ExecutionEngine.cpp revision 74cf81919d3a44457bec1cbf01b655c80f4673b1
1//===-- ExecutionEngine.cpp - Common Implementation shared by EE's --------===//
2//
3// This file defines the common interface used by the various execution engine
4// subclasses.
5//
6//===----------------------------------------------------------------------===//
7
8#define DEBUG_TYPE "jit"
9#include "ExecutionEngine.h"
10#include "GenericValue.h"
11#include "llvm/DerivedTypes.h"
12#include "llvm/Constants.h"
13#include "llvm/Module.h"
14#include "llvm/Target/TargetData.h"
15#include "Support/Debug.h"
16#include "Support/Statistic.h"
17#include "Config/dlfcn.h"
18
19Statistic<> NumInitBytes("lli", "Number of bytes of global vars initialized");
20
21// getPointerToGlobal - This returns the address of the specified global
22// value.  This may involve code generation if it's a function.
23//
24void *ExecutionEngine::getPointerToGlobal(const GlobalValue *GV) {
25  if (Function *F = const_cast<Function*>(dyn_cast<Function>(GV)))
26    return getPointerToFunction(F);
27
28  assert(GlobalAddress[GV] && "Global hasn't had an address allocated yet?");
29  return GlobalAddress[GV];
30}
31
32
33GenericValue ExecutionEngine::getConstantValue(const Constant *C) {
34  GenericValue Result;
35
36  if (ConstantExpr *CE = const_cast<ConstantExpr*>(dyn_cast<ConstantExpr>(C))) {
37    switch (CE->getOpcode()) {
38    case Instruction::GetElementPtr: {
39      Result = getConstantValue(CE->getOperand(0));
40      std::vector<Value*> Indexes(CE->op_begin()+1, CE->op_end());
41      uint64_t Offset =
42        TD->getIndexedOffset(CE->getOperand(0)->getType(), Indexes);
43
44      Result.LongVal += Offset;
45      return Result;
46    }
47    case Instruction::Cast: {
48      // We only need to handle a few cases here.  Almost all casts will
49      // automatically fold, just the ones involving pointers won't.
50      //
51      Constant *Op = CE->getOperand(0);
52
53      // Handle cast of pointer to pointer...
54      if (Op->getType()->getPrimitiveID() == C->getType()->getPrimitiveID())
55        return getConstantValue(Op);
56
57      // Handle a cast of pointer to any integral type...
58      if (isa<PointerType>(Op->getType()) &&
59          (C->getType() == Type::LongTy || C->getType() == Type::ULongTy))
60        return getConstantValue(Op);
61
62      // Handle cast of long to pointer...
63      if (isa<PointerType>(C->getType()) && (Op->getType() == Type::LongTy ||
64                                             Op->getType() == Type::ULongTy))
65        return getConstantValue(Op);
66      break;
67    }
68
69    case Instruction::Add:
70      if (CE->getOperand(0)->getType() == Type::LongTy ||
71          CE->getOperand(0)->getType() == Type::ULongTy)
72        Result.LongVal = getConstantValue(CE->getOperand(0)).LongVal +
73                         getConstantValue(CE->getOperand(1)).LongVal;
74      else
75        break;
76      return Result;
77
78    default:
79      break;
80    }
81    std::cerr << "ConstantExpr not handled as global var init: " << *CE << "\n";
82    abort();
83  }
84
85  switch (C->getType()->getPrimitiveID()) {
86#define GET_CONST_VAL(TY, CLASS) \
87  case Type::TY##TyID: Result.TY##Val = cast<CLASS>(C)->getValue(); break
88    GET_CONST_VAL(Bool   , ConstantBool);
89    GET_CONST_VAL(UByte  , ConstantUInt);
90    GET_CONST_VAL(SByte  , ConstantSInt);
91    GET_CONST_VAL(UShort , ConstantUInt);
92    GET_CONST_VAL(Short  , ConstantSInt);
93    GET_CONST_VAL(UInt   , ConstantUInt);
94    GET_CONST_VAL(Int    , ConstantSInt);
95    GET_CONST_VAL(ULong  , ConstantUInt);
96    GET_CONST_VAL(Long   , ConstantSInt);
97    GET_CONST_VAL(Float  , ConstantFP);
98    GET_CONST_VAL(Double , ConstantFP);
99#undef GET_CONST_VAL
100  case Type::PointerTyID:
101    if (isa<ConstantPointerNull>(C)) {
102      Result.PointerVal = 0;
103    } else if (const ConstantPointerRef *CPR = dyn_cast<ConstantPointerRef>(C)){
104      Result = PTOGV(getPointerToGlobal(CPR->getValue()));
105
106    } else {
107      assert(0 && "Unknown constant pointer type!");
108    }
109    break;
110  default:
111    std::cout << "ERROR: Constant unimp for type: " << C->getType() << "\n";
112    abort();
113  }
114  return Result;
115}
116
117void ExecutionEngine::StoreValueToMemory(GenericValue Val, GenericValue *Ptr,
118				     const Type *Ty) {
119  if (getTargetData().isLittleEndian()) {
120    switch (Ty->getPrimitiveID()) {
121    case Type::BoolTyID:
122    case Type::UByteTyID:
123    case Type::SByteTyID:   Ptr->Untyped[0] = Val.UByteVal; break;
124    case Type::UShortTyID:
125    case Type::ShortTyID:   Ptr->Untyped[0] = Val.UShortVal & 255;
126                            Ptr->Untyped[1] = (Val.UShortVal >> 8) & 255;
127                            break;
128    Store4BytesLittleEndian:
129    case Type::FloatTyID:
130    case Type::UIntTyID:
131    case Type::IntTyID:     Ptr->Untyped[0] =  Val.UIntVal        & 255;
132                            Ptr->Untyped[1] = (Val.UIntVal >>  8) & 255;
133                            Ptr->Untyped[2] = (Val.UIntVal >> 16) & 255;
134                            Ptr->Untyped[3] = (Val.UIntVal >> 24) & 255;
135                            break;
136    case Type::PointerTyID: if (CurMod.has32BitPointers())
137                              goto Store4BytesLittleEndian;
138    case Type::DoubleTyID:
139    case Type::ULongTyID:
140    case Type::LongTyID:    Ptr->Untyped[0] =  Val.ULongVal        & 255;
141                            Ptr->Untyped[1] = (Val.ULongVal >>  8) & 255;
142                            Ptr->Untyped[2] = (Val.ULongVal >> 16) & 255;
143                            Ptr->Untyped[3] = (Val.ULongVal >> 24) & 255;
144                            Ptr->Untyped[4] = (Val.ULongVal >> 32) & 255;
145                            Ptr->Untyped[5] = (Val.ULongVal >> 40) & 255;
146                            Ptr->Untyped[6] = (Val.ULongVal >> 48) & 255;
147                            Ptr->Untyped[7] = (Val.ULongVal >> 56) & 255;
148                            break;
149    default:
150      std::cout << "Cannot store value of type " << Ty << "!\n";
151    }
152  } else {
153    switch (Ty->getPrimitiveID()) {
154    case Type::BoolTyID:
155    case Type::UByteTyID:
156    case Type::SByteTyID:   Ptr->Untyped[0] = Val.UByteVal; break;
157    case Type::UShortTyID:
158    case Type::ShortTyID:   Ptr->Untyped[1] = Val.UShortVal & 255;
159                            Ptr->Untyped[0] = (Val.UShortVal >> 8) & 255;
160                            break;
161    Store4BytesBigEndian:
162    case Type::FloatTyID:
163    case Type::UIntTyID:
164    case Type::IntTyID:     Ptr->Untyped[3] =  Val.UIntVal        & 255;
165                            Ptr->Untyped[2] = (Val.UIntVal >>  8) & 255;
166                            Ptr->Untyped[1] = (Val.UIntVal >> 16) & 255;
167                            Ptr->Untyped[0] = (Val.UIntVal >> 24) & 255;
168                            break;
169    case Type::PointerTyID: if (CurMod.has32BitPointers())
170                              goto Store4BytesBigEndian;
171    case Type::DoubleTyID:
172    case Type::ULongTyID:
173    case Type::LongTyID:    Ptr->Untyped[7] =  Val.ULongVal        & 255;
174                            Ptr->Untyped[6] = (Val.ULongVal >>  8) & 255;
175                            Ptr->Untyped[5] = (Val.ULongVal >> 16) & 255;
176                            Ptr->Untyped[4] = (Val.ULongVal >> 24) & 255;
177                            Ptr->Untyped[3] = (Val.ULongVal >> 32) & 255;
178                            Ptr->Untyped[2] = (Val.ULongVal >> 40) & 255;
179                            Ptr->Untyped[1] = (Val.ULongVal >> 48) & 255;
180                            Ptr->Untyped[0] = (Val.ULongVal >> 56) & 255;
181                            break;
182    default:
183      std::cout << "Cannot store value of type " << Ty << "!\n";
184    }
185  }
186}
187
188GenericValue ExecutionEngine::LoadValueFromMemory(GenericValue *Ptr,
189                                                  const Type *Ty) {
190  GenericValue Result;
191  if (getTargetData().isLittleEndian()) {
192    switch (Ty->getPrimitiveID()) {
193    case Type::BoolTyID:
194    case Type::UByteTyID:
195    case Type::SByteTyID:   Result.UByteVal = Ptr->Untyped[0]; break;
196    case Type::UShortTyID:
197    case Type::ShortTyID:   Result.UShortVal = (unsigned)Ptr->Untyped[0] |
198                                              ((unsigned)Ptr->Untyped[1] << 8);
199                            break;
200    Load4BytesLittleEndian:
201    case Type::FloatTyID:
202    case Type::UIntTyID:
203    case Type::IntTyID:     Result.UIntVal = (unsigned)Ptr->Untyped[0] |
204                                            ((unsigned)Ptr->Untyped[1] <<  8) |
205                                            ((unsigned)Ptr->Untyped[2] << 16) |
206                                            ((unsigned)Ptr->Untyped[3] << 24);
207                            break;
208    case Type::PointerTyID: if (getModule().has32BitPointers())
209                              goto Load4BytesLittleEndian;
210    case Type::DoubleTyID:
211    case Type::ULongTyID:
212    case Type::LongTyID:    Result.ULongVal = (uint64_t)Ptr->Untyped[0] |
213                                             ((uint64_t)Ptr->Untyped[1] <<  8) |
214                                             ((uint64_t)Ptr->Untyped[2] << 16) |
215                                             ((uint64_t)Ptr->Untyped[3] << 24) |
216                                             ((uint64_t)Ptr->Untyped[4] << 32) |
217                                             ((uint64_t)Ptr->Untyped[5] << 40) |
218                                             ((uint64_t)Ptr->Untyped[6] << 48) |
219                                             ((uint64_t)Ptr->Untyped[7] << 56);
220                            break;
221    default:
222      std::cout << "Cannot load value of type " << *Ty << "!\n";
223      abort();
224    }
225  } else {
226    switch (Ty->getPrimitiveID()) {
227    case Type::BoolTyID:
228    case Type::UByteTyID:
229    case Type::SByteTyID:   Result.UByteVal = Ptr->Untyped[0]; break;
230    case Type::UShortTyID:
231    case Type::ShortTyID:   Result.UShortVal = (unsigned)Ptr->Untyped[1] |
232                                              ((unsigned)Ptr->Untyped[0] << 8);
233                            break;
234    Load4BytesBigEndian:
235    case Type::FloatTyID:
236    case Type::UIntTyID:
237    case Type::IntTyID:     Result.UIntVal = (unsigned)Ptr->Untyped[3] |
238                                            ((unsigned)Ptr->Untyped[2] <<  8) |
239                                            ((unsigned)Ptr->Untyped[1] << 16) |
240                                            ((unsigned)Ptr->Untyped[0] << 24);
241                            break;
242    case Type::PointerTyID: if (getModule().has32BitPointers())
243                              goto Load4BytesBigEndian;
244    case Type::DoubleTyID:
245    case Type::ULongTyID:
246    case Type::LongTyID:    Result.ULongVal = (uint64_t)Ptr->Untyped[7] |
247                                             ((uint64_t)Ptr->Untyped[6] <<  8) |
248                                             ((uint64_t)Ptr->Untyped[5] << 16) |
249                                             ((uint64_t)Ptr->Untyped[4] << 24) |
250                                             ((uint64_t)Ptr->Untyped[3] << 32) |
251                                             ((uint64_t)Ptr->Untyped[2] << 40) |
252                                             ((uint64_t)Ptr->Untyped[1] << 48) |
253                                             ((uint64_t)Ptr->Untyped[0] << 56);
254                            break;
255    default:
256      std::cout << "Cannot load value of type " << *Ty << "!\n";
257      abort();
258    }
259  }
260  return Result;
261}
262
263
264// InitializeMemory - Recursive function to apply a Constant value into the
265// specified memory location...
266//
267void ExecutionEngine::InitializeMemory(const Constant *Init, void *Addr) {
268  if (Init->getType()->isFirstClassType()) {
269    GenericValue Val = getConstantValue(Init);
270    StoreValueToMemory(Val, (GenericValue*)Addr, Init->getType());
271    return;
272  }
273
274  switch (Init->getType()->getPrimitiveID()) {
275  case Type::ArrayTyID: {
276    const ConstantArray *CPA = cast<ConstantArray>(Init);
277    const std::vector<Use> &Val = CPA->getValues();
278    unsigned ElementSize =
279      getTargetData().getTypeSize(cast<ArrayType>(CPA->getType())->getElementType());
280    for (unsigned i = 0; i < Val.size(); ++i)
281      InitializeMemory(cast<Constant>(Val[i].get()), (char*)Addr+i*ElementSize);
282    return;
283  }
284
285  case Type::StructTyID: {
286    const ConstantStruct *CPS = cast<ConstantStruct>(Init);
287    const StructLayout *SL =
288      getTargetData().getStructLayout(cast<StructType>(CPS->getType()));
289    const std::vector<Use> &Val = CPS->getValues();
290    for (unsigned i = 0; i < Val.size(); ++i)
291      InitializeMemory(cast<Constant>(Val[i].get()),
292                       (char*)Addr+SL->MemberOffsets[i]);
293    return;
294  }
295
296  default:
297    std::cerr << "Bad Type: " << Init->getType() << "\n";
298    assert(0 && "Unknown constant type to initialize memory with!");
299  }
300}
301
302void *ExecutionEngine::CreateArgv(const std::vector<std::string> &InputArgv) {
303  if (getTargetData().getPointerSize() == 8) {   // 64 bit target?
304    PointerTy *Result = new PointerTy[InputArgv.size()+1];
305    DEBUG(std::cerr << "ARGV = " << (void*)Result << "\n");
306
307    for (unsigned i = 0; i < InputArgv.size(); ++i) {
308      unsigned Size = InputArgv[i].size()+1;
309      char *Dest = new char[Size];
310      DEBUG(std::cerr << "ARGV[" << i << "] = " << (void*)Dest << "\n");
311
312      copy(InputArgv[i].begin(), InputArgv[i].end(), Dest);
313      Dest[Size-1] = 0;
314
315      // Endian safe: Result[i] = (PointerTy)Dest;
316      StoreValueToMemory(PTOGV(Dest), (GenericValue*)(Result+i), Type::LongTy);
317    }
318    Result[InputArgv.size()] = 0;
319    return Result;
320
321  } else {                                      // 32 bit target?
322    int *Result = new int[InputArgv.size()+1];
323    DEBUG(std::cerr << "ARGV = " << (void*)Result << "\n");
324
325    for (unsigned i = 0; i < InputArgv.size(); ++i) {
326      unsigned Size = InputArgv[i].size()+1;
327      char *Dest = new char[Size];
328      DEBUG(std::cerr << "ARGV[" << i << "] = " << (void*)Dest << "\n");
329
330      copy(InputArgv[i].begin(), InputArgv[i].end(), Dest);
331      Dest[Size-1] = 0;
332
333      // Endian safe: Result[i] = (PointerTy)Dest;
334      StoreValueToMemory(PTOGV(Dest), (GenericValue*)(Result+i), Type::IntTy);
335    }
336    Result[InputArgv.size()] = 0;  // null terminate it
337    return Result;
338  }
339}
340
341/// EmitGlobals - Emit all of the global variables to memory, storing their
342/// addresses into GlobalAddress.  This must make sure to copy the contents of
343/// their initializers into the memory.
344///
345void ExecutionEngine::emitGlobals() {
346  const TargetData &TD = getTargetData();
347
348  // Loop over all of the global variables in the program, allocating the memory
349  // to hold them.
350  for (Module::giterator I = getModule().gbegin(), E = getModule().gend();
351       I != E; ++I)
352    if (!I->isExternal()) {
353      // Get the type of the global...
354      const Type *Ty = I->getType()->getElementType();
355
356      // Allocate some memory for it!
357      unsigned Size = TD.getTypeSize(Ty);
358      GlobalAddress[I] = new char[Size];
359      NumInitBytes += Size;
360
361      DEBUG(std::cerr << "Global '" << I->getName() << "' -> "
362	              << (void*)GlobalAddress[I] << "\n");
363    } else {
364      // On Sparc, RTLD_SELF is already defined and it's not zero
365      // Linux/x86 wants to use a 0, other systems may differ
366#ifndef RTLD_SELF
367#define RTLD_SELF 0
368#endif
369      // External variable reference, try to use dlsym to get a pointer to it in
370      // the LLI image.
371      if (void *SymAddr = dlsym(RTLD_SELF, I->getName().c_str()))
372        GlobalAddress[I] = SymAddr;
373      else {
374        std::cerr << "Could not resolve external global address: "
375                  << I->getName() << "\n";
376        abort();
377      }
378    }
379
380  // Now that all of the globals are set up in memory, loop through them all and
381  // initialize their contents.
382  for (Module::giterator I = getModule().gbegin(), E = getModule().gend();
383       I != E; ++I)
384    if (!I->isExternal())
385      InitializeMemory(I->getInitializer(), GlobalAddress[I]);
386}
387
388