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