//===-- 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/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,
CodeGenOpt::Level OptLevel,
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, OptLevel, 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, CodeGenOpt::Level OptLevel, bool GVsWithCode)
: ExecutionEngine(M), TM(tm), TJI(tji), 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, OptLevel)) {
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;
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, CodeGenOpt::Default)) {
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, CodeGenOpt::Default)) {
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");
return rv;
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 {
assert(0 && "JIT does not have BB address for address-of-label, was"
" it eliminated by optimizer?");
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() {}