BitcodeWriter.cpp revision ce718ff9f42c7da092eaa01dd0242e8d5ba84713 
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  // SwitchInst Magic
68  SWITCH_INST_MAGIC = 0x4B5 // May 2012 => 1205 => Hex
69};
70
71static unsigned GetEncodedCastOpcode(unsigned Opcode) {
72  switch (Opcode) {
73  default: llvm_unreachable("Unknown cast instruction!");
74  case Instruction::Trunc   : return bitc::CAST_TRUNC;
75  case Instruction::ZExt    : return bitc::CAST_ZEXT;
76  case Instruction::SExt    : return bitc::CAST_SEXT;
77  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
78  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
79  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
80  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
81  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
82  case Instruction::FPExt   : return bitc::CAST_FPEXT;
83  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
84  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
85  case Instruction::BitCast : return bitc::CAST_BITCAST;
86  }
87}
88
89static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
90  switch (Opcode) {
91  default: llvm_unreachable("Unknown binary instruction!");
92  case Instruction::Add:
93  case Instruction::FAdd: return bitc::BINOP_ADD;
94  case Instruction::Sub:
95  case Instruction::FSub: return bitc::BINOP_SUB;
96  case Instruction::Mul:
97  case Instruction::FMul: return bitc::BINOP_MUL;
98  case Instruction::UDiv: return bitc::BINOP_UDIV;
99  case Instruction::FDiv:
100  case Instruction::SDiv: return bitc::BINOP_SDIV;
101  case Instruction::URem: return bitc::BINOP_UREM;
102  case Instruction::FRem:
103  case Instruction::SRem: return bitc::BINOP_SREM;
104  case Instruction::Shl:  return bitc::BINOP_SHL;
105  case Instruction::LShr: return bitc::BINOP_LSHR;
106  case Instruction::AShr: return bitc::BINOP_ASHR;
107  case Instruction::And:  return bitc::BINOP_AND;
108  case Instruction::Or:   return bitc::BINOP_OR;
109  case Instruction::Xor:  return bitc::BINOP_XOR;
110  }
111}
112
113static unsigned GetEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
114  switch (Op) {
115  default: llvm_unreachable("Unknown RMW operation!");
116  case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
117  case AtomicRMWInst::Add: return bitc::RMW_ADD;
118  case AtomicRMWInst::Sub: return bitc::RMW_SUB;
119  case AtomicRMWInst::And: return bitc::RMW_AND;
120  case AtomicRMWInst::Nand: return bitc::RMW_NAND;
121  case AtomicRMWInst::Or: return bitc::RMW_OR;
122  case AtomicRMWInst::Xor: return bitc::RMW_XOR;
123  case AtomicRMWInst::Max: return bitc::RMW_MAX;
124  case AtomicRMWInst::Min: return bitc::RMW_MIN;
125  case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
126  case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
127  }
128}
129
130static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
131  switch (Ordering) {
132  case NotAtomic: return bitc::ORDERING_NOTATOMIC;
133  case Unordered: return bitc::ORDERING_UNORDERED;
134  case Monotonic: return bitc::ORDERING_MONOTONIC;
135  case Acquire: return bitc::ORDERING_ACQUIRE;
136  case Release: return bitc::ORDERING_RELEASE;
137  case AcquireRelease: return bitc::ORDERING_ACQREL;
138  case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
139  }
140  llvm_unreachable("Invalid ordering");
141}
142
143static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
144  switch (SynchScope) {
145  case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
146  case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
147  }
148  llvm_unreachable("Invalid synch scope");
149}
150
151static void WriteStringRecord(unsigned Code, StringRef Str,
152                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
153  SmallVector<unsigned, 64> Vals;
154
155  // Code: [strchar x N]
156  for (unsigned i = 0, e = Str.size(); i != e; ++i) {
157    if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
158      AbbrevToUse = 0;
159    Vals.push_back(Str[i]);
160  }
161
162  // Emit the finished record.
163  Stream.EmitRecord(Code, Vals, AbbrevToUse);
164}
165
166// Emit information about parameter attributes.
167static void WriteAttributeTable(const ValueEnumerator &VE,
168                                BitstreamWriter &Stream) {
169  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
170  if (Attrs.empty()) return;
171
172  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
173
174  SmallVector<uint64_t, 64> Record;
175  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
176    const AttrListPtr &A = Attrs[i];
177    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
178      const AttributeWithIndex &PAWI = A.getSlot(i);
179      Record.push_back(PAWI.Index);
180      Record.push_back(Attribute::encodeLLVMAttributesForBitcode(PAWI.Attrs));
181    }
182
183    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
184    Record.clear();
185  }
186
187  Stream.ExitBlock();
188}
189
190/// WriteTypeTable - Write out the type table for a module.
191static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
192  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
193
194  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
195  SmallVector<uint64_t, 64> TypeVals;
196
197  uint64_t NumBits = Log2_32_Ceil(VE.getTypes().size()+1);
198
199  // Abbrev for TYPE_CODE_POINTER.
200  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
201  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
202  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
203  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
204  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
205
206  // Abbrev for TYPE_CODE_FUNCTION.
207  Abbv = new BitCodeAbbrev();
208  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
209  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
210  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
211  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
212
213  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
214
215  // Abbrev for TYPE_CODE_STRUCT_ANON.
216  Abbv = new BitCodeAbbrev();
217  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
218  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
219  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
220  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
221
222  unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
223
224  // Abbrev for TYPE_CODE_STRUCT_NAME.
225  Abbv = new BitCodeAbbrev();
226  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
227  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
228  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
229  unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
230
231  // Abbrev for TYPE_CODE_STRUCT_NAMED.
232  Abbv = new BitCodeAbbrev();
233  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
234  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
235  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
236  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
237
238  unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
239
240  // Abbrev for TYPE_CODE_ARRAY.
241  Abbv = new BitCodeAbbrev();
242  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
243  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
244  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
245
246  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
247
248  // Emit an entry count so the reader can reserve space.
249  TypeVals.push_back(TypeList.size());
250  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
251  TypeVals.clear();
252
253  // Loop over all of the types, emitting each in turn.
254  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
255    Type *T = TypeList[i];
256    int AbbrevToUse = 0;
257    unsigned Code = 0;
258
259    switch (T->getTypeID()) {
260    default: llvm_unreachable("Unknown type!");
261    case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;   break;
262    case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;   break;
263    case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;  break;
264    case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE; break;
265    case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80; break;
266    case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128; break;
267    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
268    case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;  break;
269    case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA; break;
270    case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX; break;
271    case Type::IntegerTyID:
272      // INTEGER: [width]
273      Code = bitc::TYPE_CODE_INTEGER;
274      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
275      break;
276    case Type::PointerTyID: {
277      PointerType *PTy = cast<PointerType>(T);
278      // POINTER: [pointee type, address space]
279      Code = bitc::TYPE_CODE_POINTER;
280      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
281      unsigned AddressSpace = PTy->getAddressSpace();
282      TypeVals.push_back(AddressSpace);
283      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
284      break;
285    }
286    case Type::FunctionTyID: {
287      FunctionType *FT = cast<FunctionType>(T);
288      // FUNCTION: [isvararg, retty, paramty x N]
289      Code = bitc::TYPE_CODE_FUNCTION;
290      TypeVals.push_back(FT->isVarArg());
291      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
292      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
293        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
294      AbbrevToUse = FunctionAbbrev;
295      break;
296    }
297    case Type::StructTyID: {
298      StructType *ST = cast<StructType>(T);
299      // STRUCT: [ispacked, eltty x N]
300      TypeVals.push_back(ST->isPacked());
301      // Output all of the element types.
302      for (StructType::element_iterator I = ST->element_begin(),
303           E = ST->element_end(); I != E; ++I)
304        TypeVals.push_back(VE.getTypeID(*I));
305
306      if (ST->isLiteral()) {
307        Code = bitc::TYPE_CODE_STRUCT_ANON;
308        AbbrevToUse = StructAnonAbbrev;
309      } else {
310        if (ST->isOpaque()) {
311          Code = bitc::TYPE_CODE_OPAQUE;
312        } else {
313          Code = bitc::TYPE_CODE_STRUCT_NAMED;
314          AbbrevToUse = StructNamedAbbrev;
315        }
316
317        // Emit the name if it is present.
318        if (!ST->getName().empty())
319          WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
320                            StructNameAbbrev, Stream);
321      }
322      break;
323    }
324    case Type::ArrayTyID: {
325      ArrayType *AT = cast<ArrayType>(T);
326      // ARRAY: [numelts, eltty]
327      Code = bitc::TYPE_CODE_ARRAY;
328      TypeVals.push_back(AT->getNumElements());
329      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
330      AbbrevToUse = ArrayAbbrev;
331      break;
332    }
333    case Type::VectorTyID: {
334      VectorType *VT = cast<VectorType>(T);
335      // VECTOR [numelts, eltty]
336      Code = bitc::TYPE_CODE_VECTOR;
337      TypeVals.push_back(VT->getNumElements());
338      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
339      break;
340    }
341    }
342
343    // Emit the finished record.
344    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
345    TypeVals.clear();
346  }
347
348  Stream.ExitBlock();
349}
350
351static unsigned getEncodedLinkage(const GlobalValue *GV) {
352  switch (GV->getLinkage()) {
353  case GlobalValue::ExternalLinkage:                 return 0;
354  case GlobalValue::WeakAnyLinkage:                  return 1;
355  case GlobalValue::AppendingLinkage:                return 2;
356  case GlobalValue::InternalLinkage:                 return 3;
357  case GlobalValue::LinkOnceAnyLinkage:              return 4;
358  case GlobalValue::DLLImportLinkage:                return 5;
359  case GlobalValue::DLLExportLinkage:                return 6;
360  case GlobalValue::ExternalWeakLinkage:             return 7;
361  case GlobalValue::CommonLinkage:                   return 8;
362  case GlobalValue::PrivateLinkage:                  return 9;
363  case GlobalValue::WeakODRLinkage:                  return 10;
364  case GlobalValue::LinkOnceODRLinkage:              return 11;
365  case GlobalValue::AvailableExternallyLinkage:      return 12;
366  case GlobalValue::LinkerPrivateLinkage:            return 13;
367  case GlobalValue::LinkerPrivateWeakLinkage:        return 14;
368  case GlobalValue::LinkerPrivateWeakDefAutoLinkage: return 15;
369  }
370  llvm_unreachable("Invalid linkage");
371}
372
373static unsigned getEncodedVisibility(const GlobalValue *GV) {
374  switch (GV->getVisibility()) {
375  case GlobalValue::DefaultVisibility:   return 0;
376  case GlobalValue::HiddenVisibility:    return 1;
377  case GlobalValue::ProtectedVisibility: return 2;
378  }
379  llvm_unreachable("Invalid visibility");
380}
381
382static unsigned getEncodedThreadLocalMode(const GlobalVariable *GV) {
383  switch (GV->getThreadLocalMode()) {
384    case GlobalVariable::NotThreadLocal:         return 0;
385    case GlobalVariable::GeneralDynamicTLSModel: return 1;
386    case GlobalVariable::LocalDynamicTLSModel:   return 2;
387    case GlobalVariable::InitialExecTLSModel:    return 3;
388    case GlobalVariable::LocalExecTLSModel:      return 4;
389  }
390  llvm_unreachable("Invalid TLS model");
391}
392
393// Emit top-level description of module, including target triple, inline asm,
394// descriptors for global variables, and function prototype info.
395static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
396                            BitstreamWriter &Stream) {
397  // Emit the list of dependent libraries for the Module.
398  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
399    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
400
401  // Emit various pieces of data attached to a module.
402  if (!M->getTargetTriple().empty())
403    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
404                      0/*TODO*/, Stream);
405  if (!M->getDataLayout().empty())
406    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
407                      0/*TODO*/, Stream);
408  if (!M->getModuleInlineAsm().empty())
409    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
410                      0/*TODO*/, Stream);
411
412  // Emit information about sections and GC, computing how many there are. Also
413  // compute the maximum alignment value.
414  std::map<std::string, unsigned> SectionMap;
415  std::map<std::string, unsigned> GCMap;
416  unsigned MaxAlignment = 0;
417  unsigned MaxGlobalType = 0;
418  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
419       GV != E; ++GV) {
420    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
421    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
422    if (GV->hasSection()) {
423      // Give section names unique ID's.
424      unsigned &Entry = SectionMap[GV->getSection()];
425      if (!Entry) {
426        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
427                          0/*TODO*/, Stream);
428        Entry = SectionMap.size();
429      }
430    }
431  }
432  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
433    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
434    if (F->hasSection()) {
435      // Give section names unique ID's.
436      unsigned &Entry = SectionMap[F->getSection()];
437      if (!Entry) {
438        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
439                          0/*TODO*/, Stream);
440        Entry = SectionMap.size();
441      }
442    }
443    if (F->hasGC()) {
444      // Same for GC names.
445      unsigned &Entry = GCMap[F->getGC()];
446      if (!Entry) {
447        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
448                          0/*TODO*/, Stream);
449        Entry = GCMap.size();
450      }
451    }
452  }
453
454  // Emit abbrev for globals, now that we know # sections and max alignment.
455  unsigned SimpleGVarAbbrev = 0;
456  if (!M->global_empty()) {
457    // Add an abbrev for common globals with no visibility or thread localness.
458    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
459    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
460    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
461                              Log2_32_Ceil(MaxGlobalType+1)));
462    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
463    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
464    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
465    if (MaxAlignment == 0)                                      // Alignment.
466      Abbv->Add(BitCodeAbbrevOp(0));
467    else {
468      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
469      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
470                               Log2_32_Ceil(MaxEncAlignment+1)));
471    }
472    if (SectionMap.empty())                                    // Section.
473      Abbv->Add(BitCodeAbbrevOp(0));
474    else
475      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
476                               Log2_32_Ceil(SectionMap.size()+1)));
477    // Don't bother emitting vis + thread local.
478    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
479  }
480
481  // Emit the global variable information.
482  SmallVector<unsigned, 64> Vals;
483  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
484       GV != E; ++GV) {
485    unsigned AbbrevToUse = 0;
486
487    // GLOBALVAR: [type, isconst, initid,
488    //             linkage, alignment, section, visibility, threadlocal,
489    //             unnamed_addr]
490    Vals.push_back(VE.getTypeID(GV->getType()));
491    Vals.push_back(GV->isConstant());
492    Vals.push_back(GV->isDeclaration() ? 0 :
493                   (VE.getValueID(GV->getInitializer()) + 1));
494    Vals.push_back(getEncodedLinkage(GV));
495    Vals.push_back(Log2_32(GV->getAlignment())+1);
496    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
497    if (GV->isThreadLocal() ||
498        GV->getVisibility() != GlobalValue::DefaultVisibility ||
499        GV->hasUnnamedAddr()) {
500      Vals.push_back(getEncodedVisibility(GV));
501      Vals.push_back(getEncodedThreadLocalMode(GV));
502      Vals.push_back(GV->hasUnnamedAddr());
503    } else {
504      AbbrevToUse = SimpleGVarAbbrev;
505    }
506
507    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
508    Vals.clear();
509  }
510
511  // Emit the function proto information.
512  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
513    // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
514    //             section, visibility, gc, unnamed_addr]
515    Vals.push_back(VE.getTypeID(F->getType()));
516    Vals.push_back(F->getCallingConv());
517    Vals.push_back(F->isDeclaration());
518    Vals.push_back(getEncodedLinkage(F));
519    Vals.push_back(VE.getAttributeID(F->getAttributes()));
520    Vals.push_back(Log2_32(F->getAlignment())+1);
521    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
522    Vals.push_back(getEncodedVisibility(F));
523    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
524    Vals.push_back(F->hasUnnamedAddr());
525
526    unsigned AbbrevToUse = 0;
527    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
528    Vals.clear();
529  }
530
531  // Emit the alias information.
532  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
533       AI != E; ++AI) {
534    // ALIAS: [alias type, aliasee val#, linkage, visibility]
535    Vals.push_back(VE.getTypeID(AI->getType()));
536    Vals.push_back(VE.getValueID(AI->getAliasee()));
537    Vals.push_back(getEncodedLinkage(AI));
538    Vals.push_back(getEncodedVisibility(AI));
539    unsigned AbbrevToUse = 0;
540    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
541    Vals.clear();
542  }
543}
544
545static uint64_t GetOptimizationFlags(const Value *V) {
546  uint64_t Flags = 0;
547
548  if (const OverflowingBinaryOperator *OBO =
549        dyn_cast<OverflowingBinaryOperator>(V)) {
550    if (OBO->hasNoSignedWrap())
551      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
552    if (OBO->hasNoUnsignedWrap())
553      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
554  } else if (const PossiblyExactOperator *PEO =
555               dyn_cast<PossiblyExactOperator>(V)) {
556    if (PEO->isExact())
557      Flags |= 1 << bitc::PEO_EXACT;
558  }
559
560  return Flags;
561}
562
563static void WriteMDNode(const MDNode *N,
564                        const ValueEnumerator &VE,
565                        BitstreamWriter &Stream,
566                        SmallVector<uint64_t, 64> &Record) {
567  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
568    if (N->getOperand(i)) {
569      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
570      Record.push_back(VE.getValueID(N->getOperand(i)));
571    } else {
572      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
573      Record.push_back(0);
574    }
575  }
576  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
577                                           bitc::METADATA_NODE;
578  Stream.EmitRecord(MDCode, Record, 0);
579  Record.clear();
580}
581
582static void WriteModuleMetadata(const Module *M,
583                                const ValueEnumerator &VE,
584                                BitstreamWriter &Stream) {
585  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
586  bool StartedMetadataBlock = false;
587  unsigned MDSAbbrev = 0;
588  SmallVector<uint64_t, 64> Record;
589  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
590
591    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
592      if (!N->isFunctionLocal() || !N->getFunction()) {
593        if (!StartedMetadataBlock) {
594          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
595          StartedMetadataBlock = true;
596        }
597        WriteMDNode(N, VE, Stream, Record);
598      }
599    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
600      if (!StartedMetadataBlock)  {
601        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
602
603        // Abbrev for METADATA_STRING.
604        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
605        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
606        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
607        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
608        MDSAbbrev = Stream.EmitAbbrev(Abbv);
609        StartedMetadataBlock = true;
610      }
611
612      // Code: [strchar x N]
613      Record.append(MDS->begin(), MDS->end());
614
615      // Emit the finished record.
616      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
617      Record.clear();
618    }
619  }
620
621  // Write named metadata.
622  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
623       E = M->named_metadata_end(); I != E; ++I) {
624    const NamedMDNode *NMD = I;
625    if (!StartedMetadataBlock)  {
626      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
627      StartedMetadataBlock = true;
628    }
629
630    // Write name.
631    StringRef Str = NMD->getName();
632    for (unsigned i = 0, e = Str.size(); i != e; ++i)
633      Record.push_back(Str[i]);
634    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
635    Record.clear();
636
637    // Write named metadata operands.
638    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
639      Record.push_back(VE.getValueID(NMD->getOperand(i)));
640    Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
641    Record.clear();
642  }
643
644  if (StartedMetadataBlock)
645    Stream.ExitBlock();
646}
647
648static void WriteFunctionLocalMetadata(const Function &F,
649                                       const ValueEnumerator &VE,
650                                       BitstreamWriter &Stream) {
651  bool StartedMetadataBlock = false;
652  SmallVector<uint64_t, 64> Record;
653  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
654  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
655    if (const MDNode *N = Vals[i])
656      if (N->isFunctionLocal() && N->getFunction() == &F) {
657        if (!StartedMetadataBlock) {
658          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
659          StartedMetadataBlock = true;
660        }
661        WriteMDNode(N, VE, Stream, Record);
662      }
663
664  if (StartedMetadataBlock)
665    Stream.ExitBlock();
666}
667
668static void WriteMetadataAttachment(const Function &F,
669                                    const ValueEnumerator &VE,
670                                    BitstreamWriter &Stream) {
671  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
672
673  SmallVector<uint64_t, 64> Record;
674
675  // Write metadata attachments
676  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
677  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
678
679  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
680    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
681         I != E; ++I) {
682      MDs.clear();
683      I->getAllMetadataOtherThanDebugLoc(MDs);
684
685      // If no metadata, ignore instruction.
686      if (MDs.empty()) continue;
687
688      Record.push_back(VE.getInstructionID(I));
689
690      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
691        Record.push_back(MDs[i].first);
692        Record.push_back(VE.getValueID(MDs[i].second));
693      }
694      Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
695      Record.clear();
696    }
697
698  Stream.ExitBlock();
699}
700
701static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
702  SmallVector<uint64_t, 64> Record;
703
704  // Write metadata kinds
705  // METADATA_KIND - [n x [id, name]]
706  SmallVector<StringRef, 4> Names;
707  M->getMDKindNames(Names);
708
709  if (Names.empty()) return;
710
711  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
712
713  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
714    Record.push_back(MDKindID);
715    StringRef KName = Names[MDKindID];
716    Record.append(KName.begin(), KName.end());
717
718    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
719    Record.clear();
720  }
721
722  Stream.ExitBlock();
723}
724
725static void EmitAPInt(SmallVectorImpl<uint64_t> &Vals,
726                      unsigned &Code, unsigned &AbbrevToUse, const APInt &Val,
727                      bool EmitSizeForWideNumbers = false
728                      ) {
729  if (Val.getBitWidth() <= 64) {
730    uint64_t V = Val.getSExtValue();
731    if ((int64_t)V >= 0)
732      Vals.push_back(V << 1);
733    else
734      Vals.push_back((-V << 1) | 1);
735    Code = bitc::CST_CODE_INTEGER;
736    AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
737  } else {
738    // Wide integers, > 64 bits in size.
739    // We have an arbitrary precision integer value to write whose
740    // bit width is > 64. However, in canonical unsigned integer
741    // format it is likely that the high bits are going to be zero.
742    // So, we only write the number of active words.
743    unsigned NWords = Val.getActiveWords();
744
745    if (EmitSizeForWideNumbers)
746      Vals.push_back(NWords);
747
748    const uint64_t *RawWords = Val.getRawData();
749    for (unsigned i = 0; i != NWords; ++i) {
750      int64_t V = RawWords[i];
751      if (V >= 0)
752        Vals.push_back(V << 1);
753      else
754        Vals.push_back((-V << 1) | 1);
755    }
756    Code = bitc::CST_CODE_WIDE_INTEGER;
757  }
758}
759
760static void WriteConstants(unsigned FirstVal, unsigned LastVal,
761                           const ValueEnumerator &VE,
762                           BitstreamWriter &Stream, bool isGlobal) {
763  if (FirstVal == LastVal) return;
764
765  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
766
767  unsigned AggregateAbbrev = 0;
768  unsigned String8Abbrev = 0;
769  unsigned CString7Abbrev = 0;
770  unsigned CString6Abbrev = 0;
771  // If this is a constant pool for the module, emit module-specific abbrevs.
772  if (isGlobal) {
773    // Abbrev for CST_CODE_AGGREGATE.
774    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
775    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
776    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
777    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
778    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
779
780    // Abbrev for CST_CODE_STRING.
781    Abbv = new BitCodeAbbrev();
782    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
783    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
784    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
785    String8Abbrev = Stream.EmitAbbrev(Abbv);
786    // Abbrev for CST_CODE_CSTRING.
787    Abbv = new BitCodeAbbrev();
788    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
789    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
790    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
791    CString7Abbrev = Stream.EmitAbbrev(Abbv);
792    // Abbrev for CST_CODE_CSTRING.
793    Abbv = new BitCodeAbbrev();
794    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
795    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
796    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
797    CString6Abbrev = Stream.EmitAbbrev(Abbv);
798  }
799
800  SmallVector<uint64_t, 64> Record;
801
802  const ValueEnumerator::ValueList &Vals = VE.getValues();
803  Type *LastTy = 0;
804  for (unsigned i = FirstVal; i != LastVal; ++i) {
805    const Value *V = Vals[i].first;
806    // If we need to switch types, do so now.
807    if (V->getType() != LastTy) {
808      LastTy = V->getType();
809      Record.push_back(VE.getTypeID(LastTy));
810      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
811                        CONSTANTS_SETTYPE_ABBREV);
812      Record.clear();
813    }
814
815    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
816      Record.push_back(unsigned(IA->hasSideEffects()) |
817                       unsigned(IA->isAlignStack()) << 1);
818
819      // Add the asm string.
820      const std::string &AsmStr = IA->getAsmString();
821      Record.push_back(AsmStr.size());
822      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
823        Record.push_back(AsmStr[i]);
824
825      // Add the constraint string.
826      const std::string &ConstraintStr = IA->getConstraintString();
827      Record.push_back(ConstraintStr.size());
828      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
829        Record.push_back(ConstraintStr[i]);
830      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
831      Record.clear();
832      continue;
833    }
834    const Constant *C = cast<Constant>(V);
835    unsigned Code = -1U;
836    unsigned AbbrevToUse = 0;
837    if (C->isNullValue()) {
838      Code = bitc::CST_CODE_NULL;
839    } else if (isa<UndefValue>(C)) {
840      Code = bitc::CST_CODE_UNDEF;
841    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
842      EmitAPInt(Record, Code, AbbrevToUse, IV->getValue());
843    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
844      Code = bitc::CST_CODE_FLOAT;
845      Type *Ty = CFP->getType();
846      if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
847        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
848      } else if (Ty->isX86_FP80Ty()) {
849        // api needed to prevent premature destruction
850        // bits are not in the same order as a normal i80 APInt, compensate.
851        APInt api = CFP->getValueAPF().bitcastToAPInt();
852        const uint64_t *p = api.getRawData();
853        Record.push_back((p[1] << 48) | (p[0] >> 16));
854        Record.push_back(p[0] & 0xffffLL);
855      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
856        APInt api = CFP->getValueAPF().bitcastToAPInt();
857        const uint64_t *p = api.getRawData();
858        Record.push_back(p[0]);
859        Record.push_back(p[1]);
860      } else {
861        assert (0 && "Unknown FP type!");
862      }
863    } else if (isa<ConstantDataSequential>(C) &&
864               cast<ConstantDataSequential>(C)->isString()) {
865      const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
866      // Emit constant strings specially.
867      unsigned NumElts = Str->getNumElements();
868      // If this is a null-terminated string, use the denser CSTRING encoding.
869      if (Str->isCString()) {
870        Code = bitc::CST_CODE_CSTRING;
871        --NumElts;  // Don't encode the null, which isn't allowed by char6.
872      } else {
873        Code = bitc::CST_CODE_STRING;
874        AbbrevToUse = String8Abbrev;
875      }
876      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
877      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
878      for (unsigned i = 0; i != NumElts; ++i) {
879        unsigned char V = Str->getElementAsInteger(i);
880        Record.push_back(V);
881        isCStr7 &= (V & 128) == 0;
882        if (isCStrChar6)
883          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
884      }
885
886      if (isCStrChar6)
887        AbbrevToUse = CString6Abbrev;
888      else if (isCStr7)
889        AbbrevToUse = CString7Abbrev;
890    } else if (const ConstantDataSequential *CDS =
891                  dyn_cast<ConstantDataSequential>(C)) {
892      Code = bitc::CST_CODE_DATA;
893      Type *EltTy = CDS->getType()->getElementType();
894      if (isa<IntegerType>(EltTy)) {
895        for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
896          Record.push_back(CDS->getElementAsInteger(i));
897      } else if (EltTy->isFloatTy()) {
898        for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
899          union { float F; uint32_t I; };
900          F = CDS->getElementAsFloat(i);
901          Record.push_back(I);
902        }
903      } else {
904        assert(EltTy->isDoubleTy() && "Unknown ConstantData element type");
905        for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i) {
906          union { double F; uint64_t I; };
907          F = CDS->getElementAsDouble(i);
908          Record.push_back(I);
909        }
910      }
911    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
912               isa<ConstantVector>(C)) {
913      Code = bitc::CST_CODE_AGGREGATE;
914      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
915        Record.push_back(VE.getValueID(C->getOperand(i)));
916      AbbrevToUse = AggregateAbbrev;
917    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
918      switch (CE->getOpcode()) {
919      default:
920        if (Instruction::isCast(CE->getOpcode())) {
921          Code = bitc::CST_CODE_CE_CAST;
922          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
923          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
924          Record.push_back(VE.getValueID(C->getOperand(0)));
925          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
926        } else {
927          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
928          Code = bitc::CST_CODE_CE_BINOP;
929          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
930          Record.push_back(VE.getValueID(C->getOperand(0)));
931          Record.push_back(VE.getValueID(C->getOperand(1)));
932          uint64_t Flags = GetOptimizationFlags(CE);
933          if (Flags != 0)
934            Record.push_back(Flags);
935        }
936        break;
937      case Instruction::GetElementPtr:
938        Code = bitc::CST_CODE_CE_GEP;
939        if (cast<GEPOperator>(C)->isInBounds())
940          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
941        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
942          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
943          Record.push_back(VE.getValueID(C->getOperand(i)));
944        }
945        break;
946      case Instruction::Select:
947        Code = bitc::CST_CODE_CE_SELECT;
948        Record.push_back(VE.getValueID(C->getOperand(0)));
949        Record.push_back(VE.getValueID(C->getOperand(1)));
950        Record.push_back(VE.getValueID(C->getOperand(2)));
951        break;
952      case Instruction::ExtractElement:
953        Code = bitc::CST_CODE_CE_EXTRACTELT;
954        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
955        Record.push_back(VE.getValueID(C->getOperand(0)));
956        Record.push_back(VE.getValueID(C->getOperand(1)));
957        break;
958      case Instruction::InsertElement:
959        Code = bitc::CST_CODE_CE_INSERTELT;
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::ShuffleVector:
965        // If the return type and argument types are the same, this is a
966        // standard shufflevector instruction.  If the types are different,
967        // then the shuffle is widening or truncating the input vectors, and
968        // the argument type must also be encoded.
969        if (C->getType() == C->getOperand(0)->getType()) {
970          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
971        } else {
972          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
973          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
974        }
975        Record.push_back(VE.getValueID(C->getOperand(0)));
976        Record.push_back(VE.getValueID(C->getOperand(1)));
977        Record.push_back(VE.getValueID(C->getOperand(2)));
978        break;
979      case Instruction::ICmp:
980      case Instruction::FCmp:
981        Code = bitc::CST_CODE_CE_CMP;
982        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
983        Record.push_back(VE.getValueID(C->getOperand(0)));
984        Record.push_back(VE.getValueID(C->getOperand(1)));
985        Record.push_back(CE->getPredicate());
986        break;
987      }
988    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
989      Code = bitc::CST_CODE_BLOCKADDRESS;
990      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
991      Record.push_back(VE.getValueID(BA->getFunction()));
992      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
993    } else {
994#ifndef NDEBUG
995      C->dump();
996#endif
997      llvm_unreachable("Unknown constant!");
998    }
999    Stream.EmitRecord(Code, Record, AbbrevToUse);
1000    Record.clear();
1001  }
1002
1003  Stream.ExitBlock();
1004}
1005
1006static void WriteModuleConstants(const ValueEnumerator &VE,
1007                                 BitstreamWriter &Stream) {
1008  const ValueEnumerator::ValueList &Vals = VE.getValues();
1009
1010  // Find the first constant to emit, which is the first non-globalvalue value.
1011  // We know globalvalues have been emitted by WriteModuleInfo.
1012  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1013    if (!isa<GlobalValue>(Vals[i].first)) {
1014      WriteConstants(i, Vals.size(), VE, Stream, true);
1015      return;
1016    }
1017  }
1018}
1019
1020/// PushValueAndType - The file has to encode both the value and type id for
1021/// many values, because we need to know what type to create for forward
1022/// references.  However, most operands are not forward references, so this type
1023/// field is not needed.
1024///
1025/// This function adds V's value ID to Vals.  If the value ID is higher than the
1026/// instruction ID, then it is a forward reference, and it also includes the
1027/// type ID.
1028static bool PushValueAndType(const Value *V, unsigned InstID,
1029                             SmallVector<unsigned, 64> &Vals,
1030                             ValueEnumerator &VE) {
1031  unsigned ValID = VE.getValueID(V);
1032  Vals.push_back(ValID);
1033  if (ValID >= InstID) {
1034    Vals.push_back(VE.getTypeID(V->getType()));
1035    return true;
1036  }
1037  return false;
1038}
1039
1040/// WriteInstruction - Emit an instruction to the specified stream.
1041static void WriteInstruction(const Instruction &I, unsigned InstID,
1042                             ValueEnumerator &VE, BitstreamWriter &Stream,
1043                             SmallVector<unsigned, 64> &Vals) {
1044  unsigned Code = 0;
1045  unsigned AbbrevToUse = 0;
1046  VE.setInstructionID(&I);
1047  switch (I.getOpcode()) {
1048  default:
1049    if (Instruction::isCast(I.getOpcode())) {
1050      Code = bitc::FUNC_CODE_INST_CAST;
1051      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1052        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1053      Vals.push_back(VE.getTypeID(I.getType()));
1054      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1055    } else {
1056      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1057      Code = bitc::FUNC_CODE_INST_BINOP;
1058      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1059        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1060      Vals.push_back(VE.getValueID(I.getOperand(1)));
1061      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1062      uint64_t Flags = GetOptimizationFlags(&I);
1063      if (Flags != 0) {
1064        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1065          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1066        Vals.push_back(Flags);
1067      }
1068    }
1069    break;
1070
1071  case Instruction::GetElementPtr:
1072    Code = bitc::FUNC_CODE_INST_GEP;
1073    if (cast<GEPOperator>(&I)->isInBounds())
1074      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
1075    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1076      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1077    break;
1078  case Instruction::ExtractValue: {
1079    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1080    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1081    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1082    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1083      Vals.push_back(*i);
1084    break;
1085  }
1086  case Instruction::InsertValue: {
1087    Code = bitc::FUNC_CODE_INST_INSERTVAL;
1088    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1089    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1090    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1091    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1092      Vals.push_back(*i);
1093    break;
1094  }
1095  case Instruction::Select:
1096    Code = bitc::FUNC_CODE_INST_VSELECT;
1097    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1098    Vals.push_back(VE.getValueID(I.getOperand(2)));
1099    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1100    break;
1101  case Instruction::ExtractElement:
1102    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1103    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1104    Vals.push_back(VE.getValueID(I.getOperand(1)));
1105    break;
1106  case Instruction::InsertElement:
1107    Code = bitc::FUNC_CODE_INST_INSERTELT;
1108    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1109    Vals.push_back(VE.getValueID(I.getOperand(1)));
1110    Vals.push_back(VE.getValueID(I.getOperand(2)));
1111    break;
1112  case Instruction::ShuffleVector:
1113    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1114    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1115    Vals.push_back(VE.getValueID(I.getOperand(1)));
1116    Vals.push_back(VE.getValueID(I.getOperand(2)));
1117    break;
1118  case Instruction::ICmp:
1119  case Instruction::FCmp:
1120    // compare returning Int1Ty or vector of Int1Ty
1121    Code = bitc::FUNC_CODE_INST_CMP2;
1122    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1123    Vals.push_back(VE.getValueID(I.getOperand(1)));
1124    Vals.push_back(cast<CmpInst>(I).getPredicate());
1125    break;
1126
1127  case Instruction::Ret:
1128    {
1129      Code = bitc::FUNC_CODE_INST_RET;
1130      unsigned NumOperands = I.getNumOperands();
1131      if (NumOperands == 0)
1132        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1133      else if (NumOperands == 1) {
1134        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1135          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1136      } else {
1137        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1138          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1139      }
1140    }
1141    break;
1142  case Instruction::Br:
1143    {
1144      Code = bitc::FUNC_CODE_INST_BR;
1145      BranchInst &II = cast<BranchInst>(I);
1146      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1147      if (II.isConditional()) {
1148        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1149        Vals.push_back(VE.getValueID(II.getCondition()));
1150      }
1151    }
1152    break;
1153  case Instruction::Switch:
1154    {
1155      // Redefine Vals, since here we need to use 64 bit values
1156      // explicitly to store large APInt numbers.
1157      SmallVector<uint64_t, 128> Vals64;
1158
1159      Code = bitc::FUNC_CODE_INST_SWITCH;
1160      SwitchInst &SI = cast<SwitchInst>(I);
1161
1162      uint32_t SwitchRecordHeader = SI.hash() | (SWITCH_INST_MAGIC << 16);
1163      Vals64.push_back(SwitchRecordHeader);
1164
1165      Vals64.push_back(VE.getTypeID(SI.getCondition()->getType()));
1166      Vals64.push_back(VE.getValueID(SI.getCondition()));
1167      Vals64.push_back(VE.getValueID(SI.getDefaultDest()));
1168      Vals64.push_back(SI.getNumCases());
1169      for (SwitchInst::CaseIt i = SI.case_begin(), e = SI.case_end();
1170           i != e; ++i) {
1171        IntegersSubset& CaseRanges = i.getCaseValueEx();
1172        unsigned Code, Abbrev; // will unused.
1173
1174        if (CaseRanges.isSingleNumber()) {
1175          Vals64.push_back(1/*NumItems = 1*/);
1176          Vals64.push_back(true/*IsSingleNumber = true*/);
1177          EmitAPInt(Vals64, Code, Abbrev, CaseRanges.getSingleNumber(0), true);
1178        } else {
1179
1180          Vals64.push_back(CaseRanges.getNumItems());
1181
1182          if (CaseRanges.isSingleNumbersOnly()) {
1183            for (unsigned ri = 0, rn = CaseRanges.getNumItems();
1184                 ri != rn; ++ri) {
1185
1186              Vals64.push_back(true/*IsSingleNumber = true*/);
1187
1188              EmitAPInt(Vals64, Code, Abbrev,
1189                        CaseRanges.getSingleNumber(ri), true);
1190            }
1191          } else
1192            for (unsigned ri = 0, rn = CaseRanges.getNumItems();
1193                 ri != rn; ++ri) {
1194              IntegersSubset::Range r = CaseRanges.getItem(ri);
1195              bool IsSingleNumber = CaseRanges.isSingleNumber(ri);
1196
1197              Vals64.push_back(IsSingleNumber);
1198
1199              EmitAPInt(Vals64, Code, Abbrev, r.getLow(), true);
1200              if (!IsSingleNumber)
1201                EmitAPInt(Vals64, Code, Abbrev, r.getHigh(), true);
1202            }
1203        }
1204        Vals64.push_back(VE.getValueID(i.getCaseSuccessor()));
1205      }
1206
1207      Stream.EmitRecord(Code, Vals64, AbbrevToUse);
1208
1209      // Also do expected action - clear external Vals collection:
1210      Vals.clear();
1211      return;
1212    }
1213    break;
1214  case Instruction::IndirectBr:
1215    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1216    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1217    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1218      Vals.push_back(VE.getValueID(I.getOperand(i)));
1219    break;
1220
1221  case Instruction::Invoke: {
1222    const InvokeInst *II = cast<InvokeInst>(&I);
1223    const Value *Callee(II->getCalledValue());
1224    PointerType *PTy = cast<PointerType>(Callee->getType());
1225    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1226    Code = bitc::FUNC_CODE_INST_INVOKE;
1227
1228    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1229    Vals.push_back(II->getCallingConv());
1230    Vals.push_back(VE.getValueID(II->getNormalDest()));
1231    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1232    PushValueAndType(Callee, InstID, Vals, VE);
1233
1234    // Emit value #'s for the fixed parameters.
1235    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1236      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1237
1238    // Emit type/value pairs for varargs params.
1239    if (FTy->isVarArg()) {
1240      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1241           i != e; ++i)
1242        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1243    }
1244    break;
1245  }
1246  case Instruction::Resume:
1247    Code = bitc::FUNC_CODE_INST_RESUME;
1248    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1249    break;
1250  case Instruction::Unreachable:
1251    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1252    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1253    break;
1254
1255  case Instruction::PHI: {
1256    const PHINode &PN = cast<PHINode>(I);
1257    Code = bitc::FUNC_CODE_INST_PHI;
1258    Vals.push_back(VE.getTypeID(PN.getType()));
1259    for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1260      Vals.push_back(VE.getValueID(PN.getIncomingValue(i)));
1261      Vals.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1262    }
1263    break;
1264  }
1265
1266  case Instruction::LandingPad: {
1267    const LandingPadInst &LP = cast<LandingPadInst>(I);
1268    Code = bitc::FUNC_CODE_INST_LANDINGPAD;
1269    Vals.push_back(VE.getTypeID(LP.getType()));
1270    PushValueAndType(LP.getPersonalityFn(), InstID, Vals, VE);
1271    Vals.push_back(LP.isCleanup());
1272    Vals.push_back(LP.getNumClauses());
1273    for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1274      if (LP.isCatch(I))
1275        Vals.push_back(LandingPadInst::Catch);
1276      else
1277        Vals.push_back(LandingPadInst::Filter);
1278      PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1279    }
1280    break;
1281  }
1282
1283  case Instruction::Alloca:
1284    Code = bitc::FUNC_CODE_INST_ALLOCA;
1285    Vals.push_back(VE.getTypeID(I.getType()));
1286    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1287    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1288    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1289    break;
1290
1291  case Instruction::Load:
1292    if (cast<LoadInst>(I).isAtomic()) {
1293      Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1294      PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1295    } else {
1296      Code = bitc::FUNC_CODE_INST_LOAD;
1297      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1298        AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1299    }
1300    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1301    Vals.push_back(cast<LoadInst>(I).isVolatile());
1302    if (cast<LoadInst>(I).isAtomic()) {
1303      Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1304      Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1305    }
1306    break;
1307  case Instruction::Store:
1308    if (cast<StoreInst>(I).isAtomic())
1309      Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1310    else
1311      Code = bitc::FUNC_CODE_INST_STORE;
1312    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1313    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1314    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1315    Vals.push_back(cast<StoreInst>(I).isVolatile());
1316    if (cast<StoreInst>(I).isAtomic()) {
1317      Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1318      Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1319    }
1320    break;
1321  case Instruction::AtomicCmpXchg:
1322    Code = bitc::FUNC_CODE_INST_CMPXCHG;
1323    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1324    Vals.push_back(VE.getValueID(I.getOperand(1)));       // cmp.
1325    Vals.push_back(VE.getValueID(I.getOperand(2)));       // newval.
1326    Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1327    Vals.push_back(GetEncodedOrdering(
1328                     cast<AtomicCmpXchgInst>(I).getOrdering()));
1329    Vals.push_back(GetEncodedSynchScope(
1330                     cast<AtomicCmpXchgInst>(I).getSynchScope()));
1331    break;
1332  case Instruction::AtomicRMW:
1333    Code = bitc::FUNC_CODE_INST_ATOMICRMW;
1334    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1335    Vals.push_back(VE.getValueID(I.getOperand(1)));       // val.
1336    Vals.push_back(GetEncodedRMWOperation(
1337                     cast<AtomicRMWInst>(I).getOperation()));
1338    Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
1339    Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
1340    Vals.push_back(GetEncodedSynchScope(
1341                     cast<AtomicRMWInst>(I).getSynchScope()));
1342    break;
1343  case Instruction::Fence:
1344    Code = bitc::FUNC_CODE_INST_FENCE;
1345    Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
1346    Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
1347    break;
1348  case Instruction::Call: {
1349    const CallInst &CI = cast<CallInst>(I);
1350    PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1351    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1352
1353    Code = bitc::FUNC_CODE_INST_CALL;
1354
1355    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1356    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1357    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1358
1359    // Emit value #'s for the fixed parameters.
1360    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1361      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1362
1363    // Emit type/value pairs for varargs params.
1364    if (FTy->isVarArg()) {
1365      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1366           i != e; ++i)
1367        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1368    }
1369    break;
1370  }
1371  case Instruction::VAArg:
1372    Code = bitc::FUNC_CODE_INST_VAARG;
1373    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1374    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1375    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1376    break;
1377  }
1378
1379  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1380  Vals.clear();
1381}
1382
1383// Emit names for globals/functions etc.
1384static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1385                                  const ValueEnumerator &VE,
1386                                  BitstreamWriter &Stream) {
1387  if (VST.empty()) return;
1388  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1389
1390  // FIXME: Set up the abbrev, we know how many values there are!
1391  // FIXME: We know if the type names can use 7-bit ascii.
1392  SmallVector<unsigned, 64> NameVals;
1393
1394  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1395       SI != SE; ++SI) {
1396
1397    const ValueName &Name = *SI;
1398
1399    // Figure out the encoding to use for the name.
1400    bool is7Bit = true;
1401    bool isChar6 = true;
1402    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1403         C != E; ++C) {
1404      if (isChar6)
1405        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1406      if ((unsigned char)*C & 128) {
1407        is7Bit = false;
1408        break;  // don't bother scanning the rest.
1409      }
1410    }
1411
1412    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1413
1414    // VST_ENTRY:   [valueid, namechar x N]
1415    // VST_BBENTRY: [bbid, namechar x N]
1416    unsigned Code;
1417    if (isa<BasicBlock>(SI->getValue())) {
1418      Code = bitc::VST_CODE_BBENTRY;
1419      if (isChar6)
1420        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1421    } else {
1422      Code = bitc::VST_CODE_ENTRY;
1423      if (isChar6)
1424        AbbrevToUse = VST_ENTRY_6_ABBREV;
1425      else if (is7Bit)
1426        AbbrevToUse = VST_ENTRY_7_ABBREV;
1427    }
1428
1429    NameVals.push_back(VE.getValueID(SI->getValue()));
1430    for (const char *P = Name.getKeyData(),
1431         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1432      NameVals.push_back((unsigned char)*P);
1433
1434    // Emit the finished record.
1435    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1436    NameVals.clear();
1437  }
1438  Stream.ExitBlock();
1439}
1440
1441/// WriteFunction - Emit a function body to the module stream.
1442static void WriteFunction(const Function &F, ValueEnumerator &VE,
1443                          BitstreamWriter &Stream) {
1444  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1445  VE.incorporateFunction(F);
1446
1447  SmallVector<unsigned, 64> Vals;
1448
1449  // Emit the number of basic blocks, so the reader can create them ahead of
1450  // time.
1451  Vals.push_back(VE.getBasicBlocks().size());
1452  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1453  Vals.clear();
1454
1455  // If there are function-local constants, emit them now.
1456  unsigned CstStart, CstEnd;
1457  VE.getFunctionConstantRange(CstStart, CstEnd);
1458  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1459
1460  // If there is function-local metadata, emit it now.
1461  WriteFunctionLocalMetadata(F, VE, Stream);
1462
1463  // Keep a running idea of what the instruction ID is.
1464  unsigned InstID = CstEnd;
1465
1466  bool NeedsMetadataAttachment = false;
1467
1468  DebugLoc LastDL;
1469
1470  // Finally, emit all the instructions, in order.
1471  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1472    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1473         I != E; ++I) {
1474      WriteInstruction(*I, InstID, VE, Stream, Vals);
1475
1476      if (!I->getType()->isVoidTy())
1477        ++InstID;
1478
1479      // If the instruction has metadata, write a metadata attachment later.
1480      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1481
1482      // If the instruction has a debug location, emit it.
1483      DebugLoc DL = I->getDebugLoc();
1484      if (DL.isUnknown()) {
1485        // nothing todo.
1486      } else if (DL == LastDL) {
1487        // Just repeat the same debug loc as last time.
1488        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1489      } else {
1490        MDNode *Scope, *IA;
1491        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1492
1493        Vals.push_back(DL.getLine());
1494        Vals.push_back(DL.getCol());
1495        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1496        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1497        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1498        Vals.clear();
1499
1500        LastDL = DL;
1501      }
1502    }
1503
1504  // Emit names for all the instructions etc.
1505  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1506
1507  if (NeedsMetadataAttachment)
1508    WriteMetadataAttachment(F, VE, Stream);
1509  VE.purgeFunction();
1510  Stream.ExitBlock();
1511}
1512
1513// Emit blockinfo, which defines the standard abbreviations etc.
1514static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1515  // We only want to emit block info records for blocks that have multiple
1516  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1517  // blocks can defined their abbrevs inline.
1518  Stream.EnterBlockInfoBlock(2);
1519
1520  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1521    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1522    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1523    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1524    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1525    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1526    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1527                                   Abbv) != VST_ENTRY_8_ABBREV)
1528      llvm_unreachable("Unexpected abbrev ordering!");
1529  }
1530
1531  { // 7-bit fixed width VST_ENTRY strings.
1532    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1533    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1534    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1535    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1536    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1537    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1538                                   Abbv) != VST_ENTRY_7_ABBREV)
1539      llvm_unreachable("Unexpected abbrev ordering!");
1540  }
1541  { // 6-bit char6 VST_ENTRY strings.
1542    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1543    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1544    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1545    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1546    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1547    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1548                                   Abbv) != VST_ENTRY_6_ABBREV)
1549      llvm_unreachable("Unexpected abbrev ordering!");
1550  }
1551  { // 6-bit char6 VST_BBENTRY strings.
1552    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1553    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1554    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1555    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1556    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1557    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1558                                   Abbv) != VST_BBENTRY_6_ABBREV)
1559      llvm_unreachable("Unexpected abbrev ordering!");
1560  }
1561
1562
1563
1564  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1565    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1566    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1567    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1568                              Log2_32_Ceil(VE.getTypes().size()+1)));
1569    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1570                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1571      llvm_unreachable("Unexpected abbrev ordering!");
1572  }
1573
1574  { // INTEGER abbrev for CONSTANTS_BLOCK.
1575    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1576    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1577    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1578    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1579                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1580      llvm_unreachable("Unexpected abbrev ordering!");
1581  }
1582
1583  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1584    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1585    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1586    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1587    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1588                              Log2_32_Ceil(VE.getTypes().size()+1)));
1589    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1590
1591    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1592                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1593      llvm_unreachable("Unexpected abbrev ordering!");
1594  }
1595  { // NULL abbrev for CONSTANTS_BLOCK.
1596    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1597    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1598    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1599                                   Abbv) != CONSTANTS_NULL_Abbrev)
1600      llvm_unreachable("Unexpected abbrev ordering!");
1601  }
1602
1603  // FIXME: This should only use space for first class types!
1604
1605  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1606    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1607    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1608    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1609    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1610    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1611    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1612                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1613      llvm_unreachable("Unexpected abbrev ordering!");
1614  }
1615  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1616    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1617    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1618    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1619    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1620    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1621    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1622                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1623      llvm_unreachable("Unexpected abbrev ordering!");
1624  }
1625  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1626    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1627    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1628    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1629    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1630    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1631    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1632    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1633                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1634      llvm_unreachable("Unexpected abbrev ordering!");
1635  }
1636  { // INST_CAST abbrev for FUNCTION_BLOCK.
1637    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1638    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1639    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1640    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1641                              Log2_32_Ceil(VE.getTypes().size()+1)));
1642    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1643    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1644                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1645      llvm_unreachable("Unexpected abbrev ordering!");
1646  }
1647
1648  { // INST_RET abbrev for FUNCTION_BLOCK.
1649    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1650    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1651    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1652                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1653      llvm_unreachable("Unexpected abbrev ordering!");
1654  }
1655  { // INST_RET abbrev for FUNCTION_BLOCK.
1656    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1657    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1658    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1659    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1660                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1661      llvm_unreachable("Unexpected abbrev ordering!");
1662  }
1663  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1664    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1665    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1666    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1667                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1668      llvm_unreachable("Unexpected abbrev ordering!");
1669  }
1670
1671  Stream.ExitBlock();
1672}
1673
1674// Sort the Users based on the order in which the reader parses the bitcode
1675// file.
1676static bool bitcodereader_order(const User *lhs, const User *rhs) {
1677  // TODO: Implement.
1678  return true;
1679}
1680
1681static void WriteUseList(const Value *V, const ValueEnumerator &VE,
1682                         BitstreamWriter &Stream) {
1683
1684  // One or zero uses can't get out of order.
1685  if (V->use_empty() || V->hasNUses(1))
1686    return;
1687
1688  // Make a copy of the in-memory use-list for sorting.
1689  unsigned UseListSize = std::distance(V->use_begin(), V->use_end());
1690  SmallVector<const User*, 8> UseList;
1691  UseList.reserve(UseListSize);
1692  for (Value::const_use_iterator I = V->use_begin(), E = V->use_end();
1693       I != E; ++I) {
1694    const User *U = *I;
1695    UseList.push_back(U);
1696  }
1697
1698  // Sort the copy based on the order read by the BitcodeReader.
1699  std::sort(UseList.begin(), UseList.end(), bitcodereader_order);
1700
1701  // TODO: Generate a diff between the BitcodeWriter in-memory use-list and the
1702  // sorted list (i.e., the expected BitcodeReader in-memory use-list).
1703
1704  // TODO: Emit the USELIST_CODE_ENTRYs.
1705}
1706
1707static void WriteFunctionUseList(const Function *F, ValueEnumerator &VE,
1708                                 BitstreamWriter &Stream) {
1709  VE.incorporateFunction(*F);
1710
1711  for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
1712       AI != AE; ++AI)
1713    WriteUseList(AI, VE, Stream);
1714  for (Function::const_iterator BB = F->begin(), FE = F->end(); BB != FE;
1715       ++BB) {
1716    WriteUseList(BB, VE, Stream);
1717    for (BasicBlock::const_iterator II = BB->begin(), IE = BB->end(); II != IE;
1718         ++II) {
1719      WriteUseList(II, VE, Stream);
1720      for (User::const_op_iterator OI = II->op_begin(), E = II->op_end();
1721           OI != E; ++OI) {
1722        if ((isa<Constant>(*OI) && !isa<GlobalValue>(*OI)) ||
1723            isa<InlineAsm>(*OI))
1724          WriteUseList(*OI, VE, Stream);
1725      }
1726    }
1727  }
1728  VE.purgeFunction();
1729}
1730
1731// Emit use-lists.
1732static void WriteModuleUseLists(const Module *M, ValueEnumerator &VE,
1733                                BitstreamWriter &Stream) {
1734  Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
1735
1736  // XXX: this modifies the module, but in a way that should never change the
1737  // behavior of any pass or codegen in LLVM. The problem is that GVs may
1738  // contain entries in the use_list that do not exist in the Module and are
1739  // not stored in the .bc file.
1740  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
1741       I != E; ++I)
1742    I->removeDeadConstantUsers();
1743
1744  // Write the global variables.
1745  for (Module::const_global_iterator GI = M->global_begin(),
1746         GE = M->global_end(); GI != GE; ++GI) {
1747    WriteUseList(GI, VE, Stream);
1748
1749    // Write the global variable initializers.
1750    if (GI->hasInitializer())
1751      WriteUseList(GI->getInitializer(), VE, Stream);
1752  }
1753
1754  // Write the functions.
1755  for (Module::const_iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI) {
1756    WriteUseList(FI, VE, Stream);
1757    if (!FI->isDeclaration())
1758      WriteFunctionUseList(FI, VE, Stream);
1759  }
1760
1761  // Write the aliases.
1762  for (Module::const_alias_iterator AI = M->alias_begin(), AE = M->alias_end();
1763       AI != AE; ++AI) {
1764    WriteUseList(AI, VE, Stream);
1765    WriteUseList(AI->getAliasee(), VE, Stream);
1766  }
1767
1768  Stream.ExitBlock();
1769}
1770
1771/// WriteModule - Emit the specified module to the bitstream.
1772static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1773  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1774
1775  // Emit the version number if it is non-zero.
1776  if (CurVersion) {
1777    SmallVector<unsigned, 1> Vals;
1778    Vals.push_back(CurVersion);
1779    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1780  }
1781
1782  // Analyze the module, enumerating globals, functions, etc.
1783  ValueEnumerator VE(M);
1784
1785  // Emit blockinfo, which defines the standard abbreviations etc.
1786  WriteBlockInfo(VE, Stream);
1787
1788  // Emit information about parameter attributes.
1789  WriteAttributeTable(VE, Stream);
1790
1791  // Emit information describing all of the types in the module.
1792  WriteTypeTable(VE, Stream);
1793
1794  // Emit top-level description of module, including target triple, inline asm,
1795  // descriptors for global variables, and function prototype info.
1796  WriteModuleInfo(M, VE, Stream);
1797
1798  // Emit constants.
1799  WriteModuleConstants(VE, Stream);
1800
1801  // Emit metadata.
1802  WriteModuleMetadata(M, VE, Stream);
1803
1804  // Emit metadata.
1805  WriteModuleMetadataStore(M, Stream);
1806
1807  // Emit names for globals/functions etc.
1808  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1809
1810  // Emit use-lists.
1811  if (EnablePreserveUseListOrdering)
1812    WriteModuleUseLists(M, VE, Stream);
1813
1814  // Emit function bodies.
1815  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1816    if (!F->isDeclaration())
1817      WriteFunction(*F, VE, Stream);
1818
1819  Stream.ExitBlock();
1820}
1821
1822/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1823/// header and trailer to make it compatible with the system archiver.  To do
1824/// this we emit the following header, and then emit a trailer that pads the
1825/// file out to be a multiple of 16 bytes.
1826///
1827/// struct bc_header {
1828///   uint32_t Magic;         // 0x0B17C0DE
1829///   uint32_t Version;       // Version, currently always 0.
1830///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1831///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1832///   uint32_t CPUType;       // CPU specifier.
1833///   ... potentially more later ...
1834/// };
1835enum {
1836  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1837  DarwinBCHeaderSize = 5*4
1838};
1839
1840static void WriteInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
1841                               uint32_t &Position) {
1842  Buffer[Position + 0] = (unsigned char) (Value >>  0);
1843  Buffer[Position + 1] = (unsigned char) (Value >>  8);
1844  Buffer[Position + 2] = (unsigned char) (Value >> 16);
1845  Buffer[Position + 3] = (unsigned char) (Value >> 24);
1846  Position += 4;
1847}
1848
1849static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
1850                                         const Triple &TT) {
1851  unsigned CPUType = ~0U;
1852
1853  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1854  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1855  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1856  // specific constants here because they are implicitly part of the Darwin ABI.
1857  enum {
1858    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1859    DARWIN_CPU_TYPE_X86        = 7,
1860    DARWIN_CPU_TYPE_ARM        = 12,
1861    DARWIN_CPU_TYPE_POWERPC    = 18
1862  };
1863
1864  Triple::ArchType Arch = TT.getArch();
1865  if (Arch == Triple::x86_64)
1866    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1867  else if (Arch == Triple::x86)
1868    CPUType = DARWIN_CPU_TYPE_X86;
1869  else if (Arch == Triple::ppc)
1870    CPUType = DARWIN_CPU_TYPE_POWERPC;
1871  else if (Arch == Triple::ppc64)
1872    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1873  else if (Arch == Triple::arm || Arch == Triple::thumb)
1874    CPUType = DARWIN_CPU_TYPE_ARM;
1875
1876  // Traditional Bitcode starts after header.
1877  assert(Buffer.size() >= DarwinBCHeaderSize &&
1878         "Expected header size to be reserved");
1879  unsigned BCOffset = DarwinBCHeaderSize;
1880  unsigned BCSize = Buffer.size()-DarwinBCHeaderSize;
1881
1882  // Write the magic and version.
1883  unsigned Position = 0;
1884  WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position);
1885  WriteInt32ToBuffer(0          , Buffer, Position); // Version.
1886  WriteInt32ToBuffer(BCOffset   , Buffer, Position);
1887  WriteInt32ToBuffer(BCSize     , Buffer, Position);
1888  WriteInt32ToBuffer(CPUType    , Buffer, Position);
1889
1890  // If the file is not a multiple of 16 bytes, insert dummy padding.
1891  while (Buffer.size() & 15)
1892    Buffer.push_back(0);
1893}
1894
1895/// WriteBitcodeToFile - Write the specified module to the specified output
1896/// stream.
1897void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1898  SmallVector<char, 1024> Buffer;
1899  Buffer.reserve(256*1024);
1900
1901  // If this is darwin or another generic macho target, reserve space for the
1902  // header.
1903  Triple TT(M->getTargetTriple());
1904  if (TT.isOSDarwin())
1905    Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0);
1906
1907  // Emit the module into the buffer.
1908  {
1909    BitstreamWriter Stream(Buffer);
1910
1911    // Emit the file header.
1912    Stream.Emit((unsigned)'B', 8);
1913    Stream.Emit((unsigned)'C', 8);
1914    Stream.Emit(0x0, 4);
1915    Stream.Emit(0xC, 4);
1916    Stream.Emit(0xE, 4);
1917    Stream.Emit(0xD, 4);
1918
1919    // Emit the module.
1920    WriteModule(M, Stream);
1921  }
1922
1923  if (TT.isOSDarwin())
1924    EmitDarwinBCHeaderAndTrailer(Buffer, TT);
1925
1926  // Write the generated bitstream to "Out".
1927  Out.write((char*)&Buffer.front(), Buffer.size());
1928}
1929