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