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 "ReaderWriter_3_2.h"
15 #include "legacy_bitcode.h"
16 #include "ValueEnumerator.h"
17 #include "llvm/ADT/Triple.h"
18 #include "llvm/Bitcode/BitstreamWriter.h"
19 #include "llvm/Bitcode/LLVMBitCodes.h"
20 #include "llvm/IR/Constants.h"
21 #include "llvm/IR/DebugInfoMetadata.h"
22 #include "llvm/IR/DerivedTypes.h"
23 #include "llvm/IR/InlineAsm.h"
24 #include "llvm/IR/Instructions.h"
25 #include "llvm/IR/Module.h"
26 #include "llvm/IR/Operator.h"
27 #include "llvm/IR/UseListOrder.h"
28 #include "llvm/IR/ValueSymbolTable.h"
29 #include "llvm/Support/CommandLine.h"
30 #include "llvm/Support/ErrorHandling.h"
31 #include "llvm/Support/MathExtras.h"
32 #include "llvm/Support/Program.h"
33 #include "llvm/Support/raw_ostream.h"
34 #include <cctype>
35 #include <map>
36 using namespace llvm;
37 
38 /// These are manifest constants used by the bitcode writer. They do not need to
39 /// be kept in sync with the reader, but need to be consistent within this file.
40 enum {
41   // VALUE_SYMTAB_BLOCK abbrev id's.
42   VST_ENTRY_8_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
43   VST_ENTRY_7_ABBREV,
44   VST_ENTRY_6_ABBREV,
45   VST_BBENTRY_6_ABBREV,
46 
47   // CONSTANTS_BLOCK abbrev id's.
48   CONSTANTS_SETTYPE_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
49   CONSTANTS_INTEGER_ABBREV,
50   CONSTANTS_CE_CAST_Abbrev,
51   CONSTANTS_NULL_Abbrev,
52 
53   // FUNCTION_BLOCK abbrev id's.
54   FUNCTION_INST_LOAD_ABBREV = bitc::FIRST_APPLICATION_ABBREV,
55   FUNCTION_INST_BINOP_ABBREV,
56   FUNCTION_INST_BINOP_FLAGS_ABBREV,
57   FUNCTION_INST_CAST_ABBREV,
58   FUNCTION_INST_RET_VOID_ABBREV,
59   FUNCTION_INST_RET_VAL_ABBREV,
60   FUNCTION_INST_UNREACHABLE_ABBREV
61 };
62 
GetEncodedCastOpcode(unsigned Opcode)63 static unsigned GetEncodedCastOpcode(unsigned Opcode) {
64   switch (Opcode) {
65   default: llvm_unreachable("Unknown cast instruction!");
66   case Instruction::Trunc   : return bitc::CAST_TRUNC;
67   case Instruction::ZExt    : return bitc::CAST_ZEXT;
68   case Instruction::SExt    : return bitc::CAST_SEXT;
69   case Instruction::FPToUI  : return bitc::CAST_FPTOUI;
70   case Instruction::FPToSI  : return bitc::CAST_FPTOSI;
71   case Instruction::UIToFP  : return bitc::CAST_UITOFP;
72   case Instruction::SIToFP  : return bitc::CAST_SITOFP;
73   case Instruction::FPTrunc : return bitc::CAST_FPTRUNC;
74   case Instruction::FPExt   : return bitc::CAST_FPEXT;
75   case Instruction::PtrToInt: return bitc::CAST_PTRTOINT;
76   case Instruction::IntToPtr: return bitc::CAST_INTTOPTR;
77   case Instruction::BitCast : return bitc::CAST_BITCAST;
78   }
79 }
80 
GetEncodedBinaryOpcode(unsigned Opcode)81 static unsigned GetEncodedBinaryOpcode(unsigned Opcode) {
82   switch (Opcode) {
83   default: llvm_unreachable("Unknown binary instruction!");
84   case Instruction::Add:
85   case Instruction::FAdd: return bitc::BINOP_ADD;
86   case Instruction::Sub:
87   case Instruction::FSub: return bitc::BINOP_SUB;
88   case Instruction::Mul:
89   case Instruction::FMul: return bitc::BINOP_MUL;
90   case Instruction::UDiv: return bitc::BINOP_UDIV;
91   case Instruction::FDiv:
92   case Instruction::SDiv: return bitc::BINOP_SDIV;
93   case Instruction::URem: return bitc::BINOP_UREM;
94   case Instruction::FRem:
95   case Instruction::SRem: return bitc::BINOP_SREM;
96   case Instruction::Shl:  return bitc::BINOP_SHL;
97   case Instruction::LShr: return bitc::BINOP_LSHR;
98   case Instruction::AShr: return bitc::BINOP_ASHR;
99   case Instruction::And:  return bitc::BINOP_AND;
100   case Instruction::Or:   return bitc::BINOP_OR;
101   case Instruction::Xor:  return bitc::BINOP_XOR;
102   }
103 }
104 
GetEncodedRMWOperation(AtomicRMWInst::BinOp Op)105 static unsigned GetEncodedRMWOperation(AtomicRMWInst::BinOp Op) {
106   switch (Op) {
107   default: llvm_unreachable("Unknown RMW operation!");
108   case AtomicRMWInst::Xchg: return bitc::RMW_XCHG;
109   case AtomicRMWInst::Add: return bitc::RMW_ADD;
110   case AtomicRMWInst::Sub: return bitc::RMW_SUB;
111   case AtomicRMWInst::And: return bitc::RMW_AND;
112   case AtomicRMWInst::Nand: return bitc::RMW_NAND;
113   case AtomicRMWInst::Or: return bitc::RMW_OR;
114   case AtomicRMWInst::Xor: return bitc::RMW_XOR;
115   case AtomicRMWInst::Max: return bitc::RMW_MAX;
116   case AtomicRMWInst::Min: return bitc::RMW_MIN;
117   case AtomicRMWInst::UMax: return bitc::RMW_UMAX;
118   case AtomicRMWInst::UMin: return bitc::RMW_UMIN;
119   }
120 }
121 
GetEncodedOrdering(AtomicOrdering Ordering)122 static unsigned GetEncodedOrdering(AtomicOrdering Ordering) {
123   switch (Ordering) {
124   case AtomicOrdering::NotAtomic: return bitc::ORDERING_NOTATOMIC;
125   case AtomicOrdering::Unordered: return bitc::ORDERING_UNORDERED;
126   case AtomicOrdering::Monotonic: return bitc::ORDERING_MONOTONIC;
127   case AtomicOrdering::Acquire: return bitc::ORDERING_ACQUIRE;
128   case AtomicOrdering::Release: return bitc::ORDERING_RELEASE;
129   case AtomicOrdering::AcquireRelease: return bitc::ORDERING_ACQREL;
130   case AtomicOrdering::SequentiallyConsistent: return bitc::ORDERING_SEQCST;
131   }
132   llvm_unreachable("Invalid ordering");
133 }
134 
GetEncodedSynchScope(SynchronizationScope SynchScope)135 static unsigned GetEncodedSynchScope(SynchronizationScope SynchScope) {
136   switch (SynchScope) {
137   case SingleThread: return bitc::SYNCHSCOPE_SINGLETHREAD;
138   case CrossThread: return bitc::SYNCHSCOPE_CROSSTHREAD;
139   }
140   llvm_unreachable("Invalid synch scope");
141 }
142 
WriteStringRecord(unsigned Code,StringRef Str,unsigned AbbrevToUse,BitstreamWriter & Stream)143 static void WriteStringRecord(unsigned Code, StringRef Str,
144                               unsigned AbbrevToUse, BitstreamWriter &Stream) {
145   SmallVector<unsigned, 64> Vals;
146 
147   // Code: [strchar x N]
148   for (unsigned i = 0, e = Str.size(); i != e; ++i) {
149     if (AbbrevToUse && !BitCodeAbbrevOp::isChar6(Str[i]))
150       AbbrevToUse = 0;
151     Vals.push_back(Str[i]);
152   }
153 
154   // Emit the finished record.
155   Stream.EmitRecord(Code, Vals, AbbrevToUse);
156 }
157 
158 // Emit information about parameter attributes.
WriteAttributeTable(const llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream)159 static void WriteAttributeTable(const llvm_3_2::ValueEnumerator &VE,
160                                 BitstreamWriter &Stream) {
161   const std::vector<AttributeSet> &Attrs = VE.getAttributes();
162   if (Attrs.empty()) return;
163 
164   Stream.EnterSubblock(bitc::PARAMATTR_BLOCK_ID, 3);
165 
166   SmallVector<uint64_t, 64> Record;
167   for (unsigned i = 0, e = Attrs.size(); i != e; ++i) {
168     const AttributeSet &A = Attrs[i];
169     for (unsigned i = 0, e = A.getNumSlots(); i != e; ++i) {
170       Record.push_back(A.getSlotIndex(i));
171       Record.push_back(encodeLLVMAttributesForBitcode(A, A.getSlotIndex(i)));
172     }
173 
174     // This needs to use the 3.2 entry type
175     Stream.EmitRecord(bitc::PARAMATTR_CODE_ENTRY_OLD, Record);
176     Record.clear();
177   }
178 
179   Stream.ExitBlock();
180 }
181 
182 /// WriteTypeTable - Write out the type table for a module.
WriteTypeTable(const llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream)183 static void WriteTypeTable(const llvm_3_2::ValueEnumerator &VE,
184                            BitstreamWriter &Stream) {
185   const llvm_3_2::ValueEnumerator::TypeList &TypeList = VE.getTypes();
186 
187   Stream.EnterSubblock(bitc::TYPE_BLOCK_ID_NEW, 4 /*count from # abbrevs */);
188   SmallVector<uint64_t, 64> TypeVals;
189 
190   uint64_t NumBits = Log2_32_Ceil(VE.getTypes().size()+1);
191 
192   // Abbrev for TYPE_CODE_POINTER.
193   BitCodeAbbrev *Abbv = new BitCodeAbbrev();
194   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_POINTER));
195   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
196   Abbv->Add(BitCodeAbbrevOp(0));  // Addrspace = 0
197   unsigned PtrAbbrev = Stream.EmitAbbrev(Abbv);
198 
199   // Abbrev for TYPE_CODE_FUNCTION.
200   Abbv = new BitCodeAbbrev();
201   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_FUNCTION));
202   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // isvararg
203   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
204   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
205 
206   unsigned FunctionAbbrev = Stream.EmitAbbrev(Abbv);
207 
208   // Abbrev for TYPE_CODE_STRUCT_ANON.
209   Abbv = new BitCodeAbbrev();
210   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_ANON));
211   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
212   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
213   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
214 
215   unsigned StructAnonAbbrev = Stream.EmitAbbrev(Abbv);
216 
217   // Abbrev for TYPE_CODE_STRUCT_NAME.
218   Abbv = new BitCodeAbbrev();
219   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAME));
220   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
221   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
222   unsigned StructNameAbbrev = Stream.EmitAbbrev(Abbv);
223 
224   // Abbrev for TYPE_CODE_STRUCT_NAMED.
225   Abbv = new BitCodeAbbrev();
226   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_STRUCT_NAMED));
227   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));  // ispacked
228   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
229   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
230 
231   unsigned StructNamedAbbrev = Stream.EmitAbbrev(Abbv);
232 
233   // Abbrev for TYPE_CODE_ARRAY.
234   Abbv = new BitCodeAbbrev();
235   Abbv->Add(BitCodeAbbrevOp(bitc::TYPE_CODE_ARRAY));
236   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));   // size
237   Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, NumBits));
238 
239   unsigned ArrayAbbrev = Stream.EmitAbbrev(Abbv);
240 
241   // Emit an entry count so the reader can reserve space.
242   TypeVals.push_back(TypeList.size());
243   Stream.EmitRecord(bitc::TYPE_CODE_NUMENTRY, TypeVals);
244   TypeVals.clear();
245 
246   // Loop over all of the types, emitting each in turn.
247   for (unsigned i = 0, e = TypeList.size(); i != e; ++i) {
248     Type *T = TypeList[i];
249     int AbbrevToUse = 0;
250     unsigned Code = 0;
251 
252     switch (T->getTypeID()) {
253     default: llvm_unreachable("Unknown type!");
254     case Type::VoidTyID:      Code = bitc::TYPE_CODE_VOID;      break;
255     case Type::HalfTyID:      Code = bitc::TYPE_CODE_HALF;      break;
256     case Type::FloatTyID:     Code = bitc::TYPE_CODE_FLOAT;     break;
257     case Type::DoubleTyID:    Code = bitc::TYPE_CODE_DOUBLE;    break;
258     case Type::X86_FP80TyID:  Code = bitc::TYPE_CODE_X86_FP80;  break;
259     case Type::FP128TyID:     Code = bitc::TYPE_CODE_FP128;     break;
260     case Type::PPC_FP128TyID: Code = bitc::TYPE_CODE_PPC_FP128; break;
261     case Type::LabelTyID:     Code = bitc::TYPE_CODE_LABEL;     break;
262     case Type::MetadataTyID:  Code = bitc::TYPE_CODE_METADATA;  break;
263     case Type::X86_MMXTyID:   Code = bitc::TYPE_CODE_X86_MMX;   break;
264     case Type::IntegerTyID:
265       // INTEGER: [width]
266       Code = bitc::TYPE_CODE_INTEGER;
267       TypeVals.push_back(cast<IntegerType>(T)->getBitWidth());
268       break;
269     case Type::PointerTyID: {
270       PointerType *PTy = cast<PointerType>(T);
271       // POINTER: [pointee type, address space]
272       Code = bitc::TYPE_CODE_POINTER;
273       TypeVals.push_back(VE.getTypeID(PTy->getElementType()));
274       unsigned AddressSpace = PTy->getAddressSpace();
275       TypeVals.push_back(AddressSpace);
276       if (AddressSpace == 0) AbbrevToUse = PtrAbbrev;
277       break;
278     }
279     case Type::FunctionTyID: {
280       FunctionType *FT = cast<FunctionType>(T);
281       // FUNCTION: [isvararg, retty, paramty x N]
282       Code = bitc::TYPE_CODE_FUNCTION;
283       TypeVals.push_back(FT->isVarArg());
284       TypeVals.push_back(VE.getTypeID(FT->getReturnType()));
285       for (unsigned i = 0, e = FT->getNumParams(); i != e; ++i)
286         TypeVals.push_back(VE.getTypeID(FT->getParamType(i)));
287       AbbrevToUse = FunctionAbbrev;
288       break;
289     }
290     case Type::StructTyID: {
291       StructType *ST = cast<StructType>(T);
292       // STRUCT: [ispacked, eltty x N]
293       TypeVals.push_back(ST->isPacked());
294       // Output all of the element types.
295       for (StructType::element_iterator I = ST->element_begin(),
296            E = ST->element_end(); I != E; ++I)
297         TypeVals.push_back(VE.getTypeID(*I));
298 
299       if (ST->isLiteral()) {
300         Code = bitc::TYPE_CODE_STRUCT_ANON;
301         AbbrevToUse = StructAnonAbbrev;
302       } else {
303         if (ST->isOpaque()) {
304           Code = bitc::TYPE_CODE_OPAQUE;
305         } else {
306           Code = bitc::TYPE_CODE_STRUCT_NAMED;
307           AbbrevToUse = StructNamedAbbrev;
308         }
309 
310         // Emit the name if it is present.
311         if (!ST->getName().empty())
312           WriteStringRecord(bitc::TYPE_CODE_STRUCT_NAME, ST->getName(),
313                             StructNameAbbrev, Stream);
314       }
315       break;
316     }
317     case Type::ArrayTyID: {
318       ArrayType *AT = cast<ArrayType>(T);
319       // ARRAY: [numelts, eltty]
320       Code = bitc::TYPE_CODE_ARRAY;
321       TypeVals.push_back(AT->getNumElements());
322       TypeVals.push_back(VE.getTypeID(AT->getElementType()));
323       AbbrevToUse = ArrayAbbrev;
324       break;
325     }
326     case Type::VectorTyID: {
327       VectorType *VT = cast<VectorType>(T);
328       // VECTOR [numelts, eltty]
329       Code = bitc::TYPE_CODE_VECTOR;
330       TypeVals.push_back(VT->getNumElements());
331       TypeVals.push_back(VE.getTypeID(VT->getElementType()));
332       break;
333     }
334     }
335 
336     // Emit the finished record.
337     Stream.EmitRecord(Code, TypeVals, AbbrevToUse);
338     TypeVals.clear();
339   }
340 
341   Stream.ExitBlock();
342 }
343 
getEncodedLinkage(const GlobalValue & GV)344 static unsigned getEncodedLinkage(const GlobalValue &GV) {
345   switch (GV.getLinkage()) {
346   case GlobalValue::ExternalLinkage:
347     return 0;
348   case GlobalValue::WeakAnyLinkage:
349     return 1;
350   case GlobalValue::AppendingLinkage:
351     return 2;
352   case GlobalValue::InternalLinkage:
353     return 3;
354   case GlobalValue::LinkOnceAnyLinkage:
355     return 4;
356   case GlobalValue::ExternalWeakLinkage:
357     return 7;
358   case GlobalValue::CommonLinkage:
359     return 8;
360   case GlobalValue::PrivateLinkage:
361     return 9;
362   case GlobalValue::WeakODRLinkage:
363     return 10;
364   case GlobalValue::LinkOnceODRLinkage:
365     return 11;
366   case GlobalValue::AvailableExternallyLinkage:
367     return 12;
368   }
369   llvm_unreachable("Invalid linkage");
370 }
371 
getEncodedVisibility(const GlobalValue & GV)372 static unsigned getEncodedVisibility(const GlobalValue &GV) {
373   switch (GV.getVisibility()) {
374   case GlobalValue::DefaultVisibility:   return 0;
375   case GlobalValue::HiddenVisibility:    return 1;
376   case GlobalValue::ProtectedVisibility: return 2;
377   }
378   llvm_unreachable("Invalid visibility");
379 }
380 
getEncodedThreadLocalMode(const GlobalVariable & GV)381 static unsigned getEncodedThreadLocalMode(const GlobalVariable &GV) {
382   switch (GV.getThreadLocalMode()) {
383     case GlobalVariable::NotThreadLocal:         return 0;
384     case GlobalVariable::GeneralDynamicTLSModel: return 1;
385     case GlobalVariable::LocalDynamicTLSModel:   return 2;
386     case GlobalVariable::InitialExecTLSModel:    return 3;
387     case GlobalVariable::LocalExecTLSModel:      return 4;
388   }
389   llvm_unreachable("Invalid TLS model");
390 }
391 
392 // Emit top-level description of module, including target triple, inline asm,
393 // descriptors for global variables, and function prototype info.
WriteModuleInfo(const Module * M,const llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream)394 static void WriteModuleInfo(const Module *M,
395                             const llvm_3_2::ValueEnumerator &VE,
396                             BitstreamWriter &Stream) {
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   const std::string &DL = M->getDataLayoutStr();
402   if (!DL.empty())
403     WriteStringRecord(bitc::MODULE_CODE_DATALAYOUT, DL, 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 (const GlobalValue &GV : M->globals()) {
415     MaxAlignment = std::max(MaxAlignment, GV.getAlignment());
416     MaxGlobalType = std::max(MaxGlobalType, VE.getTypeID(GV.getType()));
417     if (GV.hasSection()) {
418       // Give section names unique ID's.
419       unsigned &Entry = SectionMap[GV.getSection()];
420       if (!Entry) {
421         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, GV.getSection(),
422                           0/*TODO*/, Stream);
423         Entry = SectionMap.size();
424       }
425     }
426   }
427   for (const Function &F : *M) {
428     MaxAlignment = std::max(MaxAlignment, F.getAlignment());
429     if (F.hasSection()) {
430       // Give section names unique ID's.
431       unsigned &Entry = SectionMap[F.getSection()];
432       if (!Entry) {
433         WriteStringRecord(bitc::MODULE_CODE_SECTIONNAME, F.getSection(),
434                           0/*TODO*/, Stream);
435         Entry = SectionMap.size();
436       }
437     }
438     if (F.hasGC()) {
439       // Same for GC names.
440       unsigned &Entry = GCMap[F.getGC()];
441       if (!Entry) {
442         WriteStringRecord(bitc::MODULE_CODE_GCNAME, F.getGC(),
443                           0/*TODO*/, Stream);
444         Entry = GCMap.size();
445       }
446     }
447   }
448 
449   // Emit abbrev for globals, now that we know # sections and max alignment.
450   unsigned SimpleGVarAbbrev = 0;
451   if (!M->global_empty()) {
452     // Add an abbrev for common globals with no visibility or thread localness.
453     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
454     Abbv->Add(BitCodeAbbrevOp(bitc::MODULE_CODE_GLOBALVAR));
455     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
456                               Log2_32_Ceil(MaxGlobalType+1)));
457     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));      // Constant.
458     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));        // Initializer.
459     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));      // Linkage.
460     if (MaxAlignment == 0)                                      // Alignment.
461       Abbv->Add(BitCodeAbbrevOp(0));
462     else {
463       unsigned MaxEncAlignment = Log2_32(MaxAlignment)+1;
464       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
465                                Log2_32_Ceil(MaxEncAlignment+1)));
466     }
467     if (SectionMap.empty())                                    // Section.
468       Abbv->Add(BitCodeAbbrevOp(0));
469     else
470       Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
471                                Log2_32_Ceil(SectionMap.size()+1)));
472     // Don't bother emitting vis + thread local.
473     SimpleGVarAbbrev = Stream.EmitAbbrev(Abbv);
474   }
475 
476   // Emit the global variable information.
477   SmallVector<unsigned, 64> Vals;
478   for (const GlobalVariable &GV : M->globals()) {
479     unsigned AbbrevToUse = 0;
480 
481     // GLOBALVAR: [type, isconst, initid,
482     //             linkage, alignment, section, visibility, threadlocal,
483     //             unnamed_addr]
484     Vals.push_back(VE.getTypeID(GV.getType()));
485     Vals.push_back(GV.isConstant());
486     Vals.push_back(GV.isDeclaration() ? 0 :
487                    (VE.getValueID(GV.getInitializer()) + 1));
488     Vals.push_back(getEncodedLinkage(GV));
489     Vals.push_back(Log2_32(GV.getAlignment())+1);
490     Vals.push_back(GV.hasSection() ? SectionMap[GV.getSection()] : 0);
491     if (GV.isThreadLocal() ||
492         GV.getVisibility() != GlobalValue::DefaultVisibility ||
493         GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None ||
494         GV.isExternallyInitialized()) {
495       Vals.push_back(getEncodedVisibility(GV));
496       Vals.push_back(getEncodedThreadLocalMode(GV));
497       Vals.push_back(GV.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
498       Vals.push_back(GV.isExternallyInitialized());
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 (const Function &F : *M) {
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.getUnnamedAddr() != GlobalValue::UnnamedAddr::None);
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 (const GlobalAlias &A : M->aliases()) {
529     // ALIAS: [alias type, aliasee val#, linkage, visibility]
530     Vals.push_back(VE.getTypeID(A.getType()));
531     Vals.push_back(VE.getValueID(A.getAliasee()));
532     Vals.push_back(getEncodedLinkage(A));
533     Vals.push_back(getEncodedVisibility(A));
534     unsigned AbbrevToUse = 0;
535     Stream.EmitRecord(bitc::MODULE_CODE_ALIAS_OLD, Vals, AbbrevToUse);
536     Vals.clear();
537   }
538 }
539 
GetOptimizationFlags(const Value * V)540 static uint64_t GetOptimizationFlags(const Value *V) {
541   uint64_t Flags = 0;
542 
543   if (const auto *OBO = dyn_cast<OverflowingBinaryOperator>(V)) {
544     if (OBO->hasNoSignedWrap())
545       Flags |= 1 << bitc::OBO_NO_SIGNED_WRAP;
546     if (OBO->hasNoUnsignedWrap())
547       Flags |= 1 << bitc::OBO_NO_UNSIGNED_WRAP;
548   } else if (const auto *PEO = dyn_cast<PossiblyExactOperator>(V)) {
549     if (PEO->isExact())
550       Flags |= 1 << bitc::PEO_EXACT;
551   } else if (const auto *FPMO = dyn_cast<FPMathOperator>(V)) {
552     // FIXME(srhines): We don't handle fast math in llvm-rs-cc today.
553     if (false) {
554       if (FPMO->hasUnsafeAlgebra())
555         Flags |= FastMathFlags::UnsafeAlgebra;
556       if (FPMO->hasNoNaNs())
557         Flags |= FastMathFlags::NoNaNs;
558       if (FPMO->hasNoInfs())
559         Flags |= FastMathFlags::NoInfs;
560       if (FPMO->hasNoSignedZeros())
561         Flags |= FastMathFlags::NoSignedZeros;
562       if (FPMO->hasAllowReciprocal())
563         Flags |= FastMathFlags::AllowReciprocal;
564     }
565   }
566 
567   return Flags;
568 }
569 
WriteValueAsMetadata(const ValueAsMetadata * MD,const llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream,SmallVectorImpl<uint64_t> & Record)570 static void WriteValueAsMetadata(const ValueAsMetadata *MD,
571                                  const llvm_3_2::ValueEnumerator &VE,
572                                  BitstreamWriter &Stream,
573                                  SmallVectorImpl<uint64_t> &Record) {
574   // Mimic an MDNode with a value as one operand.
575   Value *V = MD->getValue();
576   Record.push_back(VE.getTypeID(V->getType()));
577   Record.push_back(VE.getValueID(V));
578   Stream.EmitRecord(bitc::METADATA_OLD_NODE, Record, 0);
579   Record.clear();
580 }
581 
WriteMDTuple(const MDTuple * N,const llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream,SmallVectorImpl<uint64_t> & Record,unsigned Abbrev)582 static void WriteMDTuple(const MDTuple *N, const llvm_3_2::ValueEnumerator &VE,
583                          BitstreamWriter &Stream,
584                          SmallVectorImpl<uint64_t> &Record, unsigned Abbrev) {
585   for (unsigned i = 0, e = N->getNumOperands(); i != e; ++i) {
586     Metadata *MD = N->getOperand(i);
587     assert(!(MD && isa<LocalAsMetadata>(MD)) &&
588            "Unexpected function-local metadata");
589     if (!MD) {
590       // TODO(srhines): I don't believe this case can exist for RS.
591       Record.push_back(VE.getTypeID(llvm::Type::getVoidTy(N->getContext())));
592       Record.push_back(0);
593     } else if (const auto *MDC = dyn_cast<ConstantAsMetadata>(MD)) {
594       Record.push_back(VE.getTypeID(MDC->getType()));
595       Record.push_back(VE.getValueID(MDC->getValue()));
596     } else {
597       Record.push_back(VE.getTypeID(
598           llvm::Type::getMetadataTy(N->getContext())));
599       Record.push_back(VE.getMetadataID(MD));
600     }
601   }
602   Stream.EmitRecord(bitc::METADATA_OLD_NODE, Record, Abbrev);
603   Record.clear();
604 }
605 
606 /*static void WriteMDLocation(const MDLocation *N, const llvm_3_2::ValueEnumerator &VE,
607                             BitstreamWriter &Stream,
608                             SmallVectorImpl<uint64_t> &Record,
609                             unsigned Abbrev) {
610   Record.push_back(N->isDistinct());
611   Record.push_back(N->getLine());
612   Record.push_back(N->getColumn());
613   Record.push_back(VE.getMetadataID(N->getScope()));
614   Record.push_back(VE.getMetadataOrNullID(N->getInlinedAt()));
615 
616   Stream.EmitRecord(bitc::METADATA_LOCATION, Record, Abbrev);
617   Record.clear();
618 }
619 
620 static void WriteGenericDebugNode(const GenericDebugNode *,
621                                   const llvm_3_2::ValueEnumerator &, BitstreamWriter &,
622                                   SmallVectorImpl<uint64_t> &, unsigned) {
623   llvm_unreachable("unimplemented");
624 }*/
625 
WriteModuleMetadata(const Module * M,const llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream)626 static void WriteModuleMetadata(const Module *M,
627                                 const llvm_3_2::ValueEnumerator &VE,
628                                 BitstreamWriter &Stream) {
629   const auto &MDs = VE.getMDs();
630   if (MDs.empty() && M->named_metadata_empty())
631     return;
632 
633   // RenderScript files *ALWAYS* have metadata!
634   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
635 
636   unsigned MDSAbbrev = 0;
637   if (VE.hasMDString()) {
638     // Abbrev for METADATA_STRING.
639     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
640     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_STRING_OLD));
641     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
642     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
643     MDSAbbrev = Stream.EmitAbbrev(Abbv);
644   }
645 
646   unsigned MDLocationAbbrev = 0;
647   if (VE.hasDILocation()) {
648     // TODO(srhines): Should be unreachable for RenderScript.
649     // Abbrev for METADATA_LOCATION.
650     //
651     // Assume the column is usually under 128, and always output the inlined-at
652     // location (it's never more expensive than building an array size 1).
653     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
654     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_LOCATION));
655     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1));
656     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
657     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
658     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
659     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));
660     MDLocationAbbrev = Stream.EmitAbbrev(Abbv);
661   }
662 
663   unsigned NameAbbrev = 0;
664   if (!M->named_metadata_empty()) {
665     // Abbrev for METADATA_NAME.
666     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
667     Abbv->Add(BitCodeAbbrevOp(bitc::METADATA_NAME));
668     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
669     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
670     NameAbbrev = Stream.EmitAbbrev(Abbv);
671   }
672 
673   unsigned MDTupleAbbrev = 0;
674   //unsigned GenericDebugNodeAbbrev = 0;
675   SmallVector<uint64_t, 64> Record;
676   for (const Metadata *MD : MDs) {
677     if (const MDNode *N = dyn_cast<MDNode>(MD)) {
678       switch (N->getMetadataID()) {
679       default:
680         llvm_unreachable("Invalid MDNode subclass");
681 #define HANDLE_SPECIALIZED_MDNODE_LEAF(CLASS)
682 #define HANDLE_MDNODE_LEAF(CLASS)                                              \
683   case Metadata::CLASS##Kind:                                                  \
684     Write##CLASS(cast<CLASS>(N), VE, Stream, Record, CLASS##Abbrev);           \
685     continue;
686 #include "llvm/IR/Metadata.def"
687       }
688     }
689     if (const auto *MDC = dyn_cast<ConstantAsMetadata>(MD)) {
690       WriteValueAsMetadata(MDC, VE, Stream, Record);
691       continue;
692     }
693     const MDString *MDS = cast<MDString>(MD);
694     // Code: [strchar x N]
695     Record.append(MDS->bytes_begin(), MDS->bytes_end());
696 
697     // Emit the finished record.
698     Stream.EmitRecord(bitc::METADATA_STRING_OLD, Record, MDSAbbrev);
699     Record.clear();
700   }
701 
702   // Write named metadata.
703   for (const NamedMDNode &NMD : M->named_metadata()) {
704     // Write name.
705     StringRef Str = NMD.getName();
706     Record.append(Str.bytes_begin(), Str.bytes_end());
707     Stream.EmitRecord(bitc::METADATA_NAME, Record, NameAbbrev);
708     Record.clear();
709 
710     // Write named metadata operands.
711     for (const MDNode *N : NMD.operands())
712       Record.push_back(VE.getMetadataID(N));
713     Stream.EmitRecord(bitc::METADATA_NAMED_NODE, Record, 0);
714     Record.clear();
715   }
716 
717   Stream.ExitBlock();
718 }
719 
WriteFunctionLocalMetadata(const Function & F,const llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream)720 static void WriteFunctionLocalMetadata(const Function &F,
721                                        const llvm_3_2::ValueEnumerator &VE,
722                                        BitstreamWriter &Stream) {
723   bool StartedMetadataBlock = false;
724   SmallVector<uint64_t, 64> Record;
725   const SmallVectorImpl<const LocalAsMetadata *> &MDs =
726       VE.getFunctionLocalMDs();
727   for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
728     assert(MDs[i] && "Expected valid function-local metadata");
729     if (!StartedMetadataBlock) {
730       Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
731       StartedMetadataBlock = true;
732     }
733     WriteValueAsMetadata(MDs[i], VE, Stream, Record);
734   }
735 
736   if (StartedMetadataBlock)
737     Stream.ExitBlock();
738 }
739 
WriteMetadataAttachment(const Function & F,const llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream)740 static void WriteMetadataAttachment(const Function &F,
741                                     const llvm_3_2::ValueEnumerator &VE,
742                                     BitstreamWriter &Stream) {
743   Stream.EnterSubblock(bitc::METADATA_ATTACHMENT_ID, 3);
744 
745   SmallVector<uint64_t, 64> Record;
746 
747   // Write metadata attachments
748   // METADATA_ATTACHMENT - [m x [value, [n x [id, mdnode]]]
749   SmallVector<std::pair<unsigned, MDNode *>, 4> MDs;
750 
751   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
752     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
753          I != E; ++I) {
754       MDs.clear();
755       I->getAllMetadataOtherThanDebugLoc(MDs);
756 
757       // If no metadata, ignore instruction.
758       if (MDs.empty()) continue;
759 
760       Record.push_back(VE.getInstructionID(&*I));
761 
762       for (unsigned i = 0, e = MDs.size(); i != e; ++i) {
763         Record.push_back(MDs[i].first);
764         Record.push_back(VE.getMetadataID(MDs[i].second));
765       }
766       Stream.EmitRecord(bitc::METADATA_ATTACHMENT, Record, 0);
767       Record.clear();
768     }
769 
770   Stream.ExitBlock();
771 }
772 
WriteModuleMetadataStore(const Module * M,BitstreamWriter & Stream)773 static void WriteModuleMetadataStore(const Module *M, BitstreamWriter &Stream) {
774   SmallVector<uint64_t, 64> Record;
775 
776   // Write metadata kinds
777   // METADATA_KIND - [n x [id, name]]
778   SmallVector<StringRef, 4> Names;
779   M->getMDKindNames(Names);
780 
781   if (Names.empty()) return;
782 
783   Stream.EnterSubblock(bitc::METADATA_BLOCK_ID, 3);
784 
785   for (unsigned MDKindID = 0, e = Names.size(); MDKindID != e; ++MDKindID) {
786     Record.push_back(MDKindID);
787     StringRef KName = Names[MDKindID];
788     Record.append(KName.begin(), KName.end());
789 
790     Stream.EmitRecord(bitc::METADATA_KIND, Record, 0);
791     Record.clear();
792   }
793 
794   Stream.ExitBlock();
795 }
796 
emitSignedInt64(SmallVectorImpl<uint64_t> & Vals,uint64_t V)797 static void emitSignedInt64(SmallVectorImpl<uint64_t> &Vals, uint64_t V) {
798   if ((int64_t)V >= 0)
799     Vals.push_back(V << 1);
800   else
801     Vals.push_back((-V << 1) | 1);
802 }
803 
WriteConstants(unsigned FirstVal,unsigned LastVal,const llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream,bool isGlobal)804 static void WriteConstants(unsigned FirstVal, unsigned LastVal,
805                            const llvm_3_2::ValueEnumerator &VE,
806                            BitstreamWriter &Stream, bool isGlobal) {
807   if (FirstVal == LastVal) return;
808 
809   Stream.EnterSubblock(bitc::CONSTANTS_BLOCK_ID, 4);
810 
811   unsigned AggregateAbbrev = 0;
812   unsigned String8Abbrev = 0;
813   unsigned CString7Abbrev = 0;
814   unsigned CString6Abbrev = 0;
815   // If this is a constant pool for the module, emit module-specific abbrevs.
816   if (isGlobal) {
817     // Abbrev for CST_CODE_AGGREGATE.
818     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
819     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_AGGREGATE));
820     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
821     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, Log2_32_Ceil(LastVal+1)));
822     AggregateAbbrev = Stream.EmitAbbrev(Abbv);
823 
824     // Abbrev for CST_CODE_STRING.
825     Abbv = new BitCodeAbbrev();
826     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_STRING));
827     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
828     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
829     String8Abbrev = Stream.EmitAbbrev(Abbv);
830     // Abbrev for CST_CODE_CSTRING.
831     Abbv = new BitCodeAbbrev();
832     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
833     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
834     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
835     CString7Abbrev = Stream.EmitAbbrev(Abbv);
836     // Abbrev for CST_CODE_CSTRING.
837     Abbv = new BitCodeAbbrev();
838     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CSTRING));
839     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
840     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
841     CString6Abbrev = Stream.EmitAbbrev(Abbv);
842   }
843 
844   SmallVector<uint64_t, 64> Record;
845 
846   const llvm_3_2::ValueEnumerator::ValueList &Vals = VE.getValues();
847   Type *LastTy = nullptr;
848   for (unsigned i = FirstVal; i != LastVal; ++i) {
849     const Value *V = Vals[i].first;
850     // If we need to switch types, do so now.
851     if (V->getType() != LastTy) {
852       LastTy = V->getType();
853       Record.push_back(VE.getTypeID(LastTy));
854       Stream.EmitRecord(bitc::CST_CODE_SETTYPE, Record,
855                         CONSTANTS_SETTYPE_ABBREV);
856       Record.clear();
857     }
858 
859     if (const InlineAsm *IA = dyn_cast<InlineAsm>(V)) {
860       Record.push_back(unsigned(IA->hasSideEffects()) |
861                        unsigned(IA->isAlignStack()) << 1 |
862                        unsigned(IA->getDialect()&1) << 2);
863 
864       // Add the asm string.
865       const std::string &AsmStr = IA->getAsmString();
866       Record.push_back(AsmStr.size());
867       for (unsigned i = 0, e = AsmStr.size(); i != e; ++i)
868         Record.push_back(AsmStr[i]);
869 
870       // Add the constraint string.
871       const std::string &ConstraintStr = IA->getConstraintString();
872       Record.push_back(ConstraintStr.size());
873       for (unsigned i = 0, e = ConstraintStr.size(); i != e; ++i)
874         Record.push_back(ConstraintStr[i]);
875       Stream.EmitRecord(bitc::CST_CODE_INLINEASM, Record);
876       Record.clear();
877       continue;
878     }
879     const Constant *C = cast<Constant>(V);
880     unsigned Code = -1U;
881     unsigned AbbrevToUse = 0;
882     if (C->isNullValue()) {
883       Code = bitc::CST_CODE_NULL;
884     } else if (isa<UndefValue>(C)) {
885       Code = bitc::CST_CODE_UNDEF;
886     } else if (const ConstantInt *IV = dyn_cast<ConstantInt>(C)) {
887       if (IV->getBitWidth() <= 64) {
888         uint64_t V = IV->getSExtValue();
889         emitSignedInt64(Record, V);
890         Code = bitc::CST_CODE_INTEGER;
891         AbbrevToUse = CONSTANTS_INTEGER_ABBREV;
892       } else {                             // Wide integers, > 64 bits in size.
893         // We have an arbitrary precision integer value to write whose
894         // bit width is > 64. However, in canonical unsigned integer
895         // format it is likely that the high bits are going to be zero.
896         // So, we only write the number of active words.
897         unsigned NWords = IV->getValue().getActiveWords();
898         const uint64_t *RawWords = IV->getValue().getRawData();
899         for (unsigned i = 0; i != NWords; ++i) {
900           emitSignedInt64(Record, RawWords[i]);
901         }
902         Code = bitc::CST_CODE_WIDE_INTEGER;
903       }
904     } else if (const ConstantFP *CFP = dyn_cast<ConstantFP>(C)) {
905       Code = bitc::CST_CODE_FLOAT;
906       Type *Ty = CFP->getType();
907       if (Ty->isHalfTy() || Ty->isFloatTy() || Ty->isDoubleTy()) {
908         Record.push_back(CFP->getValueAPF().bitcastToAPInt().getZExtValue());
909       } else if (Ty->isX86_FP80Ty()) {
910         // api needed to prevent premature destruction
911         // bits are not in the same order as a normal i80 APInt, compensate.
912         APInt api = CFP->getValueAPF().bitcastToAPInt();
913         const uint64_t *p = api.getRawData();
914         Record.push_back((p[1] << 48) | (p[0] >> 16));
915         Record.push_back(p[0] & 0xffffLL);
916       } else if (Ty->isFP128Ty() || Ty->isPPC_FP128Ty()) {
917         APInt api = CFP->getValueAPF().bitcastToAPInt();
918         const uint64_t *p = api.getRawData();
919         Record.push_back(p[0]);
920         Record.push_back(p[1]);
921       } else {
922         assert (0 && "Unknown FP type!");
923       }
924     } else if (isa<ConstantDataSequential>(C) &&
925                cast<ConstantDataSequential>(C)->isString()) {
926       const ConstantDataSequential *Str = cast<ConstantDataSequential>(C);
927       // Emit constant strings specially.
928       unsigned NumElts = Str->getNumElements();
929       // If this is a null-terminated string, use the denser CSTRING encoding.
930       if (Str->isCString()) {
931         Code = bitc::CST_CODE_CSTRING;
932         --NumElts;  // Don't encode the null, which isn't allowed by char6.
933       } else {
934         Code = bitc::CST_CODE_STRING;
935         AbbrevToUse = String8Abbrev;
936       }
937       bool isCStr7 = Code == bitc::CST_CODE_CSTRING;
938       bool isCStrChar6 = Code == bitc::CST_CODE_CSTRING;
939       for (unsigned i = 0; i != NumElts; ++i) {
940         unsigned char V = Str->getElementAsInteger(i);
941         Record.push_back(V);
942         isCStr7 &= (V & 128) == 0;
943         if (isCStrChar6)
944           isCStrChar6 = BitCodeAbbrevOp::isChar6(V);
945       }
946 
947       if (isCStrChar6)
948         AbbrevToUse = CString6Abbrev;
949       else if (isCStr7)
950         AbbrevToUse = CString7Abbrev;
951     } else if (const ConstantDataSequential *CDS =
952                   dyn_cast<ConstantDataSequential>(C)) {
953       Code = bitc::CST_CODE_DATA;
954       Type *EltTy = CDS->getType()->getElementType();
955       if (isa<IntegerType>(EltTy)) {
956         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
957           Record.push_back(CDS->getElementAsInteger(i));
958       } else {
959         for (unsigned i = 0, e = CDS->getNumElements(); i != e; ++i)
960           Record.push_back(
961               CDS->getElementAsAPFloat(i).bitcastToAPInt().getLimitedValue());
962       }
963     } else if (isa<ConstantArray>(C) || isa<ConstantStruct>(C) ||
964                isa<ConstantVector>(C)) {
965       Code = bitc::CST_CODE_AGGREGATE;
966       for (unsigned i = 0, e = C->getNumOperands(); i != e; ++i)
967         Record.push_back(VE.getValueID(C->getOperand(i)));
968       AbbrevToUse = AggregateAbbrev;
969     } else if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
970       switch (CE->getOpcode()) {
971       default:
972         if (Instruction::isCast(CE->getOpcode())) {
973           Code = bitc::CST_CODE_CE_CAST;
974           Record.push_back(GetEncodedCastOpcode(CE->getOpcode()));
975           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
976           Record.push_back(VE.getValueID(C->getOperand(0)));
977           AbbrevToUse = CONSTANTS_CE_CAST_Abbrev;
978         } else {
979           assert(CE->getNumOperands() == 2 && "Unknown constant expr!");
980           Code = bitc::CST_CODE_CE_BINOP;
981           Record.push_back(GetEncodedBinaryOpcode(CE->getOpcode()));
982           Record.push_back(VE.getValueID(C->getOperand(0)));
983           Record.push_back(VE.getValueID(C->getOperand(1)));
984           uint64_t Flags = GetOptimizationFlags(CE);
985           if (Flags != 0)
986             Record.push_back(Flags);
987         }
988         break;
989       case Instruction::GetElementPtr:
990         Code = bitc::CST_CODE_CE_GEP;
991         if (cast<GEPOperator>(C)->isInBounds())
992           Code = bitc::CST_CODE_CE_INBOUNDS_GEP;
993         for (unsigned i = 0, e = CE->getNumOperands(); i != e; ++i) {
994           Record.push_back(VE.getTypeID(C->getOperand(i)->getType()));
995           Record.push_back(VE.getValueID(C->getOperand(i)));
996         }
997         break;
998       case Instruction::Select:
999         Code = bitc::CST_CODE_CE_SELECT;
1000         Record.push_back(VE.getValueID(C->getOperand(0)));
1001         Record.push_back(VE.getValueID(C->getOperand(1)));
1002         Record.push_back(VE.getValueID(C->getOperand(2)));
1003         break;
1004       case Instruction::ExtractElement:
1005         Code = bitc::CST_CODE_CE_EXTRACTELT;
1006         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1007         Record.push_back(VE.getValueID(C->getOperand(0)));
1008         Record.push_back(VE.getValueID(C->getOperand(1)));
1009         break;
1010       case Instruction::InsertElement:
1011         Code = bitc::CST_CODE_CE_INSERTELT;
1012         Record.push_back(VE.getValueID(C->getOperand(0)));
1013         Record.push_back(VE.getValueID(C->getOperand(1)));
1014         Record.push_back(VE.getValueID(C->getOperand(2)));
1015         break;
1016       case Instruction::ShuffleVector:
1017         // If the return type and argument types are the same, this is a
1018         // standard shufflevector instruction.  If the types are different,
1019         // then the shuffle is widening or truncating the input vectors, and
1020         // the argument type must also be encoded.
1021         if (C->getType() == C->getOperand(0)->getType()) {
1022           Code = bitc::CST_CODE_CE_SHUFFLEVEC;
1023         } else {
1024           Code = bitc::CST_CODE_CE_SHUFVEC_EX;
1025           Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1026         }
1027         Record.push_back(VE.getValueID(C->getOperand(0)));
1028         Record.push_back(VE.getValueID(C->getOperand(1)));
1029         Record.push_back(VE.getValueID(C->getOperand(2)));
1030         break;
1031       case Instruction::ICmp:
1032       case Instruction::FCmp:
1033         Code = bitc::CST_CODE_CE_CMP;
1034         Record.push_back(VE.getTypeID(C->getOperand(0)->getType()));
1035         Record.push_back(VE.getValueID(C->getOperand(0)));
1036         Record.push_back(VE.getValueID(C->getOperand(1)));
1037         Record.push_back(CE->getPredicate());
1038         break;
1039       }
1040     } else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
1041       Code = bitc::CST_CODE_BLOCKADDRESS;
1042       Record.push_back(VE.getTypeID(BA->getFunction()->getType()));
1043       Record.push_back(VE.getValueID(BA->getFunction()));
1044       Record.push_back(VE.getGlobalBasicBlockID(BA->getBasicBlock()));
1045     } else {
1046 #ifndef NDEBUG
1047       C->dump();
1048 #endif
1049       llvm_unreachable("Unknown constant!");
1050     }
1051     Stream.EmitRecord(Code, Record, AbbrevToUse);
1052     Record.clear();
1053   }
1054 
1055   Stream.ExitBlock();
1056 }
1057 
WriteModuleConstants(const llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream)1058 static void WriteModuleConstants(const llvm_3_2::ValueEnumerator &VE,
1059                                  BitstreamWriter &Stream) {
1060   const llvm_3_2::ValueEnumerator::ValueList &Vals = VE.getValues();
1061 
1062   // Find the first constant to emit, which is the first non-globalvalue value.
1063   // We know globalvalues have been emitted by WriteModuleInfo.
1064   for (unsigned i = 0, e = Vals.size(); i != e; ++i) {
1065     if (!isa<GlobalValue>(Vals[i].first)) {
1066       WriteConstants(i, Vals.size(), VE, Stream, true);
1067       return;
1068     }
1069   }
1070 }
1071 
1072 /// PushValueAndType - The file has to encode both the value and type id for
1073 /// many values, because we need to know what type to create for forward
1074 /// references.  However, most operands are not forward references, so this type
1075 /// field is not needed.
1076 ///
1077 /// This function adds V's value ID to Vals.  If the value ID is higher than the
1078 /// instruction ID, then it is a forward reference, and it also includes the
1079 /// type ID.
PushValueAndType(const Value * V,unsigned InstID,SmallVector<unsigned,64> & Vals,llvm_3_2::ValueEnumerator & VE)1080 static bool PushValueAndType(const Value *V, unsigned InstID,
1081                              SmallVector<unsigned, 64> &Vals,
1082                              llvm_3_2::ValueEnumerator &VE) {
1083   unsigned ValID = VE.getValueID(V);
1084   Vals.push_back(ValID);
1085   if (ValID >= InstID) {
1086     Vals.push_back(VE.getTypeID(V->getType()));
1087     return true;
1088   }
1089   return false;
1090 }
1091 
1092 /// WriteInstruction - Emit an instruction to the specified stream.
WriteInstruction(const Instruction & I,unsigned InstID,llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream,SmallVector<unsigned,64> & Vals)1093 static void WriteInstruction(const Instruction &I, unsigned InstID,
1094                              llvm_3_2::ValueEnumerator &VE,
1095                              BitstreamWriter &Stream,
1096                              SmallVector<unsigned, 64> &Vals) {
1097   unsigned Code = 0;
1098   unsigned AbbrevToUse = 0;
1099   VE.setInstructionID(&I);
1100   switch (I.getOpcode()) {
1101   default:
1102     if (Instruction::isCast(I.getOpcode())) {
1103       Code = bitc::FUNC_CODE_INST_CAST;
1104       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1105         AbbrevToUse = FUNCTION_INST_CAST_ABBREV;
1106       Vals.push_back(VE.getTypeID(I.getType()));
1107       Vals.push_back(GetEncodedCastOpcode(I.getOpcode()));
1108     } else {
1109       assert(isa<BinaryOperator>(I) && "Unknown instruction!");
1110       Code = bitc::FUNC_CODE_INST_BINOP;
1111       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1112         AbbrevToUse = FUNCTION_INST_BINOP_ABBREV;
1113       Vals.push_back(VE.getValueID(I.getOperand(1)));
1114       Vals.push_back(GetEncodedBinaryOpcode(I.getOpcode()));
1115       uint64_t Flags = GetOptimizationFlags(&I);
1116       if (Flags != 0) {
1117         if (AbbrevToUse == FUNCTION_INST_BINOP_ABBREV)
1118           AbbrevToUse = FUNCTION_INST_BINOP_FLAGS_ABBREV;
1119         Vals.push_back(Flags);
1120       }
1121     }
1122     break;
1123 
1124   case Instruction::GetElementPtr:
1125     Code = bitc::FUNC_CODE_INST_GEP_OLD;
1126     if (cast<GEPOperator>(&I)->isInBounds())
1127       Code = bitc::FUNC_CODE_INST_INBOUNDS_GEP_OLD;
1128     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1129       PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1130     break;
1131   case Instruction::ExtractValue: {
1132     Code = bitc::FUNC_CODE_INST_EXTRACTVAL;
1133     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1134     const ExtractValueInst *EVI = cast<ExtractValueInst>(&I);
1135     for (const unsigned *i = EVI->idx_begin(), *e = EVI->idx_end(); i != e; ++i)
1136       Vals.push_back(*i);
1137     break;
1138   }
1139   case Instruction::InsertValue: {
1140     Code = bitc::FUNC_CODE_INST_INSERTVAL;
1141     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1142     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1143     const InsertValueInst *IVI = cast<InsertValueInst>(&I);
1144     for (const unsigned *i = IVI->idx_begin(), *e = IVI->idx_end(); i != e; ++i)
1145       Vals.push_back(*i);
1146     break;
1147   }
1148   case Instruction::Select:
1149     Code = bitc::FUNC_CODE_INST_VSELECT;
1150     PushValueAndType(I.getOperand(1), InstID, Vals, VE);
1151     Vals.push_back(VE.getValueID(I.getOperand(2)));
1152     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1153     break;
1154   case Instruction::ExtractElement:
1155     Code = bitc::FUNC_CODE_INST_EXTRACTELT;
1156     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1157     Vals.push_back(VE.getValueID(I.getOperand(1)));
1158     break;
1159   case Instruction::InsertElement:
1160     Code = bitc::FUNC_CODE_INST_INSERTELT;
1161     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1162     Vals.push_back(VE.getValueID(I.getOperand(1)));
1163     Vals.push_back(VE.getValueID(I.getOperand(2)));
1164     break;
1165   case Instruction::ShuffleVector:
1166     Code = bitc::FUNC_CODE_INST_SHUFFLEVEC;
1167     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1168     Vals.push_back(VE.getValueID(I.getOperand(1)));
1169     Vals.push_back(VE.getValueID(I.getOperand(2)));
1170     break;
1171   case Instruction::ICmp:
1172   case Instruction::FCmp:
1173     // compare returning Int1Ty or vector of Int1Ty
1174     Code = bitc::FUNC_CODE_INST_CMP2;
1175     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1176     Vals.push_back(VE.getValueID(I.getOperand(1)));
1177     Vals.push_back(cast<CmpInst>(I).getPredicate());
1178     break;
1179 
1180   case Instruction::Ret:
1181     {
1182       Code = bitc::FUNC_CODE_INST_RET;
1183       unsigned NumOperands = I.getNumOperands();
1184       if (NumOperands == 0)
1185         AbbrevToUse = FUNCTION_INST_RET_VOID_ABBREV;
1186       else if (NumOperands == 1) {
1187         if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))
1188           AbbrevToUse = FUNCTION_INST_RET_VAL_ABBREV;
1189       } else {
1190         for (unsigned i = 0, e = NumOperands; i != e; ++i)
1191           PushValueAndType(I.getOperand(i), InstID, Vals, VE);
1192       }
1193     }
1194     break;
1195   case Instruction::Br:
1196     {
1197       Code = bitc::FUNC_CODE_INST_BR;
1198       const BranchInst &II = cast<BranchInst>(I);
1199       Vals.push_back(VE.getValueID(II.getSuccessor(0)));
1200       if (II.isConditional()) {
1201         Vals.push_back(VE.getValueID(II.getSuccessor(1)));
1202         Vals.push_back(VE.getValueID(II.getCondition()));
1203       }
1204     }
1205     break;
1206   case Instruction::Switch:
1207     {
1208       Code = bitc::FUNC_CODE_INST_SWITCH;
1209       const SwitchInst &SI = cast<SwitchInst>(I);
1210       Vals.push_back(VE.getTypeID(SI.getCondition()->getType()));
1211       Vals.push_back(VE.getValueID(SI.getCondition()));
1212       Vals.push_back(VE.getValueID(SI.getDefaultDest()));
1213       for (SwitchInst::ConstCaseIt i = SI.case_begin(), e = SI.case_end();
1214            i != e; ++i) {
1215         Vals.push_back(VE.getValueID(i.getCaseValue()));
1216         Vals.push_back(VE.getValueID(i.getCaseSuccessor()));
1217       }
1218     }
1219     break;
1220   case Instruction::IndirectBr:
1221     Code = bitc::FUNC_CODE_INST_INDIRECTBR;
1222     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1223     for (unsigned i = 0, e = I.getNumOperands(); i != e; ++i)
1224       Vals.push_back(VE.getValueID(I.getOperand(i)));
1225     break;
1226 
1227   case Instruction::Invoke: {
1228     const InvokeInst *II = cast<InvokeInst>(&I);
1229     const Value *Callee(II->getCalledValue());
1230     PointerType *PTy = cast<PointerType>(Callee->getType());
1231     FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1232     Code = bitc::FUNC_CODE_INST_INVOKE;
1233 
1234     Vals.push_back(VE.getAttributeID(II->getAttributes()));
1235     Vals.push_back(II->getCallingConv());
1236     Vals.push_back(VE.getValueID(II->getNormalDest()));
1237     Vals.push_back(VE.getValueID(II->getUnwindDest()));
1238     PushValueAndType(Callee, InstID, Vals, VE);
1239 
1240     // Emit value #'s for the fixed parameters.
1241     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1242       Vals.push_back(VE.getValueID(I.getOperand(i)));  // fixed param.
1243 
1244     // Emit type/value pairs for varargs params.
1245     if (FTy->isVarArg()) {
1246       for (unsigned i = FTy->getNumParams(), e = I.getNumOperands()-3;
1247            i != e; ++i)
1248         PushValueAndType(I.getOperand(i), InstID, Vals, VE); // vararg
1249     }
1250     break;
1251   }
1252   case Instruction::Resume:
1253     Code = bitc::FUNC_CODE_INST_RESUME;
1254     PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1255     break;
1256   case Instruction::Unreachable:
1257     Code = bitc::FUNC_CODE_INST_UNREACHABLE;
1258     AbbrevToUse = FUNCTION_INST_UNREACHABLE_ABBREV;
1259     break;
1260 
1261   case Instruction::PHI: {
1262     const PHINode &PN = cast<PHINode>(I);
1263     Code = bitc::FUNC_CODE_INST_PHI;
1264     Vals.push_back(VE.getTypeID(PN.getType()));
1265     for (unsigned i = 0, e = PN.getNumIncomingValues(); i != e; ++i) {
1266       Vals.push_back(VE.getValueID(PN.getIncomingValue(i)));
1267       Vals.push_back(VE.getValueID(PN.getIncomingBlock(i)));
1268     }
1269     break;
1270   }
1271 
1272   case Instruction::LandingPad: {
1273     const LandingPadInst &LP = cast<LandingPadInst>(I);
1274     Code = bitc::FUNC_CODE_INST_LANDINGPAD_OLD;
1275     Vals.push_back(VE.getTypeID(LP.getType()));
1276     // TODO (rebase): is this fix enough?
1277     // PushValueAndType(LP.getPersonalityFn(), InstID, Vals, VE);
1278     Vals.push_back(LP.isCleanup());
1279     Vals.push_back(LP.getNumClauses());
1280     for (unsigned I = 0, E = LP.getNumClauses(); I != E; ++I) {
1281       if (LP.isCatch(I))
1282         Vals.push_back(LandingPadInst::Catch);
1283       else
1284         Vals.push_back(LandingPadInst::Filter);
1285       PushValueAndType(LP.getClause(I), InstID, Vals, VE);
1286     }
1287     break;
1288   }
1289 
1290   case Instruction::Alloca: {
1291     Code = bitc::FUNC_CODE_INST_ALLOCA;
1292     Vals.push_back(VE.getTypeID(I.getType()));
1293     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));
1294     Vals.push_back(VE.getValueID(I.getOperand(0))); // size.
1295     Vals.push_back(Log2_32(cast<AllocaInst>(I).getAlignment())+1);
1296     break;
1297   }
1298 
1299   case Instruction::Load:
1300     if (cast<LoadInst>(I).isAtomic()) {
1301       Code = bitc::FUNC_CODE_INST_LOADATOMIC;
1302       PushValueAndType(I.getOperand(0), InstID, Vals, VE);
1303     } else {
1304       Code = bitc::FUNC_CODE_INST_LOAD;
1305       if (!PushValueAndType(I.getOperand(0), InstID, Vals, VE))  // ptr
1306         AbbrevToUse = FUNCTION_INST_LOAD_ABBREV;
1307     }
1308     Vals.push_back(Log2_32(cast<LoadInst>(I).getAlignment())+1);
1309     Vals.push_back(cast<LoadInst>(I).isVolatile());
1310     if (cast<LoadInst>(I).isAtomic()) {
1311       Vals.push_back(GetEncodedOrdering(cast<LoadInst>(I).getOrdering()));
1312       Vals.push_back(GetEncodedSynchScope(cast<LoadInst>(I).getSynchScope()));
1313     }
1314     break;
1315   case Instruction::Store:
1316     if (cast<StoreInst>(I).isAtomic())
1317       Code = bitc::FUNC_CODE_INST_STOREATOMIC;
1318     else
1319       Code = bitc::FUNC_CODE_INST_STORE_OLD;
1320     PushValueAndType(I.getOperand(1), InstID, Vals, VE);  // ptrty + ptr
1321     Vals.push_back(VE.getValueID(I.getOperand(0)));       // val.
1322     Vals.push_back(Log2_32(cast<StoreInst>(I).getAlignment())+1);
1323     Vals.push_back(cast<StoreInst>(I).isVolatile());
1324     if (cast<StoreInst>(I).isAtomic()) {
1325       Vals.push_back(GetEncodedOrdering(cast<StoreInst>(I).getOrdering()));
1326       Vals.push_back(GetEncodedSynchScope(cast<StoreInst>(I).getSynchScope()));
1327     }
1328     break;
1329   case Instruction::AtomicCmpXchg:
1330     Code = bitc::FUNC_CODE_INST_CMPXCHG;
1331     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1332     Vals.push_back(VE.getValueID(I.getOperand(1)));       // cmp.
1333     Vals.push_back(VE.getValueID(I.getOperand(2)));       // newval.
1334     Vals.push_back(cast<AtomicCmpXchgInst>(I).isVolatile());
1335     Vals.push_back(GetEncodedOrdering(
1336                      cast<AtomicCmpXchgInst>(I).getSuccessOrdering()));
1337     Vals.push_back(GetEncodedSynchScope(
1338                      cast<AtomicCmpXchgInst>(I).getSynchScope()));
1339     break;
1340   case Instruction::AtomicRMW:
1341     Code = bitc::FUNC_CODE_INST_ATOMICRMW;
1342     PushValueAndType(I.getOperand(0), InstID, Vals, VE);  // ptrty + ptr
1343     Vals.push_back(VE.getValueID(I.getOperand(1)));       // val.
1344     Vals.push_back(GetEncodedRMWOperation(
1345                      cast<AtomicRMWInst>(I).getOperation()));
1346     Vals.push_back(cast<AtomicRMWInst>(I).isVolatile());
1347     Vals.push_back(GetEncodedOrdering(cast<AtomicRMWInst>(I).getOrdering()));
1348     Vals.push_back(GetEncodedSynchScope(
1349                      cast<AtomicRMWInst>(I).getSynchScope()));
1350     break;
1351   case Instruction::Fence:
1352     Code = bitc::FUNC_CODE_INST_FENCE;
1353     Vals.push_back(GetEncodedOrdering(cast<FenceInst>(I).getOrdering()));
1354     Vals.push_back(GetEncodedSynchScope(cast<FenceInst>(I).getSynchScope()));
1355     break;
1356   case Instruction::Call: {
1357     const CallInst &CI = cast<CallInst>(I);
1358     PointerType *PTy = cast<PointerType>(CI.getCalledValue()->getType());
1359     FunctionType *FTy = cast<FunctionType>(PTy->getElementType());
1360 
1361     Code = bitc::FUNC_CODE_INST_CALL;
1362 
1363     Vals.push_back(VE.getAttributeID(CI.getAttributes()));
1364     Vals.push_back((CI.getCallingConv() << 1) | unsigned(CI.isTailCall()));
1365     PushValueAndType(CI.getCalledValue(), InstID, Vals, VE);  // Callee
1366 
1367     // Emit value #'s for the fixed parameters.
1368     for (unsigned i = 0, e = FTy->getNumParams(); i != e; ++i)
1369       Vals.push_back(VE.getValueID(CI.getArgOperand(i)));  // fixed param.
1370 
1371     // Emit type/value pairs for varargs params.
1372     if (FTy->isVarArg()) {
1373       for (unsigned i = FTy->getNumParams(), e = CI.getNumArgOperands();
1374            i != e; ++i)
1375         PushValueAndType(CI.getArgOperand(i), InstID, Vals, VE);  // varargs
1376     }
1377     break;
1378   }
1379   case Instruction::VAArg:
1380     Code = bitc::FUNC_CODE_INST_VAARG;
1381     Vals.push_back(VE.getTypeID(I.getOperand(0)->getType()));   // valistty
1382     Vals.push_back(VE.getValueID(I.getOperand(0))); // valist.
1383     Vals.push_back(VE.getTypeID(I.getType())); // restype.
1384     break;
1385   }
1386 
1387   Stream.EmitRecord(Code, Vals, AbbrevToUse);
1388   Vals.clear();
1389 }
1390 
1391 // Emit names for globals/functions etc.
WriteValueSymbolTable(const ValueSymbolTable & VST,const llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream)1392 static void WriteValueSymbolTable(const ValueSymbolTable &VST,
1393                                   const llvm_3_2::ValueEnumerator &VE,
1394                                   BitstreamWriter &Stream) {
1395   if (VST.empty()) return;
1396   Stream.EnterSubblock(bitc::VALUE_SYMTAB_BLOCK_ID, 4);
1397 
1398   // FIXME: Set up the abbrev, we know how many values there are!
1399   // FIXME: We know if the type names can use 7-bit ascii.
1400   SmallVector<unsigned, 64> NameVals;
1401 
1402   for (ValueSymbolTable::const_iterator SI = VST.begin(), SE = VST.end();
1403        SI != SE; ++SI) {
1404 
1405     const ValueName &Name = *SI;
1406 
1407     // Figure out the encoding to use for the name.
1408     bool is7Bit = true;
1409     bool isChar6 = true;
1410     for (const char *C = Name.getKeyData(), *E = C+Name.getKeyLength();
1411          C != E; ++C) {
1412       if (isChar6)
1413         isChar6 = BitCodeAbbrevOp::isChar6(*C);
1414       if ((unsigned char)*C & 128) {
1415         is7Bit = false;
1416         break;  // don't bother scanning the rest.
1417       }
1418     }
1419 
1420     unsigned AbbrevToUse = VST_ENTRY_8_ABBREV;
1421 
1422     // VST_ENTRY:   [valueid, namechar x N]
1423     // VST_BBENTRY: [bbid, namechar x N]
1424     unsigned Code;
1425     if (isa<BasicBlock>(SI->getValue())) {
1426       Code = bitc::VST_CODE_BBENTRY;
1427       if (isChar6)
1428         AbbrevToUse = VST_BBENTRY_6_ABBREV;
1429     } else {
1430       Code = bitc::VST_CODE_ENTRY;
1431       if (isChar6)
1432         AbbrevToUse = VST_ENTRY_6_ABBREV;
1433       else if (is7Bit)
1434         AbbrevToUse = VST_ENTRY_7_ABBREV;
1435     }
1436 
1437     NameVals.push_back(VE.getValueID(SI->getValue()));
1438     for (const char *P = Name.getKeyData(),
1439          *E = Name.getKeyData()+Name.getKeyLength(); P != E; ++P)
1440       NameVals.push_back((unsigned char)*P);
1441 
1442     // Emit the finished record.
1443     Stream.EmitRecord(Code, NameVals, AbbrevToUse);
1444     NameVals.clear();
1445   }
1446   Stream.ExitBlock();
1447 }
1448 
WriteUseList(llvm_3_2::ValueEnumerator & VE,UseListOrder && Order,BitstreamWriter & Stream)1449 static void WriteUseList(llvm_3_2::ValueEnumerator &VE, UseListOrder &&Order,
1450                          BitstreamWriter &Stream) {
1451   assert(Order.Shuffle.size() >= 2 && "Shuffle too small");
1452   unsigned Code;
1453   if (isa<BasicBlock>(Order.V))
1454     Code = bitc::USELIST_CODE_BB;
1455   else
1456     Code = bitc::USELIST_CODE_DEFAULT;
1457 
1458   SmallVector<uint64_t, 64> Record;
1459   for (unsigned I : Order.Shuffle)
1460     Record.push_back(I);
1461   Record.push_back(VE.getValueID(Order.V));
1462   Stream.EmitRecord(Code, Record);
1463 }
1464 
WriteUseListBlock(const Function * F,llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream)1465 static void WriteUseListBlock(const Function *F, llvm_3_2::ValueEnumerator &VE,
1466                               BitstreamWriter &Stream) {
1467   auto hasMore = [&]() {
1468     return !VE.UseListOrders.empty() && VE.UseListOrders.back().F == F;
1469   };
1470   if (!hasMore())
1471     // Nothing to do.
1472     return;
1473 
1474   Stream.EnterSubblock(bitc::USELIST_BLOCK_ID, 3);
1475   while (hasMore()) {
1476     WriteUseList(VE, std::move(VE.UseListOrders.back()), Stream);
1477     VE.UseListOrders.pop_back();
1478   }
1479   Stream.ExitBlock();
1480 }
1481 
1482 /// WriteFunction - Emit a function body to the module stream.
WriteFunction(const Function & F,llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream)1483 static void WriteFunction(const Function &F, llvm_3_2::ValueEnumerator &VE,
1484                           BitstreamWriter &Stream) {
1485   Stream.EnterSubblock(bitc::FUNCTION_BLOCK_ID, 4);
1486   VE.incorporateFunction(F);
1487 
1488   SmallVector<unsigned, 64> Vals;
1489 
1490   // Emit the number of basic blocks, so the reader can create them ahead of
1491   // time.
1492   Vals.push_back(VE.getBasicBlocks().size());
1493   Stream.EmitRecord(bitc::FUNC_CODE_DECLAREBLOCKS, Vals);
1494   Vals.clear();
1495 
1496   // If there are function-local constants, emit them now.
1497   unsigned CstStart, CstEnd;
1498   VE.getFunctionConstantRange(CstStart, CstEnd);
1499   WriteConstants(CstStart, CstEnd, VE, Stream, false);
1500 
1501   // If there is function-local metadata, emit it now.
1502   WriteFunctionLocalMetadata(F, VE, Stream);
1503 
1504   // Keep a running idea of what the instruction ID is.
1505   unsigned InstID = CstEnd;
1506 
1507   bool NeedsMetadataAttachment = false;
1508 
1509   DILocation *LastDL = nullptr;
1510 
1511   // Finally, emit all the instructions, in order.
1512   for (Function::const_iterator BB = F.begin(), E = F.end(); BB != E; ++BB)
1513     for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
1514          I != E; ++I) {
1515       WriteInstruction(*I, InstID, VE, Stream, Vals);
1516 
1517       if (!I->getType()->isVoidTy())
1518         ++InstID;
1519 
1520       // If the instruction has metadata, write a metadata attachment later.
1521       NeedsMetadataAttachment |= I->hasMetadataOtherThanDebugLoc();
1522 
1523       // If the instruction has a debug location, emit it.
1524       DILocation *DL = I->getDebugLoc();
1525       if (!DL)
1526         continue;
1527 
1528       if (DL == LastDL) {
1529         // Just repeat the same debug loc as last time.
1530         Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC_AGAIN, Vals);
1531         continue;
1532       }
1533 
1534       Vals.push_back(DL->getLine());
1535       Vals.push_back(DL->getColumn());
1536       Vals.push_back(VE.getMetadataOrNullID(DL->getScope()));
1537       Vals.push_back(VE.getMetadataOrNullID(DL->getInlinedAt()));
1538       Stream.EmitRecord(bitc::FUNC_CODE_DEBUG_LOC, Vals);
1539       Vals.clear();
1540 
1541       // Fixme(pirama): The following line is missing from upstream
1542       // https://llvm.org/bugs/show_bug.cgi?id=23436
1543       LastDL = DL;
1544     }
1545 
1546   // Emit names for all the instructions etc.
1547   WriteValueSymbolTable(F.getValueSymbolTable(), VE, Stream);
1548 
1549   if (NeedsMetadataAttachment)
1550     WriteMetadataAttachment(F, VE, Stream);
1551   if (false)
1552     WriteUseListBlock(&F, VE, Stream);
1553   VE.purgeFunction();
1554   Stream.ExitBlock();
1555 }
1556 
1557 // Emit blockinfo, which defines the standard abbreviations etc.
WriteBlockInfo(const llvm_3_2::ValueEnumerator & VE,BitstreamWriter & Stream)1558 static void WriteBlockInfo(const llvm_3_2::ValueEnumerator &VE,
1559                            BitstreamWriter &Stream) {
1560   // We only want to emit block info records for blocks that have multiple
1561   // instances: CONSTANTS_BLOCK, FUNCTION_BLOCK and VALUE_SYMTAB_BLOCK.  Other
1562   // blocks can defined their abbrevs inline.
1563   Stream.EnterBlockInfoBlock(2);
1564 
1565   { // 8-bit fixed-width VST_ENTRY/VST_BBENTRY strings.
1566     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1567     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 3));
1568     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1569     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1570     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 8));
1571     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1572                                    Abbv) != VST_ENTRY_8_ABBREV)
1573       llvm_unreachable("Unexpected abbrev ordering!");
1574   }
1575 
1576   { // 7-bit fixed width VST_ENTRY strings.
1577     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1578     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1579     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1580     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1581     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7));
1582     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1583                                    Abbv) != VST_ENTRY_7_ABBREV)
1584       llvm_unreachable("Unexpected abbrev ordering!");
1585   }
1586   { // 6-bit char6 VST_ENTRY strings.
1587     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1588     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_ENTRY));
1589     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1590     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1591     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1592     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1593                                    Abbv) != VST_ENTRY_6_ABBREV)
1594       llvm_unreachable("Unexpected abbrev ordering!");
1595   }
1596   { // 6-bit char6 VST_BBENTRY strings.
1597     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1598     Abbv->Add(BitCodeAbbrevOp(bitc::VST_CODE_BBENTRY));
1599     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1600     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Array));
1601     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Char6));
1602     if (Stream.EmitBlockInfoAbbrev(bitc::VALUE_SYMTAB_BLOCK_ID,
1603                                    Abbv) != VST_BBENTRY_6_ABBREV)
1604       llvm_unreachable("Unexpected abbrev ordering!");
1605   }
1606 
1607 
1608 
1609   { // SETTYPE abbrev for CONSTANTS_BLOCK.
1610     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1611     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_SETTYPE));
1612     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,
1613                               Log2_32_Ceil(VE.getTypes().size()+1)));
1614     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1615                                    Abbv) != CONSTANTS_SETTYPE_ABBREV)
1616       llvm_unreachable("Unexpected abbrev ordering!");
1617   }
1618 
1619   { // INTEGER abbrev for CONSTANTS_BLOCK.
1620     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1621     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_INTEGER));
1622     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));
1623     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1624                                    Abbv) != CONSTANTS_INTEGER_ABBREV)
1625       llvm_unreachable("Unexpected abbrev ordering!");
1626   }
1627 
1628   { // CE_CAST abbrev for CONSTANTS_BLOCK.
1629     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1630     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_CE_CAST));
1631     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // cast opc
1632     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // typeid
1633                               Log2_32_Ceil(VE.getTypes().size()+1)));
1634     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 8));    // value id
1635 
1636     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1637                                    Abbv) != CONSTANTS_CE_CAST_Abbrev)
1638       llvm_unreachable("Unexpected abbrev ordering!");
1639   }
1640   { // NULL abbrev for CONSTANTS_BLOCK.
1641     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1642     Abbv->Add(BitCodeAbbrevOp(bitc::CST_CODE_NULL));
1643     if (Stream.EmitBlockInfoAbbrev(bitc::CONSTANTS_BLOCK_ID,
1644                                    Abbv) != CONSTANTS_NULL_Abbrev)
1645       llvm_unreachable("Unexpected abbrev ordering!");
1646   }
1647 
1648   // FIXME: This should only use space for first class types!
1649 
1650   { // INST_LOAD abbrev for FUNCTION_BLOCK.
1651     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1652     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_LOAD));
1653     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // Ptr
1654     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 4)); // Align
1655     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 1)); // volatile
1656     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1657                                    Abbv) != FUNCTION_INST_LOAD_ABBREV)
1658       llvm_unreachable("Unexpected abbrev ordering!");
1659   }
1660   { // INST_BINOP abbrev for FUNCTION_BLOCK.
1661     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1662     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1663     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1664     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1665     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1666     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1667                                    Abbv) != FUNCTION_INST_BINOP_ABBREV)
1668       llvm_unreachable("Unexpected abbrev ordering!");
1669   }
1670   { // INST_BINOP_FLAGS abbrev for FUNCTION_BLOCK.
1671     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1672     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_BINOP));
1673     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // LHS
1674     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // RHS
1675     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4)); // opc
1676     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 7)); // flags
1677     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1678                                    Abbv) != FUNCTION_INST_BINOP_FLAGS_ABBREV)
1679       llvm_unreachable("Unexpected abbrev ordering!");
1680   }
1681   { // INST_CAST abbrev for FUNCTION_BLOCK.
1682     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1683     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_CAST));
1684     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6));    // OpVal
1685     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed,       // dest ty
1686                               Log2_32_Ceil(VE.getTypes().size()+1)));
1687     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::Fixed, 4));  // opc
1688     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1689                                    Abbv) != FUNCTION_INST_CAST_ABBREV)
1690       llvm_unreachable("Unexpected abbrev ordering!");
1691   }
1692 
1693   { // INST_RET abbrev for FUNCTION_BLOCK.
1694     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1695     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1696     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1697                                    Abbv) != FUNCTION_INST_RET_VOID_ABBREV)
1698       llvm_unreachable("Unexpected abbrev ordering!");
1699   }
1700   { // INST_RET abbrev for FUNCTION_BLOCK.
1701     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1702     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_RET));
1703     Abbv->Add(BitCodeAbbrevOp(BitCodeAbbrevOp::VBR, 6)); // ValID
1704     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1705                                    Abbv) != FUNCTION_INST_RET_VAL_ABBREV)
1706       llvm_unreachable("Unexpected abbrev ordering!");
1707   }
1708   { // INST_UNREACHABLE abbrev for FUNCTION_BLOCK.
1709     BitCodeAbbrev *Abbv = new BitCodeAbbrev();
1710     Abbv->Add(BitCodeAbbrevOp(bitc::FUNC_CODE_INST_UNREACHABLE));
1711     if (Stream.EmitBlockInfoAbbrev(bitc::FUNCTION_BLOCK_ID,
1712                                    Abbv) != FUNCTION_INST_UNREACHABLE_ABBREV)
1713       llvm_unreachable("Unexpected abbrev ordering!");
1714   }
1715 
1716   Stream.ExitBlock();
1717 }
1718 
1719 /// WriteModule - Emit the specified module to the bitstream.
WriteModule(const Module * M,BitstreamWriter & Stream)1720 static void WriteModule(const Module *M, BitstreamWriter &Stream) {
1721   Stream.EnterSubblock(bitc::MODULE_BLOCK_ID, 3);
1722 
1723   SmallVector<unsigned, 1> Vals;
1724   // TODO(srhines): RenderScript is always version 0 for now.
1725   unsigned CurVersion = 0;
1726   if (CurVersion) {
1727     Vals.push_back(CurVersion);
1728     Stream.EmitRecord(bitc::MODULE_CODE_VERSION, Vals);
1729   }
1730 
1731   // Analyze the module, enumerating globals, functions, etc.
1732   llvm_3_2::ValueEnumerator VE(*M);
1733 
1734   // Emit blockinfo, which defines the standard abbreviations etc.
1735   WriteBlockInfo(VE, Stream);
1736 
1737   // Emit information about parameter attributes.
1738   WriteAttributeTable(VE, Stream);
1739 
1740   // Emit information describing all of the types in the module.
1741   WriteTypeTable(VE, Stream);
1742 
1743   // Emit top-level description of module, including target triple, inline asm,
1744   // descriptors for global variables, and function prototype info.
1745   WriteModuleInfo(M, VE, Stream);
1746 
1747   // Emit constants.
1748   WriteModuleConstants(VE, Stream);
1749 
1750   // Emit metadata.
1751   WriteModuleMetadata(M, VE, Stream);
1752 
1753   // Emit metadata.
1754   WriteModuleMetadataStore(M, Stream);
1755 
1756   // Emit names for globals/functions etc.
1757   WriteValueSymbolTable(M->getValueSymbolTable(), VE, Stream);
1758 
1759   // Emit module-level use-lists.
1760   if (false)
1761     WriteUseListBlock(nullptr, VE, Stream);
1762 
1763   // Emit function bodies.
1764   for (Module::const_iterator F = M->begin(), E = M->end(); F != E; ++F)
1765     if (!F->isDeclaration())
1766       WriteFunction(*F, VE, Stream);
1767 
1768   Stream.ExitBlock();
1769 }
1770 
1771 /// EmitDarwinBCHeader - If generating a bc file on darwin, we have to emit a
1772 /// header and trailer to make it compatible with the system archiver.  To do
1773 /// this we emit the following header, and then emit a trailer that pads the
1774 /// file out to be a multiple of 16 bytes.
1775 ///
1776 /// struct bc_header {
1777 ///   uint32_t Magic;         // 0x0B17C0DE
1778 ///   uint32_t Version;       // Version, currently always 0.
1779 ///   uint32_t BitcodeOffset; // Offset to traditional bitcode file.
1780 ///   uint32_t BitcodeSize;   // Size of traditional bitcode file.
1781 ///   uint32_t CPUType;       // CPU specifier.
1782 ///   ... potentially more later ...
1783 /// };
1784 enum {
1785   DarwinBCSizeFieldOffset = 3*4, // Offset to bitcode_size.
1786   DarwinBCHeaderSize = 5*4
1787 };
1788 
WriteInt32ToBuffer(uint32_t Value,SmallVectorImpl<char> & Buffer,uint32_t & Position)1789 static void WriteInt32ToBuffer(uint32_t Value, SmallVectorImpl<char> &Buffer,
1790                                uint32_t &Position) {
1791   Buffer[Position + 0] = (unsigned char) (Value >>  0);
1792   Buffer[Position + 1] = (unsigned char) (Value >>  8);
1793   Buffer[Position + 2] = (unsigned char) (Value >> 16);
1794   Buffer[Position + 3] = (unsigned char) (Value >> 24);
1795   Position += 4;
1796 }
1797 
EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> & Buffer,const Triple & TT)1798 static void EmitDarwinBCHeaderAndTrailer(SmallVectorImpl<char> &Buffer,
1799                                          const Triple &TT) {
1800   unsigned CPUType = ~0U;
1801 
1802   // Match x86_64-*, i[3-9]86-*, powerpc-*, powerpc64-*, arm-*, thumb-*,
1803   // armv[0-9]-*, thumbv[0-9]-*, armv5te-*, or armv6t2-*. The CPUType is a magic
1804   // number from /usr/include/mach/machine.h.  It is ok to reproduce the
1805   // specific constants here because they are implicitly part of the Darwin ABI.
1806   enum {
1807     DARWIN_CPU_ARCH_ABI64      = 0x01000000,
1808     DARWIN_CPU_TYPE_X86        = 7,
1809     DARWIN_CPU_TYPE_ARM        = 12,
1810     DARWIN_CPU_TYPE_POWERPC    = 18
1811   };
1812 
1813   Triple::ArchType Arch = TT.getArch();
1814   if (Arch == Triple::x86_64)
1815     CPUType = DARWIN_CPU_TYPE_X86 | DARWIN_CPU_ARCH_ABI64;
1816   else if (Arch == Triple::x86)
1817     CPUType = DARWIN_CPU_TYPE_X86;
1818   else if (Arch == Triple::ppc)
1819     CPUType = DARWIN_CPU_TYPE_POWERPC;
1820   else if (Arch == Triple::ppc64)
1821     CPUType = DARWIN_CPU_TYPE_POWERPC | DARWIN_CPU_ARCH_ABI64;
1822   else if (Arch == Triple::arm || Arch == Triple::thumb)
1823     CPUType = DARWIN_CPU_TYPE_ARM;
1824 
1825   // Traditional Bitcode starts after header.
1826   assert(Buffer.size() >= DarwinBCHeaderSize &&
1827          "Expected header size to be reserved");
1828   unsigned BCOffset = DarwinBCHeaderSize;
1829   unsigned BCSize = Buffer.size()-DarwinBCHeaderSize;
1830 
1831   // Write the magic and version.
1832   unsigned Position = 0;
1833   WriteInt32ToBuffer(0x0B17C0DE , Buffer, Position);
1834   WriteInt32ToBuffer(0          , Buffer, Position); // Version.
1835   WriteInt32ToBuffer(BCOffset   , Buffer, Position);
1836   WriteInt32ToBuffer(BCSize     , Buffer, Position);
1837   WriteInt32ToBuffer(CPUType    , Buffer, Position);
1838 
1839   // If the file is not a multiple of 16 bytes, insert placeholder padding.
1840   while (Buffer.size() & 15)
1841     Buffer.push_back(0);
1842 }
1843 
1844 /// WriteBitcodeToFile - Write the specified module to the specified output
1845 /// stream.
WriteBitcodeToFile(const Module * M,raw_ostream & Out)1846 void llvm_3_2::WriteBitcodeToFile(const Module *M, raw_ostream &Out) {
1847   SmallVector<char, 0> Buffer;
1848   Buffer.reserve(256*1024);
1849 
1850   // If this is darwin or another generic macho target, reserve space for the
1851   // header.
1852   Triple TT(M->getTargetTriple());
1853   if (TT.isOSDarwin())
1854     Buffer.insert(Buffer.begin(), DarwinBCHeaderSize, 0);
1855 
1856   // Emit the module into the buffer.
1857   {
1858     BitstreamWriter Stream(Buffer);
1859 
1860     // Emit the file header.
1861     Stream.Emit((unsigned)'B', 8);
1862     Stream.Emit((unsigned)'C', 8);
1863     Stream.Emit(0x0, 4);
1864     Stream.Emit(0xC, 4);
1865     Stream.Emit(0xE, 4);
1866     Stream.Emit(0xD, 4);
1867 
1868     // Emit the module.
1869     WriteModule(M, Stream);
1870   }
1871 
1872   if (TT.isOSDarwin())
1873     EmitDarwinBCHeaderAndTrailer(Buffer, TT);
1874 
1875   // Write the generated bitstream to "Out".
1876   Out.write((char*)&Buffer.front(), Buffer.size());
1877 }
1878