lib/ExecutionEngine/ExecutionEngine.cpp

   1 //===-- ExecutionEngine.cpp - Common Implementation shared by EEs ---------===//
   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 // This file defines the common interface used by the various execution engine
  11 // subclasses.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #define DEBUG_TYPE "jit"
  16 #include "llvm/ExecutionEngine/ExecutionEngine.h"
  17
  18 #include "llvm/Constants.h"
  19 #include "llvm/DerivedTypes.h"
  20 #include "llvm/Module.h"
  21 #include "llvm/ExecutionEngine/GenericValue.h"
  22 #include "llvm/ADT/SmallString.h"
  23 #include "llvm/ADT/Statistic.h"
  24 #include "llvm/Support/Debug.h"
  25 #include "llvm/Support/ErrorHandling.h"
  26 #include "llvm/Support/MutexGuard.h"
  27 #include "llvm/Support/ValueHandle.h"
  28 #include "llvm/Support/raw_ostream.h"
  29 #include "llvm/Support/DynamicLibrary.h"
  30 #include "llvm/Support/Host.h"
  31 #include "llvm/Target/TargetData.h"
  32 #include "llvm/Target/TargetMachine.h"
  33 #include <cmath>
  34 #include <cstring>
  35 using namespace llvm;
  36
  37 STATISTIC(NumInitBytes, "Number of bytes of global vars initialized");
  38 STATISTIC(NumGlobals  , "Number of global vars initialized");
  39
  40 ExecutionEngine *(*ExecutionEngine::JITCtor)(
  41   Module *M,
  42   std::string *ErrorStr,
  43   JITMemoryManager *JMM,
  44   CodeGenOpt::Level OptLevel,
  45   bool GVsWithCode,
  46   TargetMachine *TM) = 0;
  47 ExecutionEngine *(*ExecutionEngine::MCJITCtor)(
  48   Module *M,
  49   std::string *ErrorStr,
  50   JITMemoryManager *JMM,
  51   CodeGenOpt::Level OptLevel,
  52   bool GVsWithCode,
  53   TargetMachine *TM) = 0;
  54 ExecutionEngine *(*ExecutionEngine::InterpCtor)(Module *M,
  55                                                 std::string *ErrorStr) = 0;
  56
  57 ExecutionEngine::ExecutionEngine(Module *M)
  58   : EEState(*this),
  59     LazyFunctionCreator(0),
  60     ExceptionTableRegister(0),
  61     ExceptionTableDeregister(0) {
  62   CompilingLazily         = false;
  63   GVCompilationDisabled   = false;
  64   SymbolSearchingDisabled = false;
  65   Modules.push_back(M);
  66   assert(M && "Module is null?");
  67 }
  68
  69 ExecutionEngine::~ExecutionEngine() {
  70   clearAllGlobalMappings();
  71   for (unsigned i = 0, e = Modules.size(); i != e; ++i)
  72     delete Modules[i];
  73 }
  74
  75 void ExecutionEngine::DeregisterAllTables() {
  76   if (ExceptionTableDeregister) {
  77     DenseMap<const Function*, void*>::iterator it = AllExceptionTables.begin();
  78     DenseMap<const Function*, void*>::iterator ite = AllExceptionTables.end();
  79     for (; it != ite; ++it)
  80       ExceptionTableDeregister(it->second);
  81     AllExceptionTables.clear();
  82   }
  83 }
  84
  85 namespace {
  86 /// \brief Helper class which uses a value handler to automatically deletes the
  87 /// memory block when the GlobalVariable is destroyed.
  88 class GVMemoryBlock : public CallbackVH {
  89   GVMemoryBlock(const GlobalVariable *GV)
  90     : CallbackVH(const_cast<GlobalVariable*>(GV)) {}
  91
  92 public:
  93   /// \brief Returns the address the GlobalVariable should be written into.  The
  94   /// GVMemoryBlock object prefixes that.
  95   static char *Create(const GlobalVariable *GV, const TargetData& TD) {
  96     const Type *ElTy = GV->getType()->getElementType();
  97     size_t GVSize = (size_t)TD.getTypeAllocSize(ElTy);
  98     void *RawMemory = ::operator new(
  99       TargetData::RoundUpAlignment(sizeof(GVMemoryBlock),
 100                                    TD.getPreferredAlignment(GV))
 101       + GVSize);
 102     new(RawMemory) GVMemoryBlock(GV);
 103     return static_cast<char*>(RawMemory) + sizeof(GVMemoryBlock);
 104   }
 105
 106   virtual void deleted() {
 107     // We allocated with operator new and with some extra memory hanging off the
 108     // end, so don't just delete this.  I'm not sure if this is actually
 109     // required.
 110     this->~GVMemoryBlock();
 111     ::operator delete(this);
 112   }
 113 };
 114 }  // anonymous namespace
 115
 116 char *ExecutionEngine::getMemoryForGV(const GlobalVariable *GV) {
 117   return GVMemoryBlock::Create(GV, *getTargetData());
 118 }
 119
 120 bool ExecutionEngine::removeModule(Module *M) {
 121   for(SmallVector<Module *, 1>::iterator I = Modules.begin(),
 122         E = Modules.end(); I != E; ++I) {
 123     Module *Found = *I;
 124     if (Found == M) {
 125       Modules.erase(I);
 126       clearGlobalMappingsFromModule(M);
 127       return true;
 128     }
 129   }
 130   return false;
 131 }
 132
 133 Function *ExecutionEngine::FindFunctionNamed(const char *FnName) {
 134   for (unsigned i = 0, e = Modules.size(); i != e; ++i) {
 135     if (Function *F = Modules[i]->getFunction(FnName))
 136       return F;
 137   }
 138   return 0;
 139 }
 140
 141
 142 void *ExecutionEngineState::RemoveMapping(const MutexGuard &,
 143                                           const GlobalValue *ToUnmap) {
 144   GlobalAddressMapTy::iterator I = GlobalAddressMap.find(ToUnmap);
 145   void *OldVal;
 146
 147   // FIXME: This is silly, we shouldn't end up with a mapping -> 0 in the
 148   // GlobalAddressMap.
 149   if (I == GlobalAddressMap.end())
 150     OldVal = 0;
 151   else {
 152     OldVal = I->second;
 153     GlobalAddressMap.erase(I);
 154   }
 155
 156   GlobalAddressReverseMap.erase(OldVal);
 157   return OldVal;
 158 }
 159
 160 void ExecutionEngine::addGlobalMapping(const GlobalValue *GV, void *Addr) {
 161   MutexGuard locked(lock);
 162
 163   DEBUG(dbgs() << "JIT: Map \'" << GV->getName()
 164         << "\' to [" << Addr << "]\n";);
 165   void *&CurVal = EEState.getGlobalAddressMap(locked)[GV];
 166   assert((CurVal == 0 || Addr == 0) && "GlobalMapping already established!");
 167   CurVal = Addr;
 168
 169   // If we are using the reverse mapping, add it too.
 170   if (!EEState.getGlobalAddressReverseMap(locked).empty()) {
 171     AssertingVH<const GlobalValue> &V =
 172       EEState.getGlobalAddressReverseMap(locked)[Addr];
 173     assert((V == 0 || GV == 0) && "GlobalMapping already established!");
 174     V = GV;
 175   }
 176 }
 177
 178 void ExecutionEngine::clearAllGlobalMappings() {
 179   MutexGuard locked(lock);
 180
 181   EEState.getGlobalAddressMap(locked).clear();
 182   EEState.getGlobalAddressReverseMap(locked).clear();
 183 }
 184
 185 void ExecutionEngine::clearGlobalMappingsFromModule(Module *M) {
 186   MutexGuard locked(lock);
 187
 188   for (Module::iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI)
 189     EEState.RemoveMapping(locked, FI);
 190   for (Module::global_iterator GI = M->global_begin(), GE = M->global_end();
 191        GI != GE; ++GI)
 192     EEState.RemoveMapping(locked, GI);
 193 }
 194
 195 void *ExecutionEngine::updateGlobalMapping(const GlobalValue *GV, void *Addr) {
 196   MutexGuard locked(lock);
 197
 198   ExecutionEngineState::GlobalAddressMapTy &Map =
 199     EEState.getGlobalAddressMap(locked);
 200
 201   // Deleting from the mapping?
 202   if (Addr == 0)
 203     return EEState.RemoveMapping(locked, GV);
 204
 205   void *&CurVal = Map[GV];
 206   void *OldVal = CurVal;
 207
 208   if (CurVal && !EEState.getGlobalAddressReverseMap(locked).empty())
 209     EEState.getGlobalAddressReverseMap(locked).erase(CurVal);
 210   CurVal = Addr;
 211
 212   // If we are using the reverse mapping, add it too.
 213   if (!EEState.getGlobalAddressReverseMap(locked).empty()) {
 214     AssertingVH<const GlobalValue> &V =
 215       EEState.getGlobalAddressReverseMap(locked)[Addr];
 216     assert((V == 0 || GV == 0) && "GlobalMapping already established!");
 217     V = GV;
 218   }
 219   return OldVal;
 220 }
 221
 222 void *ExecutionEngine::getPointerToGlobalIfAvailable(const GlobalValue *GV) {
 223   MutexGuard locked(lock);
 224
 225   ExecutionEngineState::GlobalAddressMapTy::iterator I =
 226     EEState.getGlobalAddressMap(locked).find(GV);
 227   return I != EEState.getGlobalAddressMap(locked).end() ? I->second : 0;
 228 }
 229
 230 const GlobalValue *ExecutionEngine::getGlobalValueAtAddress(void *Addr) {
 231   MutexGuard locked(lock);
 232
 233   // If we haven't computed the reverse mapping yet, do so first.
 234   if (EEState.getGlobalAddressReverseMap(locked).empty()) {
 235     for (ExecutionEngineState::GlobalAddressMapTy::iterator
 236          I = EEState.getGlobalAddressMap(locked).begin(),
 237          E = EEState.getGlobalAddressMap(locked).end(); I != E; ++I)
 238       EEState.getGlobalAddressReverseMap(locked).insert(std::make_pair(
 239                                                           I->second, I->first));
 240   }
 241
 242   std::map<void *, AssertingVH<const GlobalValue> >::iterator I =
 243     EEState.getGlobalAddressReverseMap(locked).find(Addr);
 244   return I != EEState.getGlobalAddressReverseMap(locked).end() ? I->second : 0;
 245 }
 246
 247 namespace {
 248 class ArgvArray {
 249   char *Array;
 250   std::vector<char*> Values;
 251 public:
 252   ArgvArray() : Array(NULL) {}
 253   ~ArgvArray() { clear(); }
 254   void clear() {
 255     delete[] Array;
 256     Array = NULL;
 257     for (size_t I = 0, E = Values.size(); I != E; ++I) {
 258       delete[] Values[I];
 259     }
 260     Values.clear();
 261   }
 262   /// Turn a vector of strings into a nice argv style array of pointers to null
 263   /// terminated strings.
 264   void *reset(LLVMContext &C, ExecutionEngine *EE,
 265               const std::vector<std::string> &InputArgv);
 266 };
 267 }  // anonymous namespace
 268 void *ArgvArray::reset(LLVMContext &C, ExecutionEngine *EE,
 269                        const std::vector<std::string> &InputArgv) {
 270   clear();  // Free the old contents.
 271   unsigned PtrSize = EE->getTargetData()->getPointerSize();
 272   Array = new char[(InputArgv.size()+1)*PtrSize];
 273
 274   DEBUG(dbgs() << "JIT: ARGV = " << (void*)Array << "\n");
 275   const Type *SBytePtr = Type::getInt8PtrTy(C);
 276
 277   for (unsigned i = 0; i != InputArgv.size(); ++i) {
 278     unsigned Size = InputArgv[i].size()+1;
 279     char *Dest = new char[Size];
 280     Values.push_back(Dest);
 281     DEBUG(dbgs() << "JIT: ARGV[" << i << "] = " << (void*)Dest << "\n");
 282
 283     std::copy(InputArgv[i].begin(), InputArgv[i].end(), Dest);
 284     Dest[Size-1] = 0;
 285
 286     // Endian safe: Array[i] = (PointerTy)Dest;
 287     EE->StoreValueToMemory(PTOGV(Dest), (GenericValue*)(Array+i*PtrSize),
 288                            SBytePtr);
 289   }
 290
 291   // Null terminate it
 292   EE->StoreValueToMemory(PTOGV(0),
 293                          (GenericValue*)(Array+InputArgv.size()*PtrSize),
 294                          SBytePtr);
 295   return Array;
 296 }
 297
 298 void ExecutionEngine::runStaticConstructorsDestructors(Module *module,
 299                                                        bool isDtors) {
 300   const char *Name = isDtors ? "llvm.global_dtors" : "llvm.global_ctors";
 301   GlobalVariable *GV = module->getNamedGlobal(Name);
 302
 303   // If this global has internal linkage, or if it has a use, then it must be
 304   // an old-style (llvmgcc3) static ctor with __main linked in and in use.  If
 305   // this is the case, don't execute any of the global ctors, __main will do
 306   // it.
 307   if (!GV || GV->isDeclaration() || GV->hasLocalLinkage()) return;
 308
 309   // Should be an array of '{ i32, void ()* }' structs.  The first value is
 310   // the init priority, which we ignore.
 311   if (isa<ConstantAggregateZero>(GV->getInitializer()))
 312     return;
 313   ConstantArray *InitList = cast<ConstantArray>(GV->getInitializer());
 314   for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
 315     if (isa<ConstantAggregateZero>(InitList->getOperand(i)))
 316       continue;
 317     ConstantStruct *CS = cast<ConstantStruct>(InitList->getOperand(i));
 318
 319     Constant *FP = CS->getOperand(1);
 320     if (FP->isNullValue())
 321       continue;  // Found a sentinal value, ignore.
 322
 323     // Strip off constant expression casts.
 324     if (ConstantExpr *CE = dyn_cast<ConstantExpr>(FP))
 325       if (CE->isCast())
 326         FP = CE->getOperand(0);
 327
 328     // Execute the ctor/dtor function!
 329     if (Function *F = dyn_cast<Function>(FP))
 330       runFunction(F, std::vector<GenericValue>());
 331
 332     // FIXME: It is marginally lame that we just do nothing here if we see an
 333     // entry we don't recognize. It might not be unreasonable for the verifier
 334     // to not even allow this and just assert here.
 335   }
 336 }
 337
 338 void ExecutionEngine::runStaticConstructorsDestructors(bool isDtors) {
 339   // Execute global ctors/dtors for each module in the program.
 340   for (unsigned i = 0, e = Modules.size(); i != e; ++i)
 341     runStaticConstructorsDestructors(Modules[i], isDtors);
 342 }
 343
 344 #ifndef NDEBUG
 345 /// isTargetNullPtr - Return whether the target pointer stored at Loc is null.
 346 static bool isTargetNullPtr(ExecutionEngine *EE, void *Loc) {
 347   unsigned PtrSize = EE->getTargetData()->getPointerSize();
 348   for (unsigned i = 0; i < PtrSize; ++i)
 349     if (*(i + (uint8_t*)Loc))
 350       return false;
 351   return true;
 352 }
 353 #endif
 354
 355 int ExecutionEngine::runFunctionAsMain(Function *Fn,
 356                                        const std::vector<std::string> &argv,
 357                                        const char * const * envp) {
 358   std::vector<GenericValue> GVArgs;
 359   GenericValue GVArgc;
 360   GVArgc.IntVal = APInt(32, argv.size());
 361
 362   // Check main() type
 363   unsigned NumArgs = Fn->getFunctionType()->getNumParams();
 364   const FunctionType *FTy = Fn->getFunctionType();
 365   const Type* PPInt8Ty = Type::getInt8PtrTy(Fn->getContext())->getPointerTo();
 366
 367   // Check the argument types.
 368   if (NumArgs > 3)
 369     report_fatal_error("Invalid number of arguments of main() supplied");
 370   if (NumArgs >= 3 && FTy->getParamType(2) != PPInt8Ty)
 371     report_fatal_error("Invalid type for third argument of main() supplied");
 372   if (NumArgs >= 2 && FTy->getParamType(1) != PPInt8Ty)
 373     report_fatal_error("Invalid type for second argument of main() supplied");
 374   if (NumArgs >= 1 && !FTy->getParamType(0)->isIntegerTy(32))
 375     report_fatal_error("Invalid type for first argument of main() supplied");
 376   if (!FTy->getReturnType()->isIntegerTy() &&
 377       !FTy->getReturnType()->isVoidTy())
 378     report_fatal_error("Invalid return type of main() supplied");
 379
 380   ArgvArray CArgv;
 381   ArgvArray CEnv;
 382   if (NumArgs) {
 383     GVArgs.push_back(GVArgc); // Arg #0 = argc.
 384     if (NumArgs > 1) {
 385       // Arg #1 = argv.
 386       GVArgs.push_back(PTOGV(CArgv.reset(Fn->getContext(), this, argv)));
 387       assert(!isTargetNullPtr(this, GVTOP(GVArgs[1])) &&
 388              "argv[0] was null after CreateArgv");
 389       if (NumArgs > 2) {
 390         std::vector<std::string> EnvVars;
 391         for (unsigned i = 0; envp[i]; ++i)
 392           EnvVars.push_back(envp[i]);
 393         // Arg #2 = envp.
 394         GVArgs.push_back(PTOGV(CEnv.reset(Fn->getContext(), this, EnvVars)));
 395       }
 396     }
 397   }
 398
 399   return runFunction(Fn, GVArgs).IntVal.getZExtValue();
 400 }
 401
 402 ExecutionEngine *ExecutionEngine::create(Module *M,
 403                                          bool ForceInterpreter,
 404                                          std::string *ErrorStr,
 405                                          CodeGenOpt::Level OptLevel,
 406                                          bool GVsWithCode) {
 407   return EngineBuilder(M)
 408       .setEngineKind(ForceInterpreter
 409                      ? EngineKind::Interpreter
 410                      : EngineKind::JIT)
 411       .setErrorStr(ErrorStr)
 412       .setOptLevel(OptLevel)
 413       .setAllocateGVsWithCode(GVsWithCode)
 414       .create();
 415 }
 416
 417 /// createJIT - This is the factory method for creating a JIT for the current
 418 /// machine, it does not fall back to the interpreter.  This takes ownership
 419 /// of the module.
 420 ExecutionEngine *ExecutionEngine::createJIT(Module *M,
 421                                             std::string *ErrorStr,
 422                                             JITMemoryManager *JMM,
 423                                             CodeGenOpt::Level OptLevel,
 424                                             bool GVsWithCode,
 425                                             CodeModel::Model CMM) {
 426   if (ExecutionEngine::JITCtor == 0) {
 427     if (ErrorStr)
 428       *ErrorStr = "JIT has not been linked in.";
 429     return 0;
 430   }
 431
 432   // Use the defaults for extra parameters.  Users can use EngineBuilder to
 433   // set them.
 434   StringRef MArch = "";
 435   StringRef MCPU = "";
 436   SmallVector<std::string, 1> MAttrs;
 437
 438   TargetMachine *TM =
 439           EngineBuilder::selectTarget(M, MArch, MCPU, MAttrs, ErrorStr);
 440   if (!TM || (ErrorStr && ErrorStr->length() > 0)) return 0;
 441   TM->setCodeModel(CMM);
 442
 443   return ExecutionEngine::JITCtor(M, ErrorStr, JMM, OptLevel, GVsWithCode, TM);
 444 }
 445
 446 ExecutionEngine *EngineBuilder::create() {
 447   // Make sure we can resolve symbols in the program as well. The zero arg
 448   // to the function tells DynamicLibrary to load the program, not a library.
 449   if (sys::DynamicLibrary::LoadLibraryPermanently(0, ErrorStr))
 450     return 0;
 451
 452   // If the user specified a memory manager but didn't specify which engine to
 453   // create, we assume they only want the JIT, and we fail if they only want
 454   // the interpreter.
 455   if (JMM) {
 456     if (WhichEngine & EngineKind::JIT)
 457       WhichEngine = EngineKind::JIT;
 458     else {
 459       if (ErrorStr)
 460         *ErrorStr = "Cannot create an interpreter with a memory manager.";
 461       return 0;
 462     }
 463   }
 464
 465   // Unless the interpreter was explicitly selected or the JIT is not linked,
 466   // try making a JIT.
 467   if (WhichEngine & EngineKind::JIT) {
 468     if (TargetMachine *TM =
 469         EngineBuilder::selectTarget(M, MArch, MCPU, MAttrs, ErrorStr)) {
 470       TM->setCodeModel(CMModel);
 471
 472       if (UseMCJIT && ExecutionEngine::MCJITCtor) {
 473         ExecutionEngine *EE =
 474           ExecutionEngine::MCJITCtor(M, ErrorStr, JMM, OptLevel,
 475                                      AllocateGVsWithCode, TM);
 476         if (EE) return EE;
 477       } else if (ExecutionEngine::JITCtor) {
 478         ExecutionEngine *EE =
 479           ExecutionEngine::JITCtor(M, ErrorStr, JMM, OptLevel,
 480                                    AllocateGVsWithCode, TM);
 481         if (EE) return EE;
 482       }
 483     }
 484   }
 485
 486   // If we can't make a JIT and we didn't request one specifically, try making
 487   // an interpreter instead.
 488   if (WhichEngine & EngineKind::Interpreter) {
 489     if (ExecutionEngine::InterpCtor)
 490       return ExecutionEngine::InterpCtor(M, ErrorStr);
 491     if (ErrorStr)
 492       *ErrorStr = "Interpreter has not been linked in.";
 493     return 0;
 494   }
 495
 496   if ((WhichEngine & EngineKind::JIT) && ExecutionEngine::JITCtor == 0) {
 497     if (ErrorStr)
 498       *ErrorStr = "JIT has not been linked in.";
 499   }
 500
 501   return 0;
 502 }
 503
 504 void *ExecutionEngine::getPointerToGlobal(const GlobalValue *GV) {
 505   if (Function *F = const_cast<Function*>(dyn_cast<Function>(GV)))
 506     return getPointerToFunction(F);
 507
 508   MutexGuard locked(lock);
 509   if (void *P = EEState.getGlobalAddressMap(locked)[GV])
 510     return P;
 511
 512   // Global variable might have been added since interpreter started.
 513   if (GlobalVariable *GVar =
 514           const_cast<GlobalVariable *>(dyn_cast<GlobalVariable>(GV)))
 515     EmitGlobalVariable(GVar);
 516   else
 517     llvm_unreachable("Global hasn't had an address allocated yet!");
 518
 519   return EEState.getGlobalAddressMap(locked)[GV];
 520 }
 521
 522 /// \brief Converts a Constant* into a GenericValue, including handling of
 523 /// ConstantExpr values.
 524 GenericValue ExecutionEngine::getConstantValue(const Constant *C) {
 525   // If its undefined, return the garbage.
 526   if (isa<UndefValue>(C)) {
 527     GenericValue Result;
 528     switch (C->getType()->getTypeID()) {
 529     case Type::IntegerTyID:
 530     case Type::X86_FP80TyID:
 531     case Type::FP128TyID:
 532     case Type::PPC_FP128TyID:
 533       // Although the value is undefined, we still have to construct an APInt
 534       // with the correct bit width.
 535       Result.IntVal = APInt(C->getType()->getPrimitiveSizeInBits(), 0);
 536       break;
 537     default:
 538       break;
 539     }
 540     return Result;
 541   }
 542
 543   // Otherwise, if the value is a ConstantExpr...
 544   if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
 545     Constant *Op0 = CE->getOperand(0);
 546     switch (CE->getOpcode()) {
 547     case Instruction::GetElementPtr: {
 548       // Compute the index
 549       GenericValue Result = getConstantValue(Op0);
 550       SmallVector<Value*, 8> Indices(CE->op_begin()+1, CE->op_end());
 551       uint64_t Offset =
 552         TD->getIndexedOffset(Op0->getType(), &Indices[0], Indices.size());
 553
 554       char* tmp = (char*) Result.PointerVal;
 555       Result = PTOGV(tmp + Offset);
 556       return Result;
 557     }
 558     case Instruction::Trunc: {
 559       GenericValue GV = getConstantValue(Op0);
 560       uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
 561       GV.IntVal = GV.IntVal.trunc(BitWidth);
 562       return GV;
 563     }
 564     case Instruction::ZExt: {
 565       GenericValue GV = getConstantValue(Op0);
 566       uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
 567       GV.IntVal = GV.IntVal.zext(BitWidth);
 568       return GV;
 569     }
 570     case Instruction::SExt: {
 571       GenericValue GV = getConstantValue(Op0);
 572       uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
 573       GV.IntVal = GV.IntVal.sext(BitWidth);
 574       return GV;
 575     }
 576     case Instruction::FPTrunc: {
 577       // FIXME long double
 578       GenericValue GV = getConstantValue(Op0);
 579       GV.FloatVal = float(GV.DoubleVal);
 580       return GV;
 581     }
 582     case Instruction::FPExt:{
 583       // FIXME long double
 584       GenericValue GV = getConstantValue(Op0);
 585       GV.DoubleVal = double(GV.FloatVal);
 586       return GV;
 587     }
 588     case Instruction::UIToFP: {
 589       GenericValue GV = getConstantValue(Op0);
 590       if (CE->getType()->isFloatTy())
 591         GV.FloatVal = float(GV.IntVal.roundToDouble());
 592       else if (CE->getType()->isDoubleTy())
 593         GV.DoubleVal = GV.IntVal.roundToDouble();
 594       else if (CE->getType()->isX86_FP80Ty()) {
 595         APFloat apf = APFloat::getZero(APFloat::x87DoubleExtended);
 596         (void)apf.convertFromAPInt(GV.IntVal,
 597                                    false,
 598                                    APFloat::rmNearestTiesToEven);
 599         GV.IntVal = apf.bitcastToAPInt();
 600       }
 601       return GV;
 602     }
 603     case Instruction::SIToFP: {
 604       GenericValue GV = getConstantValue(Op0);
 605       if (CE->getType()->isFloatTy())
 606         GV.FloatVal = float(GV.IntVal.signedRoundToDouble());
 607       else if (CE->getType()->isDoubleTy())
 608         GV.DoubleVal = GV.IntVal.signedRoundToDouble();
 609       else if (CE->getType()->isX86_FP80Ty()) {
 610         APFloat apf = APFloat::getZero(APFloat::x87DoubleExtended);
 611         (void)apf.convertFromAPInt(GV.IntVal,
 612                                    true,
 613                                    APFloat::rmNearestTiesToEven);
 614         GV.IntVal = apf.bitcastToAPInt();
 615       }
 616       return GV;
 617     }
 618     case Instruction::FPToUI: // double->APInt conversion handles sign
 619     case Instruction::FPToSI: {
 620       GenericValue GV = getConstantValue(Op0);
 621       uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
 622       if (Op0->getType()->isFloatTy())
 623         GV.IntVal = APIntOps::RoundFloatToAPInt(GV.FloatVal, BitWidth);
 624       else if (Op0->getType()->isDoubleTy())
 625         GV.IntVal = APIntOps::RoundDoubleToAPInt(GV.DoubleVal, BitWidth);
 626       else if (Op0->getType()->isX86_FP80Ty()) {
 627         APFloat apf = APFloat(GV.IntVal);
 628         uint64_t v;
 629         bool ignored;
 630         (void)apf.convertToInteger(&v, BitWidth,
 631                                    CE->getOpcode()==Instruction::FPToSI,
 632                                    APFloat::rmTowardZero, &ignored);
 633         GV.IntVal = v; // endian?
 634       }
 635       return GV;
 636     }
 637     case Instruction::PtrToInt: {
 638       GenericValue GV = getConstantValue(Op0);
 639       uint32_t PtrWidth = TD->getPointerSizeInBits();
 640       GV.IntVal = APInt(PtrWidth, uintptr_t(GV.PointerVal));
 641       return GV;
 642     }
 643     case Instruction::IntToPtr: {
 644       GenericValue GV = getConstantValue(Op0);
 645       uint32_t PtrWidth = TD->getPointerSizeInBits();
 646       if (PtrWidth != GV.IntVal.getBitWidth())
 647         GV.IntVal = GV.IntVal.zextOrTrunc(PtrWidth);
 648       assert(GV.IntVal.getBitWidth() <= 64 && "Bad pointer width");
 649       GV.PointerVal = PointerTy(uintptr_t(GV.IntVal.getZExtValue()));
 650       return GV;
 651     }
 652     case Instruction::BitCast: {
 653       GenericValue GV = getConstantValue(Op0);
 654       const Type* DestTy = CE->getType();
 655       switch (Op0->getType()->getTypeID()) {
 656         default: llvm_unreachable("Invalid bitcast operand");
 657         case Type::IntegerTyID:
 658           assert(DestTy->isFloatingPointTy() && "invalid bitcast");
 659           if (DestTy->isFloatTy())
 660             GV.FloatVal = GV.IntVal.bitsToFloat();
 661           else if (DestTy->isDoubleTy())
 662             GV.DoubleVal = GV.IntVal.bitsToDouble();
 663           break;
 664         case Type::FloatTyID:
 665           assert(DestTy->isIntegerTy(32) && "Invalid bitcast");
 666           GV.IntVal = APInt::floatToBits(GV.FloatVal);
 667           break;
 668         case Type::DoubleTyID:
 669           assert(DestTy->isIntegerTy(64) && "Invalid bitcast");
 670           GV.IntVal = APInt::doubleToBits(GV.DoubleVal);
 671           break;
 672         case Type::PointerTyID:
 673           assert(DestTy->isPointerTy() && "Invalid bitcast");
 674           break; // getConstantValue(Op0)  above already converted it
 675       }
 676       return GV;
 677     }
 678     case Instruction::Add:
 679     case Instruction::FAdd:
 680     case Instruction::Sub:
 681     case Instruction::FSub:
 682     case Instruction::Mul:
 683     case Instruction::FMul:
 684     case Instruction::UDiv:
 685     case Instruction::SDiv:
 686     case Instruction::URem:
 687     case Instruction::SRem:
 688     case Instruction::And:
 689     case Instruction::Or:
 690     case Instruction::Xor: {
 691       GenericValue LHS = getConstantValue(Op0);
 692       GenericValue RHS = getConstantValue(CE->getOperand(1));
 693       GenericValue GV;
 694       switch (CE->getOperand(0)->getType()->getTypeID()) {
 695       default: llvm_unreachable("Bad add type!");
 696       case Type::IntegerTyID:
 697         switch (CE->getOpcode()) {
 698           default: llvm_unreachable("Invalid integer opcode");
 699           case Instruction::Add: GV.IntVal = LHS.IntVal + RHS.IntVal; break;
 700           case Instruction::Sub: GV.IntVal = LHS.IntVal - RHS.IntVal; break;
 701           case Instruction::Mul: GV.IntVal = LHS.IntVal * RHS.IntVal; break;
 702           case Instruction::UDiv:GV.IntVal = LHS.IntVal.udiv(RHS.IntVal); break;
 703           case Instruction::SDiv:GV.IntVal = LHS.IntVal.sdiv(RHS.IntVal); break;
 704           case Instruction::URem:GV.IntVal = LHS.IntVal.urem(RHS.IntVal); break;
 705           case Instruction::SRem:GV.IntVal = LHS.IntVal.srem(RHS.IntVal); break;
 706           case Instruction::And: GV.IntVal = LHS.IntVal & RHS.IntVal; break;
 707           case Instruction::Or:  GV.IntVal = LHS.IntVal | RHS.IntVal; break;
 708           case Instruction::Xor: GV.IntVal = LHS.IntVal ^ RHS.IntVal; break;
 709         }
 710         break;
 711       case Type::FloatTyID:
 712         switch (CE->getOpcode()) {
 713           default: llvm_unreachable("Invalid float opcode");
 714           case Instruction::FAdd:
 715             GV.FloatVal = LHS.FloatVal + RHS.FloatVal; break;
 716           case Instruction::FSub:
 717             GV.FloatVal = LHS.FloatVal - RHS.FloatVal; break;
 718           case Instruction::FMul:
 719             GV.FloatVal = LHS.FloatVal * RHS.FloatVal; break;
 720           case Instruction::FDiv:
 721             GV.FloatVal = LHS.FloatVal / RHS.FloatVal; break;
 722           case Instruction::FRem:
 723             GV.FloatVal = std::fmod(LHS.FloatVal,RHS.FloatVal); break;
 724         }
 725         break;
 726       case Type::DoubleTyID:
 727         switch (CE->getOpcode()) {
 728           default: llvm_unreachable("Invalid double opcode");
 729           case Instruction::FAdd:
 730             GV.DoubleVal = LHS.DoubleVal + RHS.DoubleVal; break;
 731           case Instruction::FSub:
 732             GV.DoubleVal = LHS.DoubleVal - RHS.DoubleVal; break;
 733           case Instruction::FMul:
 734             GV.DoubleVal = LHS.DoubleVal * RHS.DoubleVal; break;
 735           case Instruction::FDiv:
 736             GV.DoubleVal = LHS.DoubleVal / RHS.DoubleVal; break;
 737           case Instruction::FRem:
 738             GV.DoubleVal = std::fmod(LHS.DoubleVal,RHS.DoubleVal); break;
 739         }
 740         break;
 741       case Type::X86_FP80TyID:
 742       case Type::PPC_FP128TyID:
 743       case Type::FP128TyID: {
 744         APFloat apfLHS = APFloat(LHS.IntVal);
 745         switch (CE->getOpcode()) {
 746           default: llvm_unreachable("Invalid long double opcode");
 747           case Instruction::FAdd:
 748             apfLHS.add(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
 749             GV.IntVal = apfLHS.bitcastToAPInt();
 750             break;
 751           case Instruction::FSub:
 752             apfLHS.subtract(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
 753             GV.IntVal = apfLHS.bitcastToAPInt();
 754             break;
 755           case Instruction::FMul:
 756             apfLHS.multiply(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
 757             GV.IntVal = apfLHS.bitcastToAPInt();
 758             break;
 759           case Instruction::FDiv:
 760             apfLHS.divide(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
 761             GV.IntVal = apfLHS.bitcastToAPInt();
 762             break;
 763           case Instruction::FRem:
 764             apfLHS.mod(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
 765             GV.IntVal = apfLHS.bitcastToAPInt();
 766             break;
 767           }
 768         }
 769         break;
 770       }
 771       return GV;
 772     }
 773     default:
 774       break;
 775     }
 776
 777     SmallString<256> Msg;
 778     raw_svector_ostream OS(Msg);
 779     OS << "ConstantExpr not handled: " << *CE;
 780     report_fatal_error(OS.str());
 781   }
 782
 783   // Otherwise, we have a simple constant.
 784   GenericValue Result;
 785   switch (C->getType()->getTypeID()) {
 786   case Type::FloatTyID:
 787     Result.FloatVal = cast<ConstantFP>(C)->getValueAPF().convertToFloat();
 788     break;
 789   case Type::DoubleTyID:
 790     Result.DoubleVal = cast<ConstantFP>(C)->getValueAPF().convertToDouble();
 791     break;
 792   case Type::X86_FP80TyID:
 793   case Type::FP128TyID:
 794   case Type::PPC_FP128TyID:
 795     Result.IntVal = cast <ConstantFP>(C)->getValueAPF().bitcastToAPInt();
 796     break;
 797   case Type::IntegerTyID:
 798     Result.IntVal = cast<ConstantInt>(C)->getValue();
 799     break;
 800   case Type::PointerTyID:
 801     if (isa<ConstantPointerNull>(C))
 802       Result.PointerVal = 0;
 803     else if (const Function *F = dyn_cast<Function>(C))
 804       Result = PTOGV(getPointerToFunctionOrStub(const_cast<Function*>(F)));
 805     else if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(C))
 806       Result = PTOGV(getOrEmitGlobalVariable(const_cast<GlobalVariable*>(GV)));
 807     else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C))
 808       Result = PTOGV(getPointerToBasicBlock(const_cast<BasicBlock*>(
 809                                                         BA->getBasicBlock())));
 810     else
 811       llvm_unreachable("Unknown constant pointer type!");
 812     break;
 813   default:
 814     SmallString<256> Msg;
 815     raw_svector_ostream OS(Msg);
 816     OS << "ERROR: Constant unimplemented for type: " << *C->getType();
 817     report_fatal_error(OS.str());
 818   }
 819
 820   return Result;
 821 }
 822
 823 /// StoreIntToMemory - Fills the StoreBytes bytes of memory starting from Dst
 824 /// with the integer held in IntVal.
 825 static void StoreIntToMemory(const APInt &IntVal, uint8_t *Dst,
 826                              unsigned StoreBytes) {
 827   assert((IntVal.getBitWidth()+7)/8 >= StoreBytes && "Integer too small!");
 828   uint8_t *Src = (uint8_t *)IntVal.getRawData();
 829
 830   if (sys::isLittleEndianHost()) {
 831     // Little-endian host - the source is ordered from LSB to MSB.  Order the
 832     // destination from LSB to MSB: Do a straight copy.
 833     memcpy(Dst, Src, StoreBytes);
 834   } else {
 835     // Big-endian host - the source is an array of 64 bit words ordered from
 836     // LSW to MSW.  Each word is ordered from MSB to LSB.  Order the destination
 837     // from MSB to LSB: Reverse the word order, but not the bytes in a word.
 838     while (StoreBytes > sizeof(uint64_t)) {
 839       StoreBytes -= sizeof(uint64_t);
 840       // May not be aligned so use memcpy.
 841       memcpy(Dst + StoreBytes, Src, sizeof(uint64_t));
 842       Src += sizeof(uint64_t);
 843     }
 844
 845     memcpy(Dst, Src + sizeof(uint64_t) - StoreBytes, StoreBytes);
 846   }
 847 }
 848
 849 void ExecutionEngine::StoreValueToMemory(const GenericValue &Val,
 850                                          GenericValue *Ptr, const Type *Ty) {
 851   const unsigned StoreBytes = getTargetData()->getTypeStoreSize(Ty);
 852
 853   switch (Ty->getTypeID()) {
 854   case Type::IntegerTyID:
 855     StoreIntToMemory(Val.IntVal, (uint8_t*)Ptr, StoreBytes);
 856     break;
 857   case Type::FloatTyID:
 858     *((float*)Ptr) = Val.FloatVal;
 859     break;
 860   case Type::DoubleTyID:
 861     *((double*)Ptr) = Val.DoubleVal;
 862     break;
 863   case Type::X86_FP80TyID:
 864     memcpy(Ptr, Val.IntVal.getRawData(), 10);
 865     break;
 866   case Type::PointerTyID:
 867     // Ensure 64 bit target pointers are fully initialized on 32 bit hosts.
 868     if (StoreBytes != sizeof(PointerTy))
 869       memset(&(Ptr->PointerVal), 0, StoreBytes);
 870
 871     *((PointerTy*)Ptr) = Val.PointerVal;
 872     break;
 873   default:
 874     dbgs() << "Cannot store value of type " << *Ty << "!\n";
 875   }
 876
 877   if (sys::isLittleEndianHost() != getTargetData()->isLittleEndian())
 878     // Host and target are different endian - reverse the stored bytes.
 879     std::reverse((uint8_t*)Ptr, StoreBytes + (uint8_t*)Ptr);
 880 }
 881
 882 /// LoadIntFromMemory - Loads the integer stored in the LoadBytes bytes starting
 883 /// from Src into IntVal, which is assumed to be wide enough and to hold zero.
 884 static void LoadIntFromMemory(APInt &IntVal, uint8_t *Src, unsigned LoadBytes) {
 885   assert((IntVal.getBitWidth()+7)/8 >= LoadBytes && "Integer too small!");
 886   uint8_t *Dst = (uint8_t *)IntVal.getRawData();
 887
 888   if (sys::isLittleEndianHost())
 889     // Little-endian host - the destination must be ordered from LSB to MSB.
 890     // The source is ordered from LSB to MSB: Do a straight copy.
 891     memcpy(Dst, Src, LoadBytes);
 892   else {
 893     // Big-endian - the destination is an array of 64 bit words ordered from
 894     // LSW to MSW.  Each word must be ordered from MSB to LSB.  The source is
 895     // ordered from MSB to LSB: Reverse the word order, but not the bytes in
 896     // a word.
 897     while (LoadBytes > sizeof(uint64_t)) {
 898       LoadBytes -= sizeof(uint64_t);
 899       // May not be aligned so use memcpy.
 900       memcpy(Dst, Src + LoadBytes, sizeof(uint64_t));
 901       Dst += sizeof(uint64_t);
 902     }
 903
 904     memcpy(Dst + sizeof(uint64_t) - LoadBytes, Src, LoadBytes);
 905   }
 906 }
 907
 908 /// FIXME: document
 909 ///
 910 void ExecutionEngine::LoadValueFromMemory(GenericValue &Result,
 911                                           GenericValue *Ptr,
 912                                           const Type *Ty) {
 913   const unsigned LoadBytes = getTargetData()->getTypeStoreSize(Ty);
 914
 915   switch (Ty->getTypeID()) {
 916   case Type::IntegerTyID:
 917     // An APInt with all words initially zero.
 918     Result.IntVal = APInt(cast<IntegerType>(Ty)->getBitWidth(), 0);
 919     LoadIntFromMemory(Result.IntVal, (uint8_t*)Ptr, LoadBytes);
 920     break;
 921   case Type::FloatTyID:
 922     Result.FloatVal = *((float*)Ptr);
 923     break;
 924   case Type::DoubleTyID:
 925     Result.DoubleVal = *((double*)Ptr);
 926     break;
 927   case Type::PointerTyID:
 928     Result.PointerVal = *((PointerTy*)Ptr);
 929     break;
 930   case Type::X86_FP80TyID: {
 931     // This is endian dependent, but it will only work on x86 anyway.
 932     // FIXME: Will not trap if loading a signaling NaN.
 933     uint64_t y[2];
 934     memcpy(y, Ptr, 10);
 935     Result.IntVal = APInt(80, 2, y);
 936     break;
 937   }
 938   default:
 939     SmallString<256> Msg;
 940     raw_svector_ostream OS(Msg);
 941     OS << "Cannot load value of type " << *Ty << "!";
 942     report_fatal_error(OS.str());
 943   }
 944 }
 945
 946 void ExecutionEngine::InitializeMemory(const Constant *Init, void *Addr) {
 947   DEBUG(dbgs() << "JIT: Initializing " << Addr << " ");
 948   DEBUG(Init->dump());
 949   if (isa<UndefValue>(Init)) {
 950     return;
 951   } else if (const ConstantVector *CP = dyn_cast<ConstantVector>(Init)) {
 952     unsigned ElementSize =
 953       getTargetData()->getTypeAllocSize(CP->getType()->getElementType());
 954     for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
 955       InitializeMemory(CP->getOperand(i), (char*)Addr+i*ElementSize);
 956     return;
 957   } else if (isa<ConstantAggregateZero>(Init)) {
 958     memset(Addr, 0, (size_t)getTargetData()->getTypeAllocSize(Init->getType()));
 959     return;
 960   } else if (const ConstantArray *CPA = dyn_cast<ConstantArray>(Init)) {
 961     unsigned ElementSize =
 962       getTargetData()->getTypeAllocSize(CPA->getType()->getElementType());
 963     for (unsigned i = 0, e = CPA->getNumOperands(); i != e; ++i)
 964       InitializeMemory(CPA->getOperand(i), (char*)Addr+i*ElementSize);
 965     return;
 966   } else if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(Init)) {
 967     const StructLayout *SL =
 968       getTargetData()->getStructLayout(cast<StructType>(CPS->getType()));
 969     for (unsigned i = 0, e = CPS->getNumOperands(); i != e; ++i)
 970       InitializeMemory(CPS->getOperand(i), (char*)Addr+SL->getElementOffset(i));
 971     return;
 972   } else if (Init->getType()->isFirstClassType()) {
 973     GenericValue Val = getConstantValue(Init);
 974     StoreValueToMemory(Val, (GenericValue*)Addr, Init->getType());
 975     return;
 976   }
 977
 978   DEBUG(dbgs() << "Bad Type: " << *Init->getType() << "\n");
 979   llvm_unreachable("Unknown constant type to initialize memory with!");
 980 }
 981
 982 /// EmitGlobals - Emit all of the global variables to memory, storing their
 983 /// addresses into GlobalAddress.  This must make sure to copy the contents of
 984 /// their initializers into the memory.
 985 void ExecutionEngine::emitGlobals() {
 986   // Loop over all of the global variables in the program, allocating the memory
 987   // to hold them.  If there is more than one module, do a prepass over globals
 988   // to figure out how the different modules should link together.
 989   std::map<std::pair<std::string, const Type*>,
 990            const GlobalValue*> LinkedGlobalsMap;
 991
 992   if (Modules.size() != 1) {
 993     for (unsigned m = 0, e = Modules.size(); m != e; ++m) {
 994       Module &M = *Modules[m];
 995       for (Module::const_global_iterator I = M.global_begin(),
 996            E = M.global_end(); I != E; ++I) {
 997         const GlobalValue *GV = I;
 998         if (GV->hasLocalLinkage() || GV->isDeclaration() ||
 999             GV->hasAppendingLinkage() || !GV->hasName())
1000           continue;// Ignore external globals and globals with internal linkage.
1001
1002         const GlobalValue *&GVEntry =
1003           LinkedGlobalsMap[std::make_pair(GV->getName(), GV->getType())];
1004
1005         // If this is the first time we've seen this global, it is the canonical
1006         // version.
1007         if (!GVEntry) {
1008           GVEntry = GV;
1009           continue;
1010         }
1011
1012         // If the existing global is strong, never replace it.
1013         if (GVEntry->hasExternalLinkage() ||
1014             GVEntry->hasDLLImportLinkage() ||
1015             GVEntry->hasDLLExportLinkage())
1016           continue;
1017
1018         // Otherwise, we know it's linkonce/weak, replace it if this is a strong
1019         // symbol.  FIXME is this right for common?
1020         if (GV->hasExternalLinkage() || GVEntry->hasExternalWeakLinkage())
1021           GVEntry = GV;
1022       }
1023     }
1024   }
1025
1026   std::vector<const GlobalValue*> NonCanonicalGlobals;
1027   for (unsigned m = 0, e = Modules.size(); m != e; ++m) {
1028     Module &M = *Modules[m];
1029     for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
1030          I != E; ++I) {
1031       // In the multi-module case, see what this global maps to.
1032       if (!LinkedGlobalsMap.empty()) {
1033         if (const GlobalValue *GVEntry =
1034               LinkedGlobalsMap[std::make_pair(I->getName(), I->getType())]) {
1035           // If something else is the canonical global, ignore this one.
1036           if (GVEntry != &*I) {
1037             NonCanonicalGlobals.push_back(I);
1038             continue;
1039           }
1040         }
1041       }
1042
1043       if (!I->isDeclaration()) {
1044         addGlobalMapping(I, getMemoryForGV(I));
1045       } else {
1046         // External variable reference. Try to use the dynamic loader to
1047         // get a pointer to it.
1048         if (void *SymAddr =
1049             sys::DynamicLibrary::SearchForAddressOfSymbol(I->getName()))
1050           addGlobalMapping(I, SymAddr);
1051         else {
1052           report_fatal_error("Could not resolve external global address: "
1053                             +I->getName());
1054         }
1055       }
1056     }
1057
1058     // If there are multiple modules, map the non-canonical globals to their
1059     // canonical location.
1060     if (!NonCanonicalGlobals.empty()) {
1061       for (unsigned i = 0, e = NonCanonicalGlobals.size(); i != e; ++i) {
1062         const GlobalValue *GV = NonCanonicalGlobals[i];
1063         const GlobalValue *CGV =
1064           LinkedGlobalsMap[std::make_pair(GV->getName(), GV->getType())];
1065         void *Ptr = getPointerToGlobalIfAvailable(CGV);
1066         assert(Ptr && "Canonical global wasn't codegen'd!");
1067         addGlobalMapping(GV, Ptr);
1068       }
1069     }
1070
1071     // Now that all of the globals are set up in memory, loop through them all
1072     // and initialize their contents.
1073     for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
1074          I != E; ++I) {
1075       if (!I->isDeclaration()) {
1076         if (!LinkedGlobalsMap.empty()) {
1077           if (const GlobalValue *GVEntry =
1078                 LinkedGlobalsMap[std::make_pair(I->getName(), I->getType())])
1079             if (GVEntry != &*I)  // Not the canonical variable.
1080               continue;
1081         }
1082         EmitGlobalVariable(I);
1083       }
1084     }
1085   }
1086 }
1087
1088 // EmitGlobalVariable - This method emits the specified global variable to the
1089 // address specified in GlobalAddresses, or allocates new memory if it's not
1090 // already in the map.
1091 void ExecutionEngine::EmitGlobalVariable(const GlobalVariable *GV) {
1092   void *GA = getPointerToGlobalIfAvailable(GV);
1093
1094   if (GA == 0) {
1095     // If it's not already specified, allocate memory for the global.
1096     GA = getMemoryForGV(GV);
1097     addGlobalMapping(GV, GA);
1098   }
1099
1100   // Don't initialize if it's thread local, let the client do it.
1101   if (!GV->isThreadLocal())
1102     InitializeMemory(GV->getInitializer(), GA);
1103
1104   const Type *ElTy = GV->getType()->getElementType();
1105   size_t GVSize = (size_t)getTargetData()->getTypeAllocSize(ElTy);
1106   NumInitBytes += (unsigned)GVSize;
1107   ++NumGlobals;
1108 }
1109
1110 ExecutionEngineState::ExecutionEngineState(ExecutionEngine &EE)
1111   : EE(EE), GlobalAddressMap(this) {
1112 }
1113
1114 sys::Mutex *
1115 ExecutionEngineState::AddressMapConfig::getMutex(ExecutionEngineState *EES) {
1116   return &EES->EE.lock;
1117 }
1118
1119 void ExecutionEngineState::AddressMapConfig::onDelete(ExecutionEngineState *EES,
1120                                                       const GlobalValue *Old) {
1121   void *OldVal = EES->GlobalAddressMap.lookup(Old);
1122   EES->GlobalAddressReverseMap.erase(OldVal);
1123 }
1124
1125 void ExecutionEngineState::AddressMapConfig::onRAUW(ExecutionEngineState *,
1126                                                     const GlobalValue *,
1127                                                     const GlobalValue *) {
1128   assert(false && "The ExecutionEngine doesn't know how to handle a"
1129          " RAUW on a value it has a global mapping for.");
1130 }