType();
771      Record.push_back(VE.getTypeID(LastTy));
772      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
773                        CONSTANTS_SETTYPE_ABBREV);
774      Record.clear();
775    }
776
777    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
778      Record.push_back(unsigned(IA->hasSideEffects()) |
779                       unsigned(IA->isAlignStack()) << 1);
780
781      // Add the asm string.
782      const std::string &AsmStr = IA->getAsmString();
783      Record.push_back(AsmStr.size());
784      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
785        Record.push_back(AsmStr[i]);
786
787      // Add the constraint string.
788      const std::string &ConstraintStr = IA->getConstraintString();
789      Record.push_back(ConstraintStr.size());
790      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
791        Record.push_back(ConstraintStr[i]);
792      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
793      Record.clear();
794      continue;
795    }
796    const Constant *C = cast<Constant>(V);
797    unsigned Code = -1U;
798    unsigned AbbrevToUse = 0;
799    if (C->isNullValue()) {
800      Code = bitc::CST_CODE_NULL;
801    } else if (isa<UndefValue>(C)) {
802      Code = bitc::CST_CODE_UNDEF;
803    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
804      if (IV->getBitWidth() <= 64) {
805        uint64_t V = IV->getSExtValue();
806        if ((int64_t)V >= 0)
807          Record.push_back(V << 1);
808        else
809          Record.push_back((-V << 1) | 1);
810        Code = bitc::CST_CODE_INTEGER;
811        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
812      } else {                             // Wide integers, > 64 bits in size.
813        // We have an arbitrary precision integer value to write whose
814        // bit width is > 64. However, in canonical unsigned integer
815        // format it is likely that the high bits are going to be zero.
816        // So, we only write the number of active words.
817        unsigned NWords = IV->getValue().getActiveWords();
818        const uint64_t *RawWords = IV->getValue().getRawData();
819        for (unsigned i = 0; i != NWords; ++i) {
820          int64_t V = RawWords[i];
821          if (V >= 0)
822            Record.push_back(V << 1);
823          else
824            Record.push_back((-V << 1) | 1);
825        }
826        Code = bitc::CST_CODE_WIDE_INTEGER;
827      }
828    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
829      Code = bitc::CST_CODE_FLOAT;
830      Type *Ty = CFP->getType();
831      if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
832        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
833      } else if (Ty->isX86_FP80Ty()) {
834        // api needed to prevent premature destruction
835        // bits are not in the same order as a normal i80 APInt, compensate.
836        APInt api = CFP->getValueAPF().bitcastToAPInt();
837        const uint64_t *p = api.getRawData();
838        Record.push_back((p[1] << 48) | (p[0] >> 16));
839        Record.push_back(p[0] & 0xffffLL);
840      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
841        APInt api = CFP->getValueAPF().bitcastToAPInt();
842        const uint64_t *p = api.getRawData();
843        Record.push_back(p[0]);
844        Record.push_back(p[1]);
845      } else {
846        assert (0 && "Unknown FP type!");
847      }
848    } else if (isa<ConstantDataSequential>(C) &&
849               cast<ConstantDataSequential>(C)->isString()) {
850      const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
851      // Emit constant strings specially.
852      unsigned NumElts = Str->getNumElements();
853      // If this is a null-terminated string, use the denser CSTRING encoding.
854      if (Str->isCString()) {
855        Code = bitc::CST_CODE_CSTRING;
856        --NumElts;  // Don't encode the null, which isn't allowed by char6.
857      } else {
858        Code = bitc::CST_CODE_STRING;
859        AbbrevToUse = String8Abbrev;
860      }
861      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
862      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
863      for (unsigned i = 0; i != NumElts; ++i) {
864        unsigned char V = Str->getElementAsInteger(i);
865        Record.push_back(V);
866        isCStr7 &= (V & 128) == 0;
867        if (isCStrChar6)
868          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
869      }
870
871      if (isCStrChar6)
872        AbbrevToUse = CString6Abbrev;
873      else if (isCStr7)
874        AbbrevToUse = CString7Abbrev;
875    } else if (const ConstantDataSequential *CDS =
876                  dyn_cast<ConstantDataSequential>(C)) {
877      Code = bitc::CST_CODE_DATA;
878      Type *EltTy = CDS->getType()->getElementType();
879      if (isa<IntegerType>(EltTy)) {
880        for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
881          Record.push_back(CDS->getElementAsInteger(i));
882      } else if (EltTy->isFloatTy()) {
883        for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
884          union { float F; uint32_t I; };
885          F = CDS->getElementAsFloat(i);
886          Record.push_back(I);
887        }
888      } else {
889        assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
890        for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
891          union { double F; uint64_t I; };
892          F = CDS->getElementAsDouble(i);
893          Record.push_back(I);
894        }
895      }
896    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
897               isa<ConstantVector>(C)) {
898      Code = bitc::CST_CODE_AGGREGATE;
899      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
900        Record.push_back(VE.getValueID(C->getOperand(i)));
901      AbbrevToUse = AggregateAbbrev;
902    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
903      switch (CE->getOpcode()) {
904      default:
905        if (Instruction::isCast(CE->getOpcode())) {
906          Code = bitc::CST_CODE_CE_CAST;
907          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
908          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
909          Record.push_back(VE.getValueID(C->getOperand(0)));
910          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
911        } else {
912          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
913          Code = bitc::CST_CODE_CE_BINOP;
914          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
915          Record.push_back(VE.getValueID(C->getOperand(0)));
916          Record.push_back(VE.getValueID(C->getOperand(1)));
917          uint64_t Flags = GetOptimizationFlags(CE);
918          if (Flags != 0)
919            Record.push_back(Flags);
920        }
921        break;
922      case Instruction::GetElementPtr:
923        Code = bitc::CST_CODE_CE_GEP;
924        if (cast<GEPOperator>(C)->isInBounds())
925          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
926        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
927          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
928          Record.push_back(VE.getValueID(C->getOperand(i)));
929        }
930        break;
931      case Instruction::Select:
932        Code = bitc::CST_CODE_CE_SELECT;
933        Record.push_back(VE.getValueID(C->getOperand(0)));
934        Record.push_back(VE.getValueID(C->getOperand(1)));
935        Record.push_back(VE.getValueID(C->getOperand(2)));
936        break;
937      case Instruction::ExtractElement:
938        Code = bitc::CST_CODE_CE_EXTRACTELT;
939        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
940        Record.push_back(VE.getValueID(C->getOperand(0)));
941        Record.push_back(VE.getValueID(C->getOperand(1)));
942        break;
943      case Instruction::InsertElement:
944        Code = bitc::CST_CODE_CE_INSERTELT;
945        Record.push_back(VE.getValueID(C->getOperand(0)));
946        Record.push_back(VE.getValueID(C->getOperand(1)));
947        Record.push_back(VE.getValueID(C->getOperand(2)));
948        break;
949      case Instruction::ShuffleVector:
950        // If the return type and argument types are the same, this is a
951        // standard shufflevector instruction.  If the types are different,
952        // then the shuffle is widening or truncating the input vectors, and
953        // the argument type must also be encoded.
954        if (C->getType() == C->getOperand(0)->getType()) {
955          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
956        } else {
957          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
958          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
959        }
960        Record.push_back(VE.getValueID(C->getOperand(0)));
961        Record.push_back(VE.getValueID(C->getOperand(1)));
962        Record.push_back(VE.getValueID(C->getOperand(2)));
963        break;
964      case Instruction::ICmp:
965      case Instruction::FCmp:
966        Code = bitc::CST_CODE_CE_CMP;
967        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
968        Record.push_back(VE.getValueID(C->getOperand(0)));
969        Record.push_back(VE.getValueID(C->getOperand(1)));
970        Record.push_back(CE->getPredicate());
971        break;
972      }
973    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
974      Code = bitc::CST_CODE_BLOCKADDRESS;
975      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
976      Record.push_back(VE.getValueID(BA->getFunction()));
977      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
978    } else {
979#ifndef NDEBUG
980      C->dump();
981#endif
982      llvm_unreachable("Unknown constant!");
983    }
984    Stream.EmitRecord(Code, Record, AbbrevToUse);
985    Record.clear();
986  }
987
988  Stream.ExitBlock();
989}
990
991static void WriteModuleConstants(const ValueEnumerator &VE,
992                                 BitstreamWriter &Stream) {
993  const ValueEnumerator::ValueList &Vals = VE.getValues();
994
995  // Find the first constant to emit, which is the first non-globalvalue value.
996  // We know globalvalues have been emitted by WriteModuleInfo.
997  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
998    if (!isa<GlobalValue>(Vals[i].first)) {
999      WriteConstants(i, Vals.size(), VE, Stream, true);
1000      return;
1001    }
1002  }
1003}
1004
1005/// PushValueAndType - The file has to encode both the value and type id for
1006/// many values, because we need to know what type to create for forward
1007/// references.  However, most operands are not forward references, so this type
1008/// field is not needed.
1009///
1010/// This function adds V's value ID to Vals.  If the value ID is higher than the
1011/// instruction ID, then it is a forward reference, and it also includes the
1012/// type ID.
1013static bool PushValueAndType(const Value *V, unsigned InstID,
1014                             SmallVector<unsigned, 64> &Vals,
1015                             ValueEnumerator &VE) {
1016  unsigned ValID = VE.getValueID(V);
1017  Vals.push_back(ValID);
1018  if (ValID >= InstID) {
1019    Vals.push_back(VE.getTypeID(V->getType()));
1020    return true;
1021  }
1022  return false;
1023}
1024
1025/// WriteInstruction - Emit an instruction to the specified stream.
1026static void WriteInstruction(const Instruction &I, unsigned InstID,
1027                             ValueEnumerator &VE, BitstreamWriter &Stream,
1028                             SmallVector<unsigned, 64> &Vals) {
1029  unsigned Code = 0;
1030  unsigned AbbrevToUse = 0;
1031  VE.setInstructionID(&I);
1032  switch (I.getOpcode()) {
1033  default:
1034    if (Instruction::isCast(I.getOpcode())) {
1035      Code = bitc::FUNC_CODE_INST_CAST;
1036      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1037        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1038      Vals.push_back(VE.getTypeID(I.getType()));
1039      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1040    } else {
1041      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1042      Code = bitc::FUNC_CODE_INST_BINOP;
1043      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1044        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1045      Vals.push_back(VE.getValueID(I.getOperand(1)));
1046      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1047      uint64_t Flags = GetOptimizationFlags(&I);
1048      if (Flags != 0) {
1049        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1050          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1051        Vals.push_back(Flags);
1052      }
1053    }
1054    break;
1055
1056  case Instruction::GetElementPtr:
1057    Code = bitc::FUNC_CODE_INST_GEP;
1058    if (cast<GEPOperator>(&I)->isInBounds())
1059      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
1060    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1061      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1062    break;
1063  case Instruction::ExtractValue: {
1064    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1065    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1066    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1067    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1068      Vals.push_back(*i);
1069    break;
1070  }
1071  case Instruction::InsertValue: {
1072    Code = bitc::FUNC_CODE_INST_INSERTVAL;
1073    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1074    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1075    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1076    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1077      Vals.push_back(*i);
1078    break;
1079  }
1080  case Instruction::Select:
1081    Code = bitc::FUNC_CODE_INST_VSELECT;
1082    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1083    Vals.push_back(VE.getValueID(I.getOperand(2)));
1084    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1085    break;
1086  case Instruction::ExtractElement:
1087    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1088    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1089    Vals.push_back(VE.getValueID(I.getOperand(1)));
1090    break;
1091  case Instruction::InsertElement:
1092    Code = bitc::FUNC_CODE_INST_INSERTELT;
1093    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1094    Vals.push_back(VE.getValueID(I.getOperand(1)));
1095    Vals.push_back(VE.getValueID(I.getOperand(2)));
1096    break;
1097  case Instruction::ShuffleVector:
1098    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1099    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1100    Vals.push_back(VE.getValueID(I.getOperand(1)));
1101    Vals.push_back(VE.getValueID(I.getOperand(2)));
1102    break;
1103  case Instruction::ICmp:
1104  case Instruction::FCmp:
1105    // compare returning Int1Ty or vector of Int1Ty
1106    Code = bitc::FUNC_CODE_INST_CMP2;
1107    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1108    Vals.push_back(VE.getValueID(I.getOperand(1)));
1109    Vals.push_back(cast<CmpInst>(I).getPredicate());
1110    break;
1111
1112  case Instruction::Ret:
1113    {
1114      Code = bitc::FUNC_CODE_INST_RET;
1115      unsigned NumOperands = I.getNumOperands();
1116      if (NumOperands == 0)
1117        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1118      else if (NumOperands == 1) {
1119        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1120          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1121      } else {
1122        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1123          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1124      }
1125    }
1126    break;
1127  case Instruction::Br:
1128    {
1129      Code = bitc::FUNC_CODE_INST_BR;
1130      BranchInst &II = cast<BranchInst>(I);
1131      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1132      if (II.isConditional()) {
1133        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1134        Vals.push_back(VE.getValueID(II.getCondition()));
1135      }
1136    }
1137    break;
1138  case Instruction::Switch:
1139    {
1140      Code = bitc::FUNC_CODE_INST_SWITCH;
1141      SwitchInst &SI = cast<SwitchInst>(I);
1142      Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
1143      Vals.push_back(VE.getValueID(SI.getCondition()));
1144      Vals.push_back(VE.getValueID(SI.getDefaultDest()));
1145      for (unsigned i = 0, e = SI.getNumCases(); i != e; ++i) {
1146        Vals.push_back(VE.getValueID(SI.getCaseValue(i)));
1147        Vals.push_back(VE.getValueID(SI.getCaseSuccessor(i)));
1148      }
1149    }
1150    break;
1151  case Instruction::IndirectBr:
1152    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1153    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1154    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1155      Vals.push_back(VE.getValueID(I.getOperand(i)));
1156    break;
1157
1158  case Instruction::Invoke: {
1159    const InvokeInst *II = cast<InvokeInst>(&I);
1160    const Value *Callee(II->getCalledValue());
1161    PointerType *PTy = cast<PointerType>(Callee->getType());
1162    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1163    Code = bitc::FUNC_CODE_INST_INVOKE;
1164
1165    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1166    Vals.push_back(II->getCallingConv());
1167    Vals.push_back(VE.getValueID(II->getNormalDest()));
1168    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1169    PushValueAndType(Callee, InstID, Vals, VE);
1170
1171    // Emit value #'s for the fixed parameters.
1172    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1173      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1174
1175    // Emit type/value pairs for varargs params.
1176    if (FTy->isVarArg()) {
1177      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1178           i != e; ++i)
1179        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1180    }
1181    break;
1182  }
1183  case Instruction::Resume:
1184    Code = bitc::FUNC_CODE_INST_RESUME;
1185    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1186    break;
1187  case Instruction::Unwind:
1188    Code = bitc::FUNC_CODE_INST_UNWIND;
1189    break;
1190  case Instruction::Unreachable:
1191    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1192    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1193    break;
1194
1195  case Instruction::PHI: {
1196    const PHINode &PN = cast<PHINode>(I);
1197    Code = bitc::FUNC_CODE_INST_PHI;
1198    Vals.push_back(VE.getTypeID(PN.getType()));
1199    for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1200      Vals.push_back(VE.getValueID(PN.getIncomingValue(i)));
1201      Vals.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1202    }
1203    break;
1204  }
1205
1206  case Instruction::LandingPad: {
1207    const LandingPadInst &LP = cast<LandingPadInst>(I);
1208    Code = bitc::FUNC_CODE_INST_LANDINGPAD;
1209    Vals.push_back(VE.getTypeID(LP.getType()));
1210    PushValueAndType(LP.getPersonalityFn(), InstID, Vals, VE);
1211    Vals.push_back(LP.isCleanup());
1212    Vals.push_back(LP.getNumClauses());
1213    for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1214      if (LP.isCatch(I))
1215        Vals.push_back(LandingPadInst::Catch);
1216      else
1217        Vals.push_back(LandingPadInst::Filter);
1218      PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1219    }
1220    break;
1221  }
1222
1223  case Instruction::Alloca:
1224    Code = bitc::FUNC_CODE_INST_ALLOCA;
1225    Vals.push_back(VE.getTypeID(I.getType()));
1226    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1227    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1228    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1229    break;
1230
1231  case Instruction::Load:
1232    if (cast<LoadInst>(I).isAtomic()) {
1233      Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1234      PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1235    } else {
1236      Code = bitc::FUNC_CODE_INST_LOAD;
1237      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1238        AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1239    }
1240    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1241    Vals.push_back(cast<LoadInst>(I).isVolatile());
1242    if (cast<LoadInst>(I).isAtomic()) {
1243      Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1244      Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1245    }
1246    break;
1247  case Instruction::Store:
1248    if (cast<StoreInst>(I).isAtomic())
1249      Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1250    else
1251      Code = bitc::FUNC_CODE_INST_STORE;
1252    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1253    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1254    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1255    Vals.push_back(cast<StoreInst>(I).isVolatile());
1256    if (cast<StoreInst>(I).isAtomic()) {
1257      Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1258      Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1259    }
1260    break;
1261  case Instruction::AtomicCmpXchg:
1262    Code = bitc::FUNC_CODE_INST_CMPXCHG;
1263    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1264    Vals.push_back(VE.getValueID(I.getOperand(1)));       // cmp.
1265    Vals.push_back(VE.getValueID(I.getOperand(2)));       // newval.
1266    Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1267    Vals.push_back(GetEncodedOrdering(
1268                     cast<AtomicCmpXchgInst>(I).getOrdering()));
1269    Vals.push_back(GetEncodedSynchScope(
1270                     cast<AtomicCmpXchgInst>(I).getSynchScope()));
1271    break;
1272  case Instruction::AtomicRMW:
1273    Code = bitc::FUNC_CODE_INST_ATOMICRMW;
1274    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1275    Vals.push_back(VE.getValueID(I.getOperand(1)));       // val.
1276    Vals.push_back(GetEncodedRMWOperation(
1277                     cast<AtomicRMWInst>(I).getOperation()));
1278    Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
1279    Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
1280    Vals.push_back(GetEncodedSynchScope(
1281                     cast<AtomicRMWInst>(I).getSynchScope()));
1282    break;
1283  case Instruction::Fence:
1284    Code = bitc::FUNC_CODE_INST_FENCE;
1285    Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
1286    Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
1287    break;
1288  case Instruction::Call: {
1289    const CallInst &CI = cast<CallInst>(I);
1290    PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1291    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1292
1293    Code = bitc::FUNC_CODE_INST_CALL;
1294
1295    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1296    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1297    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1298
1299    // Emit value #'s for the fixed parameters.
1300    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1301      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1302
1303    // Emit type/value pairs for varargs params.
1304    if (FTy->isVarArg()) {
1305      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1306           i != e; ++i)
1307        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1308    }
1309    break;
1310  }
1311  case Instruction::VAArg:
1312    Code = bitc::FUNC_CODE_INST_VAARG;
1313    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1314    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1315    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1316    break;
1317  }
1318
1319  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1320  Vals.clear();
1321}
1322
1323// Emit names for globals/functions etc.
1324static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1325                                  const ValueEnumerator &VE,
1326                                  BitstreamWriter &Stream) {
1327  if (VST.empty()) return;
1328  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1329
1330  // FIXME: Set up the abbrev, we know how many values there are!
1331  // FIXME: We know if the type names can use 7-bit ascii.
1332  SmallVector<unsigned, 64> NameVals;
1333
1334  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1335       SI != SE; ++SI) {
1336
1337    const ValueName &Name = *SI;
1338
1339    // Figure out the encoding to use for the name.
1340    bool is7Bit = true;
1341    bool isChar6 = true;
1342    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1343         C != E; ++C) {
1344      if (isChar6)
1345        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1346      if ((unsigned char)*C & 128) {
1347        is7Bit = false;
1348        break;  // don't bother scanning the rest.
1349      }
1350    }
1351
1352    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1353
1354    // VST_ENTRY:   [valueid, namechar x N]
1355    // VST_BBENTRY: [bbid, namechar x N]
1356    unsigned Code;
1357    if (isa<BasicBlock>(SI->getValue())) {
1358      Code = bitc::VST_CODE_BBENTRY;
1359      if (isChar6)
1360        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1361    } else {
1362      Code = bitc::VST_CODE_ENTRY;
1363      if (isChar6)
1364        AbbrevToUse = VST_ENTRY_6_ABBREV;
1365      else if (is7Bit)
1366        AbbrevToUse = VST_ENTRY_7_ABBREV;
1367    }
1368
1369    NameVals.push_back(VE.getValueID(SI->getValue()));
1370    for (const char *P = Name.getKeyData(),
1371         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1372      NameVals.push_back((unsigned char)*P);
1373
1374    // Emit the finished record.
1375    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1376    NameVals.clear();
1377  }
1378  Stream.ExitBlock();
1379}
1380
1381/// WriteFunction - Emit a function body to the module stream.
1382static void WriteFunction(const Function &F, ValueEnumerator &VE,
1383                          BitstreamWriter &Stream) {
1384  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1385  VE.incorporateFunction(F);
1386
1387  SmallVector<unsigned, 64> Vals;
1388
1389  // Emit the number of basic blocks, so the reader can create them ahead of
1390  // time.
1391  Vals.push_back(VE.getBasicBlocks().size());
1392  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1393  Vals.clear();
1394
1395  // If there are function-local constants, emit them now.
1396  unsigned CstStart, CstEnd;
1397  VE.getFunctionConstantRange(CstStart, CstEnd);
1398  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1399
1400  // If there is function-local metadata, emit it now.
1401  WriteFunctionLocalMetadata(F, VE, Stream);
1402
1403  // Keep a running idea of what the instruction ID is.
1404  unsigned InstID = CstEnd;
1405
1406  bool NeedsMetadataAttachment = false;
1407
1408  DebugLoc LastDL;
1409
1410  // Finally, emit all the instructions, in order.
1411  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1412    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1413         I != E; ++I) {
1414      WriteInstruction(*I, InstID, VE, Stream, Vals);
1415
1416      if (!I->getType()->isVoidTy())
1417        ++InstID;
1418
1419      // If the instruction has metadata, write a metadata attachment later.
1420      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1421
1422      // If the instruction has a debug location, emit it.
1423      DebugLoc DL = I->getDebugLoc();
1424      if (DL.isUnknown()) {
1425        // nothing todo.
1426      } else if (DL == LastDL) {
1427        // Just repeat the same debug loc as last time.
1428        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1429      } else {
1430        MDNode *Scope, *IA;
1431        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1432
1433        Vals.push_back(DL.getLine());
1434        Vals.push_back(DL.getCol());
1435        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1436        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1437        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1438        Vals.clear();
1439
1440        LastDL = DL;
1441      }
1442    }
1443
1444  // Emit names for all the instructions etc.
1445  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1446
1447  if (NeedsMetadataAttachment)
1448    WriteMetadataAttachment(F, VE, Stream);
1449  VE.purgeFunction();
1450  Stream.ExitBlock();
1451}
1452
1453// Emit blockinfo, which defines the standard abbreviations etc.
1454static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1455  // We only want to emit block info records for blocks that have multiple
1456  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1457  // blocks can defined their abbrevs inline.
1458  Stream.EnterBlockInfoBlock(2);
1459
1460  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1461    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1462    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1463    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1464    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1465    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1466    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1467                                   Abbv) != VST_ENTRY_8_ABBREV)
1468      llvm_unreachable("Unexpected abbrev ordering!");
1469  }
1470
1471  { // 7-bit fixed width VST_ENTRY strings.
1472    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1473    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1474    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1475    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1476    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1477    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1478                                   Abbv) != VST_ENTRY_7_ABBREV)
1479      llvm_unreachable("Unexpected abbrev ordering!");
1480  }
1481  { // 6-bit char6 VST_ENTRY strings.
1482    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1483    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1484    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1485    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1486    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1487    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1488                                   Abbv) != VST_ENTRY_6_ABBREV)
1489      llvm_unreachable("Unexpected abbrev ordering!");
1490  }
1491  { // 6-bit char6 VST_BBENTRY strings.
1492    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1493    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1494    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1495    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1496    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1497    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1498                                   Abbv) != VST_BBENTRY_6_ABBREV)
1499      llvm_unreachable("Unexpected abbrev ordering!");
1500  }
1501
1502
1503
1504  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1505    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1506    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1507    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1508                              Log2_32_Ceil(VE.getTypes().size()+1)));
1509    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1510                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1511      llvm_unreachable("Unexpected abbrev ordering!");
1512  }
1513
1514  { // INTEGER abbrev for CONSTANTS_BLOCK.
1515    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1516    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1517    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1518    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1519                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1520      llvm_unreachable("Unexpected abbrev ordering!");
1521  }
1522
1523  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1524    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1525    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1526    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1527    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1528                              Log2_32_Ceil(VE.getTypes().size()+1)));
1529    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1530
1531    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1532                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1533      llvm_unreachable("Unexpected abbrev ordering!");
1534  }
1535  { // NULL abbrev for CONSTANTS_BLOCK.
1536    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1537    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1538    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1539                                   Abbv) != CONSTANTS_NULL_Abbrev)
1540      llvm_unreachable("Unexpected abbrev ordering!");
1541  }
1542
1543  // FIXME: This should only use space for first class types!
1544
1545  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1546    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1547    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1548    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1549    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1550    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1551    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1552                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1553      llvm_unreachable("Unexpected abbrev ordering!");
1554  }
1555  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1556    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1557    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1558    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1559    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1560    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1561    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1562                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1563      llvm_unreachable("Unexpected abbrev ordering!");
1564  }
1565  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1566    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1567    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1568    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1569    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1570    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1571    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1572    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1573                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1574      llvm_unreachable("Unexpected abbrev ordering!");
1575  }
1576  { // INST_CAST abbrev for FUNCTION_BLOCK.
1577    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1578    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1579    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1580    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1581                              Log2_32_Ceil(VE.getTypes().size()+1)));
1582    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1583    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1584                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1585      llvm_unreachable("Unexpected abbrev ordering!");
1586  }
1587
1588  { // INST_RET abbrev for FUNCTION_BLOCK.
1589    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1590    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1591    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1592                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1593      llvm_unreachable("Unexpected abbrev ordering!");
1594  }
1595  { // INST_RET abbrev for FUNCTION_BLOCK.
1596    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1597    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1598    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1599    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1600                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1601      llvm_unreachable("Unexpected abbrev ordering!");
1602  }
1603  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1604    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1605    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1606    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1607                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1608      llvm_unreachable("Unexpected abbrev ordering!");
1609  }
1610
1611  Stream.ExitBlock();
1612}
1613
1614// Sort the Users based on the order in which the reader parses the bitcode
1615// file.
1616static bool bitcodereader_order(const User *lhs, const User *rhs) {
1617  // TODO: Implement.
1618  return true;
1619}
1620
1621static void WriteUseList(const Value *V, const ValueEnumerator &VE,
1622                         BitstreamWriter &Stream) {
1623
1624  // One or zero uses can't get out of order.
1625  if (V->use_empty() || V->hasNUses(1))
1626    return;
1627
1628  // Make a copy of the in-memory use-list for sorting.
1629  unsigned UseListSize = std::distance(V->use_begin(), V->use_end());
1630  SmallVector<const User*, 8> UseList;
1631  UseList.reserve(UseListSize);
1632  for (Value::const_use_iterator I = V->use_begin(), E = V->use_end();
1633       I != E; ++I) {
1634    const User *U = *I;
1635    UseList.push_back(U);
1636  }
1637
1638  // Sort the copy based on the order read by the BitcodeReader.
1639  std::sort(UseList.begin(), UseList.end(), bitcodereader_order);
1640
1641  // TODO: Generate a diff between the BitcodeWriter in-memory use-list and the
1642  // sorted list (i.e., the expected BitcodeReader in-memory use-list).
1643
1644  // TODO: Emit the USELIST_CODE_ENTRYs.
1645}
1646
1647static void WriteFunctionUseList(const Function *F, ValueEnumerator &VE,
1648                                 BitstreamWriter &Stream) {
1649  VE.incorporateFunction(*F);
1650
1651  for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
1652       AI != AE; ++AI)
1653    WriteUseList(AI, VE, Stream);
1654  for (Function::const_iterator BB = F->begin(), FE = F->end(); BB != FE;
1655       ++BB) {
1656    WriteUseList(BB, VE, Stream);
1657    for (BasicBlock::const_iterator II = BB->begin(), IE = BB->end(); II != IE;
1658         ++II) {
1659      WriteUseList(II, VE, Stream);
1660      for (User::const_op_iterator OI = II->op_begin(), E = II->op_end();
1661           OI != E; ++OI) {
1662        if ((isa<Constant>(*OI) && !isa<GlobalValue>(*OI)) ||
1663            isa<InlineAsm>(*OI))
1664          WriteUseList(*OI, VE, Stream);
1665      }
1666    }
1667  }
1668  VE.purgeFunction();
1669}
1670
1671// Emit use-lists.
1672static void WriteModuleUseLists(const Module *M, ValueEnumerator &VE,
1673                                BitstreamWriter &Stream) {
1674  Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
1675
1676  // XXX: this modifies the module, but in a way that should never change the
1677  // behavior of any pass or codegen in LLVM. The problem is that GVs may
1678  // contain entries in the use_list that do not exist in the Module and are
1679  // not stored in the .bc file.
1680  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
1681       I != E; ++I)
1682    I->removeDeadConstantUsers();
1683
1684  // Write the global variables.
1685  for (Module::const_global_iterator GI = M->global_begin(),
1686         GE = M->global_end(); GI != GE; ++GI) {
1687    WriteUseList(GI, VE, Stream);
1688
1689    // Write the global variable initializers.
1690    if (GI->hasInitializer())
1691      WriteUseList(GI->getInitializer(), VE, Stream);
1692  }
1693
1694  // Write the functions.
1695  for (Module::const_iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI) {
1696    WriteUseList(FI, VE, Stream);
1697    if (!FI->isDeclaration())
1698      WriteFunctionUseList(FI, VE, Stream);
1699  }
1700
1701  // Write the aliases.
1702  for (Module::const_alias_iterator AI = M->alias_begin(), AE = M->alias_end();
1703       AI != AE; ++AI) {
1704    WriteUseList(AI, VE, Stream);
1705    WriteUseList(AI->getAliasee(), VE, Stream);
1706  }
1707
1708  Stream.ExitBlock();
1709}
1710
1711/// WriteModule - Emit the specified module to the bitstream.
1712static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1713  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1714
1715  // Emit the version number if it is non-zero.
1716  if (CurVersion) {
1717    SmallVector<unsigned, 1> Vals;
1718    Vals.push_back(CurVersion);
1719    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1720  }
1721
1722  // Analyze the module, enumerating globals, functions, etc.
1723  ValueEnumerator VE(M);
1724
1725  // Emit blockinfo, which defines the standard abbreviations etc.
1726  WriteBlockInfo(VE, Stream);
1727
1728  // Emit information about parameter attributes.
1729  WriteAttributeTable(VE, Stream);
1730
1731  // Emit information describing all of the types in the module.
1732  WriteTypeTable(VE, Stream);
1733
1734  // Emit top-level description of module, including target triple, inline asm,
1735  // descriptors for global variables, and function prototype info.
1736  WriteModuleInfo(M, VE, Stream);
1737
1738  // Emit constants.
1739  WriteModuleConstants(VE, Stream);
1740
1741  // Emit metadata.
1742  WriteModuleMetadata(M, VE, Stream);
1743
1744  // Emit function bodies.
1745  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1746    if (!F->isDeclaration())
1747      WriteFunction(*F, VE, Stream);
1748
1749  // Emit metadata.
1750  WriteModuleMetadataStore(M, Stream);
1751
1752  // Emit names for globals/functions etc.
1753  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1754
1755  // Emit use-lists.
1756  if (EnablePreserveUseListOrdering)
1757    WriteModuleUseLists(M, VE, Stream);
1758
1759  Stream.ExitBlock();
1760}
1761
1762/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1763/// header and trailer to make it compatible with the system archiver.  To do
1764/// this we emit the following header, and then emit a trailer that pads the
1765/// file out to be a multiple of 16 bytes.
1766///
1767/// struct bc_header {
1768///   uint32_t Magic;         // 0x0B17C0DE
1769///   uint32_t Version;       // Version, currently always 0.
1770///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1771///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1772///   uint32_t CPUType;       // CPU specifier.
1773///   ... potentially more later ...
1774/// };
1775enum {
1776  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1777  DarwinBCHeaderSize = 5*4
1778};
1779
1780static void EmitDarwinBCHeader(BitstreamWriter &Stream, const Triple &TT) {
1781  unsigned CPUType = ~0U;
1782
1783  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1784  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1785  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1786  // specific constants here because they are implicitly part of the Darwin ABI.
1787  enum {
1788    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1789    DARWIN_CPU_TYPE_X86        = 7,
1790    DARWIN_CPU_TYPE_ARM        = 12,
1791    DARWIN_CPU_TYPE_POWERPC    = 18
1792  };
1793
1794  Triple::ArchType Arch = TT.getArch();
1795  if (Arch == Triple::x86_64)
1796    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1797  else if (Arch == Triple::x86)
1798    CPUType = DARWIN_CPU_TYPE_X86;
1799  else if (Arch == Triple::ppc)
1800    CPUType = DARWIN_CPU_TYPE_POWERPC;
1801  else if (Arch == Triple::ppc64)
1802    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1803  else if (Arch == Triple::arm || Arch == Triple::thumb)
1804    CPUType = DARWIN_CPU_TYPE_ARM;
1805
1806  // Traditional Bitcode starts after header.
1807  unsigned BCOffset = DarwinBCHeaderSize;
1808
1809  Stream.Emit(0x0B17C0DE, 32);
1810  Stream.Emit(0         , 32);  // Version.
1811  Stream.Emit(BCOffset  , 32);
1812  Stream.Emit(0         , 32);  // Filled in later.
1813  Stream.Emit(CPUType   , 32);
1814}
1815
1816/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1817/// finalize the header.
1818static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1819  // Update the size field in the header.
1820  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1821
1822  // If the file is not a multiple of 16 bytes, insert dummy padding.
1823  while (BufferSize & 15) {
1824    Stream.Emit(0, 8);
1825    ++BufferSize;
1826  }
1827}
1828
1829
1830/// WriteBitcodeToFile - Write the specified module to the specified output
1831/// stream.
1832void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1833  std::vector<unsigned char> Buffer;
1834  BitstreamWriter Stream(Buffer);
1835
1836  Buffer.reserve(256*1024);
1837
1838  WriteBitcodeToStream( M, Stream );
1839
1840  // Write the generated bitstream to "Out".
1841  Out.write((char*)&Buffer.front(), Buffer.size());
1842}
1843
1844/// WriteBitcodeToStream - Write the specified module to the specified output
1845/// stream.
1846void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1847  // If this is darwin or another generic macho target, emit a file header and
1848  // trailer if needed.
1849  Triple TT(M->getTargetTriple());
1850  if (TT.isOSDarwin())
1851    EmitDarwinBCHeader(Stream, TT);
1852
1853  // Emit the file header.
1854  Stream.Emit((unsigned)'B', 8);
1855  Stream.Emit((unsigned)'C', 8);
1856  Stream.Emit(0x0, 4);
1857  Stream.Emit(0xC, 4);
1858  Stream.Emit(0xE, 4);
1859  Stream.Emit(0xD, 4);
1860
1861  // Emit the module.
1862  WriteModule(M, Stream);
1863
1864  if (TT.isOSDarwin())
1865    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1866}
1867