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      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     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   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   FunctionType *FTy = Fn->getFunctionType();
    365   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                                             Reloc::Model RM,
    426                                             CodeModel::Model CMM) {
    427   if (ExecutionEngine::JITCtor == 0) {
    428     if (ErrorStr)
    429       *ErrorStr = "JIT has not been linked in.";
    430     return 0;
    431   }
    432 
    433   // Use the defaults for extra parameters.  Users can use EngineBuilder to
    434   // set them.
    435   StringRef MArch = "";
    436   StringRef MCPU = "";
    437   SmallVector<std::string, 1> MAttrs;
    438 
    439   TargetMachine *TM =
    440     EngineBuilder::selectTarget(M, MArch, MCPU, MAttrs, RM, CMM, ErrorStr);
    441   if (!TM || (ErrorStr && ErrorStr->length() > 0)) return 0;
    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 = EngineBuilder::selectTarget(M, MArch, MCPU, MAttrs,
    469                                                         RelocModel, CMModel,
    470                                                         ErrorStr)) {
    471       if (UseMCJIT && ExecutionEngine::MCJITCtor) {
    472         ExecutionEngine *EE =
    473           ExecutionEngine::MCJITCtor(M, ErrorStr, JMM, OptLevel,
    474                                      AllocateGVsWithCode, TM);
    475         if (EE) return EE;
    476       } else if (ExecutionEngine::JITCtor) {
    477         ExecutionEngine *EE =
    478           ExecutionEngine::JITCtor(M, ErrorStr, JMM, OptLevel,
    479                                    AllocateGVsWithCode, TM);
    480         if (EE) return EE;
    481       }
    482     }
    483   }
    484 
    485   // If we can't make a JIT and we didn't request one specifically, try making
    486   // an interpreter instead.
    487   if (WhichEngine & EngineKind::Interpreter) {
    488     if (ExecutionEngine::InterpCtor)
    489       return ExecutionEngine::InterpCtor(M, ErrorStr);
    490     if (ErrorStr)
    491       *ErrorStr = "Interpreter has not been linked in.";
    492     return 0;
    493   }
    494 
    495   if ((WhichEngine & EngineKind::JIT) && ExecutionEngine::JITCtor == 0) {
    496     if (ErrorStr)
    497       *ErrorStr = "JIT has not been linked in.";
    498   }
    499 
    500   return 0;
    501 }
    502 
    503 void *ExecutionEngine::getPointerToGlobal(const GlobalValue *GV) {
    504   if (Function *F = const_cast<Function*>(dyn_cast<Function>(GV)))
    505     return getPointerToFunction(F);
    506 
    507   MutexGuard locked(lock);
    508   if (void *P = EEState.getGlobalAddressMap(locked)[GV])
    509     return P;
    510 
    511   // Global variable might have been added since interpreter started.
    512   if (GlobalVariable *GVar =
    513           const_cast<GlobalVariable *>(dyn_cast<GlobalVariable>(GV)))
    514     EmitGlobalVariable(GVar);
    515   else
    516     llvm_unreachable("Global hasn't had an address allocated yet!");
    517 
    518   return EEState.getGlobalAddressMap(locked)[GV];
    519 }
    520 
    521 /// \brief Converts a Constant* into a GenericValue, including handling of
    522 /// ConstantExpr values.
    523 GenericValue ExecutionEngine::getConstantValue(const Constant *C) {
    524   // If its undefined, return the garbage.
    525   if (isa<UndefValue>(C)) {
    526     GenericValue Result;
    527     switch (C->getType()->getTypeID()) {
    528     case Type::IntegerTyID:
    529     case Type::X86_FP80TyID:
    530     case Type::FP128TyID:
    531     case Type::PPC_FP128TyID:
    532       // Although the value is undefined, we still have to construct an APInt
    533       // with the correct bit width.
    534       Result.IntVal = APInt(C->getType()->getPrimitiveSizeInBits(), 0);
    535       break;
    536     default:
    537       break;
    538     }
    539     return Result;
    540   }
    541 
    542   // Otherwise, if the value is a ConstantExpr...
    543   if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
    544     Constant *Op0 = CE->getOperand(0);
    545     switch (CE->getOpcode()) {
    546     case Instruction::GetElementPtr: {
    547       // Compute the index
    548       GenericValue Result = getConstantValue(Op0);
    549       SmallVector<Value*, 8> Indices(CE->op_begin()+1, CE->op_end());
    550       uint64_t Offset = TD->getIndexedOffset(Op0->getType(), Indices);
    551 
    552       char* tmp = (char*) Result.PointerVal;
    553       Result = PTOGV(tmp + Offset);
    554       return Result;
    555     }
    556     case Instruction::Trunc: {
    557       GenericValue GV = getConstantValue(Op0);
    558       uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
    559       GV.IntVal = GV.IntVal.trunc(BitWidth);
    560       return GV;
    561     }
    562     case Instruction::ZExt: {
    563       GenericValue GV = getConstantValue(Op0);
    564       uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
    565       GV.IntVal = GV.IntVal.zext(BitWidth);
    566       return GV;
    567     }
    568     case Instruction::SExt: {
    569       GenericValue GV = getConstantValue(Op0);
    570       uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
    571       GV.IntVal = GV.IntVal.sext(BitWidth);
    572       return GV;
    573     }
    574     case Instruction::FPTrunc: {
    575       // FIXME long double
    576       GenericValue GV = getConstantValue(Op0);
    577       GV.FloatVal = float(GV.DoubleVal);
    578       return GV;
    579     }
    580     case Instruction::FPExt:{
    581       // FIXME long double
    582       GenericValue GV = getConstantValue(Op0);
    583       GV.DoubleVal = double(GV.FloatVal);
    584       return GV;
    585     }
    586     case Instruction::UIToFP: {
    587       GenericValue GV = getConstantValue(Op0);
    588       if (CE->getType()->isFloatTy())
    589         GV.FloatVal = float(GV.IntVal.roundToDouble());
    590       else if (CE->getType()->isDoubleTy())
    591         GV.DoubleVal = GV.IntVal.roundToDouble();
    592       else if (CE->getType()->isX86_FP80Ty()) {
    593         APFloat apf = APFloat::getZero(APFloat::x87DoubleExtended);
    594         (void)apf.convertFromAPInt(GV.IntVal,
    595                                    false,
    596                                    APFloat::rmNearestTiesToEven);
    597         GV.IntVal = apf.bitcastToAPInt();
    598       }
    599       return GV;
    600     }
    601     case Instruction::SIToFP: {
    602       GenericValue GV = getConstantValue(Op0);
    603       if (CE->getType()->isFloatTy())
    604         GV.FloatVal = float(GV.IntVal.signedRoundToDouble());
    605       else if (CE->getType()->isDoubleTy())
    606         GV.DoubleVal = GV.IntVal.signedRoundToDouble();
    607       else if (CE->getType()->isX86_FP80Ty()) {
    608         APFloat apf = APFloat::getZero(APFloat::x87DoubleExtended);
    609         (void)apf.convertFromAPInt(GV.IntVal,
    610                                    true,
    611                                    APFloat::rmNearestTiesToEven);
    612         GV.IntVal = apf.bitcastToAPInt();
    613       }
    614       return GV;
    615     }
    616     case Instruction::FPToUI: // double->APInt conversion handles sign
    617     case Instruction::FPToSI: {
    618       GenericValue GV = getConstantValue(Op0);
    619       uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
    620       if (Op0->getType()->isFloatTy())
    621         GV.IntVal = APIntOps::RoundFloatToAPInt(GV.FloatVal, BitWidth);
    622       else if (Op0->getType()->isDoubleTy())
    623         GV.IntVal = APIntOps::RoundDoubleToAPInt(GV.DoubleVal, BitWidth);
    624       else if (Op0->getType()->isX86_FP80Ty()) {
    625         APFloat apf = APFloat(GV.IntVal);
    626         uint64_t v;
    627         bool ignored;
    628         (void)apf.convertToInteger(&v, BitWidth,
    629                                    CE->getOpcode()==Instruction::FPToSI,
    630                                    APFloat::rmTowardZero, &ignored);
    631         GV.IntVal = v; // endian?
    632       }
    633       return GV;
    634     }
    635     case Instruction::PtrToInt: {
    636       GenericValue GV = getConstantValue(Op0);
    637       uint32_t PtrWidth = TD->getPointerSizeInBits();
    638       GV.IntVal = APInt(PtrWidth, uintptr_t(GV.PointerVal));
    639       return GV;
    640     }
    641     case Instruction::IntToPtr: {
    642       GenericValue GV = getConstantValue(Op0);
    643       uint32_t PtrWidth = TD->getPointerSizeInBits();
    644       if (PtrWidth != GV.IntVal.getBitWidth())
    645         GV.IntVal = GV.IntVal.zextOrTrunc(PtrWidth);
    646       assert(GV.IntVal.getBitWidth() <= 64 && "Bad pointer width");
    647       GV.PointerVal = PointerTy(uintptr_t(GV.IntVal.getZExtValue()));
    648       return GV;
    649     }
    650     case Instruction::BitCast: {
    651       GenericValue GV = getConstantValue(Op0);
    652       Type* DestTy = CE->getType();
    653       switch (Op0->getType()->getTypeID()) {
    654         default: llvm_unreachable("Invalid bitcast operand");
    655         case Type::IntegerTyID:
    656           assert(DestTy->isFloatingPointTy() && "invalid bitcast");
    657           if (DestTy->isFloatTy())
    658             GV.FloatVal = GV.IntVal.bitsToFloat();
    659           else if (DestTy->isDoubleTy())
    660             GV.DoubleVal = GV.IntVal.bitsToDouble();
    661           break;
    662         case Type::FloatTyID:
    663           assert(DestTy->isIntegerTy(32) && "Invalid bitcast");
    664           GV.IntVal = APInt::floatToBits(GV.FloatVal);
    665           break;
    666         case Type::DoubleTyID:
    667           assert(DestTy->isIntegerTy(64) && "Invalid bitcast");
    668           GV.IntVal = APInt::doubleToBits(GV.DoubleVal);
    669           break;
    670         case Type::PointerTyID:
    671           assert(DestTy->isPointerTy() && "Invalid bitcast");
    672           break; // getConstantValue(Op0)  above already converted it
    673       }
    674       return GV;
    675     }
    676     case Instruction::Add:
    677     case Instruction::FAdd:
    678     case Instruction::Sub:
    679     case Instruction::FSub:
    680     case Instruction::Mul:
    681     case Instruction::FMul:
    682     case Instruction::UDiv:
    683     case Instruction::SDiv:
    684     case Instruction::URem:
    685     case Instruction::SRem:
    686     case Instruction::And:
    687     case Instruction::Or:
    688     case Instruction::Xor: {
    689       GenericValue LHS = getConstantValue(Op0);
    690       GenericValue RHS = getConstantValue(CE->getOperand(1));
    691       GenericValue GV;
    692       switch (CE->getOperand(0)->getType()->getTypeID()) {
    693       default: llvm_unreachable("Bad add type!");
    694       case Type::IntegerTyID:
    695         switch (CE->getOpcode()) {
    696           default: llvm_unreachable("Invalid integer opcode");
    697           case Instruction::Add: GV.IntVal = LHS.IntVal + RHS.IntVal; break;
    698           case Instruction::Sub: GV.IntVal = LHS.IntVal - RHS.IntVal; break;
    699           case Instruction::Mul: GV.IntVal = LHS.IntVal * RHS.IntVal; break;
    700           case Instruction::UDiv:GV.IntVal = LHS.IntVal.udiv(RHS.IntVal); break;
    701           case Instruction::SDiv:GV.IntVal = LHS.IntVal.sdiv(RHS.IntVal); break;
    702           case Instruction::URem:GV.IntVal = LHS.IntVal.urem(RHS.IntVal); break;
    703           case Instruction::SRem:GV.IntVal = LHS.IntVal.srem(RHS.IntVal); break;
    704           case Instruction::And: GV.IntVal = LHS.IntVal & RHS.IntVal; break;
    705           case Instruction::Or:  GV.IntVal = LHS.IntVal | RHS.IntVal; break;
    706           case Instruction::Xor: GV.IntVal = LHS.IntVal ^ RHS.IntVal; break;
    707         }
    708         break;
    709       case Type::FloatTyID:
    710         switch (CE->getOpcode()) {
    711           default: llvm_unreachable("Invalid float opcode");
    712           case Instruction::FAdd:
    713             GV.FloatVal = LHS.FloatVal + RHS.FloatVal; break;
    714           case Instruction::FSub:
    715             GV.FloatVal = LHS.FloatVal - RHS.FloatVal; break;
    716           case Instruction::FMul:
    717             GV.FloatVal = LHS.FloatVal * RHS.FloatVal; break;
    718           case Instruction::FDiv:
    719             GV.FloatVal = LHS.FloatVal / RHS.FloatVal; break;
    720           case Instruction::FRem:
    721             GV.FloatVal = std::fmod(LHS.FloatVal,RHS.FloatVal); break;
    722         }
    723         break;
    724       case Type::DoubleTyID:
    725         switch (CE->getOpcode()) {
    726           default: llvm_unreachable("Invalid double opcode");
    727           case Instruction::FAdd:
    728             GV.DoubleVal = LHS.DoubleVal + RHS.DoubleVal; break;
    729           case Instruction::FSub:
    730             GV.DoubleVal = LHS.DoubleVal - RHS.DoubleVal; break;
    731           case Instruction::FMul:
    732             GV.DoubleVal = LHS.DoubleVal * RHS.DoubleVal; break;
    733           case Instruction::FDiv:
    734             GV.DoubleVal = LHS.DoubleVal / RHS.DoubleVal; break;
    735           case Instruction::FRem:
    736             GV.DoubleVal = std::fmod(LHS.DoubleVal,RHS.DoubleVal); break;
    737         }
    738         break;
    739       case Type::X86_FP80TyID:
    740       case Type::PPC_FP128TyID:
    741       case Type::FP128TyID: {
    742         APFloat apfLHS = APFloat(LHS.IntVal);
    743         switch (CE->getOpcode()) {
    744           default: llvm_unreachable("Invalid long double opcode");
    745           case Instruction::FAdd:
    746             apfLHS.add(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
    747             GV.IntVal = apfLHS.bitcastToAPInt();
    748             break;
    749           case Instruction::FSub:
    750             apfLHS.subtract(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
    751             GV.IntVal = apfLHS.bitcastToAPInt();
    752             break;
    753           case Instruction::FMul:
    754             apfLHS.multiply(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
    755             GV.IntVal = apfLHS.bitcastToAPInt();
    756             break;
    757           case Instruction::FDiv:
    758             apfLHS.divide(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
    759             GV.IntVal = apfLHS.bitcastToAPInt();
    760             break;
    761           case Instruction::FRem:
    762             apfLHS.mod(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
    763             GV.IntVal = apfLHS.bitcastToAPInt();
    764             break;
    765           }
    766         }
    767         break;
    768       }
    769       return GV;
    770     }
    771     default:
    772       break;
    773     }
    774 
    775     SmallString<256> Msg;
    776     raw_svector_ostream OS(Msg);
    777     OS << "ConstantExpr not handled: " << *CE;
    778     report_fatal_error(OS.str());
    779   }
    780 
    781   // Otherwise, we have a simple constant.
    782   GenericValue Result;
    783   switch (C->getType()->getTypeID()) {
    784   case Type::FloatTyID:
    785     Result.FloatVal = cast<ConstantFP>(C)->getValueAPF().convertToFloat();
    786     break;
    787   case Type::DoubleTyID:
    788     Result.DoubleVal = cast<ConstantFP>(C)->getValueAPF().convertToDouble();
    789     break;
    790   case Type::X86_FP80TyID:
    791   case Type::FP128TyID:
    792   case Type::PPC_FP128TyID:
    793     Result.IntVal = cast <ConstantFP>(C)->getValueAPF().bitcastToAPInt();
    794     break;
    795   case Type::IntegerTyID:
    796     Result.IntVal = cast<ConstantInt>(C)->getValue();
    797     break;
    798   case Type::PointerTyID:
    799     if (isa<ConstantPointerNull>(C))
    800       Result.PointerVal = 0;
    801     else if (const Function *F = dyn_cast<Function>(C))
    802       Result = PTOGV(getPointerToFunctionOrStub(const_cast<Function*>(F)));
    803     else if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(C))
    804       Result = PTOGV(getOrEmitGlobalVariable(const_cast<GlobalVariable*>(GV)));
    805     else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C))
    806       Result = PTOGV(getPointerToBasicBlock(const_cast<BasicBlock*>(
    807                                                         BA->getBasicBlock())));
    808     else
    809       llvm_unreachable("Unknown constant pointer type!");
    810     break;
    811   default:
    812     SmallString<256> Msg;
    813     raw_svector_ostream OS(Msg);
    814     OS << "ERROR: Constant unimplemented for type: " << *C->getType();
    815     report_fatal_error(OS.str());
    816   }
    817 
    818   return Result;
    819 }
    820 
    821 /// StoreIntToMemory - Fills the StoreBytes bytes of memory starting from Dst
    822 /// with the integer held in IntVal.
    823 static void StoreIntToMemory(const APInt &IntVal, uint8_t *Dst,
    824                              unsigned StoreBytes) {
    825   assert((IntVal.getBitWidth()+7)/8 >= StoreBytes && "Integer too small!");
    826   uint8_t *Src = (uint8_t *)IntVal.getRawData();
    827 
    828   if (sys::isLittleEndianHost()) {
    829     // Little-endian host - the source is ordered from LSB to MSB.  Order the
    830     // destination from LSB to MSB: Do a straight copy.
    831     memcpy(Dst, Src, StoreBytes);
    832   } else {
    833     // Big-endian host - the source is an array of 64 bit words ordered from
    834     // LSW to MSW.  Each word is ordered from MSB to LSB.  Order the destination
    835     // from MSB to LSB: Reverse the word order, but not the bytes in a word.
    836     while (StoreBytes > sizeof(uint64_t)) {
    837       StoreBytes -= sizeof(uint64_t);
    838       // May not be aligned so use memcpy.
    839       memcpy(Dst + StoreBytes, Src, sizeof(uint64_t));
    840       Src += sizeof(uint64_t);
    841     }
    842 
    843     memcpy(Dst, Src + sizeof(uint64_t) - StoreBytes, StoreBytes);
    844   }
    845 }
    846 
    847 void ExecutionEngine::StoreValueToMemory(const GenericValue &Val,
    848                                          GenericValue *Ptr, Type *Ty) {
    849   const unsigned StoreBytes = getTargetData()->getTypeStoreSize(Ty);
    850 
    851   switch (Ty->getTypeID()) {
    852   case Type::IntegerTyID:
    853     StoreIntToMemory(Val.IntVal, (uint8_t*)Ptr, StoreBytes);
    854     break;
    855   case Type::FloatTyID:
    856     *((float*)Ptr) = Val.FloatVal;
    857     break;
    858   case Type::DoubleTyID:
    859     *((double*)Ptr) = Val.DoubleVal;
    860     break;
    861   case Type::X86_FP80TyID:
    862     memcpy(Ptr, Val.IntVal.getRawData(), 10);
    863     break;
    864   case Type::PointerTyID:
    865     // Ensure 64 bit target pointers are fully initialized on 32 bit hosts.
    866     if (StoreBytes != sizeof(PointerTy))
    867       memset(&(Ptr->PointerVal), 0, StoreBytes);
    868 
    869     *((PointerTy*)Ptr) = Val.PointerVal;
    870     break;
    871   default:
    872     dbgs() << "Cannot store value of type " << *Ty << "!\n";
    873   }
    874 
    875   if (sys::isLittleEndianHost() != getTargetData()->isLittleEndian())
    876     // Host and target are different endian - reverse the stored bytes.
    877     std::reverse((uint8_t*)Ptr, StoreBytes + (uint8_t*)Ptr);
    878 }
    879 
    880 /// LoadIntFromMemory - Loads the integer stored in the LoadBytes bytes starting
    881 /// from Src into IntVal, which is assumed to be wide enough and to hold zero.
    882 static void LoadIntFromMemory(APInt &IntVal, uint8_t *Src, unsigned LoadBytes) {
    883   assert((IntVal.getBitWidth()+7)/8 >= LoadBytes && "Integer too small!");
    884   uint8_t *Dst = (uint8_t *)IntVal.getRawData();
    885 
    886   if (sys::isLittleEndianHost())
    887     // Little-endian host - the destination must be ordered from LSB to MSB.
    888     // The source is ordered from LSB to MSB: Do a straight copy.
    889     memcpy(Dst, Src, LoadBytes);
    890   else {
    891     // Big-endian - the destination is an array of 64 bit words ordered from
    892     // LSW to MSW.  Each word must be ordered from MSB to LSB.  The source is
    893     // ordered from MSB to LSB: Reverse the word order, but not the bytes in
    894     // a word.
    895     while (LoadBytes > sizeof(uint64_t)) {
    896       LoadBytes -= sizeof(uint64_t);
    897       // May not be aligned so use memcpy.
    898       memcpy(Dst, Src + LoadBytes, sizeof(uint64_t));
    899       Dst += sizeof(uint64_t);
    900     }
    901 
    902     memcpy(Dst + sizeof(uint64_t) - LoadBytes, Src, LoadBytes);
    903   }
    904 }
    905 
    906 /// FIXME: document
    907 ///
    908 void ExecutionEngine::LoadValueFromMemory(GenericValue &Result,
    909                                           GenericValue *Ptr,
    910                                           Type *Ty) {
    911   const unsigned LoadBytes = getTargetData()->getTypeStoreSize(Ty);
    912 
    913   switch (Ty->getTypeID()) {
    914   case Type::IntegerTyID:
    915     // An APInt with all words initially zero.
    916     Result.IntVal = APInt(cast<IntegerType>(Ty)->getBitWidth(), 0);
    917     LoadIntFromMemory(Result.IntVal, (uint8_t*)Ptr, LoadBytes);
    918     break;
    919   case Type::FloatTyID:
    920     Result.FloatVal = *((float*)Ptr);
    921     break;
    922   case Type::DoubleTyID:
    923     Result.DoubleVal = *((double*)Ptr);
    924     break;
    925   case Type::PointerTyID:
    926     Result.PointerVal = *((PointerTy*)Ptr);
    927     break;
    928   case Type::X86_FP80TyID: {
    929     // This is endian dependent, but it will only work on x86 anyway.
    930     // FIXME: Will not trap if loading a signaling NaN.
    931     uint64_t y[2];
    932     memcpy(y, Ptr, 10);
    933     Result.IntVal = APInt(80, y);
    934     break;
    935   }
    936   default:
    937     SmallString<256> Msg;
    938     raw_svector_ostream OS(Msg);
    939     OS << "Cannot load value of type " << *Ty << "!";
    940     report_fatal_error(OS.str());
    941   }
    942 }
    943 
    944 void ExecutionEngine::InitializeMemory(const Constant *Init, void *Addr) {
    945   DEBUG(dbgs() << "JIT: Initializing " << Addr << " ");
    946   DEBUG(Init->dump());
    947   if (isa<UndefValue>(Init)) {
    948     return;
    949   } else if (const ConstantVector *CP = dyn_cast<ConstantVector>(Init)) {
    950     unsigned ElementSize =
    951       getTargetData()->getTypeAllocSize(CP->getType()->getElementType());
    952     for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
    953       InitializeMemory(CP->getOperand(i), (char*)Addr+i*ElementSize);
    954     return;
    955   } else if (isa<ConstantAggregateZero>(Init)) {
    956     memset(Addr, 0, (size_t)getTargetData()->getTypeAllocSize(Init->getType()));
    957     return;
    958   } else if (const ConstantArray *CPA = dyn_cast<ConstantArray>(Init)) {
    959     unsigned ElementSize =
    960       getTargetData()->getTypeAllocSize(CPA->getType()->getElementType());
    961     for (unsigned i = 0, e = CPA->getNumOperands(); i != e; ++i)
    962       InitializeMemory(CPA->getOperand(i), (char*)Addr+i*ElementSize);
    963     return;
    964   } else if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(Init)) {
    965     const StructLayout *SL =
    966       getTargetData()->getStructLayout(cast<StructType>(CPS->getType()));
    967     for (unsigned i = 0, e = CPS->getNumOperands(); i != e; ++i)
    968       InitializeMemory(CPS->getOperand(i), (char*)Addr+SL->getElementOffset(i));
    969     return;
    970   } else if (Init->getType()->isFirstClassType()) {
    971     GenericValue Val = getConstantValue(Init);
    972     StoreValueToMemory(Val, (GenericValue*)Addr, Init->getType());
    973     return;
    974   }
    975 
    976   DEBUG(dbgs() << "Bad Type: " << *Init->getType() << "\n");
    977   llvm_unreachable("Unknown constant type to initialize memory with!");
    978 }
    979 
    980 /// EmitGlobals - Emit all of the global variables to memory, storing their
    981 /// addresses into GlobalAddress.  This must make sure to copy the contents of
    982 /// their initializers into the memory.
    983 void ExecutionEngine::emitGlobals() {
    984   // Loop over all of the global variables in the program, allocating the memory
    985   // to hold them.  If there is more than one module, do a prepass over globals
    986   // to figure out how the different modules should link together.
    987   std::map<std::pair<std::string, Type*>,
    988            const GlobalValue*> LinkedGlobalsMap;
    989 
    990   if (Modules.size() != 1) {
    991     for (unsigned m = 0, e = Modules.size(); m != e; ++m) {
    992       Module &M = *Modules[m];
    993       for (Module::const_global_iterator I = M.global_begin(),
    994            E = M.global_end(); I != E; ++I) {
    995         const GlobalValue *GV = I;
    996         if (GV->hasLocalLinkage() || GV->isDeclaration() ||
    997             GV->hasAppendingLinkage() || !GV->hasName())
    998           continue;// Ignore external globals and globals with internal linkage.
    999 
   1000         const GlobalValue *&GVEntry =
   1001           LinkedGlobalsMap[std::make_pair(GV->getName(), GV->getType())];
   1002 
   1003         // If this is the first time we've seen this global, it is the canonical
   1004         // version.
   1005         if (!GVEntry) {
   1006           GVEntry = GV;
   1007           continue;
   1008         }
   1009 
   1010         // If the existing global is strong, never replace it.
   1011         if (GVEntry->hasExternalLinkage() ||
   1012             GVEntry->hasDLLImportLinkage() ||
   1013             GVEntry->hasDLLExportLinkage())
   1014           continue;
   1015 
   1016         // Otherwise, we know it's linkonce/weak, replace it if this is a strong
   1017         // symbol.  FIXME is this right for common?
   1018         if (GV->hasExternalLinkage() || GVEntry->hasExternalWeakLinkage())
   1019           GVEntry = GV;
   1020       }
   1021     }
   1022   }
   1023 
   1024   std::vector<const GlobalValue*> NonCanonicalGlobals;
   1025   for (unsigned m = 0, e = Modules.size(); m != e; ++m) {
   1026     Module &M = *Modules[m];
   1027     for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
   1028          I != E; ++I) {
   1029       // In the multi-module case, see what this global maps to.
   1030       if (!LinkedGlobalsMap.empty()) {
   1031         if (const GlobalValue *GVEntry =
   1032               LinkedGlobalsMap[std::make_pair(I->getName(), I->getType())]) {
   1033           // If something else is the canonical global, ignore this one.
   1034           if (GVEntry != &*I) {
   1035             NonCanonicalGlobals.push_back(I);
   1036             continue;
   1037           }
   1038         }
   1039       }
   1040 
   1041       if (!I->isDeclaration()) {
   1042         addGlobalMapping(I, getMemoryForGV(I));
   1043       } else {
   1044         // External variable reference. Try to use the dynamic loader to
   1045         // get a pointer to it.
   1046         if (void *SymAddr =
   1047             sys::DynamicLibrary::SearchForAddressOfSymbol(I->getName()))
   1048           addGlobalMapping(I, SymAddr);
   1049         else {
   1050           report_fatal_error("Could not resolve external global address: "
   1051                             +I->getName());
   1052         }
   1053       }
   1054     }
   1055 
   1056     // If there are multiple modules, map the non-canonical globals to their
   1057     // canonical location.
   1058     if (!NonCanonicalGlobals.empty()) {
   1059       for (unsigned i = 0, e = NonCanonicalGlobals.size(); i != e; ++i) {
   1060         const GlobalValue *GV = NonCanonicalGlobals[i];
   1061         const GlobalValue *CGV =
   1062           LinkedGlobalsMap[std::make_pair(GV->getName(), GV->getType())];
   1063         void *Ptr = getPointerToGlobalIfAvailable(CGV);
   1064         assert(Ptr && "Canonical global wasn't codegen'd!");
   1065         addGlobalMapping(GV, Ptr);
   1066       }
   1067     }
   1068 
   1069     // Now that all of the globals are set up in memory, loop through them all
   1070     // and initialize their contents.
   1071     for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
   1072          I != E; ++I) {
   1073       if (!I->isDeclaration()) {
   1074         if (!LinkedGlobalsMap.empty()) {
   1075           if (const GlobalValue *GVEntry =
   1076                 LinkedGlobalsMap[std::make_pair(I->getName(), I->getType())])
   1077             if (GVEntry != &*I)  // Not the canonical variable.
   1078               continue;
   1079         }
   1080         EmitGlobalVariable(I);
   1081       }
   1082     }
   1083   }
   1084 }
   1085 
   1086 // EmitGlobalVariable - This method emits the specified global variable to the
   1087 // address specified in GlobalAddresses, or allocates new memory if it's not
   1088 // already in the map.
   1089 void ExecutionEngine::EmitGlobalVariable(const GlobalVariable *GV) {
   1090   void *GA = getPointerToGlobalIfAvailable(GV);
   1091 
   1092   if (GA == 0) {
   1093     // If it's not already specified, allocate memory for the global.
   1094     GA = getMemoryForGV(GV);
   1095     addGlobalMapping(GV, GA);
   1096   }
   1097 
   1098   // Don't initialize if it's thread local, let the client do it.
   1099   if (!GV->isThreadLocal())
   1100     InitializeMemory(GV->getInitializer(), GA);
   1101 
   1102   Type *ElTy = GV->getType()->getElementType();
   1103   size_t GVSize = (size_t)getTargetData()->getTypeAllocSize(ElTy);
   1104   NumInitBytes += (unsigned)GVSize;
   1105   ++NumGlobals;
   1106 }
   1107 
   1108 ExecutionEngineState::ExecutionEngineState(ExecutionEngine &EE)
   1109   : EE(EE), GlobalAddressMap(this) {
   1110 }
   1111 
   1112 sys::Mutex *
   1113 ExecutionEngineState::AddressMapConfig::getMutex(ExecutionEngineState *EES) {
   1114   return &EES->EE.lock;
   1115 }
   1116 
   1117 void ExecutionEngineState::AddressMapConfig::onDelete(ExecutionEngineState *EES,
   1118                                                       const GlobalValue *Old) {
   1119   void *OldVal = EES->GlobalAddressMap.lookup(Old);
   1120   EES->GlobalAddressReverseMap.erase(OldVal);
   1121 }
   1122 
   1123 void ExecutionEngineState::AddressMapConfig::onRAUW(ExecutionEngineState *,
   1124                                                     const GlobalValue *,
   1125                                                     const GlobalValue *) {
   1126   assert(false && "The ExecutionEngine doesn't know how to handle a"
   1127          " RAUW on a value it has a global mapping for.");
   1128 }
   1129