1 //===-- JITEmitter.cpp - Write machine code to executable memory ----------===//
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 file defines a MachineCodeEmitter object that is used by the JIT to
11 // write machine code to memory and remember where relocatable values are.
13 //===----------------------------------------------------------------------===//
15 #define DEBUG_TYPE "jit"
17 #include "JITDwarfEmitter.h"
18 #include "llvm/ADT/OwningPtr.h"
19 #include "llvm/Constants.h"
20 #include "llvm/DebugInfo.h"
21 #include "llvm/DerivedTypes.h"
22 #include "llvm/Module.h"
23 #include "llvm/CodeGen/JITCodeEmitter.h"
24 #include "llvm/CodeGen/MachineFunction.h"
25 #include "llvm/CodeGen/MachineCodeInfo.h"
26 #include "llvm/CodeGen/MachineConstantPool.h"
27 #include "llvm/CodeGen/MachineJumpTableInfo.h"
28 #include "llvm/CodeGen/MachineModuleInfo.h"
29 #include "llvm/CodeGen/MachineRelocation.h"
30 #include "llvm/ExecutionEngine/GenericValue.h"
31 #include "llvm/ExecutionEngine/JITEventListener.h"
32 #include "llvm/ExecutionEngine/JITMemoryManager.h"
33 #include "llvm/Target/TargetData.h"
34 #include "llvm/Target/TargetInstrInfo.h"
35 #include "llvm/Target/TargetJITInfo.h"
36 #include "llvm/Target/TargetMachine.h"
37 #include "llvm/Target/TargetOptions.h"
38 #include "llvm/Support/Debug.h"
39 #include "llvm/Support/ErrorHandling.h"
40 #include "llvm/Support/ManagedStatic.h"
41 #include "llvm/Support/MutexGuard.h"
42 #include "llvm/Support/ValueHandle.h"
43 #include "llvm/Support/raw_ostream.h"
44 #include "llvm/Support/Disassembler.h"
45 #include "llvm/Support/Memory.h"
46 #include "llvm/ADT/DenseMap.h"
47 #include "llvm/ADT/SmallPtrSet.h"
48 #include "llvm/ADT/SmallVector.h"
49 #include "llvm/ADT/Statistic.h"
50 #include "llvm/ADT/ValueMap.h"
57 STATISTIC(NumBytes, "Number of bytes of machine code compiled");
58 STATISTIC(NumRelos, "Number of relocations applied");
59 STATISTIC(NumRetries, "Number of retries with more memory");
62 // A declaration may stop being a declaration once it's fully read from bitcode.
63 // This function returns true if F is fully read and is still a declaration.
64 static bool isNonGhostDeclaration(const Function *F) {
65 return F->isDeclaration() && !F->isMaterializable();
68 //===----------------------------------------------------------------------===//
69 // JIT lazy compilation code.
73 class JITResolverState;
75 template<typename ValueTy>
76 struct NoRAUWValueMapConfig : public ValueMapConfig<ValueTy> {
77 typedef JITResolverState *ExtraData;
78 static void onRAUW(JITResolverState *, Value *Old, Value *New) {
79 llvm_unreachable("The JIT doesn't know how to handle a"
80 " RAUW on a value it has emitted.");
84 struct CallSiteValueMapConfig : public NoRAUWValueMapConfig<Function*> {
85 typedef JITResolverState *ExtraData;
86 static void onDelete(JITResolverState *JRS, Function *F);
89 class JITResolverState {
91 typedef ValueMap<Function*, void*, NoRAUWValueMapConfig<Function*> >
92 FunctionToLazyStubMapTy;
93 typedef std::map<void*, AssertingVH<Function> > CallSiteToFunctionMapTy;
94 typedef ValueMap<Function *, SmallPtrSet<void*, 1>,
95 CallSiteValueMapConfig> FunctionToCallSitesMapTy;
96 typedef std::map<AssertingVH<GlobalValue>, void*> GlobalToIndirectSymMapTy;
98 /// FunctionToLazyStubMap - Keep track of the lazy stub created for a
99 /// particular function so that we can reuse them if necessary.
100 FunctionToLazyStubMapTy FunctionToLazyStubMap;
102 /// CallSiteToFunctionMap - Keep track of the function that each lazy call
103 /// site corresponds to, and vice versa.
104 CallSiteToFunctionMapTy CallSiteToFunctionMap;
105 FunctionToCallSitesMapTy FunctionToCallSitesMap;
107 /// GlobalToIndirectSymMap - Keep track of the indirect symbol created for a
108 /// particular GlobalVariable so that we can reuse them if necessary.
109 GlobalToIndirectSymMapTy GlobalToIndirectSymMap;
112 /// Instance of the JIT this ResolverState serves.
117 JITResolverState(JIT *jit) : FunctionToLazyStubMap(this),
118 FunctionToCallSitesMap(this) {
124 FunctionToLazyStubMapTy& getFunctionToLazyStubMap(
125 const MutexGuard& locked) {
126 assert(locked.holds(TheJIT->lock));
127 return FunctionToLazyStubMap;
130 GlobalToIndirectSymMapTy& getGlobalToIndirectSymMap(const MutexGuard& lck) {
131 assert(lck.holds(TheJIT->lock));
132 return GlobalToIndirectSymMap;
135 std::pair<void *, Function *> LookupFunctionFromCallSite(
136 const MutexGuard &locked, void *CallSite) const {
137 assert(locked.holds(TheJIT->lock));
139 // The address given to us for the stub may not be exactly right, it
140 // might be a little bit after the stub. As such, use upper_bound to
142 CallSiteToFunctionMapTy::const_iterator I =
143 CallSiteToFunctionMap.upper_bound(CallSite);
144 assert(I != CallSiteToFunctionMap.begin() &&
145 "This is not a known call site!");
150 void AddCallSite(const MutexGuard &locked, void *CallSite, Function *F) {
151 assert(locked.holds(TheJIT->lock));
153 bool Inserted = CallSiteToFunctionMap.insert(
154 std::make_pair(CallSite, F)).second;
156 assert(Inserted && "Pair was already in CallSiteToFunctionMap");
157 FunctionToCallSitesMap[F].insert(CallSite);
160 void EraseAllCallSitesForPrelocked(Function *F);
162 // Erases _all_ call sites regardless of their function. This is used to
163 // unregister the stub addresses from the StubToResolverMap in
165 void EraseAllCallSitesPrelocked();
168 /// JITResolver - Keep track of, and resolve, call sites for functions that
169 /// have not yet been compiled.
171 typedef JITResolverState::FunctionToLazyStubMapTy FunctionToLazyStubMapTy;
172 typedef JITResolverState::CallSiteToFunctionMapTy CallSiteToFunctionMapTy;
173 typedef JITResolverState::GlobalToIndirectSymMapTy GlobalToIndirectSymMapTy;
175 /// LazyResolverFn - The target lazy resolver function that we actually
176 /// rewrite instructions to use.
177 TargetJITInfo::LazyResolverFn LazyResolverFn;
179 JITResolverState state;
181 /// ExternalFnToStubMap - This is the equivalent of FunctionToLazyStubMap
182 /// for external functions. TODO: Of course, external functions don't need
183 /// a lazy stub. It's actually here to make it more likely that far calls
184 /// succeed, but no single stub can guarantee that. I'll remove this in a
185 /// subsequent checkin when I actually fix far calls.
186 std::map<void*, void*> ExternalFnToStubMap;
188 /// revGOTMap - map addresses to indexes in the GOT
189 std::map<void*, unsigned> revGOTMap;
190 unsigned nextGOTIndex;
194 /// Instance of JIT corresponding to this Resolver.
198 explicit JITResolver(JIT &jit, JITEmitter &je)
199 : state(&jit), nextGOTIndex(0), JE(je), TheJIT(&jit) {
200 LazyResolverFn = jit.getJITInfo().getLazyResolverFunction(JITCompilerFn);
205 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function's
206 /// lazy-compilation stub if it has already been created.
207 void *getLazyFunctionStubIfAvailable(Function *F);
209 /// getLazyFunctionStub - This returns a pointer to a function's
210 /// lazy-compilation stub, creating one on demand as needed.
211 void *getLazyFunctionStub(Function *F);
213 /// getExternalFunctionStub - Return a stub for the function at the
214 /// specified address, created lazily on demand.
215 void *getExternalFunctionStub(void *FnAddr);
217 /// getGlobalValueIndirectSym - Return an indirect symbol containing the
218 /// specified GV address.
219 void *getGlobalValueIndirectSym(GlobalValue *V, void *GVAddress);
221 /// getGOTIndexForAddress - Return a new or existing index in the GOT for
222 /// an address. This function only manages slots, it does not manage the
223 /// contents of the slots or the memory associated with the GOT.
224 unsigned getGOTIndexForAddr(void *addr);
226 /// JITCompilerFn - This function is called to resolve a stub to a compiled
227 /// address. If the LLVM Function corresponding to the stub has not yet
228 /// been compiled, this function compiles it first.
229 static void *JITCompilerFn(void *Stub);
232 class StubToResolverMapTy {
233 /// Map a stub address to a specific instance of a JITResolver so that
234 /// lazily-compiled functions can find the right resolver to use.
237 std::map<void*, JITResolver*> Map;
239 /// Guards Map from concurrent accesses.
240 mutable sys::Mutex Lock;
243 /// Registers a Stub to be resolved by Resolver.
244 void RegisterStubResolver(void *Stub, JITResolver *Resolver) {
245 MutexGuard guard(Lock);
246 Map.insert(std::make_pair(Stub, Resolver));
248 /// Unregisters the Stub when it's invalidated.
249 void UnregisterStubResolver(void *Stub) {
250 MutexGuard guard(Lock);
253 /// Returns the JITResolver instance that owns the Stub.
254 JITResolver *getResolverFromStub(void *Stub) const {
255 MutexGuard guard(Lock);
256 // The address given to us for the stub may not be exactly right, it might
257 // be a little bit after the stub. As such, use upper_bound to find it.
258 // This is the same trick as in LookupFunctionFromCallSite from
260 std::map<void*, JITResolver*>::const_iterator I = Map.upper_bound(Stub);
261 assert(I != Map.begin() && "This is not a known stub!");
265 /// True if any stubs refer to the given resolver. Only used in an assert().
267 bool ResolverHasStubs(JITResolver* Resolver) const {
268 MutexGuard guard(Lock);
269 for (std::map<void*, JITResolver*>::const_iterator I = Map.begin(),
270 E = Map.end(); I != E; ++I) {
271 if (I->second == Resolver)
277 /// This needs to be static so that a lazy call stub can access it with no
278 /// context except the address of the stub.
279 ManagedStatic<StubToResolverMapTy> StubToResolverMap;
281 /// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is
282 /// used to output functions to memory for execution.
283 class JITEmitter : public JITCodeEmitter {
284 JITMemoryManager *MemMgr;
286 // When outputting a function stub in the context of some other function, we
287 // save BufferBegin/BufferEnd/CurBufferPtr here.
288 uint8_t *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr;
290 // When reattempting to JIT a function after running out of space, we store
291 // the estimated size of the function we're trying to JIT here, so we can
292 // ask the memory manager for at least this much space. When we
293 // successfully emit the function, we reset this back to zero.
294 uintptr_t SizeEstimate;
296 /// Relocations - These are the relocations that the function needs, as
298 std::vector<MachineRelocation> Relocations;
300 /// MBBLocations - This vector is a mapping from MBB ID's to their address.
301 /// It is filled in by the StartMachineBasicBlock callback and queried by
302 /// the getMachineBasicBlockAddress callback.
303 std::vector<uintptr_t> MBBLocations;
305 /// ConstantPool - The constant pool for the current function.
307 MachineConstantPool *ConstantPool;
309 /// ConstantPoolBase - A pointer to the first entry in the constant pool.
311 void *ConstantPoolBase;
313 /// ConstPoolAddresses - Addresses of individual constant pool entries.
315 SmallVector<uintptr_t, 8> ConstPoolAddresses;
317 /// JumpTable - The jump tables for the current function.
319 MachineJumpTableInfo *JumpTable;
321 /// JumpTableBase - A pointer to the first entry in the jump table.
325 /// Resolver - This contains info about the currently resolved functions.
326 JITResolver Resolver;
328 /// DE - The dwarf emitter for the jit.
329 OwningPtr<JITDwarfEmitter> DE;
331 /// LabelLocations - This vector is a mapping from Label ID's to their
333 DenseMap<MCSymbol*, uintptr_t> LabelLocations;
335 /// MMI - Machine module info for exception informations
336 MachineModuleInfo* MMI;
338 // CurFn - The llvm function being emitted. Only valid during
340 const Function *CurFn;
342 /// Information about emitted code, which is passed to the
343 /// JITEventListeners. This is reset in startFunction and used in
345 JITEvent_EmittedFunctionDetails EmissionDetails;
348 void *FunctionBody; // Beginning of the function's allocation.
349 void *Code; // The address the function's code actually starts at.
350 void *ExceptionTable;
351 EmittedCode() : FunctionBody(0), Code(0), ExceptionTable(0) {}
353 struct EmittedFunctionConfig : public ValueMapConfig<const Function*> {
354 typedef JITEmitter *ExtraData;
355 static void onDelete(JITEmitter *, const Function*);
356 static void onRAUW(JITEmitter *, const Function*, const Function*);
358 ValueMap<const Function *, EmittedCode,
359 EmittedFunctionConfig> EmittedFunctions;
363 /// Instance of the JIT
366 bool JITExceptionHandling;
369 JITEmitter(JIT &jit, JITMemoryManager *JMM, TargetMachine &TM)
370 : SizeEstimate(0), Resolver(jit, *this), MMI(0), CurFn(0),
371 EmittedFunctions(this), TheJIT(&jit),
372 JITExceptionHandling(TM.Options.JITExceptionHandling) {
373 MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager();
374 if (jit.getJITInfo().needsGOT()) {
375 MemMgr->AllocateGOT();
376 DEBUG(dbgs() << "JIT is managing a GOT\n");
379 if (JITExceptionHandling) {
380 DE.reset(new JITDwarfEmitter(jit));
387 /// classof - Methods for support type inquiry through isa, cast, and
390 static inline bool classof(const MachineCodeEmitter*) { return true; }
392 JITResolver &getJITResolver() { return Resolver; }
394 virtual void startFunction(MachineFunction &F);
395 virtual bool finishFunction(MachineFunction &F);
397 void emitConstantPool(MachineConstantPool *MCP);
398 void initJumpTableInfo(MachineJumpTableInfo *MJTI);
399 void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
401 void startGVStub(const GlobalValue* GV,
402 unsigned StubSize, unsigned Alignment = 1);
403 void startGVStub(void *Buffer, unsigned StubSize);
405 virtual void *allocIndirectGV(const GlobalValue *GV,
406 const uint8_t *Buffer, size_t Size,
409 /// allocateSpace - Reserves space in the current block if any, or
410 /// allocate a new one of the given size.
411 virtual void *allocateSpace(uintptr_t Size, unsigned Alignment);
413 /// allocateGlobal - Allocate memory for a global. Unlike allocateSpace,
414 /// this method does not allocate memory in the current output buffer,
415 /// because a global may live longer than the current function.
416 virtual void *allocateGlobal(uintptr_t Size, unsigned Alignment);
418 virtual void addRelocation(const MachineRelocation &MR) {
419 Relocations.push_back(MR);
422 virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
423 if (MBBLocations.size() <= (unsigned)MBB->getNumber())
424 MBBLocations.resize((MBB->getNumber()+1)*2);
425 MBBLocations[MBB->getNumber()] = getCurrentPCValue();
426 if (MBB->hasAddressTaken())
427 TheJIT->addPointerToBasicBlock(MBB->getBasicBlock(),
428 (void*)getCurrentPCValue());
429 DEBUG(dbgs() << "JIT: Emitting BB" << MBB->getNumber() << " at ["
430 << (void*) getCurrentPCValue() << "]\n");
433 virtual uintptr_t getConstantPoolEntryAddress(unsigned Entry) const;
434 virtual uintptr_t getJumpTableEntryAddress(unsigned Entry) const;
436 virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const{
437 assert(MBBLocations.size() > (unsigned)MBB->getNumber() &&
438 MBBLocations[MBB->getNumber()] && "MBB not emitted!");
439 return MBBLocations[MBB->getNumber()];
442 /// retryWithMoreMemory - Log a retry and deallocate all memory for the
443 /// given function. Increase the minimum allocation size so that we get
444 /// more memory next time.
445 void retryWithMoreMemory(MachineFunction &F);
447 /// deallocateMemForFunction - Deallocate all memory for the specified
449 void deallocateMemForFunction(const Function *F);
451 virtual void processDebugLoc(DebugLoc DL, bool BeforePrintingInsn);
453 virtual void emitLabel(MCSymbol *Label) {
454 LabelLocations[Label] = getCurrentPCValue();
457 virtual DenseMap<MCSymbol*, uintptr_t> *getLabelLocations() {
458 return &LabelLocations;
461 virtual uintptr_t getLabelAddress(MCSymbol *Label) const {
462 assert(LabelLocations.count(Label) && "Label not emitted!");
463 return LabelLocations.find(Label)->second;
466 virtual void setModuleInfo(MachineModuleInfo* Info) {
468 if (DE.get()) DE->setModuleInfo(Info);
472 void *getPointerToGlobal(GlobalValue *GV, void *Reference,
473 bool MayNeedFarStub);
474 void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference);
478 void CallSiteValueMapConfig::onDelete(JITResolverState *JRS, Function *F) {
479 JRS->EraseAllCallSitesForPrelocked(F);
482 void JITResolverState::EraseAllCallSitesForPrelocked(Function *F) {
483 FunctionToCallSitesMapTy::iterator F2C = FunctionToCallSitesMap.find(F);
484 if (F2C == FunctionToCallSitesMap.end())
486 StubToResolverMapTy &S2RMap = *StubToResolverMap;
487 for (SmallPtrSet<void*, 1>::const_iterator I = F2C->second.begin(),
488 E = F2C->second.end(); I != E; ++I) {
489 S2RMap.UnregisterStubResolver(*I);
490 bool Erased = CallSiteToFunctionMap.erase(*I);
492 assert(Erased && "Missing call site->function mapping");
494 FunctionToCallSitesMap.erase(F2C);
497 void JITResolverState::EraseAllCallSitesPrelocked() {
498 StubToResolverMapTy &S2RMap = *StubToResolverMap;
499 for (CallSiteToFunctionMapTy::const_iterator
500 I = CallSiteToFunctionMap.begin(),
501 E = CallSiteToFunctionMap.end(); I != E; ++I) {
502 S2RMap.UnregisterStubResolver(I->first);
504 CallSiteToFunctionMap.clear();
505 FunctionToCallSitesMap.clear();
508 JITResolver::~JITResolver() {
509 // No need to lock because we're in the destructor, and state isn't shared.
510 state.EraseAllCallSitesPrelocked();
511 assert(!StubToResolverMap->ResolverHasStubs(this) &&
512 "Resolver destroyed with stubs still alive.");
515 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function stub
516 /// if it has already been created.
517 void *JITResolver::getLazyFunctionStubIfAvailable(Function *F) {
518 MutexGuard locked(TheJIT->lock);
520 // If we already have a stub for this function, recycle it.
521 return state.getFunctionToLazyStubMap(locked).lookup(F);
524 /// getFunctionStub - This returns a pointer to a function stub, creating
525 /// one on demand as needed.
526 void *JITResolver::getLazyFunctionStub(Function *F) {
527 MutexGuard locked(TheJIT->lock);
529 // If we already have a lazy stub for this function, recycle it.
530 void *&Stub = state.getFunctionToLazyStubMap(locked)[F];
531 if (Stub) return Stub;
533 // Call the lazy resolver function if we are JIT'ing lazily. Otherwise we
534 // must resolve the symbol now.
535 void *Actual = TheJIT->isCompilingLazily()
536 ? (void *)(intptr_t)LazyResolverFn : (void *)0;
538 // If this is an external declaration, attempt to resolve the address now
539 // to place in the stub.
540 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage()) {
541 Actual = TheJIT->getPointerToFunction(F);
543 // If we resolved the symbol to a null address (eg. a weak external)
544 // don't emit a stub. Return a null pointer to the application.
545 if (!Actual) return 0;
548 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
549 JE.startGVStub(F, SL.Size, SL.Alignment);
550 // Codegen a new stub, calling the lazy resolver or the actual address of the
551 // external function, if it was resolved.
552 Stub = TheJIT->getJITInfo().emitFunctionStub(F, Actual, JE);
555 if (Actual != (void*)(intptr_t)LazyResolverFn) {
556 // If we are getting the stub for an external function, we really want the
557 // address of the stub in the GlobalAddressMap for the JIT, not the address
558 // of the external function.
559 TheJIT->updateGlobalMapping(F, Stub);
562 DEBUG(dbgs() << "JIT: Lazy stub emitted at [" << Stub << "] for function '"
563 << F->getName() << "'\n");
565 if (TheJIT->isCompilingLazily()) {
566 // Register this JITResolver as the one corresponding to this call site so
567 // JITCompilerFn will be able to find it.
568 StubToResolverMap->RegisterStubResolver(Stub, this);
570 // Finally, keep track of the stub-to-Function mapping so that the
571 // JITCompilerFn knows which function to compile!
572 state.AddCallSite(locked, Stub, F);
573 } else if (!Actual) {
574 // If we are JIT'ing non-lazily but need to call a function that does not
575 // exist yet, add it to the JIT's work list so that we can fill in the
576 // stub address later.
577 assert(!isNonGhostDeclaration(F) && !F->hasAvailableExternallyLinkage() &&
578 "'Actual' should have been set above.");
579 TheJIT->addPendingFunction(F);
585 /// getGlobalValueIndirectSym - Return a lazy pointer containing the specified
587 void *JITResolver::getGlobalValueIndirectSym(GlobalValue *GV, void *GVAddress) {
588 MutexGuard locked(TheJIT->lock);
590 // If we already have a stub for this global variable, recycle it.
591 void *&IndirectSym = state.getGlobalToIndirectSymMap(locked)[GV];
592 if (IndirectSym) return IndirectSym;
594 // Otherwise, codegen a new indirect symbol.
595 IndirectSym = TheJIT->getJITInfo().emitGlobalValueIndirectSym(GV, GVAddress,
598 DEBUG(dbgs() << "JIT: Indirect symbol emitted at [" << IndirectSym
599 << "] for GV '" << GV->getName() << "'\n");
604 /// getExternalFunctionStub - Return a stub for the function at the
605 /// specified address, created lazily on demand.
606 void *JITResolver::getExternalFunctionStub(void *FnAddr) {
607 // If we already have a stub for this function, recycle it.
608 void *&Stub = ExternalFnToStubMap[FnAddr];
609 if (Stub) return Stub;
611 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
612 JE.startGVStub(0, SL.Size, SL.Alignment);
613 Stub = TheJIT->getJITInfo().emitFunctionStub(0, FnAddr, JE);
616 DEBUG(dbgs() << "JIT: Stub emitted at [" << Stub
617 << "] for external function at '" << FnAddr << "'\n");
621 unsigned JITResolver::getGOTIndexForAddr(void* addr) {
622 unsigned idx = revGOTMap[addr];
624 idx = ++nextGOTIndex;
625 revGOTMap[addr] = idx;
626 DEBUG(dbgs() << "JIT: Adding GOT entry " << idx << " for addr ["
632 /// JITCompilerFn - This function is called when a lazy compilation stub has
633 /// been entered. It looks up which function this stub corresponds to, compiles
634 /// it if necessary, then returns the resultant function pointer.
635 void *JITResolver::JITCompilerFn(void *Stub) {
636 JITResolver *JR = StubToResolverMap->getResolverFromStub(Stub);
637 assert(JR && "Unable to find the corresponding JITResolver to the call site");
643 // Only lock for getting the Function. The call getPointerToFunction made
644 // in this function might trigger function materializing, which requires
645 // JIT lock to be unlocked.
646 MutexGuard locked(JR->TheJIT->lock);
648 // The address given to us for the stub may not be exactly right, it might
649 // be a little bit after the stub. As such, use upper_bound to find it.
650 std::pair<void*, Function*> I =
651 JR->state.LookupFunctionFromCallSite(locked, Stub);
656 // If we have already code generated the function, just return the address.
657 void *Result = JR->TheJIT->getPointerToGlobalIfAvailable(F);
660 // Otherwise we don't have it, do lazy compilation now.
662 // If lazy compilation is disabled, emit a useful error message and abort.
663 if (!JR->TheJIT->isCompilingLazily()) {
664 report_fatal_error("LLVM JIT requested to do lazy compilation of"
666 + F->getName() + "' when lazy compiles are disabled!");
669 DEBUG(dbgs() << "JIT: Lazily resolving function '" << F->getName()
670 << "' In stub ptr = " << Stub << " actual ptr = "
671 << ActualPtr << "\n");
674 Result = JR->TheJIT->getPointerToFunction(F);
677 // Reacquire the lock to update the GOT map.
678 MutexGuard locked(JR->TheJIT->lock);
680 // We might like to remove the call site from the CallSiteToFunction map, but
681 // we can't do that! Multiple threads could be stuck, waiting to acquire the
682 // lock above. As soon as the 1st function finishes compiling the function,
683 // the next one will be released, and needs to be able to find the function it
686 // FIXME: We could rewrite all references to this stub if we knew them.
688 // What we will do is set the compiled function address to map to the
689 // same GOT entry as the stub so that later clients may update the GOT
690 // if they see it still using the stub address.
691 // Note: this is done so the Resolver doesn't have to manage GOT memory
692 // Do this without allocating map space if the target isn't using a GOT
693 if(JR->revGOTMap.find(Stub) != JR->revGOTMap.end())
694 JR->revGOTMap[Result] = JR->revGOTMap[Stub];
699 //===----------------------------------------------------------------------===//
702 void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
703 bool MayNeedFarStub) {
704 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
705 return TheJIT->getOrEmitGlobalVariable(GV);
707 if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
708 return TheJIT->getPointerToGlobal(GA->resolveAliasedGlobal(false));
710 // If we have already compiled the function, return a pointer to its body.
711 Function *F = cast<Function>(V);
713 void *FnStub = Resolver.getLazyFunctionStubIfAvailable(F);
715 // Return the function stub if it's already created. We do this first so
716 // that we're returning the same address for the function as any previous
717 // call. TODO: Yes, this is wrong. The lazy stub isn't guaranteed to be
718 // close enough to call.
722 // If we know the target can handle arbitrary-distance calls, try to
723 // return a direct pointer.
724 if (!MayNeedFarStub) {
725 // If we have code, go ahead and return that.
726 void *ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
727 if (ResultPtr) return ResultPtr;
729 // If this is an external function pointer, we can force the JIT to
730 // 'compile' it, which really just adds it to the map.
731 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage())
732 return TheJIT->getPointerToFunction(F);
735 // Otherwise, we may need a to emit a stub, and, conservatively, we always do
736 // so. Note that it's possible to return null from getLazyFunctionStub in the
737 // case of a weak extern that fails to resolve.
738 return Resolver.getLazyFunctionStub(F);
741 void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) {
742 // Make sure GV is emitted first, and create a stub containing the fully
744 void *GVAddress = getPointerToGlobal(V, Reference, false);
745 void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress);
749 void JITEmitter::processDebugLoc(DebugLoc DL, bool BeforePrintingInsn) {
750 if (DL.isUnknown()) return;
751 if (!BeforePrintingInsn) return;
753 const LLVMContext &Context = EmissionDetails.MF->getFunction()->getContext();
755 if (DL.getScope(Context) != 0 && PrevDL != DL) {
756 JITEvent_EmittedFunctionDetails::LineStart NextLine;
757 NextLine.Address = getCurrentPCValue();
759 EmissionDetails.LineStarts.push_back(NextLine);
765 static unsigned GetConstantPoolSizeInBytes(MachineConstantPool *MCP,
766 const TargetData *TD) {
767 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
768 if (Constants.empty()) return 0;
771 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
772 MachineConstantPoolEntry CPE = Constants[i];
773 unsigned AlignMask = CPE.getAlignment() - 1;
774 Size = (Size + AlignMask) & ~AlignMask;
775 Type *Ty = CPE.getType();
776 Size += TD->getTypeAllocSize(Ty);
781 void JITEmitter::startFunction(MachineFunction &F) {
782 DEBUG(dbgs() << "JIT: Starting CodeGen of Function "
783 << F.getFunction()->getName() << "\n");
785 uintptr_t ActualSize = 0;
786 // Set the memory writable, if it's not already
787 MemMgr->setMemoryWritable();
789 if (SizeEstimate > 0) {
790 // SizeEstimate will be non-zero on reallocation attempts.
791 ActualSize = SizeEstimate;
794 BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(),
796 BufferEnd = BufferBegin+ActualSize;
797 EmittedFunctions[F.getFunction()].FunctionBody = BufferBegin;
799 // Ensure the constant pool/jump table info is at least 4-byte aligned.
802 emitConstantPool(F.getConstantPool());
803 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
804 initJumpTableInfo(MJTI);
806 // About to start emitting the machine code for the function.
807 emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
808 TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
809 EmittedFunctions[F.getFunction()].Code = CurBufferPtr;
811 MBBLocations.clear();
813 EmissionDetails.MF = &F;
814 EmissionDetails.LineStarts.clear();
817 bool JITEmitter::finishFunction(MachineFunction &F) {
818 if (CurBufferPtr == BufferEnd) {
819 // We must call endFunctionBody before retrying, because
820 // deallocateMemForFunction requires it.
821 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
822 retryWithMoreMemory(F);
826 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
827 emitJumpTableInfo(MJTI);
829 // FnStart is the start of the text, not the start of the constant pool and
830 // other per-function data.
832 (uint8_t *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
834 // FnEnd is the end of the function's machine code.
835 uint8_t *FnEnd = CurBufferPtr;
837 if (!Relocations.empty()) {
838 CurFn = F.getFunction();
839 NumRelos += Relocations.size();
841 // Resolve the relocations to concrete pointers.
842 for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
843 MachineRelocation &MR = Relocations[i];
845 if (!MR.letTargetResolve()) {
846 if (MR.isExternalSymbol()) {
847 ResultPtr = TheJIT->getPointerToNamedFunction(MR.getExternalSymbol(),
849 DEBUG(dbgs() << "JIT: Map \'" << MR.getExternalSymbol() << "\' to ["
850 << ResultPtr << "]\n");
852 // If the target REALLY wants a stub for this function, emit it now.
853 if (MR.mayNeedFarStub()) {
854 ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
856 } else if (MR.isGlobalValue()) {
857 ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
858 BufferBegin+MR.getMachineCodeOffset(),
859 MR.mayNeedFarStub());
860 } else if (MR.isIndirectSymbol()) {
861 ResultPtr = getPointerToGVIndirectSym(
862 MR.getGlobalValue(), BufferBegin+MR.getMachineCodeOffset());
863 } else if (MR.isBasicBlock()) {
864 ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
865 } else if (MR.isConstantPoolIndex()) {
867 (void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
869 assert(MR.isJumpTableIndex());
870 ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
873 MR.setResultPointer(ResultPtr);
876 // if we are managing the GOT and the relocation wants an index,
878 if (MR.isGOTRelative() && MemMgr->isManagingGOT()) {
879 unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
881 if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) {
882 DEBUG(dbgs() << "JIT: GOT was out of date for " << ResultPtr
883 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
885 ((void**)MemMgr->getGOTBase())[idx] = ResultPtr;
891 TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
892 Relocations.size(), MemMgr->getGOTBase());
895 // Update the GOT entry for F to point to the new code.
896 if (MemMgr->isManagingGOT()) {
897 unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
898 if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) {
899 DEBUG(dbgs() << "JIT: GOT was out of date for " << (void*)BufferBegin
900 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
902 ((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin;
906 // CurBufferPtr may have moved beyond FnEnd, due to memory allocation for
907 // global variables that were referenced in the relocations.
908 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
910 if (CurBufferPtr == BufferEnd) {
911 retryWithMoreMemory(F);
914 // Now that we've succeeded in emitting the function, reset the
915 // SizeEstimate back down to zero.
919 BufferBegin = CurBufferPtr = 0;
920 NumBytes += FnEnd-FnStart;
922 // Invalidate the icache if necessary.
923 sys::Memory::InvalidateInstructionCache(FnStart, FnEnd-FnStart);
925 TheJIT->NotifyFunctionEmitted(*F.getFunction(), FnStart, FnEnd-FnStart,
928 // Reset the previous debug location.
931 DEBUG(dbgs() << "JIT: Finished CodeGen of [" << (void*)FnStart
932 << "] Function: " << F.getFunction()->getName()
933 << ": " << (FnEnd-FnStart) << " bytes of text, "
934 << Relocations.size() << " relocations\n");
937 ConstPoolAddresses.clear();
939 // Mark code region readable and executable if it's not so already.
940 MemMgr->setMemoryExecutable();
943 if (sys::hasDisassembler()) {
944 dbgs() << "JIT: Disassembled code:\n";
945 dbgs() << sys::disassembleBuffer(FnStart, FnEnd-FnStart,
948 dbgs() << "JIT: Binary code:\n";
949 uint8_t* q = FnStart;
950 for (int i = 0; q < FnEnd; q += 4, ++i) {
954 dbgs() << "JIT: " << (long)(q - FnStart) << ": ";
956 for (int j = 3; j >= 0; --j) {
960 dbgs() << (unsigned short)q[j];
972 if (JITExceptionHandling) {
973 uintptr_t ActualSize = 0;
974 SavedBufferBegin = BufferBegin;
975 SavedBufferEnd = BufferEnd;
976 SavedCurBufferPtr = CurBufferPtr;
978 BufferBegin = CurBufferPtr = MemMgr->startExceptionTable(F.getFunction(),
980 BufferEnd = BufferBegin+ActualSize;
981 EmittedFunctions[F.getFunction()].ExceptionTable = BufferBegin;
983 uint8_t *FrameRegister = DE->EmitDwarfTable(F, *this, FnStart, FnEnd,
985 MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr,
987 BufferBegin = SavedBufferBegin;
988 BufferEnd = SavedBufferEnd;
989 CurBufferPtr = SavedCurBufferPtr;
991 if (JITExceptionHandling) {
992 TheJIT->RegisterTable(F.getFunction(), FrameRegister);
1002 void JITEmitter::retryWithMoreMemory(MachineFunction &F) {
1003 DEBUG(dbgs() << "JIT: Ran out of space for native code. Reattempting.\n");
1004 Relocations.clear(); // Clear the old relocations or we'll reapply them.
1005 ConstPoolAddresses.clear();
1007 deallocateMemForFunction(F.getFunction());
1008 // Try again with at least twice as much free space.
1009 SizeEstimate = (uintptr_t)(2 * (BufferEnd - BufferBegin));
1011 for (MachineFunction::iterator MBB = F.begin(), E = F.end(); MBB != E; ++MBB){
1012 if (MBB->hasAddressTaken())
1013 TheJIT->clearPointerToBasicBlock(MBB->getBasicBlock());
1017 /// deallocateMemForFunction - Deallocate all memory for the specified
1018 /// function body. Also drop any references the function has to stubs.
1019 /// May be called while the Function is being destroyed inside ~Value().
1020 void JITEmitter::deallocateMemForFunction(const Function *F) {
1021 ValueMap<const Function *, EmittedCode, EmittedFunctionConfig>::iterator
1022 Emitted = EmittedFunctions.find(F);
1023 if (Emitted != EmittedFunctions.end()) {
1024 MemMgr->deallocateFunctionBody(Emitted->second.FunctionBody);
1025 MemMgr->deallocateExceptionTable(Emitted->second.ExceptionTable);
1026 TheJIT->NotifyFreeingMachineCode(Emitted->second.Code);
1028 EmittedFunctions.erase(Emitted);
1031 if (JITExceptionHandling) {
1032 TheJIT->DeregisterTable(F);
1037 void *JITEmitter::allocateSpace(uintptr_t Size, unsigned Alignment) {
1039 return JITCodeEmitter::allocateSpace(Size, Alignment);
1041 // create a new memory block if there is no active one.
1042 // care must be taken so that BufferBegin is invalidated when a
1044 BufferBegin = CurBufferPtr = MemMgr->allocateSpace(Size, Alignment);
1045 BufferEnd = BufferBegin+Size;
1046 return CurBufferPtr;
1049 void *JITEmitter::allocateGlobal(uintptr_t Size, unsigned Alignment) {
1050 // Delegate this call through the memory manager.
1051 return MemMgr->allocateGlobal(Size, Alignment);
1054 void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
1055 if (TheJIT->getJITInfo().hasCustomConstantPool())
1058 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
1059 if (Constants.empty()) return;
1061 unsigned Size = GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1062 unsigned Align = MCP->getConstantPoolAlignment();
1063 ConstantPoolBase = allocateSpace(Size, Align);
1066 if (ConstantPoolBase == 0) return; // Buffer overflow.
1068 DEBUG(dbgs() << "JIT: Emitted constant pool at [" << ConstantPoolBase
1069 << "] (size: " << Size << ", alignment: " << Align << ")\n");
1071 // Initialize the memory for all of the constant pool entries.
1072 unsigned Offset = 0;
1073 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
1074 MachineConstantPoolEntry CPE = Constants[i];
1075 unsigned AlignMask = CPE.getAlignment() - 1;
1076 Offset = (Offset + AlignMask) & ~AlignMask;
1078 uintptr_t CAddr = (uintptr_t)ConstantPoolBase + Offset;
1079 ConstPoolAddresses.push_back(CAddr);
1080 if (CPE.isMachineConstantPoolEntry()) {
1081 // FIXME: add support to lower machine constant pool values into bytes!
1082 report_fatal_error("Initialize memory with machine specific constant pool"
1083 "entry has not been implemented!");
1085 TheJIT->InitializeMemory(CPE.Val.ConstVal, (void*)CAddr);
1086 DEBUG(dbgs() << "JIT: CP" << i << " at [0x";
1087 dbgs().write_hex(CAddr) << "]\n");
1089 Type *Ty = CPE.Val.ConstVal->getType();
1090 Offset += TheJIT->getTargetData()->getTypeAllocSize(Ty);
1094 void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
1095 if (TheJIT->getJITInfo().hasCustomJumpTables())
1097 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline)
1100 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1101 if (JT.empty()) return;
1103 unsigned NumEntries = 0;
1104 for (unsigned i = 0, e = JT.size(); i != e; ++i)
1105 NumEntries += JT[i].MBBs.size();
1107 unsigned EntrySize = MJTI->getEntrySize(*TheJIT->getTargetData());
1109 // Just allocate space for all the jump tables now. We will fix up the actual
1110 // MBB entries in the tables after we emit the code for each block, since then
1111 // we will know the final locations of the MBBs in memory.
1113 JumpTableBase = allocateSpace(NumEntries * EntrySize,
1114 MJTI->getEntryAlignment(*TheJIT->getTargetData()));
1117 void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
1118 if (TheJIT->getJITInfo().hasCustomJumpTables())
1121 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1122 if (JT.empty() || JumpTableBase == 0) return;
1125 switch (MJTI->getEntryKind()) {
1126 case MachineJumpTableInfo::EK_Inline:
1128 case MachineJumpTableInfo::EK_BlockAddress: {
1129 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1131 assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == sizeof(void*) &&
1134 // For each jump table, map each target in the jump table to the address of
1135 // an emitted MachineBasicBlock.
1136 intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
1138 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1139 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1140 // Store the address of the basic block for this jump table slot in the
1141 // memory we allocated for the jump table in 'initJumpTableInfo'
1142 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
1143 *SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
1148 case MachineJumpTableInfo::EK_Custom32:
1149 case MachineJumpTableInfo::EK_GPRel32BlockAddress:
1150 case MachineJumpTableInfo::EK_LabelDifference32: {
1151 assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == 4&&"Cross JIT'ing?");
1152 // For each jump table, place the offset from the beginning of the table
1153 // to the target address.
1154 int *SlotPtr = (int*)JumpTableBase;
1156 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1157 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1158 // Store the offset of the basic block for this jump table slot in the
1159 // memory we allocated for the jump table in 'initJumpTableInfo'
1160 uintptr_t Base = (uintptr_t)SlotPtr;
1161 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) {
1162 uintptr_t MBBAddr = getMachineBasicBlockAddress(MBBs[mi]);
1163 /// FIXME: USe EntryKind instead of magic "getPICJumpTableEntry" hook.
1164 *SlotPtr++ = TheJIT->getJITInfo().getPICJumpTableEntry(MBBAddr, Base);
1169 case MachineJumpTableInfo::EK_GPRel64BlockAddress:
1171 "JT Info emission not implemented for GPRel64BlockAddress yet.");
1175 void JITEmitter::startGVStub(const GlobalValue* GV,
1176 unsigned StubSize, unsigned Alignment) {
1177 SavedBufferBegin = BufferBegin;
1178 SavedBufferEnd = BufferEnd;
1179 SavedCurBufferPtr = CurBufferPtr;
1181 BufferBegin = CurBufferPtr = MemMgr->allocateStub(GV, StubSize, Alignment);
1182 BufferEnd = BufferBegin+StubSize+1;
1185 void JITEmitter::startGVStub(void *Buffer, unsigned StubSize) {
1186 SavedBufferBegin = BufferBegin;
1187 SavedBufferEnd = BufferEnd;
1188 SavedCurBufferPtr = CurBufferPtr;
1190 BufferBegin = CurBufferPtr = (uint8_t *)Buffer;
1191 BufferEnd = BufferBegin+StubSize+1;
1194 void JITEmitter::finishGVStub() {
1195 assert(CurBufferPtr != BufferEnd && "Stub overflowed allocated space.");
1196 NumBytes += getCurrentPCOffset();
1197 BufferBegin = SavedBufferBegin;
1198 BufferEnd = SavedBufferEnd;
1199 CurBufferPtr = SavedCurBufferPtr;
1202 void *JITEmitter::allocIndirectGV(const GlobalValue *GV,
1203 const uint8_t *Buffer, size_t Size,
1204 unsigned Alignment) {
1205 uint8_t *IndGV = MemMgr->allocateStub(GV, Size, Alignment);
1206 memcpy(IndGV, Buffer, Size);
1210 // getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
1211 // in the constant pool that was last emitted with the 'emitConstantPool'
1214 uintptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const {
1215 assert(ConstantNum < ConstantPool->getConstants().size() &&
1216 "Invalid ConstantPoolIndex!");
1217 return ConstPoolAddresses[ConstantNum];
1220 // getJumpTableEntryAddress - Return the address of the JumpTable with index
1221 // 'Index' in the jumpp table that was last initialized with 'initJumpTableInfo'
1223 uintptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
1224 const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
1225 assert(Index < JT.size() && "Invalid jump table index!");
1227 unsigned EntrySize = JumpTable->getEntrySize(*TheJIT->getTargetData());
1229 unsigned Offset = 0;
1230 for (unsigned i = 0; i < Index; ++i)
1231 Offset += JT[i].MBBs.size();
1233 Offset *= EntrySize;
1235 return (uintptr_t)((char *)JumpTableBase + Offset);
1238 void JITEmitter::EmittedFunctionConfig::onDelete(
1239 JITEmitter *Emitter, const Function *F) {
1240 Emitter->deallocateMemForFunction(F);
1242 void JITEmitter::EmittedFunctionConfig::onRAUW(
1243 JITEmitter *, const Function*, const Function*) {
1244 llvm_unreachable("The JIT doesn't know how to handle a"
1245 " RAUW on a value it has emitted.");
1249 //===----------------------------------------------------------------------===//
1250 // Public interface to this file
1251 //===----------------------------------------------------------------------===//
1253 JITCodeEmitter *JIT::createEmitter(JIT &jit, JITMemoryManager *JMM,
1254 TargetMachine &tm) {
1255 return new JITEmitter(jit, JMM, tm);
1258 // getPointerToFunctionOrStub - If the specified function has been
1259 // code-gen'd, return a pointer to the function. If not, compile it, or use
1260 // a stub to implement lazy compilation if available.
1262 void *JIT::getPointerToFunctionOrStub(Function *F) {
1263 // If we have already code generated the function, just return the address.
1264 if (void *Addr = getPointerToGlobalIfAvailable(F))
1267 // Get a stub if the target supports it.
1268 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1269 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1270 return JE->getJITResolver().getLazyFunctionStub(F);
1273 void JIT::updateFunctionStub(Function *F) {
1274 // Get the empty stub we generated earlier.
1275 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1276 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1277 void *Stub = JE->getJITResolver().getLazyFunctionStub(F);
1278 void *Addr = getPointerToGlobalIfAvailable(F);
1279 assert(Addr != Stub && "Function must have non-stub address to be updated.");
1281 // Tell the target jit info to rewrite the stub at the specified address,
1282 // rather than creating a new one.
1283 TargetJITInfo::StubLayout layout = getJITInfo().getStubLayout();
1284 JE->startGVStub(Stub, layout.Size);
1285 getJITInfo().emitFunctionStub(F, Addr, *getCodeEmitter());
1289 /// freeMachineCodeForFunction - release machine code memory for given Function.
1291 void JIT::freeMachineCodeForFunction(Function *F) {
1292 // Delete translation for this from the ExecutionEngine, so it will get
1293 // retranslated next time it is used.
1294 updateGlobalMapping(F, 0);
1296 // Free the actual memory for the function body and related stuff.
1297 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1298 cast<JITEmitter>(JCE)->deallocateMemForFunction(F);