ExecutionEngine.cpp revision df5a37efc997288da520ff4889443e3560d95387 
1//===-- ExecutionEngine.cpp - Common Implementation shared by EEs ---------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file was developed by the LLVM research group and is distributed under
6// the University of Illinois Open Source 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 "Interpreter/Interpreter.h"
17#include "JIT/JIT.h"
18#include "llvm/Constants.h"
19#include "llvm/DerivedTypes.h"
20#include "llvm/Module.h"
21#include "llvm/ModuleProvider.h"
22#include "llvm/ADT/Statistic.h"
23#include "llvm/CodeGen/IntrinsicLowering.h"
24#include "llvm/ExecutionEngine/ExecutionEngine.h"
25#include "llvm/ExecutionEngine/GenericValue.h"
26#include "llvm/Support/Debug.h"
27#include "llvm/System/DynamicLibrary.h"
28#include "llvm/Target/TargetData.h"
29using namespace llvm;
30
31namespace {
32  Statistic<> NumInitBytes("lli", "Number of bytes of global vars initialized");
33  Statistic<> NumGlobals  ("lli", "Number of global vars initialized");
34}
35
36ExecutionEngine::ExecutionEngine(ModuleProvider *P) :
37  CurMod(*P->getModule()), MP(P) {
38  assert(P && "ModuleProvider is null?");
39}
40
41ExecutionEngine::ExecutionEngine(Module *M) : CurMod(*M), MP(0) {
42  assert(M && "Module is null?");
43}
44
45ExecutionEngine::~ExecutionEngine() {
46  delete MP;
47}
48
49/// getGlobalValueAtAddress - Return the LLVM global value object that starts
50/// at the specified address.
51///
52const GlobalValue *ExecutionEngine::getGlobalValueAtAddress(void *Addr) {
53  // If we haven't computed the reverse mapping yet, do so first.
54  if (GlobalAddressReverseMap.empty()) {
55    for (std::map<const GlobalValue*, void *>::iterator I =
56           GlobalAddressMap.begin(), E = GlobalAddressMap.end(); I != E; ++I)
57      GlobalAddressReverseMap.insert(std::make_pair(I->second, I->first));
58  }
59
60  std::map<void *, const GlobalValue*>::iterator I =
61    GlobalAddressReverseMap.find(Addr);
62  return I != GlobalAddressReverseMap.end() ? I->second : 0;
63}
64
65// CreateArgv - Turn a vector of strings into a nice argv style array of
66// pointers to null terminated strings.
67//
68static void *CreateArgv(ExecutionEngine *EE,
69                        const std::vector<std::string> &InputArgv) {
70  unsigned PtrSize = EE->getTargetData().getPointerSize();
71  char *Result = new char[(InputArgv.size()+1)*PtrSize];
72
73  DEBUG(std::cerr << "ARGV = " << (void*)Result << "\n");
74  const Type *SBytePtr = PointerType::get(Type::SByteTy);
75
76  for (unsigned i = 0; i != InputArgv.size(); ++i) {
77    unsigned Size = InputArgv[i].size()+1;
78    char *Dest = new char[Size];
79    DEBUG(std::cerr << "ARGV[" << i << "] = " << (void*)Dest << "\n");
80
81    std::copy(InputArgv[i].begin(), InputArgv[i].end(), Dest);
82    Dest[Size-1] = 0;
83
84    // Endian safe: Result[i] = (PointerTy)Dest;
85    EE->StoreValueToMemory(PTOGV(Dest), (GenericValue*)(Result+i*PtrSize),
86                           SBytePtr);
87  }
88
89  // Null terminate it
90  EE->StoreValueToMemory(PTOGV(0),
91                         (GenericValue*)(Result+InputArgv.size()*PtrSize),
92                         SBytePtr);
93  return Result;
94}
95
96/// runFunctionAsMain - This is a helper function which wraps runFunction to
97/// handle the common task of starting up main with the specified argc, argv,
98/// and envp parameters.
99int ExecutionEngine::runFunctionAsMain(Function *Fn,
100                                       const std::vector<std::string> &argv,
101                                       const char * const * envp) {
102  std::vector<GenericValue> GVArgs;
103  GenericValue GVArgc;
104  GVArgc.IntVal = argv.size();
105  unsigned NumArgs = Fn->getFunctionType()->getNumParams();
106  if (NumArgs) {
107    GVArgs.push_back(GVArgc); // Arg #0 = argc.
108    if (NumArgs > 1) {
109      GVArgs.push_back(PTOGV(CreateArgv(this, argv))); // Arg #1 = argv.
110      assert(((char **)GVTOP(GVArgs[1]))[0] &&
111             "argv[0] was null after CreateArgv");
112      if (NumArgs > 2) {
113        std::vector<std::string> EnvVars;
114        for (unsigned i = 0; envp[i]; ++i)
115          EnvVars.push_back(envp[i]);
116        GVArgs.push_back(PTOGV(CreateArgv(this, EnvVars))); // Arg #2 = envp.
117      }
118    }
119  }
120  return runFunction(Fn, GVArgs).IntVal;
121}
122
123
124
125/// If possible, create a JIT, unless the caller specifically requests an
126/// Interpreter or there's an error. If even an Interpreter cannot be created,
127/// NULL is returned.
128///
129ExecutionEngine *ExecutionEngine::create(ModuleProvider *MP,
130                                         bool ForceInterpreter,
131                                         IntrinsicLowering *IL) {
132  ExecutionEngine *EE = 0;
133
134  // Unless the interpreter was explicitly selected, try making a JIT.
135  if (!ForceInterpreter)
136    EE = JIT::create(MP, IL);
137
138  // If we can't make a JIT, make an interpreter instead.
139  if (EE == 0) {
140    try {
141      Module *M = MP->materializeModule();
142      try {
143        EE = Interpreter::create(M, IL);
144      } catch (...) {
145        std::cerr << "Error creating the interpreter!\n";
146      }
147    } catch (std::string& errmsg) {
148      std::cerr << "Error reading the bytecode file: " << errmsg << "\n";
149    } catch (...) {
150      std::cerr << "Error reading the bytecode file!\n";
151    }
152  }
153
154  if (EE == 0)
155    delete IL;
156  else
157    // Make sure we can resolve symbols in the program as well. The zero arg
158    // to the function tells DynamicLibrary to load the program, not a library.
159    sys::DynamicLibrary::LoadLibraryPermanently(0);
160
161  return EE;
162}
163
164/// getPointerToGlobal - This returns the address of the specified global
165/// value.  This may involve code generation if it's a function.
166///
167void *ExecutionEngine::getPointerToGlobal(const GlobalValue *GV) {
168  if (Function *F = const_cast<Function*>(dyn_cast<Function>(GV)))
169    return getPointerToFunction(F);
170
171  assert(GlobalAddressMap[GV] && "Global hasn't had an address allocated yet?");
172  return GlobalAddressMap[GV];
173}
174
175/// FIXME: document
176///
177GenericValue ExecutionEngine::getConstantValue(const Constant *C) {
178  GenericValue Result;
179  if (isa<UndefValue>(C)) return Result;
180
181  if (ConstantExpr *CE = const_cast<ConstantExpr*>(dyn_cast<ConstantExpr>(C))) {
182    switch (CE->getOpcode()) {
183    case Instruction::GetElementPtr: {
184      Result = getConstantValue(CE->getOperand(0));
185      std::vector<Value*> Indexes(CE->op_begin()+1, CE->op_end());
186      uint64_t Offset =
187        TD->getIndexedOffset(CE->getOperand(0)->getType(), Indexes);
188
189      Result.LongVal += Offset;
190      return Result;
191    }
192    case Instruction::Cast: {
193      // We only need to handle a few cases here.  Almost all casts will
194      // automatically fold, just the ones involving pointers won't.
195      //
196      Constant *Op = CE->getOperand(0);
197      GenericValue GV = getConstantValue(Op);
198
199      // Handle cast of pointer to pointer...
200      if (Op->getType()->getTypeID() == C->getType()->getTypeID())
201        return GV;
202
203      // Handle a cast of pointer to any integral type...
204      if (isa<PointerType>(Op->getType()) && C->getType()->isIntegral())
205        return GV;
206
207      // Handle cast of integer to a pointer...
208      if (isa<PointerType>(C->getType()) && Op->getType()->isIntegral())
209        switch (Op->getType()->getTypeID()) {
210        case Type::BoolTyID:    return PTOGV((void*)(uintptr_t)GV.BoolVal);
211        case Type::SByteTyID:   return PTOGV((void*)( intptr_t)GV.SByteVal);
212        case Type::UByteTyID:   return PTOGV((void*)(uintptr_t)GV.UByteVal);
213        case Type::ShortTyID:   return PTOGV((void*)( intptr_t)GV.ShortVal);
214        case Type::UShortTyID:  return PTOGV((void*)(uintptr_t)GV.UShortVal);
215        case Type::IntTyID:     return PTOGV((void*)( intptr_t)GV.IntVal);
216        case Type::UIntTyID:    return PTOGV((void*)(uintptr_t)GV.UIntVal);
217        case Type::LongTyID:    return PTOGV((void*)( intptr_t)GV.LongVal);
218        case Type::ULongTyID:   return PTOGV((void*)(uintptr_t)GV.ULongVal);
219        default: assert(0 && "Unknown integral type!");
220        }
221      break;
222    }
223
224    case Instruction::Add:
225      switch (CE->getOperand(0)->getType()->getTypeID()) {
226      default: assert(0 && "Bad add type!"); abort();
227      case Type::LongTyID:
228      case Type::ULongTyID:
229        Result.LongVal = getConstantValue(CE->getOperand(0)).LongVal +
230                         getConstantValue(CE->getOperand(1)).LongVal;
231        break;
232      case Type::IntTyID:
233      case Type::UIntTyID:
234        Result.IntVal = getConstantValue(CE->getOperand(0)).IntVal +
235                        getConstantValue(CE->getOperand(1)).IntVal;
236        break;
237      case Type::ShortTyID:
238      case Type::UShortTyID:
239        Result.ShortVal = getConstantValue(CE->getOperand(0)).ShortVal +
240                          getConstantValue(CE->getOperand(1)).ShortVal;
241        break;
242      case Type::SByteTyID:
243      case Type::UByteTyID:
244        Result.SByteVal = getConstantValue(CE->getOperand(0)).SByteVal +
245                          getConstantValue(CE->getOperand(1)).SByteVal;
246        break;
247      case Type::FloatTyID:
248        Result.FloatVal = getConstantValue(CE->getOperand(0)).FloatVal +
249                          getConstantValue(CE->getOperand(1)).FloatVal;
250        break;
251      case Type::DoubleTyID:
252        Result.DoubleVal = getConstantValue(CE->getOperand(0)).DoubleVal +
253                           getConstantValue(CE->getOperand(1)).DoubleVal;
254        break;
255      }
256      return Result;
257    default:
258      break;
259    }
260    std::cerr << "ConstantExpr not handled as global var init: " << *CE << "\n";
261    abort();
262  }
263
264  switch (C->getType()->getTypeID()) {
265#define GET_CONST_VAL(TY, CLASS) \
266  case Type::TY##TyID: Result.TY##Val = cast<CLASS>(C)->getValue(); break
267    GET_CONST_VAL(Bool   , ConstantBool);
268    GET_CONST_VAL(UByte  , ConstantUInt);
269    GET_CONST_VAL(SByte  , ConstantSInt);
270    GET_CONST_VAL(UShort , ConstantUInt);
271    GET_CONST_VAL(Short  , ConstantSInt);
272    GET_CONST_VAL(UInt   , ConstantUInt);
273    GET_CONST_VAL(Int    , ConstantSInt);
274    GET_CONST_VAL(ULong  , ConstantUInt);
275    GET_CONST_VAL(Long   , ConstantSInt);
276    GET_CONST_VAL(Float  , ConstantFP);
277    GET_CONST_VAL(Double , ConstantFP);
278#undef GET_CONST_VAL
279  case Type::PointerTyID:
280    if (isa<ConstantPointerNull>(C))
281      Result.PointerVal = 0;
282    else if (const Function *F = dyn_cast<Function>(C))
283      Result = PTOGV(getPointerToFunctionOrStub(const_cast<Function*>(F)));
284    else if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C))
285      Result = PTOGV(getOrEmitGlobalVariable(const_cast<GlobalVariable*>(GV)));
286    else
287      assert(0 && "Unknown constant pointer type!");
288    break;
289  default:
290    std::cout << "ERROR: Constant unimp for type: " << *C->getType() << "\n";
291    abort();
292  }
293  return Result;
294}
295
296/// FIXME: document
297///
298void ExecutionEngine::StoreValueToMemory(GenericValue Val, GenericValue *Ptr,
299                                         const Type *Ty) {
300  if (getTargetData().isLittleEndian()) {
301    switch (Ty->getTypeID()) {
302    case Type::BoolTyID:
303    case Type::UByteTyID:
304    case Type::SByteTyID:   Ptr->Untyped[0] = Val.UByteVal; break;
305    case Type::UShortTyID:
306    case Type::ShortTyID:   Ptr->Untyped[0] = Val.UShortVal & 255;
307                            Ptr->Untyped[1] = (Val.UShortVal >> 8) & 255;
308                            break;
309    Store4BytesLittleEndian:
310    case Type::FloatTyID:
311    case Type::UIntTyID:
312    case Type::IntTyID:     Ptr->Untyped[0] =  Val.UIntVal        & 255;
313                            Ptr->Untyped[1] = (Val.UIntVal >>  8) & 255;
314                            Ptr->Untyped[2] = (Val.UIntVal >> 16) & 255;
315                            Ptr->Untyped[3] = (Val.UIntVal >> 24) & 255;
316                            break;
317    case Type::PointerTyID: if (getTargetData().getPointerSize() == 4)
318                              goto Store4BytesLittleEndian;
319    case Type::DoubleTyID:
320    case Type::ULongTyID:
321    case Type::LongTyID:    Ptr->Untyped[0] =  Val.ULongVal        & 255;
322                            Ptr->Untyped[1] = (Val.ULongVal >>  8) & 255;
323                            Ptr->Untyped[2] = (Val.ULongVal >> 16) & 255;
324                            Ptr->Untyped[3] = (Val.ULongVal >> 24) & 255;
325                            Ptr->Untyped[4] = (Val.ULongVal >> 32) & 255;
326                            Ptr->Untyped[5] = (Val.ULongVal >> 40) & 255;
327                            Ptr->Untyped[6] = (Val.ULongVal >> 48) & 255;
328                            Ptr->Untyped[7] = (Val.ULongVal >> 56) & 255;
329                            break;
330    default:
331      std::cout << "Cannot store value of type " << *Ty << "!\n";
332    }
333  } else {
334    switch (Ty->getTypeID()) {
335    case Type::BoolTyID:
336    case Type::UByteTyID:
337    case Type::SByteTyID:   Ptr->Untyped[0] = Val.UByteVal; break;
338    case Type::UShortTyID:
339    case Type::ShortTyID:   Ptr->Untyped[1] = Val.UShortVal & 255;
340                            Ptr->Untyped[0] = (Val.UShortVal >> 8) & 255;
341                            break;
342    Store4BytesBigEndian:
343    case Type::FloatTyID:
344    case Type::UIntTyID:
345    case Type::IntTyID:     Ptr->Untyped[3] =  Val.UIntVal        & 255;
346                            Ptr->Untyped[2] = (Val.UIntVal >>  8) & 255;
347                            Ptr->Untyped[1] = (Val.UIntVal >> 16) & 255;
348                            Ptr->Untyped[0] = (Val.UIntVal >> 24) & 255;
349                            break;
350    case Type::PointerTyID: if (getTargetData().getPointerSize() == 4)
351                              goto Store4BytesBigEndian;
352    case Type::DoubleTyID:
353    case Type::ULongTyID:
354    case Type::LongTyID:    Ptr->Untyped[7] =  Val.ULongVal        & 255;
355                            Ptr->Untyped[6] = (Val.ULongVal >>  8) & 255;
356                            Ptr->Untyped[5] = (Val.ULongVal >> 16) & 255;
357                            Ptr->Untyped[4] = (Val.ULongVal >> 24) & 255;
358                            Ptr->Untyped[3] = (Val.ULongVal >> 32) & 255;
359                            Ptr->Untyped[2] = (Val.ULongVal >> 40) & 255;
360                            Ptr->Untyped[1] = (Val.ULongVal >> 48) & 255;
361                            Ptr->Untyped[0] = (Val.ULongVal >> 56) & 255;
362                            break;
363    default:
364      std::cout << "Cannot store value of type " << *Ty << "!\n";
365    }
366  }
367}
368
369/// FIXME: document
370///
371GenericValue ExecutionEngine::LoadValueFromMemory(GenericValue *Ptr,
372                                                  const Type *Ty) {
373  GenericValue Result;
374  if (getTargetData().isLittleEndian()) {
375    switch (Ty->getTypeID()) {
376    case Type::BoolTyID:
377    case Type::UByteTyID:
378    case Type::SByteTyID:   Result.UByteVal = Ptr->Untyped[0]; break;
379    case Type::UShortTyID:
380    case Type::ShortTyID:   Result.UShortVal = (unsigned)Ptr->Untyped[0] |
381                                              ((unsigned)Ptr->Untyped[1] << 8);
382                            break;
383    Load4BytesLittleEndian:
384    case Type::FloatTyID:
385    case Type::UIntTyID:
386    case Type::IntTyID:     Result.UIntVal = (unsigned)Ptr->Untyped[0] |
387                                            ((unsigned)Ptr->Untyped[1] <<  8) |
388                                            ((unsigned)Ptr->Untyped[2] << 16) |
389                                            ((unsigned)Ptr->Untyped[3] << 24);
390                            break;
391    case Type::PointerTyID: if (getTargetData().getPointerSize() == 4)
392                              goto Load4BytesLittleEndian;
393    case Type::DoubleTyID:
394    case Type::ULongTyID:
395    case Type::LongTyID:    Result.ULongVal = (uint64_t)Ptr->Untyped[0] |
396                                             ((uint64_t)Ptr->Untyped[1] <<  8) |
397                                             ((uint64_t)Ptr->Untyped[2] << 16) |
398                                             ((uint64_t)Ptr->Untyped[3] << 24) |
399                                             ((uint64_t)Ptr->Untyped[4] << 32) |
400                                             ((uint64_t)Ptr->Untyped[5] << 40) |
401                                             ((uint64_t)Ptr->Untyped[6] << 48) |
402                                             ((uint64_t)Ptr->Untyped[7] << 56);
403                            break;
404    default:
405      std::cout << "Cannot load value of type " << *Ty << "!\n";
406      abort();
407    }
408  } else {
409    switch (Ty->getTypeID()) {
410    case Type::BoolTyID:
411    case Type::UByteTyID:
412    case Type::SByteTyID:   Result.UByteVal = Ptr->Untyped[0]; break;
413    case Type::UShortTyID:
414    case Type::ShortTyID:   Result.UShortVal = (unsigned)Ptr->Untyped[1] |
415                                              ((unsigned)Ptr->Untyped[0] << 8);
416                            break;
417    Load4BytesBigEndian:
418    case Type::FloatTyID:
419    case Type::UIntTyID:
420    case Type::IntTyID:     Result.UIntVal = (unsigned)Ptr->Untyped[3] |
421                                            ((unsigned)Ptr->Untyped[2] <<  8) |
422                                            ((unsigned)Ptr->Untyped[1] << 16) |
423                                            ((unsigned)Ptr->Untyped[0] << 24);
424                            break;
425    case Type::PointerTyID: if (getTargetData().getPointerSize() == 4)
426                              goto Load4BytesBigEndian;
427    case Type::DoubleTyID:
428    case Type::ULongTyID:
429    case Type::LongTyID:    Result.ULongVal = (uint64_t)Ptr->Untyped[7] |
430                                             ((uint64_t)Ptr->Untyped[6] <<  8) |
431                                             ((uint64_t)Ptr->Untyped[5] << 16) |
432                                             ((uint64_t)Ptr->Untyped[4] << 24) |
433                                             ((uint64_t)Ptr->Untyped[3] << 32) |
434                                             ((uint64_t)Ptr->Untyped[2] << 40) |
435                                             ((uint64_t)Ptr->Untyped[1] << 48) |
436                                             ((uint64_t)Ptr->Untyped[0] << 56);
437                            break;
438    default:
439      std::cout << "Cannot load value of type " << *Ty << "!\n";
440      abort();
441    }
442  }
443  return Result;
444}
445
446// InitializeMemory - Recursive function to apply a Constant value into the
447// specified memory location...
448//
449void ExecutionEngine::InitializeMemory(const Constant *Init, void *Addr) {
450  if (isa<UndefValue>(Init)) {
451    // FIXME: THIS SHOULD NOT BE NEEDED.
452    unsigned Size = getTargetData().getTypeSize(Init->getType());
453    memset(Addr, 0, Size);
454    return;
455  } else if (Init->getType()->isFirstClassType()) {
456    GenericValue Val = getConstantValue(Init);
457    StoreValueToMemory(Val, (GenericValue*)Addr, Init->getType());
458    return;
459  } else if (isa<ConstantAggregateZero>(Init)) {
460    unsigned Size = getTargetData().getTypeSize(Init->getType());
461    memset(Addr, 0, Size);
462    return;
463  }
464
465  switch (Init->getType()->getTypeID()) {
466  case Type::ArrayTyID: {
467    const ConstantArray *CPA = cast<ConstantArray>(Init);
468    unsigned ElementSize =
469      getTargetData().getTypeSize(cast<ArrayType>(CPA->getType())->getElementType());
470    for (unsigned i = 0, e = CPA->getNumOperands(); i != e; ++i)
471      InitializeMemory(CPA->getOperand(i), (char*)Addr+i*ElementSize);
472    return;
473  }
474
475  case Type::StructTyID: {
476    const ConstantStruct *CPS = cast<ConstantStruct>(Init);
477    const StructLayout *SL =
478      getTargetData().getStructLayout(cast<StructType>(CPS->getType()));
479    for (unsigned i = 0, e = CPS->getNumOperands(); i != e; ++i)
480      InitializeMemory(CPS->getOperand(i), (char*)Addr+SL->MemberOffsets[i]);
481    return;
482  }
483
484  default:
485    std::cerr << "Bad Type: " << *Init->getType() << "\n";
486    assert(0 && "Unknown constant type to initialize memory with!");
487  }
488}
489
490/// EmitGlobals - Emit all of the global variables to memory, storing their
491/// addresses into GlobalAddress.  This must make sure to copy the contents of
492/// their initializers into the memory.
493///
494void ExecutionEngine::emitGlobals() {
495  const TargetData &TD = getTargetData();
496
497  // Loop over all of the global variables in the program, allocating the memory
498  // to hold them.
499  for (Module::giterator I = getModule().gbegin(), E = getModule().gend();
500       I != E; ++I)
501    if (!I->isExternal()) {
502      // Get the type of the global...
503      const Type *Ty = I->getType()->getElementType();
504
505      // Allocate some memory for it!
506      unsigned Size = TD.getTypeSize(Ty);
507      addGlobalMapping(I, new char[Size]);
508    } else {
509      // External variable reference. Try to use the dynamic loader to
510      // get a pointer to it.
511      if (void *SymAddr = sys::DynamicLibrary::SearchForAddressOfSymbol(
512                            I->getName().c_str()))
513        addGlobalMapping(I, SymAddr);
514      else {
515        std::cerr << "Could not resolve external global address: "
516                  << I->getName() << "\n";
517        abort();
518      }
519    }
520
521  // Now that all of the globals are set up in memory, loop through them all and
522  // initialize their contents.
523  for (Module::giterator I = getModule().gbegin(), E = getModule().gend();
524       I != E; ++I)
525    if (!I->isExternal())
526      EmitGlobalVariable(I);
527}
528
529// EmitGlobalVariable - This method emits the specified global variable to the
530// address specified in GlobalAddresses, or allocates new memory if it's not
531// already in the map.
532void ExecutionEngine::EmitGlobalVariable(const GlobalVariable *GV) {
533  void *GA = getPointerToGlobalIfAvailable(GV);
534  DEBUG(std::cerr << "Global '" << GV->getName() << "' -> " << GA << "\n");
535
536  const Type *ElTy = GV->getType()->getElementType();
537  unsigned GVSize = getTargetData().getTypeSize(ElTy);
538  if (GA == 0) {
539    // If it's not already specified, allocate memory for the global.
540    GA = new char[GVSize];
541    addGlobalMapping(GV, GA);
542  }
543
544  InitializeMemory(GV->getInitializer(), GA);
545  NumInitBytes += GVSize;
546  ++NumGlobals;
547}
548