1 //===-- JIT.cpp - LLVM Just in Time Compiler ------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This tool implements a just-in-time compiler for LLVM, allowing direct
11 // execution of LLVM bitcode in an efficient manner.
13 //===----------------------------------------------------------------------===//
16 #include "llvm/Constants.h"
17 #include "llvm/DerivedTypes.h"
18 #include "llvm/Function.h"
19 #include "llvm/GlobalVariable.h"
20 #include "llvm/Instructions.h"
21 #include "llvm/ModuleProvider.h"
22 #include "llvm/CodeGen/JITCodeEmitter.h"
23 #include "llvm/CodeGen/MachineCodeInfo.h"
24 #include "llvm/ExecutionEngine/GenericValue.h"
25 #include "llvm/ExecutionEngine/JITEventListener.h"
26 #include "llvm/Target/TargetData.h"
27 #include "llvm/Target/TargetMachine.h"
28 #include "llvm/Target/TargetJITInfo.h"
29 #include "llvm/Support/Dwarf.h"
30 #include "llvm/Support/ErrorHandling.h"
31 #include "llvm/Support/MutexGuard.h"
32 #include "llvm/System/DynamicLibrary.h"
33 #include "llvm/Config/config.h"
38 // Apple gcc defaults to -fuse-cxa-atexit (i.e. calls __cxa_atexit instead
39 // of atexit). It passes the address of linker generated symbol __dso_handle
41 // This configuration change happened at version 5330.
42 # include <AvailabilityMacros.h>
43 # if defined(MAC_OS_X_VERSION_10_4) && \
44 ((MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4) || \
45 (MAC_OS_X_VERSION_MIN_REQUIRED == MAC_OS_X_VERSION_10_4 && \
46 __APPLE_CC__ >= 5330))
47 # ifndef HAVE___DSO_HANDLE
48 # define HAVE___DSO_HANDLE 1
54 extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
59 static struct RegisterJIT {
60 RegisterJIT() { JIT::Register(); }
65 extern "C" void LLVMLinkInJIT() {
69 #if defined(__GNUC__) && !defined(__ARM__EABI__)
71 // libgcc defines the __register_frame function to dynamically register new
72 // dwarf frames for exception handling. This functionality is not portable
73 // across compilers and is only provided by GCC. We use the __register_frame
74 // function here so that code generated by the JIT cooperates with the unwinding
75 // runtime of libgcc. When JITting with exception handling enable, LLVM
76 // generates dwarf frames and registers it to libgcc with __register_frame.
78 // The __register_frame function works with Linux.
80 // Unfortunately, this functionality seems to be in libgcc after the unwinding
81 // library of libgcc for darwin was written. The code for darwin overwrites the
82 // value updated by __register_frame with a value fetched with "keymgr".
83 // "keymgr" is an obsolete functionality, which should be rewritten some day.
84 // In the meantime, since "keymgr" is on all libgccs shipped with apple-gcc, we
85 // need a workaround in LLVM which uses the "keymgr" to dynamically modify the
86 // values of an opaque key, used by libgcc to find dwarf tables.
88 extern "C" void __register_frame(void*);
90 #if defined(__APPLE__) && MAC_OS_X_VERSION_MAX_ALLOWED <= 1050
100 // LibgccObject - This is the structure defined in libgcc. There is no #include
101 // provided for this structure, so we also define it here. libgcc calls it
102 // "struct object". The structure is undocumented in libgcc.
103 struct LibgccObject {
108 /// frame - Pointer to the exception table.
111 /// encoding - The encoding of the object?
114 unsigned long sorted : 1;
115 unsigned long from_array : 1;
116 unsigned long mixed_encoding : 1;
117 unsigned long encoding : 8;
118 unsigned long count : 21;
123 /// fde_end - libgcc defines this field only if some macro is defined. We
124 /// include this field even if it may not there, to make libgcc happy.
127 /// next - At least we know it's a chained list!
128 struct LibgccObject *next;
131 // "kemgr" stuff. Apparently, all frame tables are stored there.
132 extern "C" void _keymgr_set_and_unlock_processwide_ptr(int, void *);
133 extern "C" void *_keymgr_get_and_lock_processwide_ptr(int);
134 #define KEYMGR_GCC3_DW2_OBJ_LIST 302 /* Dwarf2 object list */
136 /// LibgccObjectInfo - libgcc defines this struct as km_object_info. It
137 /// probably contains all dwarf tables that are loaded.
138 struct LibgccObjectInfo {
140 /// seenObjects - LibgccObjects already parsed by the unwinding runtime.
142 struct LibgccObject* seenObjects;
144 /// unseenObjects - LibgccObjects not parsed yet by the unwinding runtime.
146 struct LibgccObject* unseenObjects;
151 /// darwin_register_frame - Since __register_frame does not work with darwin's
152 /// libgcc,we provide our own function, which "tricks" libgcc by modifying the
153 /// "Dwarf2 object list" key.
154 void DarwinRegisterFrame(void* FrameBegin) {
156 LibgccObjectInfo* LOI = (struct LibgccObjectInfo*)
157 _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST);
158 assert(LOI && "This should be preallocated by the runtime");
160 // Allocate a new LibgccObject to represent this frame. Deallocation of this
161 // object may be impossible: since darwin code in libgcc was written after
162 // the ability to dynamically register frames, things may crash if we
164 struct LibgccObject* ob = (struct LibgccObject*)
165 malloc(sizeof(struct LibgccObject));
167 // Do like libgcc for the values of the field.
168 ob->unused1 = (void *)-1;
171 ob->frame = FrameBegin;
173 ob->encoding.b.encoding = llvm::dwarf::DW_EH_PE_omit;
175 // Put the info on both places, as libgcc uses the first or the the second
176 // field. Note that we rely on having two pointers here. If fde_end was a
177 // char, things would get complicated.
178 ob->fde_end = (char*)LOI->unseenObjects;
179 ob->next = LOI->unseenObjects;
181 // Update the key's unseenObjects list.
182 LOI->unseenObjects = ob;
184 // Finally update the "key". Apparently, libgcc requires it.
185 _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST,
194 /// createJIT - This is the factory method for creating a JIT for the current
195 /// machine, it does not fall back to the interpreter. This takes ownership
196 /// of the module provider.
197 ExecutionEngine *ExecutionEngine::createJIT(ModuleProvider *MP,
198 std::string *ErrorStr,
199 JITMemoryManager *JMM,
200 CodeGenOpt::Level OptLevel,
202 ExecutionEngine *EE = JIT::createJIT(MP, ErrorStr, JMM, OptLevel,
206 // Make sure we can resolve symbols in the program as well. The zero arg
207 // to the function tells DynamicLibrary to load the program, not a library.
208 sys::DynamicLibrary::LoadLibraryPermanently(0, ErrorStr);
212 JIT::JIT(ModuleProvider *MP, TargetMachine &tm, TargetJITInfo &tji,
213 JITMemoryManager *JMM, CodeGenOpt::Level OptLevel, bool GVsWithCode)
214 : ExecutionEngine(MP), TM(tm), TJI(tji), AllocateGVsWithCode(GVsWithCode) {
215 setTargetData(TM.getTargetData());
217 jitstate = new JITState(MP);
220 JCE = createEmitter(*this, JMM);
223 MutexGuard locked(lock);
224 FunctionPassManager &PM = jitstate->getPM(locked);
225 PM.add(new TargetData(*TM.getTargetData()));
227 // Turn the machine code intermediate representation into bytes in memory that
229 if (TM.addPassesToEmitMachineCode(PM, *JCE, OptLevel)) {
230 llvm_report_error("Target does not support machine code emission!");
233 // Register routine for informing unwinding runtime about new EH frames
234 #if defined(__GNUC__) && !defined(__ARM_EABI__)
236 struct LibgccObjectInfo* LOI = (struct LibgccObjectInfo*)
237 _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST);
239 // The key is created on demand, and libgcc creates it the first time an
240 // exception occurs. Since we need the key to register frames, we create
243 LOI = (LibgccObjectInfo*)calloc(sizeof(struct LibgccObjectInfo), 1);
244 _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST, LOI);
245 InstallExceptionTableRegister(DarwinRegisterFrame);
247 InstallExceptionTableRegister(__register_frame);
251 // Initialize passes.
252 PM.doInitialization();
261 /// addModuleProvider - Add a new ModuleProvider to the JIT. If we previously
262 /// removed the last ModuleProvider, we need re-initialize jitstate with a valid
264 void JIT::addModuleProvider(ModuleProvider *MP) {
265 MutexGuard locked(lock);
267 if (Modules.empty()) {
268 assert(!jitstate && "jitstate should be NULL if Modules vector is empty!");
270 jitstate = new JITState(MP);
272 FunctionPassManager &PM = jitstate->getPM(locked);
273 PM.add(new TargetData(*TM.getTargetData()));
275 // Turn the machine code intermediate representation into bytes in memory
276 // that may be executed.
277 if (TM.addPassesToEmitMachineCode(PM, *JCE, CodeGenOpt::Default)) {
278 llvm_report_error("Target does not support machine code emission!");
281 // Initialize passes.
282 PM.doInitialization();
285 ExecutionEngine::addModuleProvider(MP);
288 /// removeModuleProvider - If we are removing the last ModuleProvider,
289 /// invalidate the jitstate since the PassManager it contains references a
290 /// released ModuleProvider.
291 Module *JIT::removeModuleProvider(ModuleProvider *MP, std::string *E) {
292 Module *result = ExecutionEngine::removeModuleProvider(MP, E);
294 MutexGuard locked(lock);
296 if (jitstate->getMP() == MP) {
301 if (!jitstate && !Modules.empty()) {
302 jitstate = new JITState(Modules[0]);
304 FunctionPassManager &PM = jitstate->getPM(locked);
305 PM.add(new TargetData(*TM.getTargetData()));
307 // Turn the machine code intermediate representation into bytes in memory
308 // that may be executed.
309 if (TM.addPassesToEmitMachineCode(PM, *JCE, CodeGenOpt::Default)) {
310 llvm_report_error("Target does not support machine code emission!");
313 // Initialize passes.
314 PM.doInitialization();
319 /// deleteModuleProvider - Remove a ModuleProvider from the list of modules,
320 /// and deletes the ModuleProvider and owned Module. Avoids materializing
321 /// the underlying module.
322 void JIT::deleteModuleProvider(ModuleProvider *MP, std::string *E) {
323 ExecutionEngine::deleteModuleProvider(MP, E);
325 MutexGuard locked(lock);
327 if (jitstate->getMP() == MP) {
332 if (!jitstate && !Modules.empty()) {
333 jitstate = new JITState(Modules[0]);
335 FunctionPassManager &PM = jitstate->getPM(locked);
336 PM.add(new TargetData(*TM.getTargetData()));
338 // Turn the machine code intermediate representation into bytes in memory
339 // that may be executed.
340 if (TM.addPassesToEmitMachineCode(PM, *JCE, CodeGenOpt::Default)) {
341 llvm_report_error("Target does not support machine code emission!");
344 // Initialize passes.
345 PM.doInitialization();
349 /// run - Start execution with the specified function and arguments.
351 GenericValue JIT::runFunction(Function *F,
352 const std::vector<GenericValue> &ArgValues) {
353 assert(F && "Function *F was null at entry to run()");
354 LLVMContext *Context = F->getContext();
356 void *FPtr = getPointerToFunction(F);
357 assert(FPtr && "Pointer to fn's code was null after getPointerToFunction");
358 const FunctionType *FTy = F->getFunctionType();
359 const Type *RetTy = FTy->getReturnType();
361 assert((FTy->getNumParams() == ArgValues.size() ||
362 (FTy->isVarArg() && FTy->getNumParams() <= ArgValues.size())) &&
363 "Wrong number of arguments passed into function!");
364 assert(FTy->getNumParams() == ArgValues.size() &&
365 "This doesn't support passing arguments through varargs (yet)!");
367 // Handle some common cases first. These cases correspond to common `main'
369 if (RetTy == Type::Int32Ty || RetTy == Type::VoidTy) {
370 switch (ArgValues.size()) {
372 if (FTy->getParamType(0) == Type::Int32Ty &&
373 isa<PointerType>(FTy->getParamType(1)) &&
374 isa<PointerType>(FTy->getParamType(2))) {
375 int (*PF)(int, char **, const char **) =
376 (int(*)(int, char **, const char **))(intptr_t)FPtr;
378 // Call the function.
380 rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
381 (char **)GVTOP(ArgValues[1]),
382 (const char **)GVTOP(ArgValues[2])));
387 if (FTy->getParamType(0) == Type::Int32Ty &&
388 isa<PointerType>(FTy->getParamType(1))) {
389 int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr;
391 // Call the function.
393 rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
394 (char **)GVTOP(ArgValues[1])));
399 if (FTy->getNumParams() == 1 &&
400 FTy->getParamType(0) == Type::Int32Ty) {
402 int (*PF)(int) = (int(*)(int))(intptr_t)FPtr;
403 rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue()));
410 // Handle cases where no arguments are passed first.
411 if (ArgValues.empty()) {
413 switch (RetTy->getTypeID()) {
414 default: llvm_unreachable("Unknown return type for function call!");
415 case Type::IntegerTyID: {
416 unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth();
418 rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)());
419 else if (BitWidth <= 8)
420 rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)());
421 else if (BitWidth <= 16)
422 rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)());
423 else if (BitWidth <= 32)
424 rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)());
425 else if (BitWidth <= 64)
426 rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)());
428 llvm_unreachable("Integer types > 64 bits not supported");
432 rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)());
434 case Type::FloatTyID:
435 rv.FloatVal = ((float(*)())(intptr_t)FPtr)();
437 case Type::DoubleTyID:
438 rv.DoubleVal = ((double(*)())(intptr_t)FPtr)();
440 case Type::X86_FP80TyID:
441 case Type::FP128TyID:
442 case Type::PPC_FP128TyID:
443 llvm_unreachable("long double not supported yet");
445 case Type::PointerTyID:
446 return PTOGV(((void*(*)())(intptr_t)FPtr)());
450 // Okay, this is not one of our quick and easy cases. Because we don't have a
451 // full FFI, we have to codegen a nullary stub function that just calls the
452 // function we are interested in, passing in constants for all of the
453 // arguments. Make this function and return.
455 // First, create the function.
456 FunctionType *STy=Context->getFunctionType(RetTy, false);
457 Function *Stub = Function::Create(STy, Function::InternalLinkage, "",
460 // Insert a basic block.
461 BasicBlock *StubBB = BasicBlock::Create("", Stub);
463 // Convert all of the GenericValue arguments over to constants. Note that we
464 // currently don't support varargs.
465 SmallVector<Value*, 8> Args;
466 for (unsigned i = 0, e = ArgValues.size(); i != e; ++i) {
468 const Type *ArgTy = FTy->getParamType(i);
469 const GenericValue &AV = ArgValues[i];
470 switch (ArgTy->getTypeID()) {
471 default: llvm_unreachable("Unknown argument type for function call!");
472 case Type::IntegerTyID:
473 C = Context->getConstantInt(AV.IntVal);
475 case Type::FloatTyID:
476 C = Context->getConstantFP(APFloat(AV.FloatVal));
478 case Type::DoubleTyID:
479 C = Context->getConstantFP(APFloat(AV.DoubleVal));
481 case Type::PPC_FP128TyID:
482 case Type::X86_FP80TyID:
483 case Type::FP128TyID:
484 C = Context->getConstantFP(APFloat(AV.IntVal));
486 case Type::PointerTyID:
487 void *ArgPtr = GVTOP(AV);
488 if (sizeof(void*) == 4)
489 C = Context->getConstantInt(Type::Int32Ty, (int)(intptr_t)ArgPtr);
491 C = Context->getConstantInt(Type::Int64Ty, (intptr_t)ArgPtr);
492 // Cast the integer to pointer
493 C = Context->getConstantExprIntToPtr(C, ArgTy);
499 CallInst *TheCall = CallInst::Create(F, Args.begin(), Args.end(),
501 TheCall->setCallingConv(F->getCallingConv());
502 TheCall->setTailCall();
503 if (TheCall->getType() != Type::VoidTy)
504 ReturnInst::Create(TheCall, StubBB); // Return result of the call.
506 ReturnInst::Create(StubBB); // Just return void.
508 // Finally, return the value returned by our nullary stub function.
509 return runFunction(Stub, std::vector<GenericValue>());
512 void JIT::RegisterJITEventListener(JITEventListener *L) {
515 MutexGuard locked(lock);
516 EventListeners.push_back(L);
518 void JIT::UnregisterJITEventListener(JITEventListener *L) {
521 MutexGuard locked(lock);
522 std::vector<JITEventListener*>::reverse_iterator I=
523 std::find(EventListeners.rbegin(), EventListeners.rend(), L);
524 if (I != EventListeners.rend()) {
525 std::swap(*I, EventListeners.back());
526 EventListeners.pop_back();
529 void JIT::NotifyFunctionEmitted(
531 void *Code, size_t Size,
532 const JITEvent_EmittedFunctionDetails &Details) {
533 MutexGuard locked(lock);
534 for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) {
535 EventListeners[I]->NotifyFunctionEmitted(F, Code, Size, Details);
539 void JIT::NotifyFreeingMachineCode(const Function &F, void *OldPtr) {
540 MutexGuard locked(lock);
541 for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) {
542 EventListeners[I]->NotifyFreeingMachineCode(F, OldPtr);
546 /// runJITOnFunction - Run the FunctionPassManager full of
547 /// just-in-time compilation passes on F, hopefully filling in
548 /// GlobalAddress[F] with the address of F's machine code.
550 void JIT::runJITOnFunction(Function *F, MachineCodeInfo *MCI) {
551 MutexGuard locked(lock);
553 class MCIListener : public JITEventListener {
554 MachineCodeInfo *const MCI;
556 MCIListener(MachineCodeInfo *mci) : MCI(mci) {}
557 virtual void NotifyFunctionEmitted(const Function &,
558 void *Code, size_t Size,
559 const EmittedFunctionDetails &) {
560 MCI->setAddress(Code);
564 MCIListener MCIL(MCI);
565 RegisterJITEventListener(&MCIL);
567 runJITOnFunctionUnlocked(F, locked);
569 UnregisterJITEventListener(&MCIL);
572 void JIT::runJITOnFunctionUnlocked(Function *F, const MutexGuard &locked) {
573 static bool isAlreadyCodeGenerating = false;
574 assert(!isAlreadyCodeGenerating && "Error: Recursive compilation detected!");
577 isAlreadyCodeGenerating = true;
578 jitstate->getPM(locked).run(*F);
579 isAlreadyCodeGenerating = false;
581 // If the function referred to another function that had not yet been
582 // read from bitcode, but we are jitting non-lazily, emit it now.
583 while (!jitstate->getPendingFunctions(locked).empty()) {
584 Function *PF = jitstate->getPendingFunctions(locked).back();
585 jitstate->getPendingFunctions(locked).pop_back();
588 isAlreadyCodeGenerating = true;
589 jitstate->getPM(locked).run(*PF);
590 isAlreadyCodeGenerating = false;
592 // Now that the function has been jitted, ask the JITEmitter to rewrite
593 // the stub with real address of the function.
594 updateFunctionStub(PF);
597 // If the JIT is configured to emit info so that dlsym can be used to
598 // rewrite stubs to external globals, do so now.
599 if (areDlsymStubsEnabled() && isLazyCompilationDisabled())
600 updateDlsymStubTable();
603 /// getPointerToFunction - This method is used to get the address of the
604 /// specified function, compiling it if neccesary.
606 void *JIT::getPointerToFunction(Function *F) {
608 if (void *Addr = getPointerToGlobalIfAvailable(F))
609 return Addr; // Check if function already code gen'd
611 MutexGuard locked(lock);
613 // Now that this thread owns the lock, check if another thread has already
614 // code gen'd the function.
615 if (void *Addr = getPointerToGlobalIfAvailable(F))
618 // Make sure we read in the function if it exists in this Module.
619 if (F->hasNotBeenReadFromBitcode()) {
620 // Determine the module provider this function is provided by.
621 Module *M = F->getParent();
622 ModuleProvider *MP = 0;
623 for (unsigned i = 0, e = Modules.size(); i != e; ++i) {
624 if (Modules[i]->getModule() == M) {
629 assert(MP && "Function isn't in a module we know about!");
631 std::string ErrorMsg;
632 if (MP->materializeFunction(F, &ErrorMsg)) {
633 llvm_report_error("Error reading function '" + F->getName()+
634 "' from bitcode file: " + ErrorMsg);
637 // Now retry to get the address.
638 if (void *Addr = getPointerToGlobalIfAvailable(F))
642 if (F->isDeclaration()) {
643 bool AbortOnFailure =
644 !areDlsymStubsEnabled() && !F->hasExternalWeakLinkage();
645 void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure);
646 addGlobalMapping(F, Addr);
650 runJITOnFunctionUnlocked(F, locked);
652 void *Addr = getPointerToGlobalIfAvailable(F);
653 assert(Addr && "Code generation didn't add function to GlobalAddress table!");
657 /// getOrEmitGlobalVariable - Return the address of the specified global
658 /// variable, possibly emitting it to memory if needed. This is used by the
660 void *JIT::getOrEmitGlobalVariable(const GlobalVariable *GV) {
661 MutexGuard locked(lock);
663 void *Ptr = getPointerToGlobalIfAvailable(GV);
666 // If the global is external, just remember the address.
667 if (GV->isDeclaration()) {
668 #if HAVE___DSO_HANDLE
669 if (GV->getName() == "__dso_handle")
670 return (void*)&__dso_handle;
672 Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(GV->getName().c_str());
673 if (Ptr == 0 && !areDlsymStubsEnabled()) {
674 llvm_report_error("Could not resolve external global address: "
677 addGlobalMapping(GV, Ptr);
679 // If the global hasn't been emitted to memory yet, allocate space and
680 // emit it into memory.
681 Ptr = getMemoryForGV(GV);
682 addGlobalMapping(GV, Ptr);
683 EmitGlobalVariable(GV); // Initialize the variable.
688 /// recompileAndRelinkFunction - This method is used to force a function
689 /// which has already been compiled, to be compiled again, possibly
690 /// after it has been modified. Then the entry to the old copy is overwritten
691 /// with a branch to the new copy. If there was no old copy, this acts
692 /// just like JIT::getPointerToFunction().
694 void *JIT::recompileAndRelinkFunction(Function *F) {
695 void *OldAddr = getPointerToGlobalIfAvailable(F);
697 // If it's not already compiled there is no reason to patch it up.
698 if (OldAddr == 0) { return getPointerToFunction(F); }
700 // Delete the old function mapping.
701 addGlobalMapping(F, 0);
703 // Recodegen the function
706 // Update state, forward the old function to the new function.
707 void *Addr = getPointerToGlobalIfAvailable(F);
708 assert(Addr && "Code generation didn't add function to GlobalAddress table!");
709 TJI.replaceMachineCodeForFunction(OldAddr, Addr);
713 /// getMemoryForGV - This method abstracts memory allocation of global
714 /// variable so that the JIT can allocate thread local variables depending
717 char* JIT::getMemoryForGV(const GlobalVariable* GV) {
720 // GlobalVariable's which are not "constant" will cause trouble in a server
721 // situation. It's returned in the same block of memory as code which may
723 if (isGVCompilationDisabled() && !GV->isConstant()) {
724 llvm_report_error("Compilation of non-internal GlobalValue is disabled!");
727 // Some applications require globals and code to live together, so they may
728 // be allocated into the same buffer, but in general globals are allocated
729 // through the memory manager which puts them near the code but not in the
731 const Type *GlobalType = GV->getType()->getElementType();
732 size_t S = getTargetData()->getTypeAllocSize(GlobalType);
733 size_t A = getTargetData()->getPreferredAlignment(GV);
734 if (GV->isThreadLocal()) {
735 MutexGuard locked(lock);
736 Ptr = TJI.allocateThreadLocalMemory(S);
737 } else if (TJI.allocateSeparateGVMemory()) {
739 Ptr = (char*)malloc(S);
741 // Allocate S+A bytes of memory, then use an aligned pointer within that
743 Ptr = (char*)malloc(S+A);
744 unsigned MisAligned = ((intptr_t)Ptr & (A-1));
745 Ptr = Ptr + (MisAligned ? (A-MisAligned) : 0);
747 } else if (AllocateGVsWithCode) {
748 Ptr = (char*)JCE->allocateSpace(S, A);
750 Ptr = (char*)JCE->allocateGlobal(S, A);
755 void JIT::addPendingFunction(Function *F) {
756 MutexGuard locked(lock);
757 jitstate->getPendingFunctions(locked).push_back(F);
761 JITEventListener::~JITEventListener() {}