ExecutionEngine.cpp revision 5a364c5561ec04e33a6f5d52c14f1bac6f247ea0 
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#include "llvm/ExecutionEngine/JITMemoryManager.h"
18#include "llvm/ExecutionEngine/ObjectCache.h"
19#include "llvm/ADT/SmallString.h"
20#include "llvm/ADT/Statistic.h"
21#include "llvm/ExecutionEngine/GenericValue.h"
22#include "llvm/IR/Constants.h"
23#include "llvm/IR/DataLayout.h"
24#include "llvm/IR/DerivedTypes.h"
25#include "llvm/IR/Module.h"
26#include "llvm/IR/Operator.h"
27#include "llvm/Support/Debug.h"
28#include "llvm/Support/DynamicLibrary.h"
29#include "llvm/Support/ErrorHandling.h"
30#include "llvm/Support/Host.h"
31#include "llvm/Support/MutexGuard.h"
32#include "llvm/Support/TargetRegistry.h"
33#include "llvm/Support/ValueHandle.h"
34#include "llvm/Support/raw_ostream.h"
35#include "llvm/Target/TargetMachine.h"
36#include <cmath>
37#include <cstring>
38using namespace llvm;
39
40STATISTIC(NumInitBytes, "Number of bytes of global vars initialized");
41STATISTIC(NumGlobals  , "Number of global vars initialized");
42
43// pin vtable to this file
44void ObjectCache::anchor() {}
45
46ExecutionEngine *(*ExecutionEngine::JITCtor)(
47  Module *M,
48  std::string *ErrorStr,
49  JITMemoryManager *JMM,
50  bool GVsWithCode,
51  TargetMachine *TM) = 0;
52ExecutionEngine *(*ExecutionEngine::MCJITCtor)(
53  Module *M,
54  std::string *ErrorStr,
55  RTDyldMemoryManager *MCJMM,
56  bool GVsWithCode,
57  TargetMachine *TM) = 0;
58ExecutionEngine *(*ExecutionEngine::InterpCtor)(Module *M,
59                                                std::string *ErrorStr) = 0;
60
61ExecutionEngine::ExecutionEngine(Module *M)
62  : EEState(*this),
63    LazyFunctionCreator(0) {
64  CompilingLazily         = false;
65  GVCompilationDisabled   = false;
66  SymbolSearchingDisabled = false;
67  Modules.push_back(M);
68  assert(M && "Module is null?");
69}
70
71ExecutionEngine::~ExecutionEngine() {
72  clearAllGlobalMappings();
73  for (unsigned i = 0, e = Modules.size(); i != e; ++i)
74    delete Modules[i];
75}
76
77namespace {
78/// \brief Helper class which uses a value handler to automatically deletes the
79/// memory block when the GlobalVariable is destroyed.
80class GVMemoryBlock : public CallbackVH {
81  GVMemoryBlock(const GlobalVariable *GV)
82    : CallbackVH(const_cast<GlobalVariable*>(GV)) {}
83
84public:
85  /// \brief Returns the address the GlobalVariable should be written into.  The
86  /// GVMemoryBlock object prefixes that.
87  static char *Create(const GlobalVariable *GV, const DataLayout& TD) {
88    Type *ElTy = GV->getType()->getElementType();
89    size_t GVSize = (size_t)TD.getTypeAllocSize(ElTy);
90    void *RawMemory = ::operator new(
91      DataLayout::RoundUpAlignment(sizeof(GVMemoryBlock),
92                                   TD.getPreferredAlignment(GV))
93      + GVSize);
94    new(RawMemory) GVMemoryBlock(GV);
95    return static_cast<char*>(RawMemory) + sizeof(GVMemoryBlock);
96  }
97
98  virtual void deleted() {
99    // We allocated with operator new and with some extra memory hanging off the
100    // end, so don't just delete this.  I'm not sure if this is actually
101    // required.
102    this->~GVMemoryBlock();
103    ::operator delete(this);
104  }
105};
106}  // anonymous namespace
107
108char *ExecutionEngine::getMemoryForGV(const GlobalVariable *GV) {
109  return GVMemoryBlock::Create(GV, *getDataLayout());
110}
111
112bool ExecutionEngine::removeModule(Module *M) {
113  for(SmallVectorImpl<Module *>::iterator I = Modules.begin(),
114        E = Modules.end(); I != E; ++I) {
115    Module *Found = *I;
116    if (Found == M) {
117      Modules.erase(I);
118      clearGlobalMappingsFromModule(M);
119      return true;
120    }
121  }
122  return false;
123}
124
125Function *ExecutionEngine::FindFunctionNamed(const char *FnName) {
126  for (unsigned i = 0, e = Modules.size(); i != e; ++i) {
127    if (Function *F = Modules[i]->getFunction(FnName))
128      return F;
129  }
130  return 0;
131}
132
133
134void *ExecutionEngineState::RemoveMapping(const MutexGuard &,
135                                          const GlobalValue *ToUnmap) {
136  GlobalAddressMapTy::iterator I = GlobalAddressMap.find(ToUnmap);
137  void *OldVal;
138
139  // FIXME: This is silly, we shouldn't end up with a mapping -> 0 in the
140  // GlobalAddressMap.
141  if (I == GlobalAddressMap.end())
142    OldVal = 0;
143  else {
144    OldVal = I->second;
145    GlobalAddressMap.erase(I);
146  }
147
148  GlobalAddressReverseMap.erase(OldVal);
149  return OldVal;
150}
151
152void ExecutionEngine::addGlobalMapping(const GlobalValue *GV, void *Addr) {
153  MutexGuard locked(lock);
154
155  DEBUG(dbgs() << "JIT: Map \'" << GV->getName()
156        << "\' to [" << Addr << "]\n";);
157  void *&CurVal = EEState.getGlobalAddressMap(locked)[GV];
158  assert((CurVal == 0 || Addr == 0) && "GlobalMapping already established!");
159  CurVal = Addr;
160
161  // If we are using the reverse mapping, add it too.
162  if (!EEState.getGlobalAddressReverseMap(locked).empty()) {
163    AssertingVH<const GlobalValue> &V =
164      EEState.getGlobalAddressReverseMap(locked)[Addr];
165    assert((V == 0 || GV == 0) && "GlobalMapping already established!");
166    V = GV;
167  }
168}
169
170void ExecutionEngine::clearAllGlobalMappings() {
171  MutexGuard locked(lock);
172
173  EEState.getGlobalAddressMap(locked).clear();
174  EEState.getGlobalAddressReverseMap(locked).clear();
175}
176
177void ExecutionEngine::clearGlobalMappingsFromModule(Module *M) {
178  MutexGuard locked(lock);
179
180  for (Module::iterator FI = M->begin(), FE = M->end(); FI != FE; ++FI)
181    EEState.RemoveMapping(locked, FI);
182  for (Module::global_iterator GI = M->global_begin(), GE = M->global_end();
183       GI != GE; ++GI)
184    EEState.RemoveMapping(locked, GI);
185}
186
187void *ExecutionEngine::updateGlobalMapping(const GlobalValue *GV, void *Addr) {
188  MutexGuard locked(lock);
189
190  ExecutionEngineState::GlobalAddressMapTy &Map =
191    EEState.getGlobalAddressMap(locked);
192
193  // Deleting from the mapping?
194  if (Addr == 0)
195    return EEState.RemoveMapping(locked, GV);
196
197  void *&CurVal = Map[GV];
198  void *OldVal = CurVal;
199
200  if (CurVal && !EEState.getGlobalAddressReverseMap(locked).empty())
201    EEState.getGlobalAddressReverseMap(locked).erase(CurVal);
202  CurVal = Addr;
203
204  // If we are using the reverse mapping, add it too.
205  if (!EEState.getGlobalAddressReverseMap(locked).empty()) {
206    AssertingVH<const GlobalValue> &V =
207      EEState.getGlobalAddressReverseMap(locked)[Addr];
208    assert((V == 0 || GV == 0) && "GlobalMapping already established!");
209    V = GV;
210  }
211  return OldVal;
212}
213
214void *ExecutionEngine::getPointerToGlobalIfAvailable(const GlobalValue *GV) {
215  MutexGuard locked(lock);
216
217  ExecutionEngineState::GlobalAddressMapTy::iterator I =
218    EEState.getGlobalAddressMap(locked).find(GV);
219  return I != EEState.getGlobalAddressMap(locked).end() ? I->second : 0;
220}
221
222const GlobalValue *ExecutionEngine::getGlobalValueAtAddress(void *Addr) {
223  MutexGuard locked(lock);
224
225  // If we haven't computed the reverse mapping yet, do so first.
226  if (EEState.getGlobalAddressReverseMap(locked).empty()) {
227    for (ExecutionEngineState::GlobalAddressMapTy::iterator
228         I = EEState.getGlobalAddressMap(locked).begin(),
229         E = EEState.getGlobalAddressMap(locked).end(); I != E; ++I)
230      EEState.getGlobalAddressReverseMap(locked).insert(std::make_pair(
231                                                          I->second, I->first));
232  }
233
234  std::map<void *, AssertingVH<const GlobalValue> >::iterator I =
235    EEState.getGlobalAddressReverseMap(locked).find(Addr);
236  return I != EEState.getGlobalAddressReverseMap(locked).end() ? I->second : 0;
237}
238
239namespace {
240class ArgvArray {
241  char *Array;
242  std::vector<char*> Values;
243public:
244  ArgvArray() : Array(NULL) {}
245  ~ArgvArray() { clear(); }
246  void clear() {
247    delete[] Array;
248    Array = NULL;
249    for (size_t I = 0, E = Values.size(); I != E; ++I) {
250      delete[] Values[I];
251    }
252    Values.clear();
253  }
254  /// Turn a vector of strings into a nice argv style array of pointers to null
255  /// terminated strings.
256  void *reset(LLVMContext &C, ExecutionEngine *EE,
257              const std::vector<std::string> &InputArgv);
258};
259}  // anonymous namespace
260void *ArgvArray::reset(LLVMContext &C, ExecutionEngine *EE,
261                       const std::vector<std::string> &InputArgv) {
262  clear();  // Free the old contents.
263  unsigned PtrSize = EE->getDataLayout()->getPointerSize();
264  Array = new char[(InputArgv.size()+1)*PtrSize];
265
266  DEBUG(dbgs() << "JIT: ARGV = " << (void*)Array << "\n");
267  Type *SBytePtr = Type::getInt8PtrTy(C);
268
269  for (unsigned i = 0; i != InputArgv.size(); ++i) {
270    unsigned Size = InputArgv[i].size()+1;
271    char *Dest = new char[Size];
272    Values.push_back(Dest);
273    DEBUG(dbgs() << "JIT: ARGV[" << i << "] = " << (void*)Dest << "\n");
274
275    std::copy(InputArgv[i].begin(), InputArgv[i].end(), Dest);
276    Dest[Size-1] = 0;
277
278    // Endian safe: Array[i] = (PointerTy)Dest;
279    EE->StoreValueToMemory(PTOGV(Dest), (GenericValue*)(Array+i*PtrSize),
280                           SBytePtr);
281  }
282
283  // Null terminate it
284  EE->StoreValueToMemory(PTOGV(0),
285                         (GenericValue*)(Array+InputArgv.size()*PtrSize),
286                         SBytePtr);
287  return Array;
288}
289
290void ExecutionEngine::runStaticConstructorsDestructors(Module *module,
291                                                       bool isDtors) {
292  const char *Name = isDtors ? "llvm.global_dtors" : "llvm.global_ctors";
293  GlobalVariable *GV = module->getNamedGlobal(Name);
294
295  // If this global has internal linkage, or if it has a use, then it must be
296  // an old-style (llvmgcc3) static ctor with __main linked in and in use.  If
297  // this is the case, don't execute any of the global ctors, __main will do
298  // it.
299  if (!GV || GV->isDeclaration() || GV->hasLocalLinkage()) return;
300
301  // Should be an array of '{ i32, void ()* }' structs.  The first value is
302  // the init priority, which we ignore.
303  ConstantArray *InitList = dyn_cast<ConstantArray>(GV->getInitializer());
304  if (InitList == 0)
305    return;
306  for (unsigned i = 0, e = InitList->getNumOperands(); i != e; ++i) {
307    ConstantStruct *CS = dyn_cast<ConstantStruct>(InitList->getOperand(i));
308    if (CS == 0) continue;
309
310    Constant *FP = CS->getOperand(1);
311    if (FP->isNullValue())
312      continue;  // Found a sentinal value, ignore.
313
314    // Strip off constant expression casts.
315    if (ConstantExpr *CE = dyn_cast<ConstantExpr>(FP))
316      if (CE->isCast())
317        FP = CE->getOperand(0);
318
319    // Execute the ctor/dtor function!
320    if (Function *F = dyn_cast<Function>(FP))
321      runFunction(F, std::vector<GenericValue>());
322
323    // FIXME: It is marginally lame that we just do nothing here if we see an
324    // entry we don't recognize. It might not be unreasonable for the verifier
325    // to not even allow this and just assert here.
326  }
327}
328
329void ExecutionEngine::runStaticConstructorsDestructors(bool isDtors) {
330  // Execute global ctors/dtors for each module in the program.
331  for (unsigned i = 0, e = Modules.size(); i != e; ++i)
332    runStaticConstructorsDestructors(Modules[i], isDtors);
333}
334
335#ifndef NDEBUG
336/// isTargetNullPtr - Return whether the target pointer stored at Loc is null.
337static bool isTargetNullPtr(ExecutionEngine *EE, void *Loc) {
338  unsigned PtrSize = EE->getDataLayout()->getPointerSize();
339  for (unsigned i = 0; i < PtrSize; ++i)
340    if (*(i + (uint8_t*)Loc))
341      return false;
342  return true;
343}
344#endif
345
346int ExecutionEngine::runFunctionAsMain(Function *Fn,
347                                       const std::vector<std::string> &argv,
348                                       const char * const * envp) {
349  std::vector<GenericValue> GVArgs;
350  GenericValue GVArgc;
351  GVArgc.IntVal = APInt(32, argv.size());
352
353  // Check main() type
354  unsigned NumArgs = Fn->getFunctionType()->getNumParams();
355  FunctionType *FTy = Fn->getFunctionType();
356  Type* PPInt8Ty = Type::getInt8PtrTy(Fn->getContext())->getPointerTo();
357
358  // Check the argument types.
359  if (NumArgs > 3)
360    report_fatal_error("Invalid number of arguments of main() supplied");
361  if (NumArgs >= 3 && FTy->getParamType(2) != PPInt8Ty)
362    report_fatal_error("Invalid type for third argument of main() supplied");
363  if (NumArgs >= 2 && FTy->getParamType(1) != PPInt8Ty)
364    report_fatal_error("Invalid type for second argument of main() supplied");
365  if (NumArgs >= 1 && !FTy->getParamType(0)->isIntegerTy(32))
366    report_fatal_error("Invalid type for first argument of main() supplied");
367  if (!FTy->getReturnType()->isIntegerTy() &&
368      !FTy->getReturnType()->isVoidTy())
369    report_fatal_error("Invalid return type of main() supplied");
370
371  ArgvArray CArgv;
372  ArgvArray CEnv;
373  if (NumArgs) {
374    GVArgs.push_back(GVArgc); // Arg #0 = argc.
375    if (NumArgs > 1) {
376      // Arg #1 = argv.
377      GVArgs.push_back(PTOGV(CArgv.reset(Fn->getContext(), this, argv)));
378      assert(!isTargetNullPtr(this, GVTOP(GVArgs[1])) &&
379             "argv[0] was null after CreateArgv");
380      if (NumArgs > 2) {
381        std::vector<std::string> EnvVars;
382        for (unsigned i = 0; envp[i]; ++i)
383          EnvVars.push_back(envp[i]);
384        // Arg #2 = envp.
385        GVArgs.push_back(PTOGV(CEnv.reset(Fn->getContext(), this, EnvVars)));
386      }
387    }
388  }
389
390  return runFunction(Fn, GVArgs).IntVal.getZExtValue();
391}
392
393ExecutionEngine *ExecutionEngine::create(Module *M,
394                                         bool ForceInterpreter,
395                                         std::string *ErrorStr,
396                                         CodeGenOpt::Level OptLevel,
397                                         bool GVsWithCode) {
398  EngineBuilder EB =  EngineBuilder(M)
399      .setEngineKind(ForceInterpreter
400                     ? EngineKind::Interpreter
401                     : EngineKind::JIT)
402      .setErrorStr(ErrorStr)
403      .setOptLevel(OptLevel)
404      .setAllocateGVsWithCode(GVsWithCode);
405
406  return EB.create();
407}
408
409/// createJIT - This is the factory method for creating a JIT for the current
410/// machine, it does not fall back to the interpreter.  This takes ownership
411/// of the module.
412ExecutionEngine *ExecutionEngine::createJIT(Module *M,
413                                            std::string *ErrorStr,
414                                            JITMemoryManager *JMM,
415                                            CodeGenOpt::Level OL,
416                                            bool GVsWithCode,
417                                            Reloc::Model RM,
418                                            CodeModel::Model CMM) {
419  if (ExecutionEngine::JITCtor == 0) {
420    if (ErrorStr)
421      *ErrorStr = "JIT has not been linked in.";
422    return 0;
423  }
424
425  // Use the defaults for extra parameters.  Users can use EngineBuilder to
426  // set them.
427  EngineBuilder EB(M);
428  EB.setEngineKind(EngineKind::JIT);
429  EB.setErrorStr(ErrorStr);
430  EB.setRelocationModel(RM);
431  EB.setCodeModel(CMM);
432  EB.setAllocateGVsWithCode(GVsWithCode);
433  EB.setOptLevel(OL);
434  EB.setJITMemoryManager(JMM);
435
436  // TODO: permit custom TargetOptions here
437  TargetMachine *TM = EB.selectTarget();
438  if (!TM || (ErrorStr && ErrorStr->length() > 0)) return 0;
439
440  return ExecutionEngine::JITCtor(M, ErrorStr, JMM, GVsWithCode, TM);
441}
442
443ExecutionEngine *EngineBuilder::create(TargetMachine *TM) {
444  OwningPtr<TargetMachine> TheTM(TM); // Take ownership.
445
446  // Make sure we can resolve symbols in the program as well. The zero arg
447  // to the function tells DynamicLibrary to load the program, not a library.
448  if (sys::DynamicLibrary::LoadLibraryPermanently(0, ErrorStr))
449    return 0;
450
451  assert(!(JMM && MCJMM));
452
453  // If the user specified a memory manager but didn't specify which engine to
454  // create, we assume they only want the JIT, and we fail if they only want
455  // the interpreter.
456  if (JMM || MCJMM) {
457    if (WhichEngine & EngineKind::JIT)
458      WhichEngine = EngineKind::JIT;
459    else {
460      if (ErrorStr)
461        *ErrorStr = "Cannot create an interpreter with a memory manager.";
462      return 0;
463    }
464  }
465
466  if (MCJMM && ! UseMCJIT) {
467    if (ErrorStr)
468      *ErrorStr =
469        "Cannot create a legacy JIT with a runtime dyld memory "
470        "manager.";
471    return 0;
472  }
473
474  // Unless the interpreter was explicitly selected or the JIT is not linked,
475  // try making a JIT.
476  if ((WhichEngine & EngineKind::JIT) && TheTM) {
477    Triple TT(M->getTargetTriple());
478    if (!TM->getTarget().hasJIT()) {
479      errs() << "WARNING: This target JIT is not designed for the host"
480             << " you are running.  If bad things happen, please choose"
481             << " a different -march switch.\n";
482    }
483
484    if (UseMCJIT && ExecutionEngine::MCJITCtor) {
485      ExecutionEngine *EE =
486        ExecutionEngine::MCJITCtor(M, ErrorStr, MCJMM ? MCJMM : JMM,
487                                   AllocateGVsWithCode, TheTM.take());
488      if (EE) return EE;
489    } else if (ExecutionEngine::JITCtor) {
490      ExecutionEngine *EE =
491        ExecutionEngine::JITCtor(M, ErrorStr, JMM,
492                                 AllocateGVsWithCode, TheTM.take());
493      if (EE) return EE;
494    }
495  }
496
497  // If we can't make a JIT and we didn't request one specifically, try making
498  // an interpreter instead.
499  if (WhichEngine & EngineKind::Interpreter) {
500    if (ExecutionEngine::InterpCtor)
501      return ExecutionEngine::InterpCtor(M, ErrorStr);
502    if (ErrorStr)
503      *ErrorStr = "Interpreter has not been linked in.";
504    return 0;
505  }
506
507  if ((WhichEngine & EngineKind::JIT) && ExecutionEngine::JITCtor == 0 &&
508      ExecutionEngine::MCJITCtor == 0) {
509    if (ErrorStr)
510      *ErrorStr = "JIT has not been linked in.";
511  }
512
513  return 0;
514}
515
516void *ExecutionEngine::getPointerToGlobal(const GlobalValue *GV) {
517  if (Function *F = const_cast<Function*>(dyn_cast<Function>(GV)))
518    return getPointerToFunction(F);
519
520  MutexGuard locked(lock);
521  if (void *P = EEState.getGlobalAddressMap(locked)[GV])
522    return P;
523
524  // Global variable might have been added since interpreter started.
525  if (GlobalVariable *GVar =
526          const_cast<GlobalVariable *>(dyn_cast<GlobalVariable>(GV)))
527    EmitGlobalVariable(GVar);
528  else
529    llvm_unreachable("Global hasn't had an address allocated yet!");
530
531  return EEState.getGlobalAddressMap(locked)[GV];
532}
533
534/// \brief Converts a Constant* into a GenericValue, including handling of
535/// ConstantExpr values.
536GenericValue ExecutionEngine::getConstantValue(const Constant *C) {
537  // If its undefined, return the garbage.
538  if (isa<UndefValue>(C)) {
539    GenericValue Result;
540    switch (C->getType()->getTypeID()) {
541    default:
542      break;
543    case Type::IntegerTyID:
544    case Type::X86_FP80TyID:
545    case Type::FP128TyID:
546    case Type::PPC_FP128TyID:
547      // Although the value is undefined, we still have to construct an APInt
548      // with the correct bit width.
549      Result.IntVal = APInt(C->getType()->getPrimitiveSizeInBits(), 0);
550      break;
551    case Type::StructTyID: {
552      // if the whole struct is 'undef' just reserve memory for the value.
553      if(StructType *STy = dyn_cast<StructType>(C->getType())) {
554        unsigned int elemNum = STy->getNumElements();
555        Result.AggregateVal.resize(elemNum);
556        for (unsigned int i = 0; i < elemNum; ++i) {
557          Type *ElemTy = STy->getElementType(i);
558          if (ElemTy->isIntegerTy())
559            Result.AggregateVal[i].IntVal =
560              APInt(ElemTy->getPrimitiveSizeInBits(), 0);
561          else if (ElemTy->isAggregateType()) {
562              const Constant *ElemUndef = UndefValue::get(ElemTy);
563              Result.AggregateVal[i] = getConstantValue(ElemUndef);
564            }
565          }
566        }
567      }
568      break;
569    case Type::VectorTyID:
570      // if the whole vector is 'undef' just reserve memory for the value.
571      const VectorType* VTy = dyn_cast<VectorType>(C->getType());
572      const Type *ElemTy = VTy->getElementType();
573      unsigned int elemNum = VTy->getNumElements();
574      Result.AggregateVal.resize(elemNum);
575      if (ElemTy->isIntegerTy())
576        for (unsigned int i = 0; i < elemNum; ++i)
577          Result.AggregateVal[i].IntVal =
578            APInt(ElemTy->getPrimitiveSizeInBits(), 0);
579      break;
580    }
581    return Result;
582  }
583
584  // Otherwise, if the value is a ConstantExpr...
585  if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
586    Constant *Op0 = CE->getOperand(0);
587    switch (CE->getOpcode()) {
588    case Instruction::GetElementPtr: {
589      // Compute the index
590      GenericValue Result = getConstantValue(Op0);
591      APInt Offset(TD->getPointerSizeInBits(), 0);
592      cast<GEPOperator>(CE)->accumulateConstantOffset(*TD, Offset);
593
594      char* tmp = (char*) Result.PointerVal;
595      Result = PTOGV(tmp + Offset.getSExtValue());
596      return Result;
597    }
598    case Instruction::Trunc: {
599      GenericValue GV = getConstantValue(Op0);
600      uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
601      GV.IntVal = GV.IntVal.trunc(BitWidth);
602      return GV;
603    }
604    case Instruction::ZExt: {
605      GenericValue GV = getConstantValue(Op0);
606      uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
607      GV.IntVal = GV.IntVal.zext(BitWidth);
608      return GV;
609    }
610    case Instruction::SExt: {
611      GenericValue GV = getConstantValue(Op0);
612      uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
613      GV.IntVal = GV.IntVal.sext(BitWidth);
614      return GV;
615    }
616    case Instruction::FPTrunc: {
617      // FIXME long double
618      GenericValue GV = getConstantValue(Op0);
619      GV.FloatVal = float(GV.DoubleVal);
620      return GV;
621    }
622    case Instruction::FPExt:{
623      // FIXME long double
624      GenericValue GV = getConstantValue(Op0);
625      GV.DoubleVal = double(GV.FloatVal);
626      return GV;
627    }
628    case Instruction::UIToFP: {
629      GenericValue GV = getConstantValue(Op0);
630      if (CE->getType()->isFloatTy())
631        GV.FloatVal = float(GV.IntVal.roundToDouble());
632      else if (CE->getType()->isDoubleTy())
633        GV.DoubleVal = GV.IntVal.roundToDouble();
634      else if (CE->getType()->isX86_FP80Ty()) {
635        APFloat apf = APFloat::getZero(APFloat::x87DoubleExtended);
636        (void)apf.convertFromAPInt(GV.IntVal,
637                                   false,
638                                   APFloat::rmNearestTiesToEven);
639        GV.IntVal = apf.bitcastToAPInt();
640      }
641      return GV;
642    }
643    case Instruction::SIToFP: {
644      GenericValue GV = getConstantValue(Op0);
645      if (CE->getType()->isFloatTy())
646        GV.FloatVal = float(GV.IntVal.signedRoundToDouble());
647      else if (CE->getType()->isDoubleTy())
648        GV.DoubleVal = GV.IntVal.signedRoundToDouble();
649      else if (CE->getType()->isX86_FP80Ty()) {
650        APFloat apf = APFloat::getZero(APFloat::x87DoubleExtended);
651        (void)apf.convertFromAPInt(GV.IntVal,
652                                   true,
653                                   APFloat::rmNearestTiesToEven);
654        GV.IntVal = apf.bitcastToAPInt();
655      }
656      return GV;
657    }
658    case Instruction::FPToUI: // double->APInt conversion handles sign
659    case Instruction::FPToSI: {
660      GenericValue GV = getConstantValue(Op0);
661      uint32_t BitWidth = cast<IntegerType>(CE->getType())->getBitWidth();
662      if (Op0->getType()->isFloatTy())
663        GV.IntVal = APIntOps::RoundFloatToAPInt(GV.FloatVal, BitWidth);
664      else if (Op0->getType()->isDoubleTy())
665        GV.IntVal = APIntOps::RoundDoubleToAPInt(GV.DoubleVal, BitWidth);
666      else if (Op0->getType()->isX86_FP80Ty()) {
667        APFloat apf = APFloat(APFloat::x87DoubleExtended, GV.IntVal);
668        uint64_t v;
669        bool ignored;
670        (void)apf.convertToInteger(&v, BitWidth,
671                                   CE->getOpcode()==Instruction::FPToSI,
672                                   APFloat::rmTowardZero, &ignored);
673        GV.IntVal = v; // endian?
674      }
675      return GV;
676    }
677    case Instruction::PtrToInt: {
678      GenericValue GV = getConstantValue(Op0);
679      uint32_t PtrWidth = TD->getTypeSizeInBits(Op0->getType());
680      assert(PtrWidth <= 64 && "Bad pointer width");
681      GV.IntVal = APInt(PtrWidth, uintptr_t(GV.PointerVal));
682      uint32_t IntWidth = TD->getTypeSizeInBits(CE->getType());
683      GV.IntVal = GV.IntVal.zextOrTrunc(IntWidth);
684      return GV;
685    }
686    case Instruction::IntToPtr: {
687      GenericValue GV = getConstantValue(Op0);
688      uint32_t PtrWidth = TD->getTypeSizeInBits(CE->getType());
689      GV.IntVal = GV.IntVal.zextOrTrunc(PtrWidth);
690      assert(GV.IntVal.getBitWidth() <= 64 && "Bad pointer width");
691      GV.PointerVal = PointerTy(uintptr_t(GV.IntVal.getZExtValue()));
692      return GV;
693    }
694    case Instruction::BitCast: {
695      GenericValue GV = getConstantValue(Op0);
696      Type* DestTy = CE->getType();
697      switch (Op0->getType()->getTypeID()) {
698        default: llvm_unreachable("Invalid bitcast operand");
699        case Type::IntegerTyID:
700          assert(DestTy->isFloatingPointTy() && "invalid bitcast");
701          if (DestTy->isFloatTy())
702            GV.FloatVal = GV.IntVal.bitsToFloat();
703          else if (DestTy->isDoubleTy())
704            GV.DoubleVal = GV.IntVal.bitsToDouble();
705          break;
706        case Type::FloatTyID:
707          assert(DestTy->isIntegerTy(32) && "Invalid bitcast");
708          GV.IntVal = APInt::floatToBits(GV.FloatVal);
709          break;
710        case Type::DoubleTyID:
711          assert(DestTy->isIntegerTy(64) && "Invalid bitcast");
712          GV.IntVal = APInt::doubleToBits(GV.DoubleVal);
713          break;
714        case Type::PointerTyID:
715          assert(DestTy->isPointerTy() && "Invalid bitcast");
716          break; // getConstantValue(Op0)  above already converted it
717      }
718      return GV;
719    }
720    case Instruction::Add:
721    case Instruction::FAdd:
722    case Instruction::Sub:
723    case Instruction::FSub:
724    case Instruction::Mul:
725    case Instruction::FMul:
726    case Instruction::UDiv:
727    case Instruction::SDiv:
728    case Instruction::URem:
729    case Instruction::SRem:
730    case Instruction::And:
731    case Instruction::Or:
732    case Instruction::Xor: {
733      GenericValue LHS = getConstantValue(Op0);
734      GenericValue RHS = getConstantValue(CE->getOperand(1));
735      GenericValue GV;
736      switch (CE->getOperand(0)->getType()->getTypeID()) {
737      default: llvm_unreachable("Bad add type!");
738      case Type::IntegerTyID:
739        switch (CE->getOpcode()) {
740          default: llvm_unreachable("Invalid integer opcode");
741          case Instruction::Add: GV.IntVal = LHS.IntVal + RHS.IntVal; break;
742          case Instruction::Sub: GV.IntVal = LHS.IntVal - RHS.IntVal; break;
743          case Instruction::Mul: GV.IntVal = LHS.IntVal * RHS.IntVal; break;
744          case Instruction::UDiv:GV.IntVal = LHS.IntVal.udiv(RHS.IntVal); break;
745          case Instruction::SDiv:GV.IntVal = LHS.IntVal.sdiv(RHS.IntVal); break;
746          case Instruction::URem:GV.IntVal = LHS.IntVal.urem(RHS.IntVal); break;
747          case Instruction::SRem:GV.IntVal = LHS.IntVal.srem(RHS.IntVal); break;
748          case Instruction::And: GV.IntVal = LHS.IntVal & RHS.IntVal; break;
749          case Instruction::Or:  GV.IntVal = LHS.IntVal | RHS.IntVal; break;
750          case Instruction::Xor: GV.IntVal = LHS.IntVal ^ RHS.IntVal; break;
751        }
752        break;
753      case Type::FloatTyID:
754        switch (CE->getOpcode()) {
755          default: llvm_unreachable("Invalid float opcode");
756          case Instruction::FAdd:
757            GV.FloatVal = LHS.FloatVal + RHS.FloatVal; break;
758          case Instruction::FSub:
759            GV.FloatVal = LHS.FloatVal - RHS.FloatVal; break;
760          case Instruction::FMul:
761            GV.FloatVal = LHS.FloatVal * RHS.FloatVal; break;
762          case Instruction::FDiv:
763            GV.FloatVal = LHS.FloatVal / RHS.FloatVal; break;
764          case Instruction::FRem:
765            GV.FloatVal = std::fmod(LHS.FloatVal,RHS.FloatVal); break;
766        }
767        break;
768      case Type::DoubleTyID:
769        switch (CE->getOpcode()) {
770          default: llvm_unreachable("Invalid double opcode");
771          case Instruction::FAdd:
772            GV.DoubleVal = LHS.DoubleVal + RHS.DoubleVal; break;
773          case Instruction::FSub:
774            GV.DoubleVal = LHS.DoubleVal - RHS.DoubleVal; break;
775          case Instruction::FMul:
776            GV.DoubleVal = LHS.DoubleVal * RHS.DoubleVal; break;
777          case Instruction::FDiv:
778            GV.DoubleVal = LHS.DoubleVal / RHS.DoubleVal; break;
779          case Instruction::FRem:
780            GV.DoubleVal = std::fmod(LHS.DoubleVal,RHS.DoubleVal); break;
781        }
782        break;
783      case Type::X86_FP80TyID:
784      case Type::PPC_FP128TyID:
785      case Type::FP128TyID: {
786        const fltSemantics &Sem = CE->getOperand(0)->getType()->getFltSemantics();
787        APFloat apfLHS = APFloat(Sem, LHS.IntVal);
788        switch (CE->getOpcode()) {
789          default: llvm_unreachable("Invalid long double opcode");
790          case Instruction::FAdd:
791            apfLHS.add(APFloat(Sem, RHS.IntVal), APFloat::rmNearestTiesToEven);
792            GV.IntVal = apfLHS.bitcastToAPInt();
793            break;
794          case Instruction::FSub:
795            apfLHS.subtract(APFloat(Sem, RHS.IntVal),
796                            APFloat::rmNearestTiesToEven);
797            GV.IntVal = apfLHS.bitcastToAPInt();
798            break;
799          case Instruction::FMul:
800            apfLHS.multiply(APFloat(Sem, RHS.IntVal),
801                            APFloat::rmNearestTiesToEven);
802            GV.IntVal = apfLHS.bitcastToAPInt();
803            break;
804          case Instruction::FDiv:
805            apfLHS.divide(APFloat(Sem, RHS.IntVal),
806                          APFloat::rmNearestTiesToEven);
807            GV.IntVal = apfLHS.bitcastToAPInt();
808            break;
809          case Instruction::FRem:
810            apfLHS.mod(APFloat(Sem, RHS.IntVal),
811                       APFloat::rmNearestTiesToEven);
812            GV.IntVal = apfLHS.bitcastToAPInt();
813            break;
814          }
815        }
816        break;
817      }
818      return GV;
819    }
820    default:
821      break;
822    }
823
824    SmallString<256> Msg;
825    raw_svector_ostream OS(Msg);
826    OS << "ConstantExpr not handled: " << *CE;
827    report_fatal_error(OS.str());
828  }
829
830  // Otherwise, we have a simple constant.
831  GenericValue Result;
832  switch (C->getType()->getTypeID()) {
833  case Type::FloatTyID:
834    Result.FloatVal = cast<ConstantFP>(C)->getValueAPF().convertToFloat();
835    break;
836  case Type::DoubleTyID:
837    Result.DoubleVal = cast<ConstantFP>(C)->getValueAPF().convertToDouble();
838    break;
839  case Type::X86_FP80TyID:
840  case Type::FP128TyID:
841  case Type::PPC_FP128TyID:
842    Result.IntVal = cast <ConstantFP>(C)->getValueAPF().bitcastToAPInt();
843    break;
844  case Type::IntegerTyID:
845    Result.IntVal = cast<ConstantInt>(C)->getValue();
846    break;
847  case Type::PointerTyID:
848    if (isa<ConstantPointerNull>(C))
849      Result.PointerVal = 0;
850    else if (const Function *F = dyn_cast<Function>(C))
851      Result = PTOGV(getPointerToFunctionOrStub(const_cast<Function*>(F)));
852    else if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(C))
853      Result = PTOGV(getOrEmitGlobalVariable(const_cast<GlobalVariable*>(GV)));
854    else if (const BlockAddress *BA = dyn_cast<BlockAddress>(C))
855      Result = PTOGV(getPointerToBasicBlock(const_cast<BasicBlock*>(
856                                                        BA->getBasicBlock())));
857    else
858      llvm_unreachable("Unknown constant pointer type!");
859    break;
860  case Type::VectorTyID: {
861    unsigned elemNum;
862    Type* ElemTy;
863    const ConstantDataVector *CDV = dyn_cast<ConstantDataVector>(C);
864    const ConstantVector *CV = dyn_cast<ConstantVector>(C);
865    const ConstantAggregateZero *CAZ = dyn_cast<ConstantAggregateZero>(C);
866
867    if (CDV) {
868        elemNum = CDV->getNumElements();
869        ElemTy = CDV->getElementType();
870    } else if (CV || CAZ) {
871        VectorType* VTy = dyn_cast<VectorType>(C->getType());
872        elemNum = VTy->getNumElements();
873        ElemTy = VTy->getElementType();
874    } else {
875        llvm_unreachable("Unknown constant vector type!");
876    }
877
878    Result.AggregateVal.resize(elemNum);
879    // Check if vector holds floats.
880    if(ElemTy->isFloatTy()) {
881      if (CAZ) {
882        GenericValue floatZero;
883        floatZero.FloatVal = 0.f;
884        std::fill(Result.AggregateVal.begin(), Result.AggregateVal.end(),
885                  floatZero);
886        break;
887      }
888      if(CV) {
889        for (unsigned i = 0; i < elemNum; ++i)
890          if (!isa<UndefValue>(CV->getOperand(i)))
891            Result.AggregateVal[i].FloatVal = cast<ConstantFP>(
892              CV->getOperand(i))->getValueAPF().convertToFloat();
893        break;
894      }
895      if(CDV)
896        for (unsigned i = 0; i < elemNum; ++i)
897          Result.AggregateVal[i].FloatVal = CDV->getElementAsFloat(i);
898
899      break;
900    }
901    // Check if vector holds doubles.
902    if (ElemTy->isDoubleTy()) {
903      if (CAZ) {
904        GenericValue doubleZero;
905        doubleZero.DoubleVal = 0.0;
906        std::fill(Result.AggregateVal.begin(), Result.AggregateVal.end(),
907                  doubleZero);
908        break;
909      }
910      if(CV) {
911        for (unsigned i = 0; i < elemNum; ++i)
912          if (!isa<UndefValue>(CV->getOperand(i)))
913            Result.AggregateVal[i].DoubleVal = cast<ConstantFP>(
914              CV->getOperand(i))->getValueAPF().convertToDouble();
915        break;
916      }
917      if(CDV)
918        for (unsigned i = 0; i < elemNum; ++i)
919          Result.AggregateVal[i].DoubleVal = CDV->getElementAsDouble(i);
920
921      break;
922    }
923    // Check if vector holds integers.
924    if (ElemTy->isIntegerTy()) {
925      if (CAZ) {
926        GenericValue intZero;
927        intZero.IntVal = APInt(ElemTy->getScalarSizeInBits(), 0ull);
928        std::fill(Result.AggregateVal.begin(), Result.AggregateVal.end(),
929                  intZero);
930        break;
931      }
932      if(CV) {
933        for (unsigned i = 0; i < elemNum; ++i)
934          if (!isa<UndefValue>(CV->getOperand(i)))
935            Result.AggregateVal[i].IntVal = cast<ConstantInt>(
936                                            CV->getOperand(i))->getValue();
937          else {
938            Result.AggregateVal[i].IntVal =
939              APInt(CV->getOperand(i)->getType()->getPrimitiveSizeInBits(), 0);
940          }
941        break;
942      }
943      if(CDV)
944        for (unsigned i = 0; i < elemNum; ++i)
945          Result.AggregateVal[i].IntVal = APInt(
946            CDV->getElementType()->getPrimitiveSizeInBits(),
947            CDV->getElementAsInteger(i));
948
949      break;
950    }
951    llvm_unreachable("Unknown constant pointer type!");
952  }
953  break;
954
955  default:
956    SmallString<256> Msg;
957    raw_svector_ostream OS(Msg);
958    OS << "ERROR: Constant unimplemented for type: " << *C->getType();
959    report_fatal_error(OS.str());
960  }
961
962  return Result;
963}
964
965/// StoreIntToMemory - Fills the StoreBytes bytes of memory starting from Dst
966/// with the integer held in IntVal.
967static void StoreIntToMemory(const APInt &IntVal, uint8_t *Dst,
968                             unsigned StoreBytes) {
969  assert((IntVal.getBitWidth()+7)/8 >= StoreBytes && "Integer too small!");
970  const uint8_t *Src = (const uint8_t *)IntVal.getRawData();
971
972  if (sys::IsLittleEndianHost) {
973    // Little-endian host - the source is ordered from LSB to MSB.  Order the
974    // destination from LSB to MSB: Do a straight copy.
975    memcpy(Dst, Src, StoreBytes);
976  } else {
977    // Big-endian host - the source is an array of 64 bit words ordered from
978    // LSW to MSW.  Each word is ordered from MSB to LSB.  Order the destination
979    // from MSB to LSB: Reverse the word order, but not the bytes in a word.
980    while (StoreBytes > sizeof(uint64_t)) {
981      StoreBytes -= sizeof(uint64_t);
982      // May not be aligned so use memcpy.
983      memcpy(Dst + StoreBytes, Src, sizeof(uint64_t));
984      Src += sizeof(uint64_t);
985    }
986
987    memcpy(Dst, Src + sizeof(uint64_t) - StoreBytes, StoreBytes);
988  }
989}
990
991void ExecutionEngine::StoreValueToMemory(const GenericValue &Val,
992                                         GenericValue *Ptr, Type *Ty) {
993  const unsigned StoreBytes = getDataLayout()->getTypeStoreSize(Ty);
994
995  switch (Ty->getTypeID()) {
996  default:
997    dbgs() << "Cannot store value of type " << *Ty << "!\n";
998    break;
999  case Type::IntegerTyID:
1000    StoreIntToMemory(Val.IntVal, (uint8_t*)Ptr, StoreBytes);
1001    break;
1002  case Type::FloatTyID:
1003    *((float*)Ptr) = Val.FloatVal;
1004    break;
1005  case Type::DoubleTyID:
1006    *((double*)Ptr) = Val.DoubleVal;
1007    break;
1008  case Type::X86_FP80TyID:
1009    memcpy(Ptr, Val.IntVal.getRawData(), 10);
1010    break;
1011  case Type::PointerTyID:
1012    // Ensure 64 bit target pointers are fully initialized on 32 bit hosts.
1013    if (StoreBytes != sizeof(PointerTy))
1014      memset(&(Ptr->PointerVal), 0, StoreBytes);
1015
1016    *((PointerTy*)Ptr) = Val.PointerVal;
1017    break;
1018  case Type::VectorTyID:
1019    for (unsigned i = 0; i < Val.AggregateVal.size(); ++i) {
1020      if (cast<VectorType>(Ty)->getElementType()->isDoubleTy())
1021        *(((double*)Ptr)+i) = Val.AggregateVal[i].DoubleVal;
1022      if (cast<VectorType>(Ty)->getElementType()->isFloatTy())
1023        *(((float*)Ptr)+i) = Val.AggregateVal[i].FloatVal;
1024      if (cast<VectorType>(Ty)->getElementType()->isIntegerTy()) {
1025        unsigned numOfBytes =(Val.AggregateVal[i].IntVal.getBitWidth()+7)/8;
1026        StoreIntToMemory(Val.AggregateVal[i].IntVal,
1027          (uint8_t*)Ptr + numOfBytes*i, numOfBytes);
1028      }
1029    }
1030    break;
1031  }
1032
1033  if (sys::IsLittleEndianHost != getDataLayout()->isLittleEndian())
1034    // Host and target are different endian - reverse the stored bytes.
1035    std::reverse((uint8_t*)Ptr, StoreBytes + (uint8_t*)Ptr);
1036}
1037
1038/// LoadIntFromMemory - Loads the integer stored in the LoadBytes bytes starting
1039/// from Src into IntVal, which is assumed to be wide enough and to hold zero.
1040static void LoadIntFromMemory(APInt &IntVal, uint8_t *Src, unsigned LoadBytes) {
1041  assert((IntVal.getBitWidth()+7)/8 >= LoadBytes && "Integer too small!");
1042  uint8_t *Dst = reinterpret_cast<uint8_t *>(
1043                   const_cast<uint64_t *>(IntVal.getRawData()));
1044
1045  if (sys::IsLittleEndianHost)
1046    // Little-endian host - the destination must be ordered from LSB to MSB.
1047    // The source is ordered from LSB to MSB: Do a straight copy.
1048    memcpy(Dst, Src, LoadBytes);
1049  else {
1050    // Big-endian - the destination is an array of 64 bit words ordered from
1051    // LSW to MSW.  Each word must be ordered from MSB to LSB.  The source is
1052    // ordered from MSB to LSB: Reverse the word order, but not the bytes in
1053    // a word.
1054    while (LoadBytes > sizeof(uint64_t)) {
1055      LoadBytes -= sizeof(uint64_t);
1056      // May not be aligned so use memcpy.
1057      memcpy(Dst, Src + LoadBytes, sizeof(uint64_t));
1058      Dst += sizeof(uint64_t);
1059    }
1060
1061    memcpy(Dst + sizeof(uint64_t) - LoadBytes, Src, LoadBytes);
1062  }
1063}
1064
1065/// FIXME: document
1066///
1067void ExecutionEngine::LoadValueFromMemory(GenericValue &Result,
1068                                          GenericValue *Ptr,
1069                                          Type *Ty) {
1070  const unsigned LoadBytes = getDataLayout()->getTypeStoreSize(Ty);
1071
1072  switch (Ty->getTypeID()) {
1073  case Type::IntegerTyID:
1074    // An APInt with all words initially zero.
1075    Result.IntVal = APInt(cast<IntegerType>(Ty)->getBitWidth(), 0);
1076    LoadIntFromMemory(Result.IntVal, (uint8_t*)Ptr, LoadBytes);
1077    break;
1078  case Type::FloatTyID:
1079    Result.FloatVal = *((float*)Ptr);
1080    break;
1081  case Type::DoubleTyID:
1082    Result.DoubleVal = *((double*)Ptr);
1083    break;
1084  case Type::PointerTyID:
1085    Result.PointerVal = *((PointerTy*)Ptr);
1086    break;
1087  case Type::X86_FP80TyID: {
1088    // This is endian dependent, but it will only work on x86 anyway.
1089    // FIXME: Will not trap if loading a signaling NaN.
1090    uint64_t y[2];
1091    memcpy(y, Ptr, 10);
1092    Result.IntVal = APInt(80, y);
1093    break;
1094  }
1095  case Type::VectorTyID: {
1096    const VectorType *VT = cast<VectorType>(Ty);
1097    const Type *ElemT = VT->getElementType();
1098    const unsigned numElems = VT->getNumElements();
1099    if (ElemT->isFloatTy()) {
1100      Result.AggregateVal.resize(numElems);
1101      for (unsigned i = 0; i < numElems; ++i)
1102        Result.AggregateVal[i].FloatVal = *((float*)Ptr+i);
1103    }
1104    if (ElemT->isDoubleTy()) {
1105      Result.AggregateVal.resize(numElems);
1106      for (unsigned i = 0; i < numElems; ++i)
1107        Result.AggregateVal[i].DoubleVal = *((double*)Ptr+i);
1108    }
1109    if (ElemT->isIntegerTy()) {
1110      GenericValue intZero;
1111      const unsigned elemBitWidth = cast<IntegerType>(ElemT)->getBitWidth();
1112      intZero.IntVal = APInt(elemBitWidth, 0);
1113      Result.AggregateVal.resize(numElems, intZero);
1114      for (unsigned i = 0; i < numElems; ++i)
1115        LoadIntFromMemory(Result.AggregateVal[i].IntVal,
1116          (uint8_t*)Ptr+((elemBitWidth+7)/8)*i, (elemBitWidth+7)/8);
1117    }
1118  break;
1119  }
1120  default:
1121    SmallString<256> Msg;
1122    raw_svector_ostream OS(Msg);
1123    OS << "Cannot load value of type " << *Ty << "!";
1124    report_fatal_error(OS.str());
1125  }
1126}
1127
1128void ExecutionEngine::InitializeMemory(const Constant *Init, void *Addr) {
1129  DEBUG(dbgs() << "JIT: Initializing " << Addr << " ");
1130  DEBUG(Init->dump());
1131  if (isa<UndefValue>(Init))
1132    return;
1133
1134  if (const ConstantVector *CP = dyn_cast<ConstantVector>(Init)) {
1135    unsigned ElementSize =
1136      getDataLayout()->getTypeAllocSize(CP->getType()->getElementType());
1137    for (unsigned i = 0, e = CP->getNumOperands(); i != e; ++i)
1138      InitializeMemory(CP->getOperand(i), (char*)Addr+i*ElementSize);
1139    return;
1140  }
1141
1142  if (isa<ConstantAggregateZero>(Init)) {
1143    memset(Addr, 0, (size_t)getDataLayout()->getTypeAllocSize(Init->getType()));
1144    return;
1145  }
1146
1147  if (const ConstantArray *CPA = dyn_cast<ConstantArray>(Init)) {
1148    unsigned ElementSize =
1149      getDataLayout()->getTypeAllocSize(CPA->getType()->getElementType());
1150    for (unsigned i = 0, e = CPA->getNumOperands(); i != e; ++i)
1151      InitializeMemory(CPA->getOperand(i), (char*)Addr+i*ElementSize);
1152    return;
1153  }
1154
1155  if (const ConstantStruct *CPS = dyn_cast<ConstantStruct>(Init)) {
1156    const StructLayout *SL =
1157      getDataLayout()->getStructLayout(cast<StructType>(CPS->getType()));
1158    for (unsigned i = 0, e = CPS->getNumOperands(); i != e; ++i)
1159      InitializeMemory(CPS->getOperand(i), (char*)Addr+SL->getElementOffset(i));
1160    return;
1161  }
1162
1163  if (const ConstantDataSequential *CDS =
1164               dyn_cast<ConstantDataSequential>(Init)) {
1165    // CDS is already laid out in host memory order.
1166    StringRef Data = CDS->getRawDataValues();
1167    memcpy(Addr, Data.data(), Data.size());
1168    return;
1169  }
1170
1171  if (Init->getType()->isFirstClassType()) {
1172    GenericValue Val = getConstantValue(Init);
1173    StoreValueToMemory(Val, (GenericValue*)Addr, Init->getType());
1174    return;
1175  }
1176
1177  DEBUG(dbgs() << "Bad Type: " << *Init->getType() << "\n");
1178  llvm_unreachable("Unknown constant type to initialize memory with!");
1179}
1180
1181/// EmitGlobals - Emit all of the global variables to memory, storing their
1182/// addresses into GlobalAddress.  This must make sure to copy the contents of
1183/// their initializers into the memory.
1184void ExecutionEngine::emitGlobals() {
1185  // Loop over all of the global variables in the program, allocating the memory
1186  // to hold them.  If there is more than one module, do a prepass over globals
1187  // to figure out how the different modules should link together.
1188  std::map<std::pair<std::string, Type*>,
1189           const GlobalValue*> LinkedGlobalsMap;
1190
1191  if (Modules.size() != 1) {
1192    for (unsigned m = 0, e = Modules.size(); m != e; ++m) {
1193      Module &M = *Modules[m];
1194      for (Module::const_global_iterator I = M.global_begin(),
1195           E = M.global_end(); I != E; ++I) {
1196        const GlobalValue *GV = I;
1197        if (GV->hasLocalLinkage() || GV->isDeclaration() ||
1198            GV->hasAppendingLinkage() || !GV->hasName())
1199          continue;// Ignore external globals and globals with internal linkage.
1200
1201        const GlobalValue *&GVEntry =
1202          LinkedGlobalsMap[std::make_pair(GV->getName(), GV->getType())];
1203
1204        // If this is the first time we've seen this global, it is the canonical
1205        // version.
1206        if (!GVEntry) {
1207          GVEntry = GV;
1208          continue;
1209        }
1210
1211        // If the existing global is strong, never replace it.
1212        if (GVEntry->hasExternalLinkage() ||
1213            GVEntry->hasDLLImportLinkage() ||
1214            GVEntry->hasDLLExportLinkage())
1215          continue;
1216
1217        // Otherwise, we know it's linkonce/weak, replace it if this is a strong
1218        // symbol.  FIXME is this right for common?
1219        if (GV->hasExternalLinkage() || GVEntry->hasExternalWeakLinkage())
1220          GVEntry = GV;
1221      }
1222    }
1223  }
1224
1225  std::vector<const GlobalValue*> NonCanonicalGlobals;
1226  for (unsigned m = 0, e = Modules.size(); m != e; ++m) {
1227    Module &M = *Modules[m];
1228    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
1229         I != E; ++I) {
1230      // In the multi-module case, see what this global maps to.
1231      if (!LinkedGlobalsMap.empty()) {
1232        if (const GlobalValue *GVEntry =
1233              LinkedGlobalsMap[std::make_pair(I->getName(), I->getType())]) {
1234          // If something else is the canonical global, ignore this one.
1235          if (GVEntry != &*I) {
1236            NonCanonicalGlobals.push_back(I);
1237            continue;
1238          }
1239        }
1240      }
1241
1242      if (!I->isDeclaration()) {
1243        addGlobalMapping(I, getMemoryForGV(I));
1244      } else {
1245        // External variable reference. Try to use the dynamic loader to
1246        // get a pointer to it.
1247        if (void *SymAddr =
1248            sys::DynamicLibrary::SearchForAddressOfSymbol(I->getName()))
1249          addGlobalMapping(I, SymAddr);
1250        else {
1251          report_fatal_error("Could not resolve external global address: "
1252                            +I->getName());
1253        }
1254      }
1255    }
1256
1257    // If there are multiple modules, map the non-canonical globals to their
1258    // canonical location.
1259    if (!NonCanonicalGlobals.empty()) {
1260      for (unsigned i = 0, e = NonCanonicalGlobals.size(); i != e; ++i) {
1261        const GlobalValue *GV = NonCanonicalGlobals[i];
1262        const GlobalValue *CGV =
1263          LinkedGlobalsMap[std::make_pair(GV->getName(), GV->getType())];
1264        void *Ptr = getPointerToGlobalIfAvailable(CGV);
1265        assert(Ptr && "Canonical global wasn't codegen'd!");
1266        addGlobalMapping(GV, Ptr);
1267      }
1268    }
1269
1270    // Now that all of the globals are set up in memory, loop through them all
1271    // and initialize their contents.
1272    for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
1273         I != E; ++I) {
1274      if (!I->isDeclaration()) {
1275        if (!LinkedGlobalsMap.empty()) {
1276          if (const GlobalValue *GVEntry =
1277                LinkedGlobalsMap[std::make_pair(I->getName(), I->getType())])
1278            if (GVEntry != &*I)  // Not the canonical variable.
1279              continue;
1280        }
1281        EmitGlobalVariable(I);
1282      }
1283    }
1284  }
1285}
1286
1287// EmitGlobalVariable - This method emits the specified global variable to the
1288// address specified in GlobalAddresses, or allocates new memory if it's not
1289// already in the map.
1290void ExecutionEngine::EmitGlobalVariable(const GlobalVariable *GV) {
1291  void *GA = getPointerToGlobalIfAvailable(GV);
1292
1293  if (GA == 0) {
1294    // If it's not already specified, allocate memory for the global.
1295    GA = getMemoryForGV(GV);
1296
1297    // If we failed to allocate memory for this global, return.
1298    if (GA == 0) return;
1299
1300    addGlobalMapping(GV, GA);
1301  }
1302
1303  // Don't initialize if it's thread local, let the client do it.
1304  if (!GV->isThreadLocal())
1305    InitializeMemory(GV->getInitializer(), GA);
1306
1307  Type *ElTy = GV->getType()->getElementType();
1308  size_t GVSize = (size_t)getDataLayout()->getTypeAllocSize(ElTy);
1309  NumInitBytes += (unsigned)GVSize;
1310  ++NumGlobals;
1311}
1312
1313ExecutionEngineState::ExecutionEngineState(ExecutionEngine &EE)
1314  : EE(EE), GlobalAddressMap(this) {
1315}
1316
1317sys::Mutex *
1318ExecutionEngineState::AddressMapConfig::getMutex(ExecutionEngineState *EES) {
1319  return &EES->EE.lock;
1320}
1321
1322void ExecutionEngineState::AddressMapConfig::onDelete(ExecutionEngineState *EES,
1323                                                      const GlobalValue *Old) {
1324  void *OldVal = EES->GlobalAddressMap.lookup(Old);
1325  EES->GlobalAddressReverseMap.erase(OldVal);
1326}
1327
1328void ExecutionEngineState::AddressMapConfig::onRAUW(ExecutionEngineState *,
1329                                                    const GlobalValue *,
1330                                                    const GlobalValue *) {
1331  llvm_unreachable("The ExecutionEngine doesn't know how to handle a"
1332                   " RAUW on a value it has a global mapping for.");
1333}
1334