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Current File : //usr/src/contrib/llvm/lib/ExecutionEngine/JIT/JIT.cpp |
//===-- JIT.cpp - LLVM Just in Time Compiler ------------------------------===// // // The LLVM Compiler Infrastructure // // This file is distributed under the University of Illinois Open Source // License. See LICENSE.TXT for details. // //===----------------------------------------------------------------------===// // // This tool implements a just-in-time compiler for LLVM, allowing direct // execution of LLVM bitcode in an efficient manner. // //===----------------------------------------------------------------------===// #include "JIT.h" #include "llvm/Constants.h" #include "llvm/DerivedTypes.h" #include "llvm/Function.h" #include "llvm/GlobalVariable.h" #include "llvm/Instructions.h" #include "llvm/ADT/SmallPtrSet.h" #include "llvm/CodeGen/JITCodeEmitter.h" #include "llvm/CodeGen/MachineCodeInfo.h" #include "llvm/ExecutionEngine/GenericValue.h" #include "llvm/ExecutionEngine/JITEventListener.h" #include "llvm/ExecutionEngine/JITMemoryManager.h" #include "llvm/Target/TargetData.h" #include "llvm/Target/TargetMachine.h" #include "llvm/Target/TargetJITInfo.h" #include "llvm/Support/Dwarf.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/ManagedStatic.h" #include "llvm/Support/MutexGuard.h" #include "llvm/Support/DynamicLibrary.h" #include "llvm/Config/config.h" using namespace llvm; #ifdef __APPLE__ // Apple gcc defaults to -fuse-cxa-atexit (i.e. calls __cxa_atexit instead // of atexit). It passes the address of linker generated symbol __dso_handle // to the function. // This configuration change happened at version 5330. # include <AvailabilityMacros.h> # if defined(MAC_OS_X_VERSION_10_4) && \ ((MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4) || \ (MAC_OS_X_VERSION_MIN_REQUIRED == MAC_OS_X_VERSION_10_4 && \ __APPLE_CC__ >= 5330)) # ifndef HAVE___DSO_HANDLE # define HAVE___DSO_HANDLE 1 # endif # endif #endif #if HAVE___DSO_HANDLE extern void *__dso_handle __attribute__ ((__visibility__ ("hidden"))); #endif namespace { static struct RegisterJIT { RegisterJIT() { JIT::Register(); } } JITRegistrator; } extern "C" void LLVMLinkInJIT() { } // Determine whether we can register EH tables. #if (defined(__GNUC__) && !defined(__ARM_EABI__) && \ !defined(__USING_SJLJ_EXCEPTIONS__)) #define HAVE_EHTABLE_SUPPORT 1 #else #define HAVE_EHTABLE_SUPPORT 0 #endif #if HAVE_EHTABLE_SUPPORT // libgcc defines the __register_frame function to dynamically register new // dwarf frames for exception handling. This functionality is not portable // across compilers and is only provided by GCC. We use the __register_frame // function here so that code generated by the JIT cooperates with the unwinding // runtime of libgcc. When JITting with exception handling enable, LLVM // generates dwarf frames and registers it to libgcc with __register_frame. // // The __register_frame function works with Linux. // // Unfortunately, this functionality seems to be in libgcc after the unwinding // library of libgcc for darwin was written. The code for darwin overwrites the // value updated by __register_frame with a value fetched with "keymgr". // "keymgr" is an obsolete functionality, which should be rewritten some day. // In the meantime, since "keymgr" is on all libgccs shipped with apple-gcc, we // need a workaround in LLVM which uses the "keymgr" to dynamically modify the // values of an opaque key, used by libgcc to find dwarf tables. extern "C" void __register_frame(void*); extern "C" void __deregister_frame(void*); #if defined(__APPLE__) && MAC_OS_X_VERSION_MAX_ALLOWED <= 1050 # define USE_KEYMGR 1 #else # define USE_KEYMGR 0 #endif #if USE_KEYMGR namespace { // LibgccObject - This is the structure defined in libgcc. There is no #include // provided for this structure, so we also define it here. libgcc calls it // "struct object". The structure is undocumented in libgcc. struct LibgccObject { void *unused1; void *unused2; void *unused3; /// frame - Pointer to the exception table. void *frame; /// encoding - The encoding of the object? union { struct { unsigned long sorted : 1; unsigned long from_array : 1; unsigned long mixed_encoding : 1; unsigned long encoding : 8; unsigned long count : 21; } b; size_t i; } encoding; /// fde_end - libgcc defines this field only if some macro is defined. We /// include this field even if it may not there, to make libgcc happy. char *fde_end; /// next - At least we know it's a chained list! struct LibgccObject *next; }; // "kemgr" stuff. Apparently, all frame tables are stored there. extern "C" void _keymgr_set_and_unlock_processwide_ptr(int, void *); extern "C" void *_keymgr_get_and_lock_processwide_ptr(int); #define KEYMGR_GCC3_DW2_OBJ_LIST 302 /* Dwarf2 object list */ /// LibgccObjectInfo - libgcc defines this struct as km_object_info. It /// probably contains all dwarf tables that are loaded. struct LibgccObjectInfo { /// seenObjects - LibgccObjects already parsed by the unwinding runtime. /// struct LibgccObject* seenObjects; /// unseenObjects - LibgccObjects not parsed yet by the unwinding runtime. /// struct LibgccObject* unseenObjects; unsigned unused[2]; }; /// darwin_register_frame - Since __register_frame does not work with darwin's /// libgcc,we provide our own function, which "tricks" libgcc by modifying the /// "Dwarf2 object list" key. void DarwinRegisterFrame(void* FrameBegin) { // Get the key. LibgccObjectInfo* LOI = (struct LibgccObjectInfo*) _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST); assert(LOI && "This should be preallocated by the runtime"); // Allocate a new LibgccObject to represent this frame. Deallocation of this // object may be impossible: since darwin code in libgcc was written after // the ability to dynamically register frames, things may crash if we // deallocate it. struct LibgccObject* ob = (struct LibgccObject*) malloc(sizeof(struct LibgccObject)); // Do like libgcc for the values of the field. ob->unused1 = (void *)-1; ob->unused2 = 0; ob->unused3 = 0; ob->frame = FrameBegin; ob->encoding.i = 0; ob->encoding.b.encoding = llvm::dwarf::DW_EH_PE_omit; // Put the info on both places, as libgcc uses the first or the second // field. Note that we rely on having two pointers here. If fde_end was a // char, things would get complicated. ob->fde_end = (char*)LOI->unseenObjects; ob->next = LOI->unseenObjects; // Update the key's unseenObjects list. LOI->unseenObjects = ob; // Finally update the "key". Apparently, libgcc requires it. _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST, LOI); } } #endif // __APPLE__ #endif // HAVE_EHTABLE_SUPPORT /// createJIT - This is the factory method for creating a JIT for the current /// machine, it does not fall back to the interpreter. This takes ownership /// of the module. ExecutionEngine *JIT::createJIT(Module *M, std::string *ErrorStr, JITMemoryManager *JMM, bool GVsWithCode, TargetMachine *TM) { // Try to register the program as a source of symbols to resolve against. // // FIXME: Don't do this here. sys::DynamicLibrary::LoadLibraryPermanently(0, NULL); // If the target supports JIT code generation, create the JIT. if (TargetJITInfo *TJ = TM->getJITInfo()) { return new JIT(M, *TM, *TJ, JMM, GVsWithCode); } else { if (ErrorStr) *ErrorStr = "target does not support JIT code generation"; return 0; } } namespace { /// This class supports the global getPointerToNamedFunction(), which allows /// bugpoint or gdb users to search for a function by name without any context. class JitPool { SmallPtrSet<JIT*, 1> JITs; // Optimize for process containing just 1 JIT. mutable sys::Mutex Lock; public: void Add(JIT *jit) { MutexGuard guard(Lock); JITs.insert(jit); } void Remove(JIT *jit) { MutexGuard guard(Lock); JITs.erase(jit); } void *getPointerToNamedFunction(const char *Name) const { MutexGuard guard(Lock); assert(JITs.size() != 0 && "No Jit registered"); //search function in every instance of JIT for (SmallPtrSet<JIT*, 1>::const_iterator Jit = JITs.begin(), end = JITs.end(); Jit != end; ++Jit) { if (Function *F = (*Jit)->FindFunctionNamed(Name)) return (*Jit)->getPointerToFunction(F); } // The function is not available : fallback on the first created (will // search in symbol of the current program/library) return (*JITs.begin())->getPointerToNamedFunction(Name); } }; ManagedStatic<JitPool> AllJits; } extern "C" { // getPointerToNamedFunction - This function is used as a global wrapper to // JIT::getPointerToNamedFunction for the purpose of resolving symbols when // bugpoint is debugging the JIT. In that scenario, we are loading an .so and // need to resolve function(s) that are being mis-codegenerated, so we need to // resolve their addresses at runtime, and this is the way to do it. void *getPointerToNamedFunction(const char *Name) { return AllJits->getPointerToNamedFunction(Name); } } JIT::JIT(Module *M, TargetMachine &tm, TargetJITInfo &tji, JITMemoryManager *jmm, bool GVsWithCode) : ExecutionEngine(M), TM(tm), TJI(tji), JMM(jmm ? jmm : JITMemoryManager::CreateDefaultMemManager()), AllocateGVsWithCode(GVsWithCode), isAlreadyCodeGenerating(false) { setTargetData(TM.getTargetData()); jitstate = new JITState(M); // Initialize JCE JCE = createEmitter(*this, JMM, TM); // Register in global list of all JITs. AllJits->Add(this); // Add target data MutexGuard locked(lock); FunctionPassManager &PM = jitstate->getPM(locked); PM.add(new TargetData(*TM.getTargetData())); // Turn the machine code intermediate representation into bytes in memory that // may be executed. if (TM.addPassesToEmitMachineCode(PM, *JCE)) { report_fatal_error("Target does not support machine code emission!"); } // Register routine for informing unwinding runtime about new EH frames #if HAVE_EHTABLE_SUPPORT #if USE_KEYMGR struct LibgccObjectInfo* LOI = (struct LibgccObjectInfo*) _keymgr_get_and_lock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST); // The key is created on demand, and libgcc creates it the first time an // exception occurs. Since we need the key to register frames, we create // it now. if (!LOI) LOI = (LibgccObjectInfo*)calloc(sizeof(struct LibgccObjectInfo), 1); _keymgr_set_and_unlock_processwide_ptr(KEYMGR_GCC3_DW2_OBJ_LIST, LOI); InstallExceptionTableRegister(DarwinRegisterFrame); // Not sure about how to deregister on Darwin. #else InstallExceptionTableRegister(__register_frame); InstallExceptionTableDeregister(__deregister_frame); #endif // __APPLE__ #endif // HAVE_EHTABLE_SUPPORT // Initialize passes. PM.doInitialization(); } JIT::~JIT() { // Unregister all exception tables registered by this JIT. DeregisterAllTables(); // Cleanup. AllJits->Remove(this); delete jitstate; delete JCE; // JMM is a ownership of JCE, so we no need delete JMM here. delete &TM; } /// addModule - Add a new Module to the JIT. If we previously removed the last /// Module, we need re-initialize jitstate with a valid Module. void JIT::addModule(Module *M) { MutexGuard locked(lock); if (Modules.empty()) { assert(!jitstate && "jitstate should be NULL if Modules vector is empty!"); jitstate = new JITState(M); FunctionPassManager &PM = jitstate->getPM(locked); PM.add(new TargetData(*TM.getTargetData())); // Turn the machine code intermediate representation into bytes in memory // that may be executed. if (TM.addPassesToEmitMachineCode(PM, *JCE)) { report_fatal_error("Target does not support machine code emission!"); } // Initialize passes. PM.doInitialization(); } ExecutionEngine::addModule(M); } /// removeModule - If we are removing the last Module, invalidate the jitstate /// since the PassManager it contains references a released Module. bool JIT::removeModule(Module *M) { bool result = ExecutionEngine::removeModule(M); MutexGuard locked(lock); if (jitstate->getModule() == M) { delete jitstate; jitstate = 0; } if (!jitstate && !Modules.empty()) { jitstate = new JITState(Modules[0]); FunctionPassManager &PM = jitstate->getPM(locked); PM.add(new TargetData(*TM.getTargetData())); // Turn the machine code intermediate representation into bytes in memory // that may be executed. if (TM.addPassesToEmitMachineCode(PM, *JCE)) { report_fatal_error("Target does not support machine code emission!"); } // Initialize passes. PM.doInitialization(); } return result; } /// run - Start execution with the specified function and arguments. /// GenericValue JIT::runFunction(Function *F, const std::vector<GenericValue> &ArgValues) { assert(F && "Function *F was null at entry to run()"); void *FPtr = getPointerToFunction(F); assert(FPtr && "Pointer to fn's code was null after getPointerToFunction"); FunctionType *FTy = F->getFunctionType(); Type *RetTy = FTy->getReturnType(); assert((FTy->getNumParams() == ArgValues.size() || (FTy->isVarArg() && FTy->getNumParams() <= ArgValues.size())) && "Wrong number of arguments passed into function!"); assert(FTy->getNumParams() == ArgValues.size() && "This doesn't support passing arguments through varargs (yet)!"); // Handle some common cases first. These cases correspond to common `main' // prototypes. if (RetTy->isIntegerTy(32) || RetTy->isVoidTy()) { switch (ArgValues.size()) { case 3: if (FTy->getParamType(0)->isIntegerTy(32) && FTy->getParamType(1)->isPointerTy() && FTy->getParamType(2)->isPointerTy()) { int (*PF)(int, char **, const char **) = (int(*)(int, char **, const char **))(intptr_t)FPtr; // Call the function. GenericValue rv; rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(), (char **)GVTOP(ArgValues[1]), (const char **)GVTOP(ArgValues[2]))); return rv; } break; case 2: if (FTy->getParamType(0)->isIntegerTy(32) && FTy->getParamType(1)->isPointerTy()) { int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr; // Call the function. GenericValue rv; rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(), (char **)GVTOP(ArgValues[1]))); return rv; } break; case 1: if (FTy->getNumParams() == 1 && FTy->getParamType(0)->isIntegerTy(32)) { GenericValue rv; int (*PF)(int) = (int(*)(int))(intptr_t)FPtr; rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue())); return rv; } break; } } // Handle cases where no arguments are passed first. if (ArgValues.empty()) { GenericValue rv; switch (RetTy->getTypeID()) { default: llvm_unreachable("Unknown return type for function call!"); case Type::IntegerTyID: { unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth(); if (BitWidth == 1) rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)()); else if (BitWidth <= 8) rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)()); else if (BitWidth <= 16) rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)()); else if (BitWidth <= 32) rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)()); else if (BitWidth <= 64) rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)()); else llvm_unreachable("Integer types > 64 bits not supported"); return rv; } case Type::VoidTyID: rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)()); return rv; case Type::FloatTyID: rv.FloatVal = ((float(*)())(intptr_t)FPtr)(); return rv; case Type::DoubleTyID: rv.DoubleVal = ((double(*)())(intptr_t)FPtr)(); return rv; case Type::X86_FP80TyID: case Type::FP128TyID: case Type::PPC_FP128TyID: llvm_unreachable("long double not supported yet"); case Type::PointerTyID: return PTOGV(((void*(*)())(intptr_t)FPtr)()); } } // Okay, this is not one of our quick and easy cases. Because we don't have a // full FFI, we have to codegen a nullary stub function that just calls the // function we are interested in, passing in constants for all of the // arguments. Make this function and return. // First, create the function. FunctionType *STy=FunctionType::get(RetTy, false); Function *Stub = Function::Create(STy, Function::InternalLinkage, "", F->getParent()); // Insert a basic block. BasicBlock *StubBB = BasicBlock::Create(F->getContext(), "", Stub); // Convert all of the GenericValue arguments over to constants. Note that we // currently don't support varargs. SmallVector<Value*, 8> Args; for (unsigned i = 0, e = ArgValues.size(); i != e; ++i) { Constant *C = 0; Type *ArgTy = FTy->getParamType(i); const GenericValue &AV = ArgValues[i]; switch (ArgTy->getTypeID()) { default: llvm_unreachable("Unknown argument type for function call!"); case Type::IntegerTyID: C = ConstantInt::get(F->getContext(), AV.IntVal); break; case Type::FloatTyID: C = ConstantFP::get(F->getContext(), APFloat(AV.FloatVal)); break; case Type::DoubleTyID: C = ConstantFP::get(F->getContext(), APFloat(AV.DoubleVal)); break; case Type::PPC_FP128TyID: case Type::X86_FP80TyID: case Type::FP128TyID: C = ConstantFP::get(F->getContext(), APFloat(AV.IntVal)); break; case Type::PointerTyID: void *ArgPtr = GVTOP(AV); if (sizeof(void*) == 4) C = ConstantInt::get(Type::getInt32Ty(F->getContext()), (int)(intptr_t)ArgPtr); else C = ConstantInt::get(Type::getInt64Ty(F->getContext()), (intptr_t)ArgPtr); // Cast the integer to pointer C = ConstantExpr::getIntToPtr(C, ArgTy); break; } Args.push_back(C); } CallInst *TheCall = CallInst::Create(F, Args, "", StubBB); TheCall->setCallingConv(F->getCallingConv()); TheCall->setTailCall(); if (!TheCall->getType()->isVoidTy()) // Return result of the call. ReturnInst::Create(F->getContext(), TheCall, StubBB); else ReturnInst::Create(F->getContext(), StubBB); // Just return void. // Finally, call our nullary stub function. GenericValue Result = runFunction(Stub, std::vector<GenericValue>()); // Erase it, since no other function can have a reference to it. Stub->eraseFromParent(); // And return the result. return Result; } void JIT::RegisterJITEventListener(JITEventListener *L) { if (L == NULL) return; MutexGuard locked(lock); EventListeners.push_back(L); } void JIT::UnregisterJITEventListener(JITEventListener *L) { if (L == NULL) return; MutexGuard locked(lock); std::vector<JITEventListener*>::reverse_iterator I= std::find(EventListeners.rbegin(), EventListeners.rend(), L); if (I != EventListeners.rend()) { std::swap(*I, EventListeners.back()); EventListeners.pop_back(); } } void JIT::NotifyFunctionEmitted( const Function &F, void *Code, size_t Size, const JITEvent_EmittedFunctionDetails &Details) { MutexGuard locked(lock); for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) { EventListeners[I]->NotifyFunctionEmitted(F, Code, Size, Details); } } void JIT::NotifyFreeingMachineCode(void *OldPtr) { MutexGuard locked(lock); for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) { EventListeners[I]->NotifyFreeingMachineCode(OldPtr); } } /// runJITOnFunction - Run the FunctionPassManager full of /// just-in-time compilation passes on F, hopefully filling in /// GlobalAddress[F] with the address of F's machine code. /// void JIT::runJITOnFunction(Function *F, MachineCodeInfo *MCI) { MutexGuard locked(lock); class MCIListener : public JITEventListener { MachineCodeInfo *const MCI; public: MCIListener(MachineCodeInfo *mci) : MCI(mci) {} virtual void NotifyFunctionEmitted(const Function &, void *Code, size_t Size, const EmittedFunctionDetails &) { MCI->setAddress(Code); MCI->setSize(Size); } }; MCIListener MCIL(MCI); if (MCI) RegisterJITEventListener(&MCIL); runJITOnFunctionUnlocked(F, locked); if (MCI) UnregisterJITEventListener(&MCIL); } void JIT::runJITOnFunctionUnlocked(Function *F, const MutexGuard &locked) { assert(!isAlreadyCodeGenerating && "Error: Recursive compilation detected!"); jitTheFunction(F, locked); // If the function referred to another function that had not yet been // read from bitcode, and we are jitting non-lazily, emit it now. while (!jitstate->getPendingFunctions(locked).empty()) { Function *PF = jitstate->getPendingFunctions(locked).back(); jitstate->getPendingFunctions(locked).pop_back(); assert(!PF->hasAvailableExternallyLinkage() && "Externally-defined function should not be in pending list."); jitTheFunction(PF, locked); // Now that the function has been jitted, ask the JITEmitter to rewrite // the stub with real address of the function. updateFunctionStub(PF); } } void JIT::jitTheFunction(Function *F, const MutexGuard &locked) { isAlreadyCodeGenerating = true; jitstate->getPM(locked).run(*F); isAlreadyCodeGenerating = false; // clear basic block addresses after this function is done getBasicBlockAddressMap(locked).clear(); } /// getPointerToFunction - This method is used to get the address of the /// specified function, compiling it if necessary. /// void *JIT::getPointerToFunction(Function *F) { if (void *Addr = getPointerToGlobalIfAvailable(F)) return Addr; // Check if function already code gen'd MutexGuard locked(lock); // Now that this thread owns the lock, make sure we read in the function if it // exists in this Module. std::string ErrorMsg; if (F->Materialize(&ErrorMsg)) { report_fatal_error("Error reading function '" + F->getName()+ "' from bitcode file: " + ErrorMsg); } // ... and check if another thread has already code gen'd the function. if (void *Addr = getPointerToGlobalIfAvailable(F)) return Addr; if (F->isDeclaration() || F->hasAvailableExternallyLinkage()) { bool AbortOnFailure = !F->hasExternalWeakLinkage(); void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure); addGlobalMapping(F, Addr); return Addr; } runJITOnFunctionUnlocked(F, locked); void *Addr = getPointerToGlobalIfAvailable(F); assert(Addr && "Code generation didn't add function to GlobalAddress table!"); return Addr; } void JIT::addPointerToBasicBlock(const BasicBlock *BB, void *Addr) { MutexGuard locked(lock); BasicBlockAddressMapTy::iterator I = getBasicBlockAddressMap(locked).find(BB); if (I == getBasicBlockAddressMap(locked).end()) { getBasicBlockAddressMap(locked)[BB] = Addr; } else { // ignore repeats: some BBs can be split into few MBBs? } } void JIT::clearPointerToBasicBlock(const BasicBlock *BB) { MutexGuard locked(lock); getBasicBlockAddressMap(locked).erase(BB); } void *JIT::getPointerToBasicBlock(BasicBlock *BB) { // make sure it's function is compiled by JIT (void)getPointerToFunction(BB->getParent()); // resolve basic block address MutexGuard locked(lock); BasicBlockAddressMapTy::iterator I = getBasicBlockAddressMap(locked).find(BB); if (I != getBasicBlockAddressMap(locked).end()) { return I->second; } else { llvm_unreachable("JIT does not have BB address for address-of-label, was" " it eliminated by optimizer?"); } } void *JIT::getPointerToNamedFunction(const std::string &Name, bool AbortOnFailure){ if (!isSymbolSearchingDisabled()) { void *ptr = JMM->getPointerToNamedFunction(Name, false); if (ptr) return ptr; } /// If a LazyFunctionCreator is installed, use it to get/create the function. if (LazyFunctionCreator) if (void *RP = LazyFunctionCreator(Name)) return RP; if (AbortOnFailure) { report_fatal_error("Program used external function '"+Name+ "' which could not be resolved!"); } return 0; } /// getOrEmitGlobalVariable - Return the address of the specified global /// variable, possibly emitting it to memory if needed. This is used by the /// Emitter. void *JIT::getOrEmitGlobalVariable(const GlobalVariable *GV) { MutexGuard locked(lock); void *Ptr = getPointerToGlobalIfAvailable(GV); if (Ptr) return Ptr; // If the global is external, just remember the address. if (GV->isDeclaration() || GV->hasAvailableExternallyLinkage()) { #if HAVE___DSO_HANDLE if (GV->getName() == "__dso_handle") return (void*)&__dso_handle; #endif Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(GV->getName()); if (Ptr == 0) { report_fatal_error("Could not resolve external global address: " +GV->getName()); } addGlobalMapping(GV, Ptr); } else { // If the global hasn't been emitted to memory yet, allocate space and // emit it into memory. Ptr = getMemoryForGV(GV); addGlobalMapping(GV, Ptr); EmitGlobalVariable(GV); // Initialize the variable. } return Ptr; } /// recompileAndRelinkFunction - This method is used to force a function /// which has already been compiled, to be compiled again, possibly /// after it has been modified. Then the entry to the old copy is overwritten /// with a branch to the new copy. If there was no old copy, this acts /// just like JIT::getPointerToFunction(). /// void *JIT::recompileAndRelinkFunction(Function *F) { void *OldAddr = getPointerToGlobalIfAvailable(F); // If it's not already compiled there is no reason to patch it up. if (OldAddr == 0) { return getPointerToFunction(F); } // Delete the old function mapping. addGlobalMapping(F, 0); // Recodegen the function runJITOnFunction(F); // Update state, forward the old function to the new function. void *Addr = getPointerToGlobalIfAvailable(F); assert(Addr && "Code generation didn't add function to GlobalAddress table!"); TJI.replaceMachineCodeForFunction(OldAddr, Addr); return Addr; } /// getMemoryForGV - This method abstracts memory allocation of global /// variable so that the JIT can allocate thread local variables depending /// on the target. /// char* JIT::getMemoryForGV(const GlobalVariable* GV) { char *Ptr; // GlobalVariable's which are not "constant" will cause trouble in a server // situation. It's returned in the same block of memory as code which may // not be writable. if (isGVCompilationDisabled() && !GV->isConstant()) { report_fatal_error("Compilation of non-internal GlobalValue is disabled!"); } // Some applications require globals and code to live together, so they may // be allocated into the same buffer, but in general globals are allocated // through the memory manager which puts them near the code but not in the // same buffer. Type *GlobalType = GV->getType()->getElementType(); size_t S = getTargetData()->getTypeAllocSize(GlobalType); size_t A = getTargetData()->getPreferredAlignment(GV); if (GV->isThreadLocal()) { MutexGuard locked(lock); Ptr = TJI.allocateThreadLocalMemory(S); } else if (TJI.allocateSeparateGVMemory()) { if (A <= 8) { Ptr = (char*)malloc(S); } else { // Allocate S+A bytes of memory, then use an aligned pointer within that // space. Ptr = (char*)malloc(S+A); unsigned MisAligned = ((intptr_t)Ptr & (A-1)); Ptr = Ptr + (MisAligned ? (A-MisAligned) : 0); } } else if (AllocateGVsWithCode) { Ptr = (char*)JCE->allocateSpace(S, A); } else { Ptr = (char*)JCE->allocateGlobal(S, A); } return Ptr; } void JIT::addPendingFunction(Function *F) { MutexGuard locked(lock); jitstate->getPendingFunctions(locked).push_back(F); } JITEventListener::~JITEventListener() {}