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/ADT/SmallPtrSet.h"
17 #include "llvm/CodeGen/JITCodeEmitter.h"
18 #include "llvm/CodeGen/MachineCodeInfo.h"
19 #include "llvm/Config/config.h"
20 #include "llvm/ExecutionEngine/GenericValue.h"
21 #include "llvm/ExecutionEngine/JITEventListener.h"
22 #include "llvm/ExecutionEngine/JITMemoryManager.h"
23 #include "llvm/IR/Constants.h"
24 #include "llvm/IR/DataLayout.h"
25 #include "llvm/IR/DerivedTypes.h"
26 #include "llvm/IR/Function.h"
27 #include "llvm/IR/GlobalVariable.h"
28 #include "llvm/IR/Instructions.h"
29 #include "llvm/Support/Dwarf.h"
30 #include "llvm/Support/DynamicLibrary.h"
31 #include "llvm/Support/ErrorHandling.h"
32 #include "llvm/Support/ManagedStatic.h"
33 #include "llvm/Support/MutexGuard.h"
34 #include "llvm/Target/TargetJITInfo.h"
35 #include "llvm/Target/TargetMachine.h"
40 // Apple gcc defaults to -fuse-cxa-atexit (i.e. calls __cxa_atexit instead
41 // of atexit). It passes the address of linker generated symbol __dso_handle
43 // This configuration change happened at version 5330.
44 # include <AvailabilityMacros.h>
45 # if defined(MAC_OS_X_VERSION_10_4) && \
46 ((MAC_OS_X_VERSION_MIN_REQUIRED > MAC_OS_X_VERSION_10_4) || \
47 (MAC_OS_X_VERSION_MIN_REQUIRED == MAC_OS_X_VERSION_10_4 && \
48 __APPLE_CC__ >= 5330))
49 # ifndef HAVE___DSO_HANDLE
50 # define HAVE___DSO_HANDLE 1
56 extern void *__dso_handle __attribute__ ((__visibility__ ("hidden")));
61 static struct RegisterJIT {
62 RegisterJIT() { JIT::Register(); }
67 extern "C" void LLVMLinkInJIT() {
70 /// createJIT - This is the factory method for creating a JIT for the current
71 /// machine, it does not fall back to the interpreter. This takes ownership
73 ExecutionEngine *JIT::createJIT(Module *M,
74 std::string *ErrorStr,
75 JITMemoryManager *JMM,
78 // Try to register the program as a source of symbols to resolve against.
80 // FIXME: Don't do this here.
81 sys::DynamicLibrary::LoadLibraryPermanently(0, NULL);
83 // If the target supports JIT code generation, create the JIT.
84 if (TargetJITInfo *TJ = TM->getJITInfo()) {
85 return new JIT(M, *TM, *TJ, JMM, GVsWithCode);
88 *ErrorStr = "target does not support JIT code generation";
94 /// This class supports the global getPointerToNamedFunction(), which allows
95 /// bugpoint or gdb users to search for a function by name without any context.
97 SmallPtrSet<JIT*, 1> JITs; // Optimize for process containing just 1 JIT.
98 mutable sys::Mutex Lock;
101 MutexGuard guard(Lock);
104 void Remove(JIT *jit) {
105 MutexGuard guard(Lock);
108 void *getPointerToNamedFunction(const char *Name) const {
109 MutexGuard guard(Lock);
110 assert(JITs.size() != 0 && "No Jit registered");
111 //search function in every instance of JIT
112 for (SmallPtrSet<JIT*, 1>::const_iterator Jit = JITs.begin(),
115 if (Function *F = (*Jit)->FindFunctionNamed(Name))
116 return (*Jit)->getPointerToFunction(F);
118 // The function is not available : fallback on the first created (will
119 // search in symbol of the current program/library)
120 return (*JITs.begin())->getPointerToNamedFunction(Name);
123 ManagedStatic<JitPool> AllJits;
126 // getPointerToNamedFunction - This function is used as a global wrapper to
127 // JIT::getPointerToNamedFunction for the purpose of resolving symbols when
128 // bugpoint is debugging the JIT. In that scenario, we are loading an .so and
129 // need to resolve function(s) that are being mis-codegenerated, so we need to
130 // resolve their addresses at runtime, and this is the way to do it.
131 void *getPointerToNamedFunction(const char *Name) {
132 return AllJits->getPointerToNamedFunction(Name);
136 JIT::JIT(Module *M, TargetMachine &tm, TargetJITInfo &tji,
137 JITMemoryManager *jmm, bool GVsWithCode)
138 : ExecutionEngine(M), TM(tm), TJI(tji),
139 JMM(jmm ? jmm : JITMemoryManager::CreateDefaultMemManager()),
140 AllocateGVsWithCode(GVsWithCode), isAlreadyCodeGenerating(false) {
141 setDataLayout(TM.getDataLayout());
143 jitstate = new JITState(M);
146 JCE = createEmitter(*this, JMM, TM);
148 // Register in global list of all JITs.
152 MutexGuard locked(lock);
153 FunctionPassManager &PM = jitstate->getPM(locked);
154 PM.add(new DataLayoutPass(*TM.getDataLayout()));
156 // Turn the machine code intermediate representation into bytes in memory that
158 if (TM.addPassesToEmitMachineCode(PM, *JCE)) {
159 report_fatal_error("Target does not support machine code emission!");
162 // Initialize passes.
163 PM.doInitialization();
168 AllJits->Remove(this);
171 // JMM is a ownership of JCE, so we no need delete JMM here.
175 /// addModule - Add a new Module to the JIT. If we previously removed the last
176 /// Module, we need re-initialize jitstate with a valid Module.
177 void JIT::addModule(Module *M) {
178 MutexGuard locked(lock);
180 if (Modules.empty()) {
181 assert(!jitstate && "jitstate should be NULL if Modules vector is empty!");
183 jitstate = new JITState(M);
185 FunctionPassManager &PM = jitstate->getPM(locked);
186 PM.add(new DataLayoutPass(*TM.getDataLayout()));
188 // Turn the machine code intermediate representation into bytes in memory
189 // that may be executed.
190 if (TM.addPassesToEmitMachineCode(PM, *JCE)) {
191 report_fatal_error("Target does not support machine code emission!");
194 // Initialize passes.
195 PM.doInitialization();
198 ExecutionEngine::addModule(M);
201 /// removeModule - If we are removing the last Module, invalidate the jitstate
202 /// since the PassManager it contains references a released Module.
203 bool JIT::removeModule(Module *M) {
204 bool result = ExecutionEngine::removeModule(M);
206 MutexGuard locked(lock);
208 if (jitstate && jitstate->getModule() == M) {
213 if (!jitstate && !Modules.empty()) {
214 jitstate = new JITState(Modules[0]);
216 FunctionPassManager &PM = jitstate->getPM(locked);
217 PM.add(new DataLayoutPass(*TM.getDataLayout()));
219 // Turn the machine code intermediate representation into bytes in memory
220 // that may be executed.
221 if (TM.addPassesToEmitMachineCode(PM, *JCE)) {
222 report_fatal_error("Target does not support machine code emission!");
225 // Initialize passes.
226 PM.doInitialization();
231 /// run - Start execution with the specified function and arguments.
233 GenericValue JIT::runFunction(Function *F,
234 const std::vector<GenericValue> &ArgValues) {
235 assert(F && "Function *F was null at entry to run()");
237 void *FPtr = getPointerToFunction(F);
238 assert(FPtr && "Pointer to fn's code was null after getPointerToFunction");
239 FunctionType *FTy = F->getFunctionType();
240 Type *RetTy = FTy->getReturnType();
242 assert((FTy->getNumParams() == ArgValues.size() ||
243 (FTy->isVarArg() && FTy->getNumParams() <= ArgValues.size())) &&
244 "Wrong number of arguments passed into function!");
245 assert(FTy->getNumParams() == ArgValues.size() &&
246 "This doesn't support passing arguments through varargs (yet)!");
248 // Handle some common cases first. These cases correspond to common `main'
250 if (RetTy->isIntegerTy(32) || RetTy->isVoidTy()) {
251 switch (ArgValues.size()) {
253 if (FTy->getParamType(0)->isIntegerTy(32) &&
254 FTy->getParamType(1)->isPointerTy() &&
255 FTy->getParamType(2)->isPointerTy()) {
256 int (*PF)(int, char **, const char **) =
257 (int(*)(int, char **, const char **))(intptr_t)FPtr;
259 // Call the function.
261 rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
262 (char **)GVTOP(ArgValues[1]),
263 (const char **)GVTOP(ArgValues[2])));
268 if (FTy->getParamType(0)->isIntegerTy(32) &&
269 FTy->getParamType(1)->isPointerTy()) {
270 int (*PF)(int, char **) = (int(*)(int, char **))(intptr_t)FPtr;
272 // Call the function.
274 rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue(),
275 (char **)GVTOP(ArgValues[1])));
280 if (FTy->getParamType(0)->isIntegerTy(32)) {
282 int (*PF)(int) = (int(*)(int))(intptr_t)FPtr;
283 rv.IntVal = APInt(32, PF(ArgValues[0].IntVal.getZExtValue()));
286 if (FTy->getParamType(0)->isPointerTy()) {
288 int (*PF)(char *) = (int(*)(char *))(intptr_t)FPtr;
289 rv.IntVal = APInt(32, PF((char*)GVTOP(ArgValues[0])));
296 // Handle cases where no arguments are passed first.
297 if (ArgValues.empty()) {
299 switch (RetTy->getTypeID()) {
300 default: llvm_unreachable("Unknown return type for function call!");
301 case Type::IntegerTyID: {
302 unsigned BitWidth = cast<IntegerType>(RetTy)->getBitWidth();
304 rv.IntVal = APInt(BitWidth, ((bool(*)())(intptr_t)FPtr)());
305 else if (BitWidth <= 8)
306 rv.IntVal = APInt(BitWidth, ((char(*)())(intptr_t)FPtr)());
307 else if (BitWidth <= 16)
308 rv.IntVal = APInt(BitWidth, ((short(*)())(intptr_t)FPtr)());
309 else if (BitWidth <= 32)
310 rv.IntVal = APInt(BitWidth, ((int(*)())(intptr_t)FPtr)());
311 else if (BitWidth <= 64)
312 rv.IntVal = APInt(BitWidth, ((int64_t(*)())(intptr_t)FPtr)());
314 llvm_unreachable("Integer types > 64 bits not supported");
318 rv.IntVal = APInt(32, ((int(*)())(intptr_t)FPtr)());
320 case Type::FloatTyID:
321 rv.FloatVal = ((float(*)())(intptr_t)FPtr)();
323 case Type::DoubleTyID:
324 rv.DoubleVal = ((double(*)())(intptr_t)FPtr)();
326 case Type::X86_FP80TyID:
327 case Type::FP128TyID:
328 case Type::PPC_FP128TyID:
329 llvm_unreachable("long double not supported yet");
330 case Type::PointerTyID:
331 return PTOGV(((void*(*)())(intptr_t)FPtr)());
335 // Okay, this is not one of our quick and easy cases. Because we don't have a
336 // full FFI, we have to codegen a nullary stub function that just calls the
337 // function we are interested in, passing in constants for all of the
338 // arguments. Make this function and return.
340 // First, create the function.
341 FunctionType *STy=FunctionType::get(RetTy, false);
342 Function *Stub = Function::Create(STy, Function::InternalLinkage, "",
345 // Insert a basic block.
346 BasicBlock *StubBB = BasicBlock::Create(F->getContext(), "", Stub);
348 // Convert all of the GenericValue arguments over to constants. Note that we
349 // currently don't support varargs.
350 SmallVector<Value*, 8> Args;
351 for (unsigned i = 0, e = ArgValues.size(); i != e; ++i) {
353 Type *ArgTy = FTy->getParamType(i);
354 const GenericValue &AV = ArgValues[i];
355 switch (ArgTy->getTypeID()) {
356 default: llvm_unreachable("Unknown argument type for function call!");
357 case Type::IntegerTyID:
358 C = ConstantInt::get(F->getContext(), AV.IntVal);
360 case Type::FloatTyID:
361 C = ConstantFP::get(F->getContext(), APFloat(AV.FloatVal));
363 case Type::DoubleTyID:
364 C = ConstantFP::get(F->getContext(), APFloat(AV.DoubleVal));
366 case Type::PPC_FP128TyID:
367 case Type::X86_FP80TyID:
368 case Type::FP128TyID:
369 C = ConstantFP::get(F->getContext(), APFloat(ArgTy->getFltSemantics(),
372 case Type::PointerTyID:
373 void *ArgPtr = GVTOP(AV);
374 if (sizeof(void*) == 4)
375 C = ConstantInt::get(Type::getInt32Ty(F->getContext()),
376 (int)(intptr_t)ArgPtr);
378 C = ConstantInt::get(Type::getInt64Ty(F->getContext()),
380 // Cast the integer to pointer
381 C = ConstantExpr::getIntToPtr(C, ArgTy);
387 CallInst *TheCall = CallInst::Create(F, Args, "", StubBB);
388 TheCall->setCallingConv(F->getCallingConv());
389 TheCall->setTailCall();
390 if (!TheCall->getType()->isVoidTy())
391 // Return result of the call.
392 ReturnInst::Create(F->getContext(), TheCall, StubBB);
394 ReturnInst::Create(F->getContext(), StubBB); // Just return void.
396 // Finally, call our nullary stub function.
397 GenericValue Result = runFunction(Stub, std::vector<GenericValue>());
398 // Erase it, since no other function can have a reference to it.
399 Stub->eraseFromParent();
400 // And return the result.
404 void JIT::RegisterJITEventListener(JITEventListener *L) {
407 MutexGuard locked(lock);
408 EventListeners.push_back(L);
410 void JIT::UnregisterJITEventListener(JITEventListener *L) {
413 MutexGuard locked(lock);
414 std::vector<JITEventListener*>::reverse_iterator I=
415 std::find(EventListeners.rbegin(), EventListeners.rend(), L);
416 if (I != EventListeners.rend()) {
417 std::swap(*I, EventListeners.back());
418 EventListeners.pop_back();
421 void JIT::NotifyFunctionEmitted(
423 void *Code, size_t Size,
424 const JITEvent_EmittedFunctionDetails &Details) {
425 MutexGuard locked(lock);
426 for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) {
427 EventListeners[I]->NotifyFunctionEmitted(F, Code, Size, Details);
431 void JIT::NotifyFreeingMachineCode(void *OldPtr) {
432 MutexGuard locked(lock);
433 for (unsigned I = 0, S = EventListeners.size(); I < S; ++I) {
434 EventListeners[I]->NotifyFreeingMachineCode(OldPtr);
438 /// runJITOnFunction - Run the FunctionPassManager full of
439 /// just-in-time compilation passes on F, hopefully filling in
440 /// GlobalAddress[F] with the address of F's machine code.
442 void JIT::runJITOnFunction(Function *F, MachineCodeInfo *MCI) {
443 MutexGuard locked(lock);
445 class MCIListener : public JITEventListener {
446 MachineCodeInfo *const MCI;
448 MCIListener(MachineCodeInfo *mci) : MCI(mci) {}
449 virtual void NotifyFunctionEmitted(const Function &,
450 void *Code, size_t Size,
451 const EmittedFunctionDetails &) {
452 MCI->setAddress(Code);
456 MCIListener MCIL(MCI);
458 RegisterJITEventListener(&MCIL);
460 runJITOnFunctionUnlocked(F, locked);
463 UnregisterJITEventListener(&MCIL);
466 void JIT::runJITOnFunctionUnlocked(Function *F, const MutexGuard &locked) {
467 assert(!isAlreadyCodeGenerating && "Error: Recursive compilation detected!");
469 jitTheFunction(F, locked);
471 // If the function referred to another function that had not yet been
472 // read from bitcode, and we are jitting non-lazily, emit it now.
473 while (!jitstate->getPendingFunctions(locked).empty()) {
474 Function *PF = jitstate->getPendingFunctions(locked).back();
475 jitstate->getPendingFunctions(locked).pop_back();
477 assert(!PF->hasAvailableExternallyLinkage() &&
478 "Externally-defined function should not be in pending list.");
480 jitTheFunction(PF, locked);
482 // Now that the function has been jitted, ask the JITEmitter to rewrite
483 // the stub with real address of the function.
484 updateFunctionStub(PF);
488 void JIT::jitTheFunction(Function *F, const MutexGuard &locked) {
489 isAlreadyCodeGenerating = true;
490 jitstate->getPM(locked).run(*F);
491 isAlreadyCodeGenerating = false;
493 // clear basic block addresses after this function is done
494 getBasicBlockAddressMap(locked).clear();
497 /// getPointerToFunction - This method is used to get the address of the
498 /// specified function, compiling it if necessary.
500 void *JIT::getPointerToFunction(Function *F) {
502 if (void *Addr = getPointerToGlobalIfAvailable(F))
503 return Addr; // Check if function already code gen'd
505 MutexGuard locked(lock);
507 // Now that this thread owns the lock, make sure we read in the function if it
508 // exists in this Module.
509 std::string ErrorMsg;
510 if (F->Materialize(&ErrorMsg)) {
511 report_fatal_error("Error reading function '" + F->getName()+
512 "' from bitcode file: " + ErrorMsg);
515 // ... and check if another thread has already code gen'd the function.
516 if (void *Addr = getPointerToGlobalIfAvailable(F))
519 if (F->isDeclaration() || F->hasAvailableExternallyLinkage()) {
520 bool AbortOnFailure = !F->hasExternalWeakLinkage();
521 void *Addr = getPointerToNamedFunction(F->getName(), AbortOnFailure);
522 addGlobalMapping(F, Addr);
526 runJITOnFunctionUnlocked(F, locked);
528 void *Addr = getPointerToGlobalIfAvailable(F);
529 assert(Addr && "Code generation didn't add function to GlobalAddress table!");
533 void JIT::addPointerToBasicBlock(const BasicBlock *BB, void *Addr) {
534 MutexGuard locked(lock);
536 BasicBlockAddressMapTy::iterator I =
537 getBasicBlockAddressMap(locked).find(BB);
538 if (I == getBasicBlockAddressMap(locked).end()) {
539 getBasicBlockAddressMap(locked)[BB] = Addr;
541 // ignore repeats: some BBs can be split into few MBBs?
545 void JIT::clearPointerToBasicBlock(const BasicBlock *BB) {
546 MutexGuard locked(lock);
547 getBasicBlockAddressMap(locked).erase(BB);
550 void *JIT::getPointerToBasicBlock(BasicBlock *BB) {
551 // make sure it's function is compiled by JIT
552 (void)getPointerToFunction(BB->getParent());
554 // resolve basic block address
555 MutexGuard locked(lock);
557 BasicBlockAddressMapTy::iterator I =
558 getBasicBlockAddressMap(locked).find(BB);
559 if (I != getBasicBlockAddressMap(locked).end()) {
562 llvm_unreachable("JIT does not have BB address for address-of-label, was"
563 " it eliminated by optimizer?");
567 void *JIT::getPointerToNamedFunction(const std::string &Name,
568 bool AbortOnFailure){
569 if (!isSymbolSearchingDisabled()) {
570 void *ptr = JMM->getPointerToNamedFunction(Name, false);
575 /// If a LazyFunctionCreator is installed, use it to get/create the function.
576 if (LazyFunctionCreator)
577 if (void *RP = LazyFunctionCreator(Name))
580 if (AbortOnFailure) {
581 report_fatal_error("Program used external function '"+Name+
582 "' which could not be resolved!");
588 /// getOrEmitGlobalVariable - Return the address of the specified global
589 /// variable, possibly emitting it to memory if needed. This is used by the
591 void *JIT::getOrEmitGlobalVariable(const GlobalVariable *GV) {
592 MutexGuard locked(lock);
594 void *Ptr = getPointerToGlobalIfAvailable(GV);
597 // If the global is external, just remember the address.
598 if (GV->isDeclaration() || GV->hasAvailableExternallyLinkage()) {
599 #if HAVE___DSO_HANDLE
600 if (GV->getName() == "__dso_handle")
601 return (void*)&__dso_handle;
603 Ptr = sys::DynamicLibrary::SearchForAddressOfSymbol(GV->getName());
605 report_fatal_error("Could not resolve external global address: "
608 addGlobalMapping(GV, Ptr);
610 // If the global hasn't been emitted to memory yet, allocate space and
611 // emit it into memory.
612 Ptr = getMemoryForGV(GV);
613 addGlobalMapping(GV, Ptr);
614 EmitGlobalVariable(GV); // Initialize the variable.
619 /// recompileAndRelinkFunction - This method is used to force a function
620 /// which has already been compiled, to be compiled again, possibly
621 /// after it has been modified. Then the entry to the old copy is overwritten
622 /// with a branch to the new copy. If there was no old copy, this acts
623 /// just like JIT::getPointerToFunction().
625 void *JIT::recompileAndRelinkFunction(Function *F) {
626 void *OldAddr = getPointerToGlobalIfAvailable(F);
628 // If it's not already compiled there is no reason to patch it up.
629 if (OldAddr == 0) { return getPointerToFunction(F); }
631 // Delete the old function mapping.
632 addGlobalMapping(F, 0);
634 // Recodegen the function
637 // Update state, forward the old function to the new function.
638 void *Addr = getPointerToGlobalIfAvailable(F);
639 assert(Addr && "Code generation didn't add function to GlobalAddress table!");
640 TJI.replaceMachineCodeForFunction(OldAddr, Addr);
644 /// getMemoryForGV - This method abstracts memory allocation of global
645 /// variable so that the JIT can allocate thread local variables depending
648 char* JIT::getMemoryForGV(const GlobalVariable* GV) {
651 // GlobalVariable's which are not "constant" will cause trouble in a server
652 // situation. It's returned in the same block of memory as code which may
654 if (isGVCompilationDisabled() && !GV->isConstant()) {
655 report_fatal_error("Compilation of non-internal GlobalValue is disabled!");
658 // Some applications require globals and code to live together, so they may
659 // be allocated into the same buffer, but in general globals are allocated
660 // through the memory manager which puts them near the code but not in the
662 Type *GlobalType = GV->getType()->getElementType();
663 size_t S = getDataLayout()->getTypeAllocSize(GlobalType);
664 size_t A = getDataLayout()->getPreferredAlignment(GV);
665 if (GV->isThreadLocal()) {
666 MutexGuard locked(lock);
667 Ptr = TJI.allocateThreadLocalMemory(S);
668 } else if (TJI.allocateSeparateGVMemory()) {
670 Ptr = (char*)malloc(S);
672 // Allocate S+A bytes of memory, then use an aligned pointer within that
674 Ptr = (char*)malloc(S+A);
675 unsigned MisAligned = ((intptr_t)Ptr & (A-1));
676 Ptr = Ptr + (MisAligned ? (A-MisAligned) : 0);
678 } else if (AllocateGVsWithCode) {
679 Ptr = (char*)JCE->allocateSpace(S, A);
681 Ptr = (char*)JCE->allocateGlobal(S, A);
686 void JIT::addPendingFunction(Function *F) {
687 MutexGuard locked(lock);
688 jitstate->getPendingFunctions(locked).push_back(F);
692 JITEventListener::~JITEventListener() {}