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/Support/TargetRegistry.h"
32#include "llvm/Target/TargetData.h"
33#include "llvm/Target/TargetMachine.h"
34#include <cmath>
35#include <cstring>
36using namespace llvm;
37
38STATISTIC(NumInitBytes, "Number of bytes of global vars initialized");
39STATISTIC(NumGlobals  , "Number of global vars initialized");
40
41ExecutionEngine *(*ExecutionEngine::JITCtor)(
42  Module *M,
43  std::string *ErrorStr,
44  JITMemoryManager *JMM,
45  bool GVsWithCode,
46  TargetMachine *TM) = 0;
47ExecutionEngine *(*ExecutionEngine::MCJITCtor)(
48  Module *M,
49  std::string *ErrorStr,
50  JITMemoryManager *JMM,
51  bool GVsWithCode,
52  TargetMachine *TM) = 0;
53ExecutionEngine *(*ExecutionEngine::InterpCtor)(Module *M,
54                                                std::string *ErrorStr) = 0;
55
56ExecutionEngine::ExecutionEngine(Module *M)
57  : EEState(*this),
58    LazyFunctionCreator(0),
59    ExceptionTableRegister(0),
60    ExceptionTableDeregister(0) {
61  CompilingLazily         = false;
62  GVCompilationDisabled   = false;
63  SymbolSearchingDisabled = false;
64  Modules.push_back(M);
65  assert(M && "Module is null?");
66}
67
68ExecutionEngine::~ExecutionEngine() {
69  clearAllGlobalMappings();
70  for (unsigned i = 0, e = Modules.size(); i != e; ++i)
71    delete Modules[i];
72}
73
74void ExecutionEngine::DeregisterAllTables() {
75  if (ExceptionTableDeregister) {
76    DenseMap<const Function*, void*>::iterator it = AllExceptionTables.begin();
77    DenseMap<const Function*, void*>::iterator ite = AllExceptionTables.end();
78    for (; it != ite; ++it)
79      ExceptionTableDeregister(it->second);
80    AllExceptionTables.clear();
81  }
82}
83
84namespace {
85/// \brief Helper class which uses a value handler to automatically deletes the
86/// memory block when the GlobalVariable is destroyed.
87class GVMemoryBlock : public CallbackVH {
88  GVMemoryBlock(const GlobalVariable *GV)
89    : CallbackVH(const_cast<GlobalVariable*>(GV)) {}
90
91public:
92  /// \brief Returns the address the GlobalVariable should be written into.  The
93  /// GVMemoryBlock object prefixes that.
94  static char *Create(const GlobalVariable *GV, const TargetData& TD) {
95    Type *ElTy = GV->getType()->getElementType();
96    size_t GVSize = (size_t)TD.getTypeAllocSize(ElTy);
97    void *RawMemory = ::operator new(
98      TargetData::RoundUpAlignment(sizeof(GVMemoryBlock),
99                                   TD.getPreferredAlignment(GV))
100      + GVSize);
101    new(RawMemory) GVMemoryBlock(GV);
102    return static_cast<char*>(RawMemory) + sizeof(GVMemoryBlock);
103  }
104
105  virtual void deleted() {
106    // We allocated with operator new and with some extra memory hanging off the
107    // end, so don't just delete this.  I'm not sure if this is actually
108    // required.
109    this->~GVMemoryBlock();
110    ::operator delete(this);
111  }
112};
113}  // anonymous namespace
114
115char *ExecutionEngine::getMemoryForGV(const GlobalVariable *GV) {
116  return GVMemoryBlock::Create(GV, *getTargetData());
117}
118
119bool ExecutionEngine::removeModule(Module *M) {
120  for(SmallVector<Module *, 1>::iterator I = Modules.begin(),
121        E = Modules.end(); I != E; ++I) {
122    Module *Found = *I;
123    if (Found == M) {
124      Modules.erase(I);
125      clearGlobalMappingsFromModule(M);
126      return true;
127    }
128  }
129  return false;
130}
131
132Function *ExecutionEngine::FindFunctionNamed(const char *FnName) {
133  for (unsigned i = 0, e = Modules.size(); i != e; ++i) {
134    if (Function *F = Modules[i]->getFunction(FnName))
135      return F;
136  }
137  return 0;
138}
139
140
141void *ExecutionEngineState::RemoveMapping(const MutexGuard &,
142                                          const GlobalValue *ToUnmap) {
143  GlobalAddressMapTy::iterator I = GlobalAddressMap.find(ToUnmap);
144  void *OldVal;
145
146  // FIXME: This is silly, we shouldn't end up with a mapping -> 0 in the
147  // GlobalAddressMap.
148  if (I == GlobalAddressMap.end())
149    OldVal = 0;
150  else {
151    OldVal = I->second;
152    GlobalAddressMap.erase(I);
153  }
154
155  GlobalAddressReverseMap.erase(OldVal);
156  return OldVal;
157}
158
159void ExecutionEngine::addGlobalMapping(const GlobalValue *GV, void *Addr) {
160  MutexGuard locked(lock);
161
162  DEBUG(dbgs() << "JIT: Map \'" << GV->getName()
163        << "\' to [" << Addr << "]\n";);
164  void *&CurVal = EEState.getGlobalAddressMap(locked)[GV];
165  assert((CurVal == 0 || Addr == 0) && "GlobalMapping already established!");
166  CurVal = Addr;
167
168  // If we are using the reverse mapping, add it too.
169  if (!EEState.getGlobalAddressReverseMap(locked).empty()) {
170    AssertingVH<const GlobalValue> &V =
171      EEState.getGlobalAddressReverseMap(locked)[Addr];
172    assert((V == 0 || GV == 0) && "GlobalMapping already established!");
173    V = GV;
174  }
175}
176
177void ExecutionEngine::clearAllGlobalMappings() {
178  MutexGuard locked(lock);
179
180  EEState.getGlobalAddressMap(locked).clear();
181  EEState.getGlobalAddressReverseMap(locked).clear();
182}
183
184void ExecutionEngine::clearGlobalMappingsFromModule(Module *M) {
185  MutexGuard locked(lock);
186
187  for (Module::iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI)
188    EEState.RemoveMapping(locked, FI);
189  for (Module::global_iterator GI = M->global_begin(), GE = M->global_end();
190       GI != GE; ++GI)
191    EEState.RemoveMapping(locked, GI);
192}
193
194void *ExecutionEngine::updateGlobalMapping(const GlobalValue *GV, void *Addr) {
195  MutexGuard locked(lock);
196
197  ExecutionEngineState::GlobalAddressMapTy &Map =
198    EEState.getGlobalAddressMap(locked);
199
200  // Deleting from the mapping?
201  if (Addr == 0)
202    return EEState.RemoveMapping(locked, GV);
203
204  void *&CurVal = Map[GV];
205  void *OldVal = CurVal;
206
207  if (CurVal && !EEState.getGlobalAddressReverseMap(locked).empty())
208    EEState.getGlobalAddressReverseMap(locked).erase(CurVal);
209  CurVal = Addr;
210
211  // If we are using the reverse mapping, add it too.
212  if (!EEState.getGlobalAddressReverseMap(locked).empty()) {
213    AssertingVH<const GlobalValue> &V =
214      EEState.getGlobalAddressReverseMap(locked)[Addr];
215    assert((V == 0 || GV == 0) && "GlobalMapping already established!");
216    V = GV;
217  }
218  return OldVal;
219}
220
221void *ExecutionEngine::getPointerToGlobalIfAvailable(const GlobalValue *GV) {
222  MutexGuard locked(lock);
223
224  ExecutionEngineState::GlobalAddressMapTy::iterator I =
225    EEState.getGlobalAddressMap(locked).find(GV);
226  return I != EEState.getGlobalAddressMap(locked).end() ? I->second : 0;
227}
228
229const GlobalValue *ExecutionEngine::getGlobalValueAtAddress(void *Addr) {
230  MutexGuard locked(lock);
231
232  // If we haven't computed the reverse mapping yet, do so first.
233  if (EEState.getGlobalAddressReverseMap(locked).empty()) {
234    for (ExecutionEngineState::GlobalAddressMapTy::iterator
235         I = EEState.getGlobalAddressMap(locked).begin(),
236         E = EEState.getGlobalAddressMap(locked).end(); I != E; ++I)
237      EEState.getGlobalAddressReverseMap(locked).insert(std::make_pair(
238                                                          I->second, I->first));
239  }
240
241  std::map<void *, AssertingVH<const GlobalValue> >::iterator I =
242    EEState.getGlobalAddressReverseMap(locked).find(Addr);
243  return I != EEState.getGlobalAddressReverseMap(locked).end() ? I->second : 0;
244}
245
246namespace {
247class ArgvArray {
248  char *Array;
249  std::vector<char*> Values;
250public:
251  ArgvArray() : Array(NULL) {}
252  ~ArgvArray() { clear(); }
253  void clear() {
254    delete[] Array;
255    Array = NULL;
256    for (size_t I = 0, E = Values.size(); I != E; ++I) {
257      delete[] Values[I];
258    }
259    Values.clear();
260  }
261  /// Turn a vector of strings into a nice argv style array of pointers to null
262  /// terminated strings.
263  void *reset(LLVMContext &C, ExecutionEngine *EE,
264              const std::vector<std::string> &InputArgv);
265};
266}  // anonymous namespace
267void *ArgvArray::reset(LLVMContext &C, ExecutionEngine *EE,
268                       const std::vector<std::string> &InputArgv) {
269  clear();  // Free the old contents.
270  unsigned PtrSize = EE->getTargetData()->getPointerSize();
271  Array = new char[(InputArgv.size()+1)*PtrSize];
272
273  DEBUG(dbgs() << "JIT: ARGV = " << (void*)Array << "\n");
274  Type *SBytePtr = Type::getInt8PtrTy(C);
275
276  for (unsigned i = 0; i != InputArgv.size(); ++i) {
277    unsigned Size = InputArgv[i].size()+1;
278    char *Dest = new char[Size];
279    Values.push_back(Dest);
280    DEBUG(dbgs() << "JIT: ARGV[" << i << "] = " << (void*)Dest << "\n");
281
282    std::copy(InputArgv[i].begin(), InputArgv[i].end(), Dest);
283    Dest[Size-1] = 0;
284
285    // Endian safe: Array[i] = (PointerTy)Dest;
286    EE->StoreValueToMemory(PTOGV(Dest), (GenericValue*)(Array+i*PtrSize),
287                           SBytePtr);
288  }
289
290  // Null terminate it
291  EE->StoreValueToMemory(PTOGV(0),
292                         (GenericValue*)(Array+InputArgv.size()*PtrSize),
293                         SBytePtr);
294  return Array;
295}
296
297void ExecutionEngine::runStaticConstructorsDestructors(Module *module,
298                                                       bool isDtors) {
299  const char *Name = isDtors ? "llvm.global_dtors" : "llvm.global_ctors";
300  GlobalVariable *GV = module->getNamedGlobal(Name);
301
302  // If this global has internal linkage, or if it has a use, then it must be
303  // an old-style (llvmgcc3) static ctor with __main linked in and in use.  If
304  // this is the case, don't execute any of the global ctors, __main will do
305  // it.
306  if (!GV || GV->isDeclaration() || GV->hasLocalLinkage()) return;
307
308  // Should be an array of '{ i32, void ()* }' structs.  The first value is
309  // the init priority, which we ignore.
310  ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
311  if (InitList == 0)
312    return;
313  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
314    ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i));
315    if (CS == 0) continue;
316
317    Constant *FP = CS->getOperand(1);
318    if (FP->isNullValue())
319      continue;  // Found a sentinal value, ignore.
320
321    // Strip off constant expression casts.
322    if (ConstantExpr *CE = dyn_cast<ConstantExpr>(FP))
323      if (CE->isCast())
324        FP = CE->getOperand(0);
325
326    // Execute the ctor/dtor function!
327    if (Function *F = dyn_cast<Function>(FP))
328      runFunction(F, std::vector<GenericValue>());
329
330    // FIXME: It is marginally lame that we just do nothing here if we see an
331    // entry we don't recognize. It might not be unreasonable for the verifier
332    // to not even allow this and just assert here.
333  }
334}
335
336void ExecutionEngine::runStaticConstructorsDestructors(bool isDtors) {
337  // Execute global ctors/dtors for each module in the program.
338  for (unsigned i = 0, e = Modules.size(); i != e; ++i)
339    runStaticConstructorsDestructors(Modules[i], isDtors);
340}
341
342#ifndef NDEBUG
343/// isTargetNullPtr - Return whether the target pointer stored at Loc is null.
344static bool isTargetNullPtr(ExecutionEngine *EE, void *Loc) {
345  unsigned PtrSize = EE->getTargetData()->getPointerSize();
346  for (unsigned i = 0; i < PtrSize; ++i)
347    if (*(i + (uint8_t*)Loc))
348      return false;
349  return true;
350}
351#endif
352
353int ExecutionEngine::runFunctionAsMain(Function *Fn,
354                                       const std::vector<std::string> &argv,
355                                       const char * const * envp) {
356  std::vector<GenericValue> GVArgs;
357  GenericValue GVArgc;
358  GVArgc.IntVal = APInt(32, argv.size());
359
360  // Check main() type
361  unsigned NumArgs = Fn->getFunctionType()->getNumParams();
362  FunctionType *FTy = Fn->getFunctionType();
363  Type* PPInt8Ty = Type::getInt8PtrTy(Fn->getContext())->getPointerTo();
364
365  // Check the argument types.
366  if (NumArgs > 3)
367    report_fatal_error("Invalid number of arguments of main() supplied");
368  if (NumArgs >= 3 && FTy->getParamType(2) != PPInt8Ty)
369    report_fatal_error("Invalid type for third argument of main() supplied");
370  if (NumArgs >= 2 && FTy->getParamType(1) != PPInt8Ty)
371    report_fatal_error("Invalid type for second argument of main() supplied");
372  if (NumArgs >= 1 && !FTy->getParamType(0)->isIntegerTy(32))
373    report_fatal_error("Invalid type for first argument of main() supplied");
374  if (!FTy->getReturnType()->isIntegerTy() &&
375      !FTy->getReturnType()->isVoidTy())
376    report_fatal_error("Invalid return type of main() supplied");
377
378  ArgvArray CArgv;
379  ArgvArray CEnv;
380  if (NumArgs) {
381    GVArgs.push_back(GVArgc); // Arg #0 = argc.
382    if (NumArgs > 1) {
383      // Arg #1 = argv.
384      GVArgs.push_back(PTOGV(CArgv.reset(Fn->getContext(), this, argv)));
385      assert(!isTargetNullPtr(this, GVTOP(GVArgs[1])) &&
386             "argv[0] was null after CreateArgv");
387      if (NumArgs > 2) {
388        std::vector<std::string> EnvVars;
389        for (unsigned i = 0; envp[i]; ++i)
390          EnvVars.push_back(envp[i]);
391        // Arg #2 = envp.
392        GVArgs.push_back(PTOGV(CEnv.reset(Fn->getContext(), this, EnvVars)));
393      }
394    }
395  }
396
397  return runFunction(Fn, GVArgs).IntVal.getZExtValue();
398}
399
400ExecutionEngine *ExecutionEngine::create(Module *M,
401                                         bool ForceInterpreter,
402                                         std::string *ErrorStr,
403                                         CodeGenOpt::Level OptLevel,
404                                         bool GVsWithCode) {
405  EngineBuilder EB =  EngineBuilder(M)
406      .setEngineKind(ForceInterpreter
407                     ? EngineKind::Interpreter
408                     : EngineKind::JIT)
409      .setErrorStr(ErrorStr)
410      .setOptLevel(OptLevel)
411      .setAllocateGVsWithCode(GVsWithCode);
412
413  return EB.create();
414}
415
416/// createJIT - This is the factory method for creating a JIT for the current
417/// machine, it does not fall back to the interpreter.  This takes ownership
418/// of the module.
419ExecutionEngine *ExecutionEngine::createJIT(Module *M,
420                                            std::string *ErrorStr,
421                                            JITMemoryManager *JMM,
422                                            CodeGenOpt::Level OL,
423                                            bool GVsWithCode,
424                                            Reloc::Model RM,
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  EngineBuilder EB(M);
435  EB.setEngineKind(EngineKind::JIT);
436  EB.setErrorStr(ErrorStr);
437  EB.setRelocationModel(RM);
438  EB.setCodeModel(CMM);
439  EB.setAllocateGVsWithCode(GVsWithCode);
440  EB.setOptLevel(OL);
441  EB.setJITMemoryManager(JMM);
442
443  // TODO: permit custom TargetOptions here
444  TargetMachine *TM = EB.selectTarget();
445  if (!TM || (ErrorStr && ErrorStr->length() > 0)) return 0;
446
447  return ExecutionEngine::JITCtor(M, ErrorStr, JMM, GVsWithCode, TM);
448}
449
450ExecutionEngine *EngineBuilder::create(TargetMachine *TM) {
451  OwningPtr<TargetMachine> TheTM(TM); // Take ownership.
452
453  // Make sure we can resolve symbols in the program as well. The zero arg
454  // to the function tells DynamicLibrary to load the program, not a library.
455  if (sys::DynamicLibrary::LoadLibraryPermanently(0, ErrorStr))
456    return 0;
457
458  // If the user specified a memory manager but didn't specify which engine to
459  // create, we assume they only want the JIT, and we fail if they only want
460  // the interpreter.
461  if (JMM) {
462    if (WhichEngine & EngineKind::JIT)
463      WhichEngine = EngineKind::JIT;
464    else {
465      if (ErrorStr)
466        *ErrorStr = "Cannot create an interpreter with a memory manager.";
467      return 0;
468    }
469  }
470
471  // Unless the interpreter was explicitly selected or the JIT is not linked,
472  // try making a JIT.
473  if ((WhichEngine & EngineKind::JIT) && TheTM) {
474    Triple TT(M->getTargetTriple());
475    if (!TM->getTarget().hasJIT()) {
476      errs() << "WARNING: This target JIT is not designed for the host"
477             << " you are running.  If bad things happen, please choose"
478             << " a different -march switch.\n";
479    }
480
481    if (UseMCJIT && ExecutionEngine::MCJITCtor) {
482      ExecutionEngine *EE =
483        ExecutionEngine::MCJITCtor(M, ErrorStr, JMM,
484                                   AllocateGVsWithCode, TheTM.take());
485      if (EE) return EE;
486    } else if (ExecutionEngine::JITCtor) {
487      ExecutionEngine *EE =
488        ExecutionEngine::JITCtor(M, ErrorStr, JMM,
489                                 AllocateGVsWithCode, TheTM.take());
490      if (EE) return EE;
491    }
492  }
493
494  // If we can't make a JIT and we didn't request one specifically, try making
495  // an interpreter instead.
496  if (WhichEngine & EngineKind::Interpreter) {
497    if (ExecutionEngine::InterpCtor)
498      return ExecutionEngine::InterpCtor(M, ErrorStr);
499    if (ErrorStr)
500      *ErrorStr = "Interpreter has not been linked in.";
501    return 0;
502  }
503
504  if ((WhichEngine & EngineKind::JIT) && ExecutionEngine::JITCtor == 0 &&
505      ExecutionEngine::MCJITCtor == 0) {
506    if (ErrorStr)
507      *ErrorStr = "JIT has not been linked in.";
508  }
509
510  return 0;
511}
512
513void *ExecutionEngine::getPointerToGlobal(const GlobalValue *GV) {
514  if (Function *F = const_cast<Function*>(dyn_cast<Function>(GV)))
515    return getPointerToFunction(F);
516
517  MutexGuard locked(lock);
518  if (void *P = EEState.getGlobalAddressMap(locked)[GV])
519    return P;
520
521  // Global variable might have been added since interpreter started.
522  if (GlobalVariable *GVar =
523          const_cast<GlobalVariable *>(dyn_cast<GlobalVariable>(GV)))
524    EmitGlobalVariable(GVar);
525  else
526    llvm_unreachable("Global hasn't had an address allocated yet!");
527
528  return EEState.getGlobalAddressMap(locked)[GV];
529}
530
531/// \brief Converts a Constant* into a GenericValue, including handling of
532/// ConstantExpr values.
533GenericValue ExecutionEngine::getConstantValue(const Constant *C) {
534  // If its undefined, return the garbage.
535  if (isa<UndefValue>(C)) {
536    GenericValue Result;
537    switch (C->getType()->getTypeID()) {
538    case Type::IntegerTyID:
539    case Type::X86_FP80TyID:
540    case Type::FP128TyID:
541    case Type::PPC_FP128TyID:
542      // Although the value is undefined, we still have to construct an APInt
543      // with the correct bit width.
544      Result.IntVal = APInt(C->getType()->getPrimitiveSizeInBits(), 0);
545      break;
546    default:
547      break;
548    }
549    return Result;
550  }
551
552  // Otherwise, if the value is a ConstantExpr...
553  if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
554    Constant *Op0 = CE->getOperand(0);
555    switch (CE->getOpcode()) {
556    case Instruction::GetElementPtr: {
557      // Compute the index
558      GenericValue Result = getConstantValue(Op0);
559      SmallVector<Value*, 8> Indices(CE->op_begin()+1, CE->op_end());
560      uint64_t Offset = TD->getIndexedOffset(Op0->getType(), Indices);
561
562      char* tmp = (char*) Result.PointerVal;
563      Result = PTOGV(tmp + Offset);
564      return Result;
565    }
566    case Instruction::Trunc: {
567      GenericValue GV = getConstantValue(Op0);
568      uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
569      GV.IntVal = GV.IntVal.trunc(BitWidth);
570      return GV;
571    }
572    case Instruction::ZExt: {
573      GenericValue GV = getConstantValue(Op0);
574      uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
575      GV.IntVal = GV.IntVal.zext(BitWidth);
576      return GV;
577    }
578    case Instruction::SExt: {
579      GenericValue GV = getConstantValue(Op0);
580      uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
581      GV.IntVal = GV.IntVal.sext(BitWidth);
582      return GV;
583    }
584    case Instruction::FPTrunc: {
585      // FIXME long double
586      GenericValue GV = getConstantValue(Op0);
587      GV.FloatVal = float(GV.DoubleVal);
588      return GV;
589    }
590    case Instruction::FPExt:{
591      // FIXME long double
592      GenericValue GV = getConstantValue(Op0);
593      GV.DoubleVal = double(GV.FloatVal);
594      return GV;
595    }
596    case Instruction::UIToFP: {
597      GenericValue GV = getConstantValue(Op0);
598      if (CE->getType()->isFloatTy())
599        GV.FloatVal = float(GV.IntVal.roundToDouble());
600      else if (CE->getType()->isDoubleTy())
601        GV.DoubleVal = GV.IntVal.roundToDouble();
602      else if (CE->getType()->isX86_FP80Ty()) {
603        APFloat apf = APFloat::getZero(APFloat::x87DoubleExtended);
604        (void)apf.convertFromAPInt(GV.IntVal,
605                                   false,
606                                   APFloat::rmNearestTiesToEven);
607        GV.IntVal = apf.bitcastToAPInt();
608      }
609      return GV;
610    }
611    case Instruction::SIToFP: {
612      GenericValue GV = getConstantValue(Op0);
613      if (CE->getType()->isFloatTy())
614        GV.FloatVal = float(GV.IntVal.signedRoundToDouble());
615      else if (CE->getType()->isDoubleTy())
616        GV.DoubleVal = GV.IntVal.signedRoundToDouble();
617      else if (CE->getType()->isX86_FP80Ty()) {
618        APFloat apf = APFloat::getZero(APFloat::x87DoubleExtended);
619        (void)apf.convertFromAPInt(GV.IntVal,
620                                   true,
621                                   APFloat::rmNearestTiesToEven);
622        GV.IntVal = apf.bitcastToAPInt();
623      }
624      return GV;
625    }
626    case Instruction::FPToUI: // double->APInt conversion handles sign
627    case Instruction::FPToSI: {
628      GenericValue GV = getConstantValue(Op0);
629      uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
630      if (Op0->getType()->isFloatTy())
631        GV.IntVal = APIntOps::RoundFloatToAPInt(GV.FloatVal, BitWidth);
632      else if (Op0->getType()->isDoubleTy())
633        GV.IntVal = APIntOps::RoundDoubleToAPInt(GV.DoubleVal, BitWidth);
634      else if (Op0->getType()->isX86_FP80Ty()) {
635        APFloat apf = APFloat(GV.IntVal);
636        uint64_t v;
637        bool ignored;
638        (void)apf.convertToInteger(&v, BitWidth,
639                                   CE->getOpcode()==Instruction::FPToSI,
640                                   APFloat::rmTowardZero, &ignored);
641        GV.IntVal = v; // endian?
642      }
643      return GV;
644    }
645    case Instruction::PtrToInt: {
646      GenericValue GV = getConstantValue(Op0);
647      uint32_t PtrWidth = TD->getPointerSizeInBits();
648      GV.IntVal = APInt(PtrWidth, uintptr_t(GV.PointerVal));
649      return GV;
650    }
651    case Instruction::IntToPtr: {
652      GenericValue GV = getConstantValue(Op0);
653      uint32_t PtrWidth = TD->getPointerSizeInBits();
654      if (PtrWidth != GV.IntVal.getBitWidth())
655        GV.IntVal = GV.IntVal.zextOrTrunc(PtrWidth);
656      assert(GV.IntVal.getBitWidth() <= 64 && "Bad pointer width");
657      GV.PointerVal = PointerTy(uintptr_t(GV.IntVal.getZExtValue()));
658      return GV;
659    }
660    case Instruction::BitCast: {
661      GenericValue GV = getConstantValue(Op0);
662      Type* DestTy = CE->getType();
663      switch (Op0->getType()->getTypeID()) {
664        default: llvm_unreachable("Invalid bitcast operand");
665        case Type::IntegerTyID:
666          assert(DestTy->isFloatingPointTy() && "invalid bitcast");
667          if (DestTy->isFloatTy())
668            GV.FloatVal = GV.IntVal.bitsToFloat();
669          else if (DestTy->isDoubleTy())
670            GV.DoubleVal = GV.IntVal.bitsToDouble();
671          break;
672        case Type::FloatTyID:
673          assert(DestTy->isIntegerTy(32) && "Invalid bitcast");
674          GV.IntVal = APInt::floatToBits(GV.FloatVal);
675          break;
676        case Type::DoubleTyID:
677          assert(DestTy->isIntegerTy(64) && "Invalid bitcast");
678          GV.IntVal = APInt::doubleToBits(GV.DoubleVal);
679          break;
680        case Type::PointerTyID:
681          assert(DestTy->isPointerTy() && "Invalid bitcast");
682          break; // getConstantValue(Op0)  above already converted it
683      }
684      return GV;
685    }
686    case Instruction::Add:
687    case Instruction::FAdd:
688    case Instruction::Sub:
689    case Instruction::FSub:
690    case Instruction::Mul:
691    case Instruction::FMul:
692    case Instruction::UDiv:
693    case Instruction::SDiv:
694    case Instruction::URem:
695    case Instruction::SRem:
696    case Instruction::And:
697    case Instruction::Or:
698    case Instruction::Xor: {
699      GenericValue LHS = getConstantValue(Op0);
700      GenericValue RHS = getConstantValue(CE->getOperand(1));
701      GenericValue GV;
702      switch (CE->getOperand(0)->getType()->getTypeID()) {
703      default: llvm_unreachable("Bad add type!");
704      case Type::IntegerTyID:
705        switch (CE->getOpcode()) {
706          default: llvm_unreachable("Invalid integer opcode");
707          case Instruction::Add: GV.IntVal = LHS.IntVal + RHS.IntVal; break;
708          case Instruction::Sub: GV.IntVal = LHS.IntVal - RHS.IntVal; break;
709          case Instruction::Mul: GV.IntVal = LHS.IntVal * RHS.IntVal; break;
710          case Instruction::UDiv:GV.IntVal = LHS.IntVal.udiv(RHS.IntVal); break;
711          case Instruction::SDiv:GV.IntVal = LHS.IntVal.sdiv(RHS.IntVal); break;
712          case Instruction::URem:GV.IntVal = LHS.IntVal.urem(RHS.IntVal); break;
713          case Instruction::SRem:GV.IntVal = LHS.IntVal.srem(RHS.IntVal); break;
714          case Instruction::And: GV.IntVal = LHS.IntVal & RHS.IntVal; break;
715          case Instruction::Or:  GV.IntVal = LHS.IntVal | RHS.IntVal; break;
716          case Instruction::Xor: GV.IntVal = LHS.IntVal ^ RHS.IntVal; break;
717        }
718        break;
719      case Type::FloatTyID:
720        switch (CE->getOpcode()) {
721          default: llvm_unreachable("Invalid float opcode");
722          case Instruction::FAdd:
723            GV.FloatVal = LHS.FloatVal + RHS.FloatVal; break;
724          case Instruction::FSub:
725            GV.FloatVal = LHS.FloatVal - RHS.FloatVal; break;
726          case Instruction::FMul:
727            GV.FloatVal = LHS.FloatVal * RHS.FloatVal; break;
728          case Instruction::FDiv:
729            GV.FloatVal = LHS.FloatVal / RHS.FloatVal; break;
730          case Instruction::FRem:
731            GV.FloatVal = std::fmod(LHS.FloatVal,RHS.FloatVal); break;
732        }
733        break;
734      case Type::DoubleTyID:
735        switch (CE->getOpcode()) {
736          default: llvm_unreachable("Invalid double opcode");
737          case Instruction::FAdd:
738            GV.DoubleVal = LHS.DoubleVal + RHS.DoubleVal; break;
739          case Instruction::FSub:
740            GV.DoubleVal = LHS.DoubleVal - RHS.DoubleVal; break;
741          case Instruction::FMul:
742            GV.DoubleVal = LHS.DoubleVal * RHS.DoubleVal; break;
743          case Instruction::FDiv:
744            GV.DoubleVal = LHS.DoubleVal / RHS.DoubleVal; break;
745          case Instruction::FRem:
746            GV.DoubleVal = std::fmod(LHS.DoubleVal,RHS.DoubleVal); break;
747        }
748        break;
749      case Type::X86_FP80TyID:
750      case Type::PPC_FP128TyID:
751      case Type::FP128TyID: {
752        APFloat apfLHS = APFloat(LHS.IntVal);
753        switch (CE->getOpcode()) {
754          default: llvm_unreachable("Invalid long double opcode");
755          case Instruction::FAdd:
756            apfLHS.add(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
757            GV.IntVal = apfLHS.bitcastToAPInt();
758            break;
759          case Instruction::FSub:
760            apfLHS.subtract(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
761            GV.IntVal = apfLHS.bitcastToAPInt();
762            break;
763          case Instruction::FMul:
764            apfLHS.multiply(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
765            GV.IntVal = apfLHS.bitcastToAPInt();
766            break;
767          case Instruction::FDiv:
768            apfLHS.divide(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
769            GV.IntVal = apfLHS.bitcastToAPInt();
770            break;
771          case Instruction::FRem:
772            apfLHS.mod(APFloat(RHS.IntVal), APFloat::rmNearestTiesToEven);
773            GV.IntVal = apfLHS.bitcastToAPInt();
774            break;
775          }
776        }
777        break;
778      }
779      return GV;
780    }
781    default:
782      break;
783    }
784
785    SmallString<256> Msg;
786    raw_svector_ostream OS(Msg);
787    OS << "ConstantExpr not handled: " << *CE;
788    report_fatal_error(OS.str());
789  }
790
791  // Otherwise, we have a simple constant.
792  GenericValue Result;
793  switch (C->getType()->getTypeID()) {
794  case Type::FloatTyID:
795    Result.FloatVal = cast<ConstantFP>(C)->getValueAPF().convertToFloat();
796    break;
797  case Type::DoubleTyID:
798    Result.DoubleVal = cast<ConstantFP>(C)->getValueAPF().convertToDouble();
799    break;
800  case Type::X86_FP80TyID:
801  case Type::FP128TyID:
802  case Type::PPC_FP128TyID:
803    Result.IntVal = cast <ConstantFP>(C)->getValueAPF().bitcastToAPInt();
804    break;
805  case Type::IntegerTyID:
806    Result.IntVal = cast<ConstantInt>(C)->getValue();
807    break;
808  case Type::PointerTyID:
809    if (isa<ConstantPointerNull>(C))
810      Result.PointerVal = 0;
811    else if (const Function *F = dyn_cast<Function>(C))
812      Result = PTOGV(getPointerToFunctionOrStub(const_cast<Function*>(F)));
813    else if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(C))
814      Result = PTOGV(getOrEmitGlobalVariable(const_cast<GlobalVariable*>(GV)));
815    else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C))
816      Result = PTOGV(getPointerToBasicBlock(const_cast<BasicBlock*>(
817                                                        BA->getBasicBlock())));
818    else
819      llvm_unreachable("Unknown constant pointer type!");
820    break;
821  default:
822    SmallString<256> Msg;
823    raw_svector_ostream OS(Msg);
824    OS << "ERROR: Constant unimplemented for type: " << *C->getType();
825    report_fatal_error(OS.str());
826  }
827
828  return Result;
829}
830
831/// StoreIntToMemory - Fills the StoreBytes bytes of memory starting from Dst
832/// with the integer held in IntVal.
833static void StoreIntToMemory(const APInt &IntVal, uint8_t *Dst,
834                             unsigned StoreBytes) {
835  assert((IntVal.getBitWidth()+7)/8 >= StoreBytes && "Integer too small!");
836  const uint8_t *Src = (const uint8_t *)IntVal.getRawData();
837
838  if (sys::isLittleEndianHost()) {
839    // Little-endian host - the source is ordered from LSB to MSB.  Order the
840    // destination from LSB to MSB: Do a straight copy.
841    memcpy(Dst, Src, StoreBytes);
842  } else {
843    // Big-endian host - the source is an array of 64 bit words ordered from
844    // LSW to MSW.  Each word is ordered from MSB to LSB.  Order the destination
845    // from MSB to LSB: Reverse the word order, but not the bytes in a word.
846    while (StoreBytes > sizeof(uint64_t)) {
847      StoreBytes -= sizeof(uint64_t);
848      // May not be aligned so use memcpy.
849      memcpy(Dst + StoreBytes, Src, sizeof(uint64_t));
850      Src += sizeof(uint64_t);
851    }
852
853    memcpy(Dst, Src + sizeof(uint64_t) - StoreBytes, StoreBytes);
854  }
855}
856
857void ExecutionEngine::StoreValueToMemory(const GenericValue &Val,
858                                         GenericValue *Ptr, Type *Ty) {
859  const unsigned StoreBytes = getTargetData()->getTypeStoreSize(Ty);
860
861  switch (Ty->getTypeID()) {
862  case Type::IntegerTyID:
863    StoreIntToMemory(Val.IntVal, (uint8_t*)Ptr, StoreBytes);
864    break;
865  case Type::FloatTyID:
866    *((float*)Ptr) = Val.FloatVal;
867    break;
868  case Type::DoubleTyID:
869    *((double*)Ptr) = Val.DoubleVal;
870    break;
871  case Type::X86_FP80TyID:
872    memcpy(Ptr, Val.IntVal.getRawData(), 10);
873    break;
874  case Type::PointerTyID:
875    // Ensure 64 bit target pointers are fully initialized on 32 bit hosts.
876    if (StoreBytes != sizeof(PointerTy))
877      memset(&(Ptr->PointerVal), 0, StoreBytes);
878
879    *((PointerTy*)Ptr) = Val.PointerVal;
880    break;
881  default:
882    dbgs() << "Cannot store value of type " << *Ty << "!\n";
883  }
884
885  if (sys::isLittleEndianHost() != getTargetData()->isLittleEndian())
886    // Host and target are different endian - reverse the stored bytes.
887    std::reverse((uint8_t*)Ptr, StoreBytes + (uint8_t*)Ptr);
888}
889
890/// LoadIntFromMemory - Loads the integer stored in the LoadBytes bytes starting
891/// from Src into IntVal, which is assumed to be wide enough and to hold zero.
892static void LoadIntFromMemory(APInt &IntVal, uint8_t *Src, unsigned LoadBytes) {
893  assert((IntVal.getBitWidth()+7)/8 >= LoadBytes && "Integer too small!");
894  uint8_t *Dst = (uint8_t *)IntVal.getRawData();
895
896  if (sys::isLittleEndianHost())
897    // Little-endian host - the destination must be ordered from LSB to MSB.
898    // The source is ordered from LSB to MSB: Do a straight copy.
899    memcpy(Dst, Src, LoadBytes);
900  else {
901    // Big-endian - the destination is an array of 64 bit words ordered from
902    // LSW to MSW.  Each word must be ordered from MSB to LSB.  The source is
903    // ordered from MSB to LSB: Reverse the word order, but not the bytes in
904    // a word.
905    while (LoadBytes > sizeof(uint64_t)) {
906      LoadBytes -= sizeof(uint64_t);
907      // May not be aligned so use memcpy.
908      memcpy(Dst, Src + LoadBytes, sizeof(uint64_t));
909      Dst += sizeof(uint64_t);
910    }
911
912    memcpy(Dst + sizeof(uint64_t) - LoadBytes, Src, LoadBytes);
913  }
914}
915
916/// FIXME: document
917///
918void ExecutionEngine::LoadValueFromMemory(GenericValue &Result,
919                                          GenericValue *Ptr,
920                                          Type *Ty) {
921  const unsigned LoadBytes = getTargetData()->getTypeStoreSize(Ty);
922
923  switch (Ty->getTypeID()) {
924  case Type::IntegerTyID:
925    // An APInt with all words initially zero.
926    Result.IntVal = APInt(cast<IntegerType>(Ty)->getBitWidth(), 0);
927    LoadIntFromMemory(Result.IntVal, (uint8_t*)Ptr, LoadBytes);
928    break;
929  case Type::FloatTyID:
930    Result.FloatVal = *((float*)Ptr);
931    break;
932  case Type::DoubleTyID:
933    Result.DoubleVal = *((double*)Ptr);
934    break;
935  case Type::PointerTyID:
936    Result.PointerVal = *((PointerTy*)Ptr);
937    break;
938  case Type::X86_FP80TyID: {
939    // This is endian dependent, but it will only work on x86 anyway.
940    // FIXME: Will not trap if loading a signaling NaN.
941    uint64_t y[2];
942    memcpy(y, Ptr, 10);
943    Result.IntVal = APInt(80, y);
944    break;
945  }
946  default:
947    SmallString<256> Msg;
948    raw_svector_ostream OS(Msg);
949    OS << "Cannot load value of type " << *Ty << "!";
950    report_fatal_error(OS.str());
951  }
952}
953
954void ExecutionEngine::InitializeMemory(const Constant *Init, void *Addr) {
955  DEBUG(dbgs() << "JIT: Initializing " << Addr << " ");
956  DEBUG(Init->dump());
957  if (isa<UndefValue>(Init))
958    return;
959
960  if (const ConstantVector *CP = dyn_cast<ConstantVector>(Init)) {
961    unsigned ElementSize =
962      getTargetData()->getTypeAllocSize(CP->getType()->getElementType());
963    for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
964      InitializeMemory(CP->getOperand(i), (char*)Addr+i*ElementSize);
965    return;
966  }
967
968  if (isa<ConstantAggregateZero>(Init)) {
969    memset(Addr, 0, (size_t)getTargetData()->getTypeAllocSize(Init->getType()));
970    return;
971  }
972
973  if (const ConstantArray *CPA = dyn_cast<ConstantArray>(Init)) {
974    unsigned ElementSize =
975      getTargetData()->getTypeAllocSize(CPA->getType()->getElementType());
976    for (unsigned i = 0, e = CPA->getNumOperands(); i != e; ++i)
977      InitializeMemory(CPA->getOperand(i), (char*)Addr+i*ElementSize);
978    return;
979  }
980
981  if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(Init)) {
982    const StructLayout *SL =
983      getTargetData()->getStructLayout(cast<StructType>(CPS->getType()));
984    for (unsigned i = 0, e = CPS->getNumOperands(); i != e; ++i)
985      InitializeMemory(CPS->getOperand(i), (char*)Addr+SL->getElementOffset(i));
986    return;
987  }
988
989  if (const ConstantDataSequential *CDS =
990               dyn_cast<ConstantDataSequential>(Init)) {
991    // CDS is already laid out in host memory order.
992    StringRef Data = CDS->getRawDataValues();
993    memcpy(Addr, Data.data(), Data.size());
994    return;
995  }
996
997  if (Init->getType()->isFirstClassType()) {
998    GenericValue Val = getConstantValue(Init);
999    StoreValueToMemory(Val, (GenericValue*)Addr, Init->getType());
1000    return;
1001  }
1002
1003  DEBUG(dbgs() << "Bad Type: " << *Init->getType() << "\n");
1004  llvm_unreachable("Unknown constant type to initialize memory with!");
1005}
1006
1007/// EmitGlobals - Emit all of the global variables to memory, storing their
1008/// addresses into GlobalAddress.  This must make sure to copy the contents of
1009/// their initializers into the memory.
1010void ExecutionEngine::emitGlobals() {
1011  // Loop over all of the global variables in the program, allocating the memory
1012  // to hold them.  If there is more than one module, do a prepass over globals
1013  // to figure out how the different modules should link together.
1014  std::map<std::pair<std::string, Type*>,
1015           const GlobalValue*> LinkedGlobalsMap;
1016
1017  if (Modules.size() != 1) {
1018    for (unsigned m = 0, e = Modules.size(); m != e; ++m) {
1019      Module &M = *Modules[m];
1020      for (Module::const_global_iterator I = M.global_begin(),
1021           E = M.global_end(); I != E; ++I) {
1022        const GlobalValue *GV = I;
1023        if (GV->hasLocalLinkage() || GV->isDeclaration() ||
1024            GV->hasAppendingLinkage() || !GV->hasName())
1025          continue;// Ignore external globals and globals with internal linkage.
1026
1027        const GlobalValue *&GVEntry =
1028          LinkedGlobalsMap[std::make_pair(GV->getName(), GV->getType())];
1029
1030        // If this is the first time we've seen this global, it is the canonical
1031        // version.
1032        if (!GVEntry) {
1033          GVEntry = GV;
1034          continue;
1035        }
1036
1037        // If the existing global is strong, never replace it.
1038        if (GVEntry->hasExternalLinkage() ||
1039            GVEntry->hasDLLImportLinkage() ||
1040            GVEntry->hasDLLExportLinkage())
1041          continue;
1042
1043        // Otherwise, we know it's linkonce/weak, replace it if this is a strong
1044        // symbol.  FIXME is this right for common?
1045        if (GV->hasExternalLinkage() || GVEntry->hasExternalWeakLinkage())
1046          GVEntry = GV;
1047      }
1048    }
1049  }
1050
1051  std::vector<const GlobalValue*> NonCanonicalGlobals;
1052  for (unsigned m = 0, e = Modules.size(); m != e; ++m) {
1053    Module &M = *Modules[m];
1054    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
1055         I != E; ++I) {
1056      // In the multi-module case, see what this global maps to.
1057      if (!LinkedGlobalsMap.empty()) {
1058        if (const GlobalValue *GVEntry =
1059              LinkedGlobalsMap[std::make_pair(I->getName(), I->getType())]) {
1060          // If something else is the canonical global, ignore this one.
1061          if (GVEntry != &*I) {
1062            NonCanonicalGlobals.push_back(I);
1063            continue;
1064          }
1065        }
1066      }
1067
1068      if (!I->isDeclaration()) {
1069        addGlobalMapping(I, getMemoryForGV(I));
1070      } else {
1071        // External variable reference. Try to use the dynamic loader to
1072        // get a pointer to it.
1073        if (void *SymAddr =
1074            sys::DynamicLibrary::SearchForAddressOfSymbol(I->getName()))
1075          addGlobalMapping(I, SymAddr);
1076        else {
1077          report_fatal_error("Could not resolve external global address: "
1078                            +I->getName());
1079        }
1080      }
1081    }
1082
1083    // If there are multiple modules, map the non-canonical globals to their
1084    // canonical location.
1085    if (!NonCanonicalGlobals.empty()) {
1086      for (unsigned i = 0, e = NonCanonicalGlobals.size(); i != e; ++i) {
1087        const GlobalValue *GV = NonCanonicalGlobals[i];
1088        const GlobalValue *CGV =
1089          LinkedGlobalsMap[std::make_pair(GV->getName(), GV->getType())];
1090        void *Ptr = getPointerToGlobalIfAvailable(CGV);
1091        assert(Ptr && "Canonical global wasn't codegen'd!");
1092        addGlobalMapping(GV, Ptr);
1093      }
1094    }
1095
1096    // Now that all of the globals are set up in memory, loop through them all
1097    // and initialize their contents.
1098    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
1099         I != E; ++I) {
1100      if (!I->isDeclaration()) {
1101        if (!LinkedGlobalsMap.empty()) {
1102          if (const GlobalValue *GVEntry =
1103                LinkedGlobalsMap[std::make_pair(I->getName(), I->getType())])
1104            if (GVEntry != &*I)  // Not the canonical variable.
1105              continue;
1106        }
1107        EmitGlobalVariable(I);
1108      }
1109    }
1110  }
1111}
1112
1113// EmitGlobalVariable - This method emits the specified global variable to the
1114// address specified in GlobalAddresses, or allocates new memory if it's not
1115// already in the map.
1116void ExecutionEngine::EmitGlobalVariable(const GlobalVariable *GV) {
1117  void *GA = getPointerToGlobalIfAvailable(GV);
1118
1119  if (GA == 0) {
1120    // If it's not already specified, allocate memory for the global.
1121    GA = getMemoryForGV(GV);
1122    addGlobalMapping(GV, GA);
1123  }
1124
1125  // Don't initialize if it's thread local, let the client do it.
1126  if (!GV->isThreadLocal())
1127    InitializeMemory(GV->getInitializer(), GA);
1128
1129  Type *ElTy = GV->getType()->getElementType();
1130  size_t GVSize = (size_t)getTargetData()->getTypeAllocSize(ElTy);
1131  NumInitBytes += (unsigned)GVSize;
1132  ++NumGlobals;
1133}
1134
1135ExecutionEngineState::ExecutionEngineState(ExecutionEngine &EE)
1136  : EE(EE), GlobalAddressMap(this) {
1137}
1138
1139sys::Mutex *
1140ExecutionEngineState::AddressMapConfig::getMutex(ExecutionEngineState *EES) {
1141  return &EES->EE.lock;
1142}
1143
1144void ExecutionEngineState::AddressMapConfig::onDelete(ExecutionEngineState *EES,
1145                                                      const GlobalValue *Old) {
1146  void *OldVal = EES->GlobalAddressMap.lookup(Old);
1147  EES->GlobalAddressReverseMap.erase(OldVal);
1148}
1149
1150void ExecutionEngineState::AddressMapConfig::onRAUW(ExecutionEngineState *,
1151                                                    const GlobalValue *,
1152                                                    const GlobalValue *) {
1153  llvm_unreachable("The ExecutionEngine doesn't know how to handle a"
1154                   " RAUW on a value it has a global mapping for.");
1155}
1156