BitcodeWriter.cpp revision ce16339930a2b03e53b4e6399ef59c092a7f2cfa 
1//===--- Bitcode/Writer/BitcodeWriter.cpp - Bitcode Writer ----------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Bitcode writer implementation.
11//
12//===----------------------------------------------------------------------===//
13
14#include "llvm/Bitcode/ReaderWriter.h"
15#include "llvm/Bitcode/BitstreamWriter.h"
16#include "llvm/Bitcode/LLVMBitCodes.h"
17#include "ValueEnumerator.h"
18#include "llvm/Constants.h"
19#include "llvm/DerivedTypes.h"
20#include "llvm/InlineAsm.h"
21#include "llvm/Instructions.h"
22#include "llvm/Module.h"
23#include "llvm/Operator.h"
24#include "llvm/ValueSymbolTable.h"
25#include "llvm/ADT/Triple.h"
26#include "llvm/Support/CommandLine.h"
27#include "llvm/Support/ErrorHandling.h"
28#include "llvm/Support/MathExtras.h"
29#include "llvm/Support/raw_ostream.h"
30#include "llvm/Support/Program.h"
31#include <cctype>
32#include <map>
33using namespace llvm;
34
35static cl::opt<bool>
36EnablePreserveUseListOrdering("enable-bc-uselist-preserve",
37                              cl::desc("Turn on experimental support for "
38                                       "use-list order preservation."),
39                              cl::init(false), cl::Hidden);
40
41/// These are manifest constants used by the bitcode writer. They do not need to
42/// be kept in sync with the reader, but need to be consistent within this file.
43enum {
44  CurVersion = 0,
45
46  // VALUE_SYMTAB_BLOCK abbrev id's.
47  VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
48  VST_ENTRY_7_ABBREV,
49  VST_ENTRY_6_ABBREV,
50  VST_BBENTRY_6_ABBREV,
51
52  // CONSTANTS_BLOCK abbrev id's.
53  CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
54  CONSTANTS_INTEGER_ABBREV,
55  CONSTANTS_CE_CAST_Abbrev,
56  CONSTANTS_NULL_Abbrev,
57
58  // FUNCTION_BLOCK abbrev id's.
59  FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
60  FUNCTION_INST_BINOP_ABBREV,
61  FUNCTION_INST_BINOP_FLAGS_ABBREV,
62  FUNCTION_INST_CAST_ABBREV,
63  FUNCTION_INST_RET_VOID_ABBREV,
64  FUNCTION_INST_RET_VAL_ABBREV,
65  FUNCTION_INST_UNREACHABLE_ABBREV
66};
67
68static unsigned GetEncodedCastOpcode(unsigned Opcode) {
69  switch (Opcode) {
70  default: llvm_unreachable("Unknown cast instruction!");
71  case Instruction::Trunc   : return bitc::CAST_TRUNC;
72  case Instruction::ZExt    : return bitc::CAST_ZEXT;
73  case Instruction::SExt    : return bitc::CAST_SEXT;
74  case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
75  case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
76  case Instruction::UIToFP  : return bitc::CAST_UITOFP;
77  case Instruction::SIToFP  : return bitc::CAST_SITOFP;
78  case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
79  case Instruction::FPExt   : return bitc::CAST_FPEXT;
80  case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
81  case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
82  case Instruction::BitCast : return bitc::CAST_BITCAST;
83  }
84}
85
86static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
87  switch (Opcode) {
88  default: llvm_unreachable("Unknown binary instruction!");
89  case Instruction::Add:
90  case Instruction::FAdd: return bitc::BINOP_ADD;
91  case Instruction::Sub:
92  case Instruction::FSub: return bitc::BINOP_SUB;
93  case Instruction::Mul:
94  case Instruction::FMul: return bitc::BINOP_MUL;
95  case Instruction::UDiv: return bitc::BINOP_UDIV;
96  case Instruction::FDiv:
97  case Instruction::SDiv: return bitc::BINOP_SDIV;
98  case Instruction::URem: return bitc::BINOP_UREM;
99  case Instruction::FRem:
100  case Instruction::SRem: return bitc::BINOP_SREM;
101  case Instruction::Shl:  return bitc::BINOP_SHL;
102  case Instruction::LShr: return bitc::BINOP_LSHR;
103  case Instruction::AShr: return bitc::BINOP_ASHR;
104  case Instruction::And:  return bitc::BINOP_AND;
105  case Instruction::Or:   return bitc::BINOP_OR;
106  case Instruction::Xor:  return bitc::BINOP_XOR;
107  }
108}
109
110static unsigned GetEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
111  switch (Op) {
112  default: llvm_unreachable("Unknown RMW operation!");
113  case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
114  case AtomicRMWInst::Add: return bitc::RMW_ADD;
115  case AtomicRMWInst::Sub: return bitc::RMW_SUB;
116  case AtomicRMWInst::And: return bitc::RMW_AND;
117  case AtomicRMWInst::Nand: return bitc::RMW_NAND;
118  case AtomicRMWInst::Or: return bitc::RMW_OR;
119  case AtomicRMWInst::Xor: return bitc::RMW_XOR;
120  case AtomicRMWInst::Max: return bitc::RMW_MAX;
121  case AtomicRMWInst::Min: return bitc::RMW_MIN;
122  case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
123  case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
124  }
125}
126
127static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
128  switch (Ordering) {
129  default: llvm_unreachable("Unknown atomic ordering");
130  case NotAtomic: return bitc::ORDERING_NOTATOMIC;
131  case Unordered: return bitc::ORDERING_UNORDERED;
132  case Monotonic: return bitc::ORDERING_MONOTONIC;
133  case Acquire: return bitc::ORDERING_ACQUIRE;
134  case Release: return bitc::ORDERING_RELEASE;
135  case AcquireRelease: return bitc::ORDERING_ACQREL;
136  case SequentiallyConsistent: return bitc::ORDERING_SEQCST;
137  }
138}
139
140static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
141  switch (SynchScope) {
142  default: llvm_unreachable("Unknown synchronization scope");
143  case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
144  case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
145  }
146}
147
148static void WriteStringRecord(unsigned Code, StringRef Str,
149                              unsigned AbbrevToUse, BitstreamWriter &Stream) {
150  SmallVector<unsigned, 64> Vals;
151
152  // Code: [strchar x N]
153  for (unsigned i = 0, e = Str.size(); i != e; ++i) {
154    if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
155      AbbrevToUse = 0;
156    Vals.push_back(Str[i]);
157  }
158
159  // Emit the finished record.
160  Stream.EmitRecord(Code, Vals, AbbrevToUse);
161}
162
163// Emit information about parameter attributes.
164static void WriteAttributeTable(const ValueEnumerator &VE,
165                                BitstreamWriter &Stream) {
166  const std::vector<AttrListPtr> &Attrs = VE.getAttributes();
167  if (Attrs.empty()) return;
168
169  Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
170
171  SmallVector<uint64_t, 64> Record;
172  for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
173    const AttrListPtr &A = Attrs[i];
174    for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
175      const AttributeWithIndex &PAWI = A.getSlot(i);
176      Record.push_back(PAWI.Index);
177
178      // FIXME: remove in LLVM 3.0
179      // Store the alignment in the bitcode as a 16-bit raw value instead of a
180      // 5-bit log2 encoded value. Shift the bits above the alignment up by
181      // 11 bits.
182      uint64_t FauxAttr = PAWI.Attrs & 0xffff;
183      if (PAWI.Attrs & Attribute::Alignment)
184        FauxAttr |= (1ull<<16)<<(((PAWI.Attrs & Attribute::Alignment)-1) >> 16);
185      FauxAttr |= (PAWI.Attrs & (0x3FFull << 21)) << 11;
186
187      Record.push_back(FauxAttr);
188    }
189
190    Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY, Record);
191    Record.clear();
192  }
193
194  Stream.ExitBlock();
195}
196
197/// WriteTypeTable - Write out the type table for a module.
198static void WriteTypeTable(const ValueEnumerator &VE, BitstreamWriter &Stream) {
199  const ValueEnumerator::TypeList &TypeList = VE.getTypes();
200
201  Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
202  SmallVector<uint64_t, 64> TypeVals;
203
204  uint64_t NumBits = Log2_32_Ceil(VE.getTypes().size()+1);
205
206  // Abbrev for TYPE_CODE_POINTER.
207  BitCodeAbbrev *Abbv = new BitCodeAbbrev();
208  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
209  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
210  Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
211  unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
212
213  // Abbrev for TYPE_CODE_FUNCTION.
214  Abbv = new BitCodeAbbrev();
215  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
216  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
217  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
218  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
219
220  unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
221
222  // Abbrev for TYPE_CODE_STRUCT_ANON.
223  Abbv = new BitCodeAbbrev();
224  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
225  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
226  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
227  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
228
229  unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
230
231  // Abbrev for TYPE_CODE_STRUCT_NAME.
232  Abbv = new BitCodeAbbrev();
233  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
234  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
235  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
236  unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
237
238  // Abbrev for TYPE_CODE_STRUCT_NAMED.
239  Abbv = new BitCodeAbbrev();
240  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
241  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
242  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
243  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
244
245  unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
246
247  // Abbrev for TYPE_CODE_ARRAY.
248  Abbv = new BitCodeAbbrev();
249  Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
250  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
251  Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
252
253  unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
254
255  // Emit an entry count so the reader can reserve space.
256  TypeVals.push_back(TypeList.size());
257  Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
258  TypeVals.clear();
259
260  // Loop over all of the types, emitting each in turn.
261  for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
262    Type *T = TypeList[i];
263    int AbbrevToUse = 0;
264    unsigned Code = 0;
265
266    switch (T->getTypeID()) {
267    default: llvm_unreachable("Unknown type!");
268    case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;   break;
269    case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;   break;
270    case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;  break;
271    case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE; break;
272    case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80; break;
273    case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128; break;
274    case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
275    case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;  break;
276    case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA; break;
277    case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX; break;
278    case Type::IntegerTyID:
279      // INTEGER: [width]
280      Code = bitc::TYPE_CODE_INTEGER;
281      TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
282      break;
283    case Type::PointerTyID: {
284      PointerType *PTy = cast<PointerType>(T);
285      // POINTER: [pointee type, address space]
286      Code = bitc::TYPE_CODE_POINTER;
287      TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
288      unsigned AddressSpace = PTy->getAddressSpace();
289      TypeVals.push_back(AddressSpace);
290      if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
291      break;
292    }
293    case Type::FunctionTyID: {
294      FunctionType *FT = cast<FunctionType>(T);
295      // FUNCTION: [isvararg, retty, paramty x N]
296      Code = bitc::TYPE_CODE_FUNCTION;
297      TypeVals.push_back(FT->isVarArg());
298      TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
299      for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
300        TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
301      AbbrevToUse = FunctionAbbrev;
302      break;
303    }
304    case Type::StructTyID: {
305      StructType *ST = cast<StructType>(T);
306      // STRUCT: [ispacked, eltty x N]
307      TypeVals.push_back(ST->isPacked());
308      // Output all of the element types.
309      for (StructType::element_iterator I = ST->element_begin(),
310           E = ST->element_end(); I != E; ++I)
311        TypeVals.push_back(VE.getTypeID(*I));
312
313      if (ST->isLiteral()) {
314        Code = bitc::TYPE_CODE_STRUCT_ANON;
315        AbbrevToUse = StructAnonAbbrev;
316      } else {
317        if (ST->isOpaque()) {
318          Code = bitc::TYPE_CODE_OPAQUE;
319        } else {
320          Code = bitc::TYPE_CODE_STRUCT_NAMED;
321          AbbrevToUse = StructNamedAbbrev;
322        }
323
324        // Emit the name if it is present.
325        if (!ST->getName().empty())
326          WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
327                            StructNameAbbrev, Stream);
328      }
329      break;
330    }
331    case Type::ArrayTyID: {
332      ArrayType *AT = cast<ArrayType>(T);
333      // ARRAY: [numelts, eltty]
334      Code = bitc::TYPE_CODE_ARRAY;
335      TypeVals.push_back(AT->getNumElements());
336      TypeVals.push_back(VE.getTypeID(AT->getElementType()));
337      AbbrevToUse = ArrayAbbrev;
338      break;
339    }
340    case Type::VectorTyID: {
341      VectorType *VT = cast<VectorType>(T);
342      // VECTOR [numelts, eltty]
343      Code = bitc::TYPE_CODE_VECTOR;
344      TypeVals.push_back(VT->getNumElements());
345      TypeVals.push_back(VE.getTypeID(VT->getElementType()));
346      break;
347    }
348    }
349
350    // Emit the finished record.
351    Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
352    TypeVals.clear();
353  }
354
355  Stream.ExitBlock();
356}
357
358static unsigned getEncodedLinkage(const GlobalValue *GV) {
359  switch (GV->getLinkage()) {
360  default: llvm_unreachable("Invalid linkage!");
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}
379
380static unsigned getEncodedVisibility(const GlobalValue *GV) {
381  switch (GV->getVisibility()) {
382  default: llvm_unreachable("Invalid visibility!");
383  case GlobalValue::DefaultVisibility:   return 0;
384  case GlobalValue::HiddenVisibility:    return 1;
385  case GlobalValue::ProtectedVisibility: return 2;
386  }
387}
388
389// Emit top-level description of module, including target triple, inline asm,
390// descriptors for global variables, and function prototype info.
391static void WriteModuleInfo(const Module *M, const ValueEnumerator &VE,
392                            BitstreamWriter &Stream) {
393  // Emit the list of dependent libraries for the Module.
394  for (Module::lib_iterator I = M->lib_begin(), E = M->lib_end(); I != E; ++I)
395    WriteStringRecord(bitc::MODULE_CODE_DEPLIB, *I, 0/*TODO*/, Stream);
396
397  // Emit various pieces of data attached to a module.
398  if (!M->getTargetTriple().empty())
399    WriteStringRecord(bitc::MODULE_CODE_TRIPLE, M->getTargetTriple(),
400                      0/*TODO*/, Stream);
401  if (!M->getDataLayout().empty())
402    WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, M->getDataLayout(),
403                      0/*TODO*/, Stream);
404  if (!M->getModuleInlineAsm().empty())
405    WriteStringRecord(bitc::MODULE_CODE_ASM, M->getModuleInlineAsm(),
406                      0/*TODO*/, Stream);
407
408  // Emit information about sections and GC, computing how many there are. Also
409  // compute the maximum alignment value.
410  std::map<std::string, unsigned> SectionMap;
411  std::map<std::string, unsigned> GCMap;
412  unsigned MaxAlignment = 0;
413  unsigned MaxGlobalType = 0;
414  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
415       GV != E; ++GV) {
416    MaxAlignment = std::max(MaxAlignment, GV->getAlignment());
417    MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV->getType()));
418    if (GV->hasSection()) {
419      // Give section names unique ID's.
420      unsigned &Entry = SectionMap[GV->getSection()];
421      if (!Entry) {
422        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV->getSection(),
423                          0/*TODO*/, Stream);
424        Entry = SectionMap.size();
425      }
426    }
427  }
428  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
429    MaxAlignment = std::max(MaxAlignment, F->getAlignment());
430    if (F->hasSection()) {
431      // Give section names unique ID's.
432      unsigned &Entry = SectionMap[F->getSection()];
433      if (!Entry) {
434        WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F->getSection(),
435                          0/*TODO*/, Stream);
436        Entry = SectionMap.size();
437      }
438    }
439    if (F->hasGC()) {
440      // Same for GC names.
441      unsigned &Entry = GCMap[F->getGC()];
442      if (!Entry) {
443        WriteStringRecord(bitc::MODULE_CODE_GCNAME, F->getGC(),
444                          0/*TODO*/, Stream);
445        Entry = GCMap.size();
446      }
447    }
448  }
449
450  // Emit abbrev for globals, now that we know # sections and max alignment.
451  unsigned SimpleGVarAbbrev = 0;
452  if (!M->global_empty()) {
453    // Add an abbrev for common globals with no visibility or thread localness.
454    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
455    Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
456    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
457                              Log2_32_Ceil(MaxGlobalType+1)));
458    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
459    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
460    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
461    if (MaxAlignment == 0)                                      // Alignment.
462      Abbv->Add(BitCodeAbbrevOp(0));
463    else {
464      unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
465      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
466                               Log2_32_Ceil(MaxEncAlignment+1)));
467    }
468    if (SectionMap.empty())                                    // Section.
469      Abbv->Add(BitCodeAbbrevOp(0));
470    else
471      Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
472                               Log2_32_Ceil(SectionMap.size()+1)));
473    // Don't bother emitting vis + thread local.
474    SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
475  }
476
477  // Emit the global variable information.
478  SmallVector<unsigned, 64> Vals;
479  for (Module::const_global_iterator GV = M->global_begin(),E = M->global_end();
480       GV != E; ++GV) {
481    unsigned AbbrevToUse = 0;
482
483    // GLOBALVAR: [type, isconst, initid,
484    //             linkage, alignment, section, visibility, threadlocal,
485    //             unnamed_addr]
486    Vals.push_back(VE.getTypeID(GV->getType()));
487    Vals.push_back(GV->isConstant());
488    Vals.push_back(GV->isDeclaration() ? 0 :
489                   (VE.getValueID(GV->getInitializer()) + 1));
490    Vals.push_back(getEncodedLinkage(GV));
491    Vals.push_back(Log2_32(GV->getAlignment())+1);
492    Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
493    if (GV->isThreadLocal() ||
494        GV->getVisibility() != GlobalValue::DefaultVisibility ||
495        GV->hasUnnamedAddr()) {
496      Vals.push_back(getEncodedVisibility(GV));
497      Vals.push_back(GV->isThreadLocal());
498      Vals.push_back(GV->hasUnnamedAddr());
499    } else {
500      AbbrevToUse = SimpleGVarAbbrev;
501    }
502
503    Stream.EmitRecord(bitc::MODULE_CODE_GLOBALVAR, Vals, AbbrevToUse);
504    Vals.clear();
505  }
506
507  // Emit the function proto information.
508  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F) {
509    // FUNCTION:  [type, callingconv, isproto, linkage, paramattrs, alignment,
510    //             section, visibility, gc, unnamed_addr]
511    Vals.push_back(VE.getTypeID(F->getType()));
512    Vals.push_back(F->getCallingConv());
513    Vals.push_back(F->isDeclaration());
514    Vals.push_back(getEncodedLinkage(F));
515    Vals.push_back(VE.getAttributeID(F->getAttributes()));
516    Vals.push_back(Log2_32(F->getAlignment())+1);
517    Vals.push_back(F->hasSection() ? SectionMap[F->getSection()] : 0);
518    Vals.push_back(getEncodedVisibility(F));
519    Vals.push_back(F->hasGC() ? GCMap[F->getGC()] : 0);
520    Vals.push_back(F->hasUnnamedAddr());
521
522    unsigned AbbrevToUse = 0;
523    Stream.EmitRecord(bitc::MODULE_CODE_FUNCTION, Vals, AbbrevToUse);
524    Vals.clear();
525  }
526
527  // Emit the alias information.
528  for (Module::const_alias_iterator AI = M->alias_begin(), E = M->alias_end();
529       AI != E; ++AI) {
530    // ALIAS: [alias type, aliasee val#, linkage, visibility]
531    Vals.push_back(VE.getTypeID(AI->getType()));
532    Vals.push_back(VE.getValueID(AI->getAliasee()));
533    Vals.push_back(getEncodedLinkage(AI));
534    Vals.push_back(getEncodedVisibility(AI));
535    unsigned AbbrevToUse = 0;
536    Stream.EmitRecord(bitc::MODULE_CODE_ALIAS, Vals, AbbrevToUse);
537    Vals.clear();
538  }
539}
540
541static uint64_t GetOptimizationFlags(const Value *V) {
542  uint64_t Flags = 0;
543
544  if (const OverflowingBinaryOperator *OBO =
545        dyn_cast<OverflowingBinaryOperator>(V)) {
546    if (OBO->hasNoSignedWrap())
547      Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
548    if (OBO->hasNoUnsignedWrap())
549      Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
550  } else if (const PossiblyExactOperator *PEO =
551               dyn_cast<PossiblyExactOperator>(V)) {
552    if (PEO->isExact())
553      Flags |= 1 << bitc::PEO_EXACT;
554  }
555
556  return Flags;
557}
558
559static void WriteMDNode(const MDNode *N,
560                        const ValueEnumerator &VE,
561                        BitstreamWriter &Stream,
562                        SmallVector<uint64_t, 64> &Record) {
563  for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
564    if (N->getOperand(i)) {
565      Record.push_back(VE.getTypeID(N->getOperand(i)->getType()));
566      Record.push_back(VE.getValueID(N->getOperand(i)));
567    } else {
568      Record.push_back(VE.getTypeID(Type::getVoidTy(N->getContext())));
569      Record.push_back(0);
570    }
571  }
572  unsigned MDCode = N->isFunctionLocal() ? bitc::METADATA_FN_NODE :
573                                           bitc::METADATA_NODE;
574  Stream.EmitRecord(MDCode, Record, 0);
575  Record.clear();
576}
577
578static void WriteModuleMetadata(const Module *M,
579                                const ValueEnumerator &VE,
580                                BitstreamWriter &Stream) {
581  const ValueEnumerator::ValueList &Vals = VE.getMDValues();
582  bool StartedMetadataBlock = false;
583  unsigned MDSAbbrev = 0;
584  SmallVector<uint64_t, 64> Record;
585  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
586
587    if (const MDNode *N = dyn_cast<MDNode>(Vals[i].first)) {
588      if (!N->isFunctionLocal() || !N->getFunction()) {
589        if (!StartedMetadataBlock) {
590          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
591          StartedMetadataBlock = true;
592        }
593        WriteMDNode(N, VE, Stream, Record);
594      }
595    } else if (const MDString *MDS = dyn_cast<MDString>(Vals[i].first)) {
596      if (!StartedMetadataBlock)  {
597        Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
598
599        // Abbrev for METADATA_STRING.
600        BitCodeAbbrev *Abbv = new BitCodeAbbrev();
601        Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING));
602        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
603        Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
604        MDSAbbrev = Stream.EmitAbbrev(Abbv);
605        StartedMetadataBlock = true;
606      }
607
608      // Code: [strchar x N]
609      Record.append(MDS->begin(), MDS->end());
610
611      // Emit the finished record.
612      Stream.EmitRecord(bitc::METADATA_STRING, Record, MDSAbbrev);
613      Record.clear();
614    }
615  }
616
617  // Write named metadata.
618  for (Module::const_named_metadata_iterator I = M->named_metadata_begin(),
619       E = M->named_metadata_end(); I != E; ++I) {
620    const NamedMDNode *NMD = I;
621    if (!StartedMetadataBlock)  {
622      Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
623      StartedMetadataBlock = true;
624    }
625
626    // Write name.
627    StringRef Str = NMD->getName();
628    for (unsigned i = 0, e = Str.size(); i != e; ++i)
629      Record.push_back(Str[i]);
630    Stream.EmitRecord(bitc::METADATA_NAME, Record, 0/*TODO*/);
631    Record.clear();
632
633    // Write named metadata operands.
634    for (unsigned i = 0, e = NMD->getNumOperands(); i != e; ++i)
635      Record.push_back(VE.getValueID(NMD->getOperand(i)));
636    Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
637    Record.clear();
638  }
639
640  if (StartedMetadataBlock)
641    Stream.ExitBlock();
642}
643
644static void WriteFunctionLocalMetadata(const Function &F,
645                                       const ValueEnumerator &VE,
646                                       BitstreamWriter &Stream) {
647  bool StartedMetadataBlock = false;
648  SmallVector<uint64_t, 64> Record;
649  const SmallVector<const MDNode *, 8> &Vals = VE.getFunctionLocalMDValues();
650  for (unsigned i = 0, e = Vals.size(); i != e; ++i)
651    if (const MDNode *N = Vals[i])
652      if (N->isFunctionLocal() && N->getFunction() == &F) {
653        if (!StartedMetadataBlock) {
654          Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
655          StartedMetadataBlock = true;
656        }
657        WriteMDNode(N, VE, Stream, Record);
658      }
659
660  if (StartedMetadataBlock)
661    Stream.ExitBlock();
662}
663
664static void WriteMetadataAttachment(const Function &F,
665                                    const ValueEnumerator &VE,
666                                    BitstreamWriter &Stream) {
667  Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
668
669  SmallVector<uint64_t, 64> Record;
670
671  // Write metadata attachments
672  // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
673  SmallVector<std::pair<unsigned, MDNode*>, 4> MDs;
674
675  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
676    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
677         I != E; ++I) {
678      MDs.clear();
679      I->getAllMetadataOtherThanDebugLoc(MDs);
680
681      // If no metadata, ignore instruction.
682      if (MDs.empty()) continue;
683
684      Record.push_back(VE.getInstructionID(I));
685
686      for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
687        Record.push_back(MDs[i].first);
688        Record.push_back(VE.getValueID(MDs[i].second));
689      }
690      Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
691      Record.clear();
692    }
693
694  Stream.ExitBlock();
695}
696
697static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
698  SmallVector<uint64_t, 64> Record;
699
700  // Write metadata kinds
701  // METADATA_KIND - [n x [id, name]]
702  SmallVector<StringRef, 4> Names;
703  M->getMDKindNames(Names);
704
705  if (Names.empty()) return;
706
707  Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
708
709  for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
710    Record.push_back(MDKindID);
711    StringRef KName = Names[MDKindID];
712    Record.append(KName.begin(), KName.end());
713
714    Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
715    Record.clear();
716  }
717
718  Stream.ExitBlock();
719}
720
721static void WriteConstants(unsigned FirstVal, unsigned LastVal,
722                           const ValueEnumerator &VE,
723                           BitstreamWriter &Stream, bool isGlobal) {
724  if (FirstVal == LastVal) return;
725
726  Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
727
728  unsigned AggregateAbbrev = 0;
729  unsigned String8Abbrev = 0;
730  unsigned CString7Abbrev = 0;
731  unsigned CString6Abbrev = 0;
732  // If this is a constant pool for the module, emit module-specific abbrevs.
733  if (isGlobal) {
734    // Abbrev for CST_CODE_AGGREGATE.
735    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
736    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
737    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
738    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
739    AggregateAbbrev = Stream.EmitAbbrev(Abbv);
740
741    // Abbrev for CST_CODE_STRING.
742    Abbv = new BitCodeAbbrev();
743    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
744    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
745    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
746    String8Abbrev = Stream.EmitAbbrev(Abbv);
747    // Abbrev for CST_CODE_CSTRING.
748    Abbv = new BitCodeAbbrev();
749    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
750    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
751    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
752    CString7Abbrev = Stream.EmitAbbrev(Abbv);
753    // Abbrev for CST_CODE_CSTRING.
754    Abbv = new BitCodeAbbrev();
755    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
756    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
757    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
758    CString6Abbrev = Stream.EmitAbbrev(Abbv);
759  }
760
761  SmallVector<uint64_t, 64> Record;
762
763  const ValueEnumerator::ValueList &Vals = VE.getValues();
764  Type *LastTy = 0;
765  for (unsigned i = FirstVal; i != LastVal; ++i) {
766    const Value *V = Vals[i].first;
767    // If we need to switch types, do so now.
768    if (V->getType() != LastTy) {
769      LastTy = V->getType();
770      Record.push_back(VE.getTypeID(LastTy));
771      Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
772                        CONSTANTS_SETTYPE_ABBREV);
773      Record.clear();
774    }
775
776    if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
777      Record.push_back(unsigned(IA->hasSideEffects()) |
778                       unsigned(IA->isAlignStack()) << 1);
779
780      // Add the asm string.
781      const std::string &AsmStr = IA->getAsmString();
782      Record.push_back(AsmStr.size());
783      for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
784        Record.push_back(AsmStr[i]);
785
786      // Add the constraint string.
787      const std::string &ConstraintStr = IA->getConstraintString();
788      Record.push_back(ConstraintStr.size());
789      for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
790        Record.push_back(ConstraintStr[i]);
791      Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
792      Record.clear();
793      continue;
794    }
795    const Constant *C = cast<Constant>(V);
796    unsigned Code = -1U;
797    unsigned AbbrevToUse = 0;
798    if (C->isNullValue()) {
799      Code = bitc::CST_CODE_NULL;
800    } else if (isa<UndefValue>(C)) {
801      Code = bitc::CST_CODE_UNDEF;
802    } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
803      if (IV->getBitWidth() <= 64) {
804        uint64_t V = IV->getSExtValue();
805        if ((int64_t)V >= 0)
806          Record.push_back(V << 1);
807        else
808          Record.push_back((-V << 1) | 1);
809        Code = bitc::CST_CODE_INTEGER;
810        AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
811      } else {                             // Wide integers, > 64 bits in size.
812        // We have an arbitrary precision integer value to write whose
813        // bit width is > 64. However, in canonical unsigned integer
814        // format it is likely that the high bits are going to be zero.
815        // So, we only write the number of active words.
816        unsigned NWords = IV->getValue().getActiveWords();
817        const uint64_t *RawWords = IV->getValue().getRawData();
818        for (unsigned i = 0; i != NWords; ++i) {
819          int64_t V = RawWords[i];
820          if (V >= 0)
821            Record.push_back(V << 1);
822          else
823            Record.push_back((-V << 1) | 1);
824        }
825        Code = bitc::CST_CODE_WIDE_INTEGER;
826      }
827    } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
828      Code = bitc::CST_CODE_FLOAT;
829      Type *Ty = CFP->getType();
830      if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
831        Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
832      } else if (Ty->isX86_FP80Ty()) {
833        // api needed to prevent premature destruction
834        // bits are not in the same order as a normal i80 APInt, compensate.
835        APInt api = CFP->getValueAPF().bitcastToAPInt();
836        const uint64_t *p = api.getRawData();
837        Record.push_back((p[1] << 48) | (p[0] >> 16));
838        Record.push_back(p[0] & 0xffffLL);
839      } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
840        APInt api = CFP->getValueAPF().bitcastToAPInt();
841        const uint64_t *p = api.getRawData();
842        Record.push_back(p[0]);
843        Record.push_back(p[1]);
844      } else {
845        assert (0 && "Unknown FP type!");
846      }
847    } else if (isa<ConstantArray>(C) && cast<ConstantArray>(C)->isString()) {
848      const ConstantArray *CA = cast<ConstantArray>(C);
849      // Emit constant strings specially.
850      unsigned NumOps = CA->getNumOperands();
851      // If this is a null-terminated string, use the denser CSTRING encoding.
852      if (CA->getOperand(NumOps-1)->isNullValue()) {
853        Code = bitc::CST_CODE_CSTRING;
854        --NumOps;  // Don't encode the null, which isn't allowed by char6.
855      } else {
856        Code = bitc::CST_CODE_STRING;
857        AbbrevToUse = String8Abbrev;
858      }
859      bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
860      bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
861      for (unsigned i = 0; i != NumOps; ++i) {
862        unsigned char V = cast<ConstantInt>(CA->getOperand(i))->getZExtValue();
863        Record.push_back(V);
864        isCStr7 &= (V & 128) == 0;
865        if (isCStrChar6)
866          isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
867      }
868
869      if (isCStrChar6)
870        AbbrevToUse = CString6Abbrev;
871      else if (isCStr7)
872        AbbrevToUse = CString7Abbrev;
873    } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(V) ||
874               isa<ConstantVector>(V)) {
875      Code = bitc::CST_CODE_AGGREGATE;
876      for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
877        Record.push_back(VE.getValueID(C->getOperand(i)));
878      AbbrevToUse = AggregateAbbrev;
879    } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
880      switch (CE->getOpcode()) {
881      default:
882        if (Instruction::isCast(CE->getOpcode())) {
883          Code = bitc::CST_CODE_CE_CAST;
884          Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
885          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
886          Record.push_back(VE.getValueID(C->getOperand(0)));
887          AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
888        } else {
889          assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
890          Code = bitc::CST_CODE_CE_BINOP;
891          Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
892          Record.push_back(VE.getValueID(C->getOperand(0)));
893          Record.push_back(VE.getValueID(C->getOperand(1)));
894          uint64_t Flags = GetOptimizationFlags(CE);
895          if (Flags != 0)
896            Record.push_back(Flags);
897        }
898        break;
899      case Instruction::GetElementPtr:
900        Code = bitc::CST_CODE_CE_GEP;
901        if (cast<GEPOperator>(C)->isInBounds())
902          Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
903        for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
904          Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
905          Record.push_back(VE.getValueID(C->getOperand(i)));
906        }
907        break;
908      case Instruction::Select:
909        Code = bitc::CST_CODE_CE_SELECT;
910        Record.push_back(VE.getValueID(C->getOperand(0)));
911        Record.push_back(VE.getValueID(C->getOperand(1)));
912        Record.push_back(VE.getValueID(C->getOperand(2)));
913        break;
914      case Instruction::ExtractElement:
915        Code = bitc::CST_CODE_CE_EXTRACTELT;
916        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
917        Record.push_back(VE.getValueID(C->getOperand(0)));
918        Record.push_back(VE.getValueID(C->getOperand(1)));
919        break;
920      case Instruction::InsertElement:
921        Code = bitc::CST_CODE_CE_INSERTELT;
922        Record.push_back(VE.getValueID(C->getOperand(0)));
923        Record.push_back(VE.getValueID(C->getOperand(1)));
924        Record.push_back(VE.getValueID(C->getOperand(2)));
925        break;
926      case Instruction::ShuffleVector:
927        // If the return type and argument types are the same, this is a
928        // standard shufflevector instruction.  If the types are different,
929        // then the shuffle is widening or truncating the input vectors, and
930        // the argument type must also be encoded.
931        if (C->getType() == C->getOperand(0)->getType()) {
932          Code = bitc::CST_CODE_CE_SHUFFLEVEC;
933        } else {
934          Code = bitc::CST_CODE_CE_SHUFVEC_EX;
935          Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
936        }
937        Record.push_back(VE.getValueID(C->getOperand(0)));
938        Record.push_back(VE.getValueID(C->getOperand(1)));
939        Record.push_back(VE.getValueID(C->getOperand(2)));
940        break;
941      case Instruction::ICmp:
942      case Instruction::FCmp:
943        Code = bitc::CST_CODE_CE_CMP;
944        Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
945        Record.push_back(VE.getValueID(C->getOperand(0)));
946        Record.push_back(VE.getValueID(C->getOperand(1)));
947        Record.push_back(CE->getPredicate());
948        break;
949      }
950    } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
951      Code = bitc::CST_CODE_BLOCKADDRESS;
952      Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
953      Record.push_back(VE.getValueID(BA->getFunction()));
954      Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
955    } else {
956#ifndef NDEBUG
957      C->dump();
958#endif
959      llvm_unreachable("Unknown constant!");
960    }
961    Stream.EmitRecord(Code, Record, AbbrevToUse);
962    Record.clear();
963  }
964
965  Stream.ExitBlock();
966}
967
968static void WriteModuleConstants(const ValueEnumerator &VE,
969                                 BitstreamWriter &Stream) {
970  const ValueEnumerator::ValueList &Vals = VE.getValues();
971
972  // Find the first constant to emit, which is the first non-globalvalue value.
973  // We know globalvalues have been emitted by WriteModuleInfo.
974  for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
975    if (!isa<GlobalValue>(Vals[i].first)) {
976      WriteConstants(i, Vals.size(), VE, Stream, true);
977      return;
978    }
979  }
980}
981
982/// PushValueAndType - The file has to encode both the value and type id for
983/// many values, because we need to know what type to create for forward
984/// references.  However, most operands are not forward references, so this type
985/// field is not needed.
986///
987/// This function adds V's value ID to Vals.  If the value ID is higher than the
988/// instruction ID, then it is a forward reference, and it also includes the
989/// type ID.
990static bool PushValueAndType(const Value *V, unsigned InstID,
991                             SmallVector<unsigned, 64> &Vals,
992                             ValueEnumerator &VE) {
993  unsigned ValID = VE.getValueID(V);
994  Vals.push_back(ValID);
995  if (ValID >= InstID) {
996    Vals.push_back(VE.getTypeID(V->getType()));
997    return true;
998  }
999  return false;
1000}
1001
1002/// WriteInstruction - Emit an instruction to the specified stream.
1003static void WriteInstruction(const Instruction &I, unsigned InstID,
1004                             ValueEnumerator &VE, BitstreamWriter &Stream,
1005                             SmallVector<unsigned, 64> &Vals) {
1006  unsigned Code = 0;
1007  unsigned AbbrevToUse = 0;
1008  VE.setInstructionID(&I);
1009  switch (I.getOpcode()) {
1010  default:
1011    if (Instruction::isCast(I.getOpcode())) {
1012      Code = bitc::FUNC_CODE_INST_CAST;
1013      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1014        AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1015      Vals.push_back(VE.getTypeID(I.getType()));
1016      Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1017    } else {
1018      assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1019      Code = bitc::FUNC_CODE_INST_BINOP;
1020      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1021        AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1022      Vals.push_back(VE.getValueID(I.getOperand(1)));
1023      Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1024      uint64_t Flags = GetOptimizationFlags(&I);
1025      if (Flags != 0) {
1026        if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1027          AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1028        Vals.push_back(Flags);
1029      }
1030    }
1031    break;
1032
1033  case Instruction::GetElementPtr:
1034    Code = bitc::FUNC_CODE_INST_GEP;
1035    if (cast<GEPOperator>(&I)->isInBounds())
1036      Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP;
1037    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1038      PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1039    break;
1040  case Instruction::ExtractValue: {
1041    Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1042    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1043    const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1044    for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1045      Vals.push_back(*i);
1046    break;
1047  }
1048  case Instruction::InsertValue: {
1049    Code = bitc::FUNC_CODE_INST_INSERTVAL;
1050    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1051    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1052    const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1053    for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1054      Vals.push_back(*i);
1055    break;
1056  }
1057  case Instruction::Select:
1058    Code = bitc::FUNC_CODE_INST_VSELECT;
1059    PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1060    Vals.push_back(VE.getValueID(I.getOperand(2)));
1061    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1062    break;
1063  case Instruction::ExtractElement:
1064    Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1065    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1066    Vals.push_back(VE.getValueID(I.getOperand(1)));
1067    break;
1068  case Instruction::InsertElement:
1069    Code = bitc::FUNC_CODE_INST_INSERTELT;
1070    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1071    Vals.push_back(VE.getValueID(I.getOperand(1)));
1072    Vals.push_back(VE.getValueID(I.getOperand(2)));
1073    break;
1074  case Instruction::ShuffleVector:
1075    Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1076    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1077    Vals.push_back(VE.getValueID(I.getOperand(1)));
1078    Vals.push_back(VE.getValueID(I.getOperand(2)));
1079    break;
1080  case Instruction::ICmp:
1081  case Instruction::FCmp:
1082    // compare returning Int1Ty or vector of Int1Ty
1083    Code = bitc::FUNC_CODE_INST_CMP2;
1084    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1085    Vals.push_back(VE.getValueID(I.getOperand(1)));
1086    Vals.push_back(cast<CmpInst>(I).getPredicate());
1087    break;
1088
1089  case Instruction::Ret:
1090    {
1091      Code = bitc::FUNC_CODE_INST_RET;
1092      unsigned NumOperands = I.getNumOperands();
1093      if (NumOperands == 0)
1094        AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1095      else if (NumOperands == 1) {
1096        if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1097          AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1098      } else {
1099        for (unsigned i = 0, e = NumOperands; i != e; ++i)
1100          PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1101      }
1102    }
1103    break;
1104  case Instruction::Br:
1105    {
1106      Code = bitc::FUNC_CODE_INST_BR;
1107      BranchInst &II = cast<BranchInst>(I);
1108      Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1109      if (II.isConditional()) {
1110        Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1111        Vals.push_back(VE.getValueID(II.getCondition()));
1112      }
1113    }
1114    break;
1115  case Instruction::Switch:
1116    Code = bitc::FUNC_CODE_INST_SWITCH;
1117    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1118    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1119      Vals.push_back(VE.getValueID(I.getOperand(i)));
1120    break;
1121  case Instruction::IndirectBr:
1122    Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1123    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1124    for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1125      Vals.push_back(VE.getValueID(I.getOperand(i)));
1126    break;
1127
1128  case Instruction::Invoke: {
1129    const InvokeInst *II = cast<InvokeInst>(&I);
1130    const Value *Callee(II->getCalledValue());
1131    PointerType *PTy = cast<PointerType>(Callee->getType());
1132    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1133    Code = bitc::FUNC_CODE_INST_INVOKE;
1134
1135    Vals.push_back(VE.getAttributeID(II->getAttributes()));
1136    Vals.push_back(II->getCallingConv());
1137    Vals.push_back(VE.getValueID(II->getNormalDest()));
1138    Vals.push_back(VE.getValueID(II->getUnwindDest()));
1139    PushValueAndType(Callee, InstID, Vals, VE);
1140
1141    // Emit value #'s for the fixed parameters.
1142    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1143      Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1144
1145    // Emit type/value pairs for varargs params.
1146    if (FTy->isVarArg()) {
1147      for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1148           i != e; ++i)
1149        PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1150    }
1151    break;
1152  }
1153  case Instruction::Resume:
1154    Code = bitc::FUNC_CODE_INST_RESUME;
1155    PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1156    break;
1157  case Instruction::Unwind:
1158    Code = bitc::FUNC_CODE_INST_UNWIND;
1159    break;
1160  case Instruction::Unreachable:
1161    Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1162    AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1163    break;
1164
1165  case Instruction::PHI: {
1166    const PHINode &PN = cast<PHINode>(I);
1167    Code = bitc::FUNC_CODE_INST_PHI;
1168    Vals.push_back(VE.getTypeID(PN.getType()));
1169    for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1170      Vals.push_back(VE.getValueID(PN.getIncomingValue(i)));
1171      Vals.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1172    }
1173    break;
1174  }
1175
1176  case Instruction::LandingPad: {
1177    const LandingPadInst &LP = cast<LandingPadInst>(I);
1178    Code = bitc::FUNC_CODE_INST_LANDINGPAD;
1179    Vals.push_back(VE.getTypeID(LP.getType()));
1180    PushValueAndType(LP.getPersonalityFn(), InstID, Vals, VE);
1181    Vals.push_back(LP.isCleanup());
1182    Vals.push_back(LP.getNumClauses());
1183    for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1184      if (LP.isCatch(I))
1185        Vals.push_back(LandingPadInst::Catch);
1186      else
1187        Vals.push_back(LandingPadInst::Filter);
1188      PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1189    }
1190    break;
1191  }
1192
1193  case Instruction::Alloca:
1194    Code = bitc::FUNC_CODE_INST_ALLOCA;
1195    Vals.push_back(VE.getTypeID(I.getType()));
1196    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1197    Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1198    Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1199    break;
1200
1201  case Instruction::Load:
1202    if (cast<LoadInst>(I).isAtomic()) {
1203      Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1204      PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1205    } else {
1206      Code = bitc::FUNC_CODE_INST_LOAD;
1207      if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1208        AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1209    }
1210    Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1211    Vals.push_back(cast<LoadInst>(I).isVolatile());
1212    if (cast<LoadInst>(I).isAtomic()) {
1213      Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1214      Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1215    }
1216    break;
1217  case Instruction::Store:
1218    if (cast<StoreInst>(I).isAtomic())
1219      Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1220    else
1221      Code = bitc::FUNC_CODE_INST_STORE;
1222    PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1223    Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1224    Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1225    Vals.push_back(cast<StoreInst>(I).isVolatile());
1226    if (cast<StoreInst>(I).isAtomic()) {
1227      Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1228      Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1229    }
1230    break;
1231  case Instruction::AtomicCmpXchg:
1232    Code = bitc::FUNC_CODE_INST_CMPXCHG;
1233    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1234    Vals.push_back(VE.getValueID(I.getOperand(1)));       // cmp.
1235    Vals.push_back(VE.getValueID(I.getOperand(2)));       // newval.
1236    Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1237    Vals.push_back(GetEncodedOrdering(
1238                     cast<AtomicCmpXchgInst>(I).getOrdering()));
1239    Vals.push_back(GetEncodedSynchScope(
1240                     cast<AtomicCmpXchgInst>(I).getSynchScope()));
1241    break;
1242  case Instruction::AtomicRMW:
1243    Code = bitc::FUNC_CODE_INST_ATOMICRMW;
1244    PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1245    Vals.push_back(VE.getValueID(I.getOperand(1)));       // val.
1246    Vals.push_back(GetEncodedRMWOperation(
1247                     cast<AtomicRMWInst>(I).getOperation()));
1248    Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
1249    Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
1250    Vals.push_back(GetEncodedSynchScope(
1251                     cast<AtomicRMWInst>(I).getSynchScope()));
1252    break;
1253  case Instruction::Fence:
1254    Code = bitc::FUNC_CODE_INST_FENCE;
1255    Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
1256    Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
1257    break;
1258  case Instruction::Call: {
1259    const CallInst &CI = cast<CallInst>(I);
1260    PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1261    FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1262
1263    Code = bitc::FUNC_CODE_INST_CALL;
1264
1265    Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1266    Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1267    PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1268
1269    // Emit value #'s for the fixed parameters.
1270    for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1271      Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1272
1273    // Emit type/value pairs for varargs params.
1274    if (FTy->isVarArg()) {
1275      for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1276           i != e; ++i)
1277        PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1278    }
1279    break;
1280  }
1281  case Instruction::VAArg:
1282    Code = bitc::FUNC_CODE_INST_VAARG;
1283    Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1284    Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1285    Vals.push_back(VE.getTypeID(I.getType())); // restype.
1286    break;
1287  }
1288
1289  Stream.EmitRecord(Code, Vals, AbbrevToUse);
1290  Vals.clear();
1291}
1292
1293// Emit names for globals/functions etc.
1294static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1295                                  const ValueEnumerator &VE,
1296                                  BitstreamWriter &Stream) {
1297  if (VST.empty()) return;
1298  Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1299
1300  // FIXME: Set up the abbrev, we know how many values there are!
1301  // FIXME: We know if the type names can use 7-bit ascii.
1302  SmallVector<unsigned, 64> NameVals;
1303
1304  for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1305       SI != SE; ++SI) {
1306
1307    const ValueName &Name = *SI;
1308
1309    // Figure out the encoding to use for the name.
1310    bool is7Bit = true;
1311    bool isChar6 = true;
1312    for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1313         C != E; ++C) {
1314      if (isChar6)
1315        isChar6 = BitCodeAbbrevOp::isChar6(*C);
1316      if ((unsigned char)*C & 128) {
1317        is7Bit = false;
1318        break;  // don't bother scanning the rest.
1319      }
1320    }
1321
1322    unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1323
1324    // VST_ENTRY:   [valueid, namechar x N]
1325    // VST_BBENTRY: [bbid, namechar x N]
1326    unsigned Code;
1327    if (isa<BasicBlock>(SI->getValue())) {
1328      Code = bitc::VST_CODE_BBENTRY;
1329      if (isChar6)
1330        AbbrevToUse = VST_BBENTRY_6_ABBREV;
1331    } else {
1332      Code = bitc::VST_CODE_ENTRY;
1333      if (isChar6)
1334        AbbrevToUse = VST_ENTRY_6_ABBREV;
1335      else if (is7Bit)
1336        AbbrevToUse = VST_ENTRY_7_ABBREV;
1337    }
1338
1339    NameVals.push_back(VE.getValueID(SI->getValue()));
1340    for (const char *P = Name.getKeyData(),
1341         *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1342      NameVals.push_back((unsigned char)*P);
1343
1344    // Emit the finished record.
1345    Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1346    NameVals.clear();
1347  }
1348  Stream.ExitBlock();
1349}
1350
1351/// WriteFunction - Emit a function body to the module stream.
1352static void WriteFunction(const Function &F, ValueEnumerator &VE,
1353                          BitstreamWriter &Stream) {
1354  Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1355  VE.incorporateFunction(F);
1356
1357  SmallVector<unsigned, 64> Vals;
1358
1359  // Emit the number of basic blocks, so the reader can create them ahead of
1360  // time.
1361  Vals.push_back(VE.getBasicBlocks().size());
1362  Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1363  Vals.clear();
1364
1365  // If there are function-local constants, emit them now.
1366  unsigned CstStart, CstEnd;
1367  VE.getFunctionConstantRange(CstStart, CstEnd);
1368  WriteConstants(CstStart, CstEnd, VE, Stream, false);
1369
1370  // If there is function-local metadata, emit it now.
1371  WriteFunctionLocalMetadata(F, VE, Stream);
1372
1373  // Keep a running idea of what the instruction ID is.
1374  unsigned InstID = CstEnd;
1375
1376  bool NeedsMetadataAttachment = false;
1377
1378  DebugLoc LastDL;
1379
1380  // Finally, emit all the instructions, in order.
1381  for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1382    for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1383         I != E; ++I) {
1384      WriteInstruction(*I, InstID, VE, Stream, Vals);
1385
1386      if (!I->getType()->isVoidTy())
1387        ++InstID;
1388
1389      // If the instruction has metadata, write a metadata attachment later.
1390      NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1391
1392      // If the instruction has a debug location, emit it.
1393      DebugLoc DL = I->getDebugLoc();
1394      if (DL.isUnknown()) {
1395        // nothing todo.
1396      } else if (DL == LastDL) {
1397        // Just repeat the same debug loc as last time.
1398        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1399      } else {
1400        MDNode *Scope, *IA;
1401        DL.getScopeAndInlinedAt(Scope, IA, I->getContext());
1402
1403        Vals.push_back(DL.getLine());
1404        Vals.push_back(DL.getCol());
1405        Vals.push_back(Scope ? VE.getValueID(Scope)+1 : 0);
1406        Vals.push_back(IA ? VE.getValueID(IA)+1 : 0);
1407        Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1408        Vals.clear();
1409
1410        LastDL = DL;
1411      }
1412    }
1413
1414  // Emit names for all the instructions etc.
1415  WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1416
1417  if (NeedsMetadataAttachment)
1418    WriteMetadataAttachment(F, VE, Stream);
1419  VE.purgeFunction();
1420  Stream.ExitBlock();
1421}
1422
1423// Emit blockinfo, which defines the standard abbreviations etc.
1424static void WriteBlockInfo(const ValueEnumerator &VE, BitstreamWriter &Stream) {
1425  // We only want to emit block info records for blocks that have multiple
1426  // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1427  // blocks can defined their abbrevs inline.
1428  Stream.EnterBlockInfoBlock(2);
1429
1430  { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1431    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1432    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1433    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1434    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1435    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1436    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1437                                   Abbv) != VST_ENTRY_8_ABBREV)
1438      llvm_unreachable("Unexpected abbrev ordering!");
1439  }
1440
1441  { // 7-bit fixed width VST_ENTRY strings.
1442    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1443    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1444    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1445    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1446    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1447    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1448                                   Abbv) != VST_ENTRY_7_ABBREV)
1449      llvm_unreachable("Unexpected abbrev ordering!");
1450  }
1451  { // 6-bit char6 VST_ENTRY strings.
1452    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1453    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1454    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1455    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1456    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1457    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1458                                   Abbv) != VST_ENTRY_6_ABBREV)
1459      llvm_unreachable("Unexpected abbrev ordering!");
1460  }
1461  { // 6-bit char6 VST_BBENTRY strings.
1462    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1463    Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1464    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1465    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1466    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1467    if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1468                                   Abbv) != VST_BBENTRY_6_ABBREV)
1469      llvm_unreachable("Unexpected abbrev ordering!");
1470  }
1471
1472
1473
1474  { // SETTYPE abbrev for CONSTANTS_BLOCK.
1475    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1476    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1477    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1478                              Log2_32_Ceil(VE.getTypes().size()+1)));
1479    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1480                                   Abbv) != CONSTANTS_SETTYPE_ABBREV)
1481      llvm_unreachable("Unexpected abbrev ordering!");
1482  }
1483
1484  { // INTEGER abbrev for CONSTANTS_BLOCK.
1485    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1486    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1487    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1488    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1489                                   Abbv) != CONSTANTS_INTEGER_ABBREV)
1490      llvm_unreachable("Unexpected abbrev ordering!");
1491  }
1492
1493  { // CE_CAST abbrev for CONSTANTS_BLOCK.
1494    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1495    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1496    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1497    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1498                              Log2_32_Ceil(VE.getTypes().size()+1)));
1499    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1500
1501    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1502                                   Abbv) != CONSTANTS_CE_CAST_Abbrev)
1503      llvm_unreachable("Unexpected abbrev ordering!");
1504  }
1505  { // NULL abbrev for CONSTANTS_BLOCK.
1506    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1507    Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1508    if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1509                                   Abbv) != CONSTANTS_NULL_Abbrev)
1510      llvm_unreachable("Unexpected abbrev ordering!");
1511  }
1512
1513  // FIXME: This should only use space for first class types!
1514
1515  { // INST_LOAD abbrev for FUNCTION_BLOCK.
1516    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1517    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1518    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1519    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1520    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1521    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1522                                   Abbv) != FUNCTION_INST_LOAD_ABBREV)
1523      llvm_unreachable("Unexpected abbrev ordering!");
1524  }
1525  { // INST_BINOP abbrev for FUNCTION_BLOCK.
1526    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1527    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1528    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1529    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1530    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1531    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1532                                   Abbv) != FUNCTION_INST_BINOP_ABBREV)
1533      llvm_unreachable("Unexpected abbrev ordering!");
1534  }
1535  { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1536    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1537    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1538    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1539    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1540    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1541    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1542    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1543                                   Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1544      llvm_unreachable("Unexpected abbrev ordering!");
1545  }
1546  { // INST_CAST abbrev for FUNCTION_BLOCK.
1547    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1548    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1549    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1550    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1551                              Log2_32_Ceil(VE.getTypes().size()+1)));
1552    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1553    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1554                                   Abbv) != FUNCTION_INST_CAST_ABBREV)
1555      llvm_unreachable("Unexpected abbrev ordering!");
1556  }
1557
1558  { // INST_RET abbrev for FUNCTION_BLOCK.
1559    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1560    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1561    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1562                                   Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1563      llvm_unreachable("Unexpected abbrev ordering!");
1564  }
1565  { // INST_RET abbrev for FUNCTION_BLOCK.
1566    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1567    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1568    Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1569    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1570                                   Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1571      llvm_unreachable("Unexpected abbrev ordering!");
1572  }
1573  { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1574    BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1575    Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1576    if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1577                                   Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1578      llvm_unreachable("Unexpected abbrev ordering!");
1579  }
1580
1581  Stream.ExitBlock();
1582}
1583
1584// Sort the Users based on the order in which the reader parses the bitcode
1585// file.
1586static bool bitcodereader_order(const User *lhs, const User *rhs) {
1587  // TODO: Implement.
1588  return true;
1589}
1590
1591static void WriteUseList(const Value *V, const ValueEnumerator &VE,
1592                         BitstreamWriter &Stream) {
1593
1594  // One or zero uses can't get out of order.
1595  if (V->use_empty() || V->hasNUses(1))
1596    return;
1597
1598  // Make a copy of the in-memory use-list for sorting.
1599  unsigned UseListSize = std::distance(V->use_begin(), V->use_end());
1600  SmallVector<const User*, 8> UseList;
1601  UseList.reserve(UseListSize);
1602  for (Value::const_use_iterator I = V->use_begin(), E = V->use_end();
1603       I != E; ++I) {
1604    const User *U = *I;
1605    UseList.push_back(U);
1606  }
1607
1608  // Sort the copy based on the order read by the BitcodeReader.
1609  std::sort(UseList.begin(), UseList.end(), bitcodereader_order);
1610
1611  // TODO: Generate a diff between the BitcodeWriter in-memory use-list and the
1612  // sorted list (i.e., the expected BitcodeReader in-memory use-list).
1613
1614  // TODO: Emit the USELIST_CODE_ENTRYs.
1615}
1616
1617static void WriteFunctionUseList(const Function *F, ValueEnumerator &VE,
1618                                 BitstreamWriter &Stream) {
1619  VE.incorporateFunction(*F);
1620
1621  for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end();
1622       AI != AE; ++AI)
1623    WriteUseList(AI, VE, Stream);
1624  for (Function::const_iterator BB = F->begin(), FE = F->end(); BB != FE;
1625       ++BB) {
1626    WriteUseList(BB, VE, Stream);
1627    for (BasicBlock::const_iterator II = BB->begin(), IE = BB->end(); II != IE;
1628         ++II) {
1629      WriteUseList(II, VE, Stream);
1630      for (User::const_op_iterator OI = II->op_begin(), E = II->op_end();
1631           OI != E; ++OI) {
1632        if ((isa<Constant>(*OI) && !isa<GlobalValue>(*OI)) ||
1633            isa<InlineAsm>(*OI))
1634          WriteUseList(*OI, VE, Stream);
1635      }
1636    }
1637  }
1638  VE.purgeFunction();
1639}
1640
1641// Emit use-lists.
1642static void WriteModuleUseLists(const Module *M, ValueEnumerator &VE,
1643                                BitstreamWriter &Stream) {
1644  Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
1645
1646  // XXX: this modifies the module, but in a way that should never change the
1647  // behavior of any pass or codegen in LLVM. The problem is that GVs may
1648  // contain entries in the use_list that do not exist in the Module and are
1649  // not stored in the .bc file.
1650  for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
1651       I != E; ++I)
1652    I->removeDeadConstantUsers();
1653
1654  // Write the global variables.
1655  for (Module::const_global_iterator GI = M->global_begin(),
1656         GE = M->global_end(); GI != GE; ++GI) {
1657    WriteUseList(GI, VE, Stream);
1658
1659    // Write the global variable initializers.
1660    if (GI->hasInitializer())
1661      WriteUseList(GI->getInitializer(), VE, Stream);
1662  }
1663
1664  // Write the functions.
1665  for (Module::const_iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI) {
1666    WriteUseList(FI, VE, Stream);
1667    if (!FI->isDeclaration())
1668      WriteFunctionUseList(FI, VE, Stream);
1669  }
1670
1671  // Write the aliases.
1672  for (Module::const_alias_iterator AI = M->alias_begin(), AE = M->alias_end();
1673       AI != AE; ++AI) {
1674    WriteUseList(AI, VE, Stream);
1675    WriteUseList(AI->getAliasee(), VE, Stream);
1676  }
1677
1678  Stream.ExitBlock();
1679}
1680
1681/// WriteModule - Emit the specified module to the bitstream.
1682static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1683  Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1684
1685  // Emit the version number if it is non-zero.
1686  if (CurVersion) {
1687    SmallVector<unsigned, 1> Vals;
1688    Vals.push_back(CurVersion);
1689    Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1690  }
1691
1692  // Analyze the module, enumerating globals, functions, etc.
1693  ValueEnumerator VE(M);
1694
1695  // Emit blockinfo, which defines the standard abbreviations etc.
1696  WriteBlockInfo(VE, Stream);
1697
1698  // Emit information about parameter attributes.
1699  WriteAttributeTable(VE, Stream);
1700
1701  // Emit information describing all of the types in the module.
1702  WriteTypeTable(VE, Stream);
1703
1704  // Emit top-level description of module, including target triple, inline asm,
1705  // descriptors for global variables, and function prototype info.
1706  WriteModuleInfo(M, VE, Stream);
1707
1708  // Emit constants.
1709  WriteModuleConstants(VE, Stream);
1710
1711  // Emit metadata.
1712  WriteModuleMetadata(M, VE, Stream);
1713
1714  // Emit function bodies.
1715  for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1716    if (!F->isDeclaration())
1717      WriteFunction(*F, VE, Stream);
1718
1719  // Emit metadata.
1720  WriteModuleMetadataStore(M, Stream);
1721
1722  // Emit names for globals/functions etc.
1723  WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1724
1725  // Emit use-lists.
1726  if (EnablePreserveUseListOrdering)
1727    WriteModuleUseLists(M, VE, Stream);
1728
1729  Stream.ExitBlock();
1730}
1731
1732/// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1733/// header and trailer to make it compatible with the system archiver.  To do
1734/// this we emit the following header, and then emit a trailer that pads the
1735/// file out to be a multiple of 16 bytes.
1736///
1737/// struct bc_header {
1738///   uint32_t Magic;         // 0x0B17C0DE
1739///   uint32_t Version;       // Version, currently always 0.
1740///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1741///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1742///   uint32_t CPUType;       // CPU specifier.
1743///   ... potentially more later ...
1744/// };
1745enum {
1746  DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1747  DarwinBCHeaderSize = 5*4
1748};
1749
1750static void EmitDarwinBCHeader(BitstreamWriter &Stream, const Triple &TT) {
1751  unsigned CPUType = ~0U;
1752
1753  // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1754  // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1755  // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1756  // specific constants here because they are implicitly part of the Darwin ABI.
1757  enum {
1758    DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1759    DARWIN_CPU_TYPE_X86        = 7,
1760    DARWIN_CPU_TYPE_ARM        = 12,
1761    DARWIN_CPU_TYPE_POWERPC    = 18
1762  };
1763
1764  Triple::ArchType Arch = TT.getArch();
1765  if (Arch == Triple::x86_64)
1766    CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1767  else if (Arch == Triple::x86)
1768    CPUType = DARWIN_CPU_TYPE_X86;
1769  else if (Arch == Triple::ppc)
1770    CPUType = DARWIN_CPU_TYPE_POWERPC;
1771  else if (Arch == Triple::ppc64)
1772    CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1773  else if (Arch == Triple::arm || Arch == Triple::thumb)
1774    CPUType = DARWIN_CPU_TYPE_ARM;
1775
1776  // Traditional Bitcode starts after header.
1777  unsigned BCOffset = DarwinBCHeaderSize;
1778
1779  Stream.Emit(0x0B17C0DE, 32);
1780  Stream.Emit(0         , 32);  // Version.
1781  Stream.Emit(BCOffset  , 32);
1782  Stream.Emit(0         , 32);  // Filled in later.
1783  Stream.Emit(CPUType   , 32);
1784}
1785
1786/// EmitDarwinBCTrailer - Emit the darwin epilog after the bitcode file and
1787/// finalize the header.
1788static void EmitDarwinBCTrailer(BitstreamWriter &Stream, unsigned BufferSize) {
1789  // Update the size field in the header.
1790  Stream.BackpatchWord(DarwinBCSizeFieldOffset, BufferSize-DarwinBCHeaderSize);
1791
1792  // If the file is not a multiple of 16 bytes, insert dummy padding.
1793  while (BufferSize & 15) {
1794    Stream.Emit(0, 8);
1795    ++BufferSize;
1796  }
1797}
1798
1799
1800/// WriteBitcodeToFile - Write the specified module to the specified output
1801/// stream.
1802void llvm::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1803  std::vector<unsigned char> Buffer;
1804  BitstreamWriter Stream(Buffer);
1805
1806  Buffer.reserve(256*1024);
1807
1808  WriteBitcodeToStream( M, Stream );
1809
1810  // Write the generated bitstream to "Out".
1811  Out.write((char*)&Buffer.front(), Buffer.size());
1812}
1813
1814/// WriteBitcodeToStream - Write the specified module to the specified output
1815/// stream.
1816void llvm::WriteBitcodeToStream(const Module *M, BitstreamWriter &Stream) {
1817  // If this is darwin or another generic macho target, emit a file header and
1818  // trailer if needed.
1819  Triple TT(M->getTargetTriple());
1820  if (TT.isOSDarwin())
1821    EmitDarwinBCHeader(Stream, TT);
1822
1823  // Emit the file header.
1824  Stream.Emit((unsigned)'B', 8);
1825  Stream.Emit((unsigned)'C', 8);
1826  Stream.Emit(0x0, 4);
1827  Stream.Emit(0xC, 4);
1828  Stream.Emit(0xE, 4);
1829  Stream.Emit(0xD, 4);
1830
1831  // Emit the module.
1832  WriteModule(M, Stream);
1833
1834  if (TT.isOSDarwin())
1835    EmitDarwinBCTrailer(Stream, Stream.getBuffer().size());
1836}
1837