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 "JITDebugRegisterer.h"
18 #include "JITDwarfEmitter.h"
19 #include "llvm/ADT/OwningPtr.h"
20 #include "llvm/Constants.h"
21 #include "llvm/Module.h"
22 #include "llvm/DerivedTypes.h"
23 #include "llvm/Analysis/DebugInfo.h"
24 #include "llvm/CodeGen/JITCodeEmitter.h"
25 #include "llvm/CodeGen/MachineFunction.h"
26 #include "llvm/CodeGen/MachineCodeInfo.h"
27 #include "llvm/CodeGen/MachineConstantPool.h"
28 #include "llvm/CodeGen/MachineJumpTableInfo.h"
29 #include "llvm/CodeGen/MachineModuleInfo.h"
30 #include "llvm/CodeGen/MachineRelocation.h"
31 #include "llvm/ExecutionEngine/GenericValue.h"
32 #include "llvm/ExecutionEngine/JITEventListener.h"
33 #include "llvm/ExecutionEngine/JITMemoryManager.h"
34 #include "llvm/Target/TargetData.h"
35 #include "llvm/Target/TargetInstrInfo.h"
36 #include "llvm/Target/TargetJITInfo.h"
37 #include "llvm/Target/TargetMachine.h"
38 #include "llvm/Target/TargetOptions.h"
39 #include "llvm/Support/Debug.h"
40 #include "llvm/Support/ErrorHandling.h"
41 #include "llvm/Support/ManagedStatic.h"
42 #include "llvm/Support/MutexGuard.h"
43 #include "llvm/Support/ValueHandle.h"
44 #include "llvm/Support/raw_ostream.h"
45 #include "llvm/Support/Disassembler.h"
46 #include "llvm/Support/Memory.h"
47 #include "llvm/ADT/DenseMap.h"
48 #include "llvm/ADT/SmallPtrSet.h"
49 #include "llvm/ADT/SmallVector.h"
50 #include "llvm/ADT/Statistic.h"
51 #include "llvm/ADT/ValueMap.h"
58 STATISTIC(NumBytes, "Number of bytes of machine code compiled");
59 STATISTIC(NumRelos, "Number of relocations applied");
60 STATISTIC(NumRetries, "Number of retries with more memory");
63 // A declaration may stop being a declaration once it's fully read from bitcode.
64 // This function returns true if F is fully read and is still a declaration.
65 static bool isNonGhostDeclaration(const Function *F) {
66 return F->isDeclaration() && !F->isMaterializable();
69 //===----------------------------------------------------------------------===//
70 // JIT lazy compilation code.
74 class JITResolverState;
76 template<typename ValueTy>
77 struct NoRAUWValueMapConfig : public ValueMapConfig<ValueTy> {
78 typedef JITResolverState *ExtraData;
79 static void onRAUW(JITResolverState *, Value *Old, Value *New) {
80 assert(false && "The JIT doesn't know how to handle a"
81 " RAUW on a value it has emitted.");
85 struct CallSiteValueMapConfig : public NoRAUWValueMapConfig<Function*> {
86 typedef JITResolverState *ExtraData;
87 static void onDelete(JITResolverState *JRS, Function *F);
90 class JITResolverState {
92 typedef ValueMap<Function*, void*, NoRAUWValueMapConfig<Function*> >
93 FunctionToLazyStubMapTy;
94 typedef std::map<void*, AssertingVH<Function> > CallSiteToFunctionMapTy;
95 typedef ValueMap<Function *, SmallPtrSet<void*, 1>,
96 CallSiteValueMapConfig> FunctionToCallSitesMapTy;
97 typedef std::map<AssertingVH<GlobalValue>, void*> GlobalToIndirectSymMapTy;
99 /// FunctionToLazyStubMap - Keep track of the lazy stub created for a
100 /// particular function so that we can reuse them if necessary.
101 FunctionToLazyStubMapTy FunctionToLazyStubMap;
103 /// CallSiteToFunctionMap - Keep track of the function that each lazy call
104 /// site corresponds to, and vice versa.
105 CallSiteToFunctionMapTy CallSiteToFunctionMap;
106 FunctionToCallSitesMapTy FunctionToCallSitesMap;
108 /// GlobalToIndirectSymMap - Keep track of the indirect symbol created for a
109 /// particular GlobalVariable so that we can reuse them if necessary.
110 GlobalToIndirectSymMapTy GlobalToIndirectSymMap;
112 /// Instance of the JIT this ResolverState serves.
116 JITResolverState(JIT *jit) : FunctionToLazyStubMap(this),
117 FunctionToCallSitesMap(this),
120 FunctionToLazyStubMapTy& getFunctionToLazyStubMap(
121 const MutexGuard& locked) {
122 assert(locked.holds(TheJIT->lock));
123 return FunctionToLazyStubMap;
126 GlobalToIndirectSymMapTy& getGlobalToIndirectSymMap(const MutexGuard& locked) {
127 assert(locked.holds(TheJIT->lock));
128 return GlobalToIndirectSymMap;
131 pair<void *, Function *> LookupFunctionFromCallSite(
132 const MutexGuard &locked, void *CallSite) const {
133 assert(locked.holds(TheJIT->lock));
135 // The address given to us for the stub may not be exactly right, it might be
136 // a little bit after the stub. As such, use upper_bound to find it.
137 CallSiteToFunctionMapTy::const_iterator I =
138 CallSiteToFunctionMap.upper_bound(CallSite);
139 assert(I != CallSiteToFunctionMap.begin() &&
140 "This is not a known call site!");
145 void AddCallSite(const MutexGuard &locked, void *CallSite, Function *F) {
146 assert(locked.holds(TheJIT->lock));
148 bool Inserted = CallSiteToFunctionMap.insert(
149 std::make_pair(CallSite, F)).second;
151 assert(Inserted && "Pair was already in CallSiteToFunctionMap");
152 FunctionToCallSitesMap[F].insert(CallSite);
155 void EraseAllCallSitesForPrelocked(Function *F);
157 // Erases _all_ call sites regardless of their function. This is used to
158 // unregister the stub addresses from the StubToResolverMap in
160 void EraseAllCallSitesPrelocked();
163 /// JITResolver - Keep track of, and resolve, call sites for functions that
164 /// have not yet been compiled.
166 typedef JITResolverState::FunctionToLazyStubMapTy FunctionToLazyStubMapTy;
167 typedef JITResolverState::CallSiteToFunctionMapTy CallSiteToFunctionMapTy;
168 typedef JITResolverState::GlobalToIndirectSymMapTy GlobalToIndirectSymMapTy;
170 /// LazyResolverFn - The target lazy resolver function that we actually
171 /// rewrite instructions to use.
172 TargetJITInfo::LazyResolverFn LazyResolverFn;
174 JITResolverState state;
176 /// ExternalFnToStubMap - This is the equivalent of FunctionToLazyStubMap
177 /// for external functions. TODO: Of course, external functions don't need
178 /// a lazy stub. It's actually here to make it more likely that far calls
179 /// succeed, but no single stub can guarantee that. I'll remove this in a
180 /// subsequent checkin when I actually fix far calls.
181 std::map<void*, void*> ExternalFnToStubMap;
183 /// revGOTMap - map addresses to indexes in the GOT
184 std::map<void*, unsigned> revGOTMap;
185 unsigned nextGOTIndex;
189 /// Instance of JIT corresponding to this Resolver.
193 explicit JITResolver(JIT &jit, JITEmitter &je)
194 : state(&jit), nextGOTIndex(0), JE(je), TheJIT(&jit) {
195 LazyResolverFn = jit.getJITInfo().getLazyResolverFunction(JITCompilerFn);
200 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function's
201 /// lazy-compilation stub if it has already been created.
202 void *getLazyFunctionStubIfAvailable(Function *F);
204 /// getLazyFunctionStub - This returns a pointer to a function's
205 /// lazy-compilation stub, creating one on demand as needed.
206 void *getLazyFunctionStub(Function *F);
208 /// getExternalFunctionStub - Return a stub for the function at the
209 /// specified address, created lazily on demand.
210 void *getExternalFunctionStub(void *FnAddr);
212 /// getGlobalValueIndirectSym - Return an indirect symbol containing the
213 /// specified GV address.
214 void *getGlobalValueIndirectSym(GlobalValue *V, void *GVAddress);
216 /// getGOTIndexForAddress - Return a new or existing index in the GOT for
217 /// an address. This function only manages slots, it does not manage the
218 /// contents of the slots or the memory associated with the GOT.
219 unsigned getGOTIndexForAddr(void *addr);
221 /// JITCompilerFn - This function is called to resolve a stub to a compiled
222 /// address. If the LLVM Function corresponding to the stub has not yet
223 /// been compiled, this function compiles it first.
224 static void *JITCompilerFn(void *Stub);
227 class StubToResolverMapTy {
228 /// Map a stub address to a specific instance of a JITResolver so that
229 /// lazily-compiled functions can find the right resolver to use.
232 std::map<void*, JITResolver*> Map;
234 /// Guards Map from concurrent accesses.
235 mutable sys::Mutex Lock;
238 /// Registers a Stub to be resolved by Resolver.
239 void RegisterStubResolver(void *Stub, JITResolver *Resolver) {
240 MutexGuard guard(Lock);
241 Map.insert(std::make_pair(Stub, Resolver));
243 /// Unregisters the Stub when it's invalidated.
244 void UnregisterStubResolver(void *Stub) {
245 MutexGuard guard(Lock);
248 /// Returns the JITResolver instance that owns the Stub.
249 JITResolver *getResolverFromStub(void *Stub) const {
250 MutexGuard guard(Lock);
251 // The address given to us for the stub may not be exactly right, it might
252 // be a little bit after the stub. As such, use upper_bound to find it.
253 // This is the same trick as in LookupFunctionFromCallSite from
255 std::map<void*, JITResolver*>::const_iterator I = Map.upper_bound(Stub);
256 assert(I != Map.begin() && "This is not a known stub!");
260 /// True if any stubs refer to the given resolver. Only used in an assert().
262 bool ResolverHasStubs(JITResolver* Resolver) const {
263 MutexGuard guard(Lock);
264 for (std::map<void*, JITResolver*>::const_iterator I = Map.begin(),
265 E = Map.end(); I != E; ++I) {
266 if (I->second == Resolver)
272 /// This needs to be static so that a lazy call stub can access it with no
273 /// context except the address of the stub.
274 ManagedStatic<StubToResolverMapTy> StubToResolverMap;
276 /// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is
277 /// used to output functions to memory for execution.
278 class JITEmitter : public JITCodeEmitter {
279 JITMemoryManager *MemMgr;
281 // When outputting a function stub in the context of some other function, we
282 // save BufferBegin/BufferEnd/CurBufferPtr here.
283 uint8_t *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr;
285 // When reattempting to JIT a function after running out of space, we store
286 // the estimated size of the function we're trying to JIT here, so we can
287 // ask the memory manager for at least this much space. When we
288 // successfully emit the function, we reset this back to zero.
289 uintptr_t SizeEstimate;
291 /// Relocations - These are the relocations that the function needs, as
293 std::vector<MachineRelocation> Relocations;
295 /// MBBLocations - This vector is a mapping from MBB ID's to their address.
296 /// It is filled in by the StartMachineBasicBlock callback and queried by
297 /// the getMachineBasicBlockAddress callback.
298 std::vector<uintptr_t> MBBLocations;
300 /// ConstantPool - The constant pool for the current function.
302 MachineConstantPool *ConstantPool;
304 /// ConstantPoolBase - A pointer to the first entry in the constant pool.
306 void *ConstantPoolBase;
308 /// ConstPoolAddresses - Addresses of individual constant pool entries.
310 SmallVector<uintptr_t, 8> ConstPoolAddresses;
312 /// JumpTable - The jump tables for the current function.
314 MachineJumpTableInfo *JumpTable;
316 /// JumpTableBase - A pointer to the first entry in the jump table.
320 /// Resolver - This contains info about the currently resolved functions.
321 JITResolver Resolver;
323 /// DE - The dwarf emitter for the jit.
324 OwningPtr<JITDwarfEmitter> DE;
326 /// DR - The debug registerer for the jit.
327 OwningPtr<JITDebugRegisterer> DR;
329 /// LabelLocations - This vector is a mapping from Label ID's to their
331 DenseMap<MCSymbol*, uintptr_t> LabelLocations;
333 /// MMI - Machine module info for exception informations
334 MachineModuleInfo* MMI;
336 // CurFn - The llvm function being emitted. Only valid during
338 const Function *CurFn;
340 /// Information about emitted code, which is passed to the
341 /// JITEventListeners. This is reset in startFunction and used in
343 JITEvent_EmittedFunctionDetails EmissionDetails;
346 void *FunctionBody; // Beginning of the function's allocation.
347 void *Code; // The address the function's code actually starts at.
348 void *ExceptionTable;
349 EmittedCode() : FunctionBody(0), Code(0), ExceptionTable(0) {}
351 struct EmittedFunctionConfig : public ValueMapConfig<const Function*> {
352 typedef JITEmitter *ExtraData;
353 static void onDelete(JITEmitter *, const Function*);
354 static void onRAUW(JITEmitter *, const Function*, const Function*);
356 ValueMap<const Function *, EmittedCode,
357 EmittedFunctionConfig> EmittedFunctions;
361 /// Instance of the JIT
365 JITEmitter(JIT &jit, JITMemoryManager *JMM, TargetMachine &TM)
366 : SizeEstimate(0), Resolver(jit, *this), MMI(0), CurFn(0),
367 EmittedFunctions(this), TheJIT(&jit) {
368 MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager();
369 if (jit.getJITInfo().needsGOT()) {
370 MemMgr->AllocateGOT();
371 DEBUG(dbgs() << "JIT is managing a GOT\n");
374 if (JITExceptionHandling || JITEmitDebugInfo) {
375 DE.reset(new JITDwarfEmitter(jit));
377 if (JITEmitDebugInfo) {
378 DR.reset(new JITDebugRegisterer(TM));
385 /// classof - Methods for support type inquiry through isa, cast, and
388 static inline bool classof(const MachineCodeEmitter*) { return true; }
390 JITResolver &getJITResolver() { return Resolver; }
392 virtual void startFunction(MachineFunction &F);
393 virtual bool finishFunction(MachineFunction &F);
395 void emitConstantPool(MachineConstantPool *MCP);
396 void initJumpTableInfo(MachineJumpTableInfo *MJTI);
397 void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
399 void startGVStub(const GlobalValue* GV,
400 unsigned StubSize, unsigned Alignment = 1);
401 void startGVStub(void *Buffer, unsigned StubSize);
403 virtual void *allocIndirectGV(const GlobalValue *GV,
404 const uint8_t *Buffer, size_t Size,
407 /// allocateSpace - Reserves space in the current block if any, or
408 /// allocate a new one of the given size.
409 virtual void *allocateSpace(uintptr_t Size, unsigned Alignment);
411 /// allocateGlobal - Allocate memory for a global. Unlike allocateSpace,
412 /// this method does not allocate memory in the current output buffer,
413 /// because a global may live longer than the current function.
414 virtual void *allocateGlobal(uintptr_t Size, unsigned Alignment);
416 virtual void addRelocation(const MachineRelocation &MR) {
417 Relocations.push_back(MR);
420 virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
421 if (MBBLocations.size() <= (unsigned)MBB->getNumber())
422 MBBLocations.resize((MBB->getNumber()+1)*2);
423 MBBLocations[MBB->getNumber()] = getCurrentPCValue();
424 if (MBB->hasAddressTaken())
425 TheJIT->addPointerToBasicBlock(MBB->getBasicBlock(),
426 (void*)getCurrentPCValue());
427 DEBUG(dbgs() << "JIT: Emitting BB" << MBB->getNumber() << " at ["
428 << (void*) getCurrentPCValue() << "]\n");
431 virtual uintptr_t getConstantPoolEntryAddress(unsigned Entry) const;
432 virtual uintptr_t getJumpTableEntryAddress(unsigned Entry) const;
434 virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const{
435 assert(MBBLocations.size() > (unsigned)MBB->getNumber() &&
436 MBBLocations[MBB->getNumber()] && "MBB not emitted!");
437 return MBBLocations[MBB->getNumber()];
440 /// retryWithMoreMemory - Log a retry and deallocate all memory for the
441 /// given function. Increase the minimum allocation size so that we get
442 /// more memory next time.
443 void retryWithMoreMemory(MachineFunction &F);
445 /// deallocateMemForFunction - Deallocate all memory for the specified
447 void deallocateMemForFunction(const Function *F);
449 virtual void processDebugLoc(DebugLoc DL, bool BeforePrintingInsn);
451 virtual void emitLabel(MCSymbol *Label) {
452 LabelLocations[Label] = getCurrentPCValue();
455 virtual DenseMap<MCSymbol*, uintptr_t> *getLabelLocations() {
456 return &LabelLocations;
459 virtual uintptr_t getLabelAddress(MCSymbol *Label) const {
460 assert(LabelLocations.count(Label) && "Label not emitted!");
461 return LabelLocations.find(Label)->second;
464 virtual void setModuleInfo(MachineModuleInfo* Info) {
466 if (DE.get()) DE->setModuleInfo(Info);
470 void *getPointerToGlobal(GlobalValue *GV, void *Reference,
471 bool MayNeedFarStub);
472 void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference);
476 void CallSiteValueMapConfig::onDelete(JITResolverState *JRS, Function *F) {
477 JRS->EraseAllCallSitesForPrelocked(F);
480 void JITResolverState::EraseAllCallSitesForPrelocked(Function *F) {
481 FunctionToCallSitesMapTy::iterator F2C = FunctionToCallSitesMap.find(F);
482 if (F2C == FunctionToCallSitesMap.end())
484 StubToResolverMapTy &S2RMap = *StubToResolverMap;
485 for (SmallPtrSet<void*, 1>::const_iterator I = F2C->second.begin(),
486 E = F2C->second.end(); I != E; ++I) {
487 S2RMap.UnregisterStubResolver(*I);
488 bool Erased = CallSiteToFunctionMap.erase(*I);
490 assert(Erased && "Missing call site->function mapping");
492 FunctionToCallSitesMap.erase(F2C);
495 void JITResolverState::EraseAllCallSitesPrelocked() {
496 StubToResolverMapTy &S2RMap = *StubToResolverMap;
497 for (CallSiteToFunctionMapTy::const_iterator
498 I = CallSiteToFunctionMap.begin(),
499 E = CallSiteToFunctionMap.end(); I != E; ++I) {
500 S2RMap.UnregisterStubResolver(I->first);
502 CallSiteToFunctionMap.clear();
503 FunctionToCallSitesMap.clear();
506 JITResolver::~JITResolver() {
507 // No need to lock because we're in the destructor, and state isn't shared.
508 state.EraseAllCallSitesPrelocked();
509 assert(!StubToResolverMap->ResolverHasStubs(this) &&
510 "Resolver destroyed with stubs still alive.");
513 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function stub
514 /// if it has already been created.
515 void *JITResolver::getLazyFunctionStubIfAvailable(Function *F) {
516 MutexGuard locked(TheJIT->lock);
518 // If we already have a stub for this function, recycle it.
519 return state.getFunctionToLazyStubMap(locked).lookup(F);
522 /// getFunctionStub - This returns a pointer to a function stub, creating
523 /// one on demand as needed.
524 void *JITResolver::getLazyFunctionStub(Function *F) {
525 MutexGuard locked(TheJIT->lock);
527 // If we already have a lazy stub for this function, recycle it.
528 void *&Stub = state.getFunctionToLazyStubMap(locked)[F];
529 if (Stub) return Stub;
531 // Call the lazy resolver function if we are JIT'ing lazily. Otherwise we
532 // must resolve the symbol now.
533 void *Actual = TheJIT->isCompilingLazily()
534 ? (void *)(intptr_t)LazyResolverFn : (void *)0;
536 // If this is an external declaration, attempt to resolve the address now
537 // to place in the stub.
538 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage()) {
539 Actual = TheJIT->getPointerToFunction(F);
541 // If we resolved the symbol to a null address (eg. a weak external)
542 // don't emit a stub. Return a null pointer to the application.
543 if (!Actual) return 0;
546 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
547 JE.startGVStub(F, SL.Size, SL.Alignment);
548 // Codegen a new stub, calling the lazy resolver or the actual address of the
549 // external function, if it was resolved.
550 Stub = TheJIT->getJITInfo().emitFunctionStub(F, Actual, JE);
553 if (Actual != (void*)(intptr_t)LazyResolverFn) {
554 // If we are getting the stub for an external function, we really want the
555 // address of the stub in the GlobalAddressMap for the JIT, not the address
556 // of the external function.
557 TheJIT->updateGlobalMapping(F, Stub);
560 DEBUG(dbgs() << "JIT: Lazy stub emitted at [" << Stub << "] for function '"
561 << F->getName() << "'\n");
563 if (TheJIT->isCompilingLazily()) {
564 // Register this JITResolver as the one corresponding to this call site so
565 // JITCompilerFn will be able to find it.
566 StubToResolverMap->RegisterStubResolver(Stub, this);
568 // Finally, keep track of the stub-to-Function mapping so that the
569 // JITCompilerFn knows which function to compile!
570 state.AddCallSite(locked, Stub, F);
571 } else if (!Actual) {
572 // If we are JIT'ing non-lazily but need to call a function that does not
573 // exist yet, add it to the JIT's work list so that we can fill in the
574 // stub address later.
575 assert(!isNonGhostDeclaration(F) && !F->hasAvailableExternallyLinkage() &&
576 "'Actual' should have been set above.");
577 TheJIT->addPendingFunction(F);
583 /// getGlobalValueIndirectSym - Return a lazy pointer containing the specified
585 void *JITResolver::getGlobalValueIndirectSym(GlobalValue *GV, void *GVAddress) {
586 MutexGuard locked(TheJIT->lock);
588 // If we already have a stub for this global variable, recycle it.
589 void *&IndirectSym = state.getGlobalToIndirectSymMap(locked)[GV];
590 if (IndirectSym) return IndirectSym;
592 // Otherwise, codegen a new indirect symbol.
593 IndirectSym = TheJIT->getJITInfo().emitGlobalValueIndirectSym(GV, GVAddress,
596 DEBUG(dbgs() << "JIT: Indirect symbol emitted at [" << IndirectSym
597 << "] for GV '" << GV->getName() << "'\n");
602 /// getExternalFunctionStub - Return a stub for the function at the
603 /// specified address, created lazily on demand.
604 void *JITResolver::getExternalFunctionStub(void *FnAddr) {
605 // If we already have a stub for this function, recycle it.
606 void *&Stub = ExternalFnToStubMap[FnAddr];
607 if (Stub) return Stub;
609 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
610 JE.startGVStub(0, SL.Size, SL.Alignment);
611 Stub = TheJIT->getJITInfo().emitFunctionStub(0, FnAddr, JE);
614 DEBUG(dbgs() << "JIT: Stub emitted at [" << Stub
615 << "] for external function at '" << FnAddr << "'\n");
619 unsigned JITResolver::getGOTIndexForAddr(void* addr) {
620 unsigned idx = revGOTMap[addr];
622 idx = ++nextGOTIndex;
623 revGOTMap[addr] = idx;
624 DEBUG(dbgs() << "JIT: Adding GOT entry " << idx << " for addr ["
630 /// JITCompilerFn - This function is called when a lazy compilation stub has
631 /// been entered. It looks up which function this stub corresponds to, compiles
632 /// it if necessary, then returns the resultant function pointer.
633 void *JITResolver::JITCompilerFn(void *Stub) {
634 JITResolver *JR = StubToResolverMap->getResolverFromStub(Stub);
635 assert(JR && "Unable to find the corresponding JITResolver to the call site");
641 // Only lock for getting the Function. The call getPointerToFunction made
642 // in this function might trigger function materializing, which requires
643 // JIT lock to be unlocked.
644 MutexGuard locked(JR->TheJIT->lock);
646 // The address given to us for the stub may not be exactly right, it might
647 // be a little bit after the stub. As such, use upper_bound to find it.
648 pair<void*, Function*> I =
649 JR->state.LookupFunctionFromCallSite(locked, Stub);
654 // If we have already code generated the function, just return the address.
655 void *Result = JR->TheJIT->getPointerToGlobalIfAvailable(F);
658 // Otherwise we don't have it, do lazy compilation now.
660 // If lazy compilation is disabled, emit a useful error message and abort.
661 if (!JR->TheJIT->isCompilingLazily()) {
662 report_fatal_error("LLVM JIT requested to do lazy compilation of function '"
663 + F->getName() + "' when lazy compiles are disabled!");
666 DEBUG(dbgs() << "JIT: Lazily resolving function '" << F->getName()
667 << "' In stub ptr = " << Stub << " actual ptr = "
668 << ActualPtr << "\n");
670 Result = JR->TheJIT->getPointerToFunction(F);
673 // Reacquire the lock to update the GOT map.
674 MutexGuard locked(JR->TheJIT->lock);
676 // We might like to remove the call site from the CallSiteToFunction map, but
677 // we can't do that! Multiple threads could be stuck, waiting to acquire the
678 // lock above. As soon as the 1st function finishes compiling the function,
679 // the next one will be released, and needs to be able to find the function it
682 // FIXME: We could rewrite all references to this stub if we knew them.
684 // What we will do is set the compiled function address to map to the
685 // same GOT entry as the stub so that later clients may update the GOT
686 // if they see it still using the stub address.
687 // Note: this is done so the Resolver doesn't have to manage GOT memory
688 // Do this without allocating map space if the target isn't using a GOT
689 if(JR->revGOTMap.find(Stub) != JR->revGOTMap.end())
690 JR->revGOTMap[Result] = JR->revGOTMap[Stub];
695 //===----------------------------------------------------------------------===//
698 void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
699 bool MayNeedFarStub) {
700 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
701 return TheJIT->getOrEmitGlobalVariable(GV);
703 if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
704 return TheJIT->getPointerToGlobal(GA->resolveAliasedGlobal(false));
706 // If we have already compiled the function, return a pointer to its body.
707 Function *F = cast<Function>(V);
709 void *FnStub = Resolver.getLazyFunctionStubIfAvailable(F);
711 // Return the function stub if it's already created. We do this first so
712 // that we're returning the same address for the function as any previous
713 // call. TODO: Yes, this is wrong. The lazy stub isn't guaranteed to be
714 // close enough to call.
718 // If we know the target can handle arbitrary-distance calls, try to
719 // return a direct pointer.
720 if (!MayNeedFarStub) {
721 // If we have code, go ahead and return that.
722 void *ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
723 if (ResultPtr) return ResultPtr;
725 // If this is an external function pointer, we can force the JIT to
726 // 'compile' it, which really just adds it to the map.
727 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage())
728 return TheJIT->getPointerToFunction(F);
731 // Otherwise, we may need a to emit a stub, and, conservatively, we always do
732 // so. Note that it's possible to return null from getLazyFunctionStub in the
733 // case of a weak extern that fails to resolve.
734 return Resolver.getLazyFunctionStub(F);
737 void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) {
738 // Make sure GV is emitted first, and create a stub containing the fully
740 void *GVAddress = getPointerToGlobal(V, Reference, false);
741 void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress);
745 void JITEmitter::processDebugLoc(DebugLoc DL, bool BeforePrintingInsn) {
746 if (DL.isUnknown()) return;
747 if (!BeforePrintingInsn) return;
749 const LLVMContext &Context = EmissionDetails.MF->getFunction()->getContext();
751 if (DL.getScope(Context) != 0 && PrevDL != DL) {
752 JITEvent_EmittedFunctionDetails::LineStart NextLine;
753 NextLine.Address = getCurrentPCValue();
755 EmissionDetails.LineStarts.push_back(NextLine);
761 static unsigned GetConstantPoolSizeInBytes(MachineConstantPool *MCP,
762 const TargetData *TD) {
763 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
764 if (Constants.empty()) return 0;
767 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
768 MachineConstantPoolEntry CPE = Constants[i];
769 unsigned AlignMask = CPE.getAlignment() - 1;
770 Size = (Size + AlignMask) & ~AlignMask;
771 const Type *Ty = CPE.getType();
772 Size += TD->getTypeAllocSize(Ty);
777 void JITEmitter::startFunction(MachineFunction &F) {
778 DEBUG(dbgs() << "JIT: Starting CodeGen of Function "
779 << F.getFunction()->getName() << "\n");
781 uintptr_t ActualSize = 0;
782 // Set the memory writable, if it's not already
783 MemMgr->setMemoryWritable();
785 if (SizeEstimate > 0) {
786 // SizeEstimate will be non-zero on reallocation attempts.
787 ActualSize = SizeEstimate;
790 BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(),
792 BufferEnd = BufferBegin+ActualSize;
793 EmittedFunctions[F.getFunction()].FunctionBody = BufferBegin;
795 // Ensure the constant pool/jump table info is at least 4-byte aligned.
798 emitConstantPool(F.getConstantPool());
799 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
800 initJumpTableInfo(MJTI);
802 // About to start emitting the machine code for the function.
803 emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
804 TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
805 EmittedFunctions[F.getFunction()].Code = CurBufferPtr;
807 MBBLocations.clear();
809 EmissionDetails.MF = &F;
810 EmissionDetails.LineStarts.clear();
813 bool JITEmitter::finishFunction(MachineFunction &F) {
814 if (CurBufferPtr == BufferEnd) {
815 // We must call endFunctionBody before retrying, because
816 // deallocateMemForFunction requires it.
817 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
818 retryWithMoreMemory(F);
822 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
823 emitJumpTableInfo(MJTI);
825 // FnStart is the start of the text, not the start of the constant pool and
826 // other per-function data.
828 (uint8_t *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
830 // FnEnd is the end of the function's machine code.
831 uint8_t *FnEnd = CurBufferPtr;
833 if (!Relocations.empty()) {
834 CurFn = F.getFunction();
835 NumRelos += Relocations.size();
837 // Resolve the relocations to concrete pointers.
838 for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
839 MachineRelocation &MR = Relocations[i];
841 if (!MR.letTargetResolve()) {
842 if (MR.isExternalSymbol()) {
843 ResultPtr = TheJIT->getPointerToNamedFunction(MR.getExternalSymbol(),
845 DEBUG(dbgs() << "JIT: Map \'" << MR.getExternalSymbol() << "\' to ["
846 << ResultPtr << "]\n");
848 // If the target REALLY wants a stub for this function, emit it now.
849 if (MR.mayNeedFarStub()) {
850 ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
852 } else if (MR.isGlobalValue()) {
853 ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
854 BufferBegin+MR.getMachineCodeOffset(),
855 MR.mayNeedFarStub());
856 } else if (MR.isIndirectSymbol()) {
857 ResultPtr = getPointerToGVIndirectSym(
858 MR.getGlobalValue(), BufferBegin+MR.getMachineCodeOffset());
859 } else if (MR.isBasicBlock()) {
860 ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
861 } else if (MR.isConstantPoolIndex()) {
862 ResultPtr = (void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
864 assert(MR.isJumpTableIndex());
865 ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
868 MR.setResultPointer(ResultPtr);
871 // if we are managing the GOT and the relocation wants an index,
873 if (MR.isGOTRelative() && MemMgr->isManagingGOT()) {
874 unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
876 if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) {
877 DEBUG(dbgs() << "JIT: GOT was out of date for " << ResultPtr
878 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
880 ((void**)MemMgr->getGOTBase())[idx] = ResultPtr;
886 TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
887 Relocations.size(), MemMgr->getGOTBase());
890 // Update the GOT entry for F to point to the new code.
891 if (MemMgr->isManagingGOT()) {
892 unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
893 if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) {
894 DEBUG(dbgs() << "JIT: GOT was out of date for " << (void*)BufferBegin
895 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
897 ((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin;
901 // CurBufferPtr may have moved beyond FnEnd, due to memory allocation for
902 // global variables that were referenced in the relocations.
903 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
905 if (CurBufferPtr == BufferEnd) {
906 retryWithMoreMemory(F);
909 // Now that we've succeeded in emitting the function, reset the
910 // SizeEstimate back down to zero.
914 BufferBegin = CurBufferPtr = 0;
915 NumBytes += FnEnd-FnStart;
917 // Invalidate the icache if necessary.
918 sys::Memory::InvalidateInstructionCache(FnStart, FnEnd-FnStart);
920 TheJIT->NotifyFunctionEmitted(*F.getFunction(), FnStart, FnEnd-FnStart,
923 // Reset the previous debug location.
926 DEBUG(dbgs() << "JIT: Finished CodeGen of [" << (void*)FnStart
927 << "] Function: " << F.getFunction()->getName()
928 << ": " << (FnEnd-FnStart) << " bytes of text, "
929 << Relocations.size() << " relocations\n");
932 ConstPoolAddresses.clear();
934 // Mark code region readable and executable if it's not so already.
935 MemMgr->setMemoryExecutable();
938 if (sys::hasDisassembler()) {
939 dbgs() << "JIT: Disassembled code:\n";
940 dbgs() << sys::disassembleBuffer(FnStart, FnEnd-FnStart,
943 dbgs() << "JIT: Binary code:\n";
944 uint8_t* q = FnStart;
945 for (int i = 0; q < FnEnd; q += 4, ++i) {
949 dbgs() << "JIT: " << (long)(q - FnStart) << ": ";
951 for (int j = 3; j >= 0; --j) {
955 dbgs() << (unsigned short)q[j];
967 if (JITExceptionHandling || JITEmitDebugInfo) {
968 uintptr_t ActualSize = 0;
969 SavedBufferBegin = BufferBegin;
970 SavedBufferEnd = BufferEnd;
971 SavedCurBufferPtr = CurBufferPtr;
973 BufferBegin = CurBufferPtr = MemMgr->startExceptionTable(F.getFunction(),
975 BufferEnd = BufferBegin+ActualSize;
976 EmittedFunctions[F.getFunction()].ExceptionTable = BufferBegin;
978 uint8_t *FrameRegister = DE->EmitDwarfTable(F, *this, FnStart, FnEnd,
980 MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr,
982 uint8_t *EhEnd = CurBufferPtr;
983 BufferBegin = SavedBufferBegin;
984 BufferEnd = SavedBufferEnd;
985 CurBufferPtr = SavedCurBufferPtr;
987 if (JITExceptionHandling) {
988 TheJIT->RegisterTable(F.getFunction(), FrameRegister);
991 if (JITEmitDebugInfo) {
997 DR->RegisterFunction(F.getFunction(), I);
1007 void JITEmitter::retryWithMoreMemory(MachineFunction &F) {
1008 DEBUG(dbgs() << "JIT: Ran out of space for native code. Reattempting.\n");
1009 Relocations.clear(); // Clear the old relocations or we'll reapply them.
1010 ConstPoolAddresses.clear();
1012 deallocateMemForFunction(F.getFunction());
1013 // Try again with at least twice as much free space.
1014 SizeEstimate = (uintptr_t)(2 * (BufferEnd - BufferBegin));
1016 for (MachineFunction::iterator MBB = F.begin(), E = F.end(); MBB != E; ++MBB){
1017 if (MBB->hasAddressTaken())
1018 TheJIT->clearPointerToBasicBlock(MBB->getBasicBlock());
1022 /// deallocateMemForFunction - Deallocate all memory for the specified
1023 /// function body. Also drop any references the function has to stubs.
1024 /// May be called while the Function is being destroyed inside ~Value().
1025 void JITEmitter::deallocateMemForFunction(const Function *F) {
1026 ValueMap<const Function *, EmittedCode, EmittedFunctionConfig>::iterator
1027 Emitted = EmittedFunctions.find(F);
1028 if (Emitted != EmittedFunctions.end()) {
1029 MemMgr->deallocateFunctionBody(Emitted->second.FunctionBody);
1030 MemMgr->deallocateExceptionTable(Emitted->second.ExceptionTable);
1031 TheJIT->NotifyFreeingMachineCode(Emitted->second.Code);
1033 EmittedFunctions.erase(Emitted);
1036 if(JITExceptionHandling) {
1037 TheJIT->DeregisterTable(F);
1040 if (JITEmitDebugInfo) {
1041 DR->UnregisterFunction(F);
1046 void* JITEmitter::allocateSpace(uintptr_t Size, unsigned Alignment) {
1048 return JITCodeEmitter::allocateSpace(Size, Alignment);
1050 // create a new memory block if there is no active one.
1051 // care must be taken so that BufferBegin is invalidated when a
1053 BufferBegin = CurBufferPtr = MemMgr->allocateSpace(Size, Alignment);
1054 BufferEnd = BufferBegin+Size;
1055 return CurBufferPtr;
1058 void* JITEmitter::allocateGlobal(uintptr_t Size, unsigned Alignment) {
1059 // Delegate this call through the memory manager.
1060 return MemMgr->allocateGlobal(Size, Alignment);
1063 void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
1064 if (TheJIT->getJITInfo().hasCustomConstantPool())
1067 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
1068 if (Constants.empty()) return;
1070 unsigned Size = GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1071 unsigned Align = MCP->getConstantPoolAlignment();
1072 ConstantPoolBase = allocateSpace(Size, Align);
1075 if (ConstantPoolBase == 0) return; // Buffer overflow.
1077 DEBUG(dbgs() << "JIT: Emitted constant pool at [" << ConstantPoolBase
1078 << "] (size: " << Size << ", alignment: " << Align << ")\n");
1080 // Initialize the memory for all of the constant pool entries.
1081 unsigned Offset = 0;
1082 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
1083 MachineConstantPoolEntry CPE = Constants[i];
1084 unsigned AlignMask = CPE.getAlignment() - 1;
1085 Offset = (Offset + AlignMask) & ~AlignMask;
1087 uintptr_t CAddr = (uintptr_t)ConstantPoolBase + Offset;
1088 ConstPoolAddresses.push_back(CAddr);
1089 if (CPE.isMachineConstantPoolEntry()) {
1090 // FIXME: add support to lower machine constant pool values into bytes!
1091 report_fatal_error("Initialize memory with machine specific constant pool"
1092 "entry has not been implemented!");
1094 TheJIT->InitializeMemory(CPE.Val.ConstVal, (void*)CAddr);
1095 DEBUG(dbgs() << "JIT: CP" << i << " at [0x";
1096 dbgs().write_hex(CAddr) << "]\n");
1098 const Type *Ty = CPE.Val.ConstVal->getType();
1099 Offset += TheJIT->getTargetData()->getTypeAllocSize(Ty);
1103 void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
1104 if (TheJIT->getJITInfo().hasCustomJumpTables())
1106 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline)
1109 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1110 if (JT.empty()) return;
1112 unsigned NumEntries = 0;
1113 for (unsigned i = 0, e = JT.size(); i != e; ++i)
1114 NumEntries += JT[i].MBBs.size();
1116 unsigned EntrySize = MJTI->getEntrySize(*TheJIT->getTargetData());
1118 // Just allocate space for all the jump tables now. We will fix up the actual
1119 // MBB entries in the tables after we emit the code for each block, since then
1120 // we will know the final locations of the MBBs in memory.
1122 JumpTableBase = allocateSpace(NumEntries * EntrySize,
1123 MJTI->getEntryAlignment(*TheJIT->getTargetData()));
1126 void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
1127 if (TheJIT->getJITInfo().hasCustomJumpTables())
1130 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1131 if (JT.empty() || JumpTableBase == 0) return;
1134 switch (MJTI->getEntryKind()) {
1135 case MachineJumpTableInfo::EK_Inline:
1137 case MachineJumpTableInfo::EK_BlockAddress: {
1138 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1140 assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == sizeof(void*) &&
1143 // For each jump table, map each target in the jump table to the address of
1144 // an emitted MachineBasicBlock.
1145 intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
1147 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1148 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1149 // Store the address of the basic block for this jump table slot in the
1150 // memory we allocated for the jump table in 'initJumpTableInfo'
1151 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
1152 *SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
1157 case MachineJumpTableInfo::EK_Custom32:
1158 case MachineJumpTableInfo::EK_GPRel32BlockAddress:
1159 case MachineJumpTableInfo::EK_LabelDifference32: {
1160 assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == 4&&"Cross JIT'ing?");
1161 // For each jump table, place the offset from the beginning of the table
1162 // to the target address.
1163 int *SlotPtr = (int*)JumpTableBase;
1165 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1166 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1167 // Store the offset of the basic block for this jump table slot in the
1168 // memory we allocated for the jump table in 'initJumpTableInfo'
1169 uintptr_t Base = (uintptr_t)SlotPtr;
1170 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) {
1171 uintptr_t MBBAddr = getMachineBasicBlockAddress(MBBs[mi]);
1172 /// FIXME: USe EntryKind instead of magic "getPICJumpTableEntry" hook.
1173 *SlotPtr++ = TheJIT->getJITInfo().getPICJumpTableEntry(MBBAddr, Base);
1181 void JITEmitter::startGVStub(const GlobalValue* GV,
1182 unsigned StubSize, unsigned Alignment) {
1183 SavedBufferBegin = BufferBegin;
1184 SavedBufferEnd = BufferEnd;
1185 SavedCurBufferPtr = CurBufferPtr;
1187 BufferBegin = CurBufferPtr = MemMgr->allocateStub(GV, StubSize, Alignment);
1188 BufferEnd = BufferBegin+StubSize+1;
1191 void JITEmitter::startGVStub(void *Buffer, unsigned StubSize) {
1192 SavedBufferBegin = BufferBegin;
1193 SavedBufferEnd = BufferEnd;
1194 SavedCurBufferPtr = CurBufferPtr;
1196 BufferBegin = CurBufferPtr = (uint8_t *)Buffer;
1197 BufferEnd = BufferBegin+StubSize+1;
1200 void JITEmitter::finishGVStub() {
1201 assert(CurBufferPtr != BufferEnd && "Stub overflowed allocated space.");
1202 NumBytes += getCurrentPCOffset();
1203 BufferBegin = SavedBufferBegin;
1204 BufferEnd = SavedBufferEnd;
1205 CurBufferPtr = SavedCurBufferPtr;
1208 void *JITEmitter::allocIndirectGV(const GlobalValue *GV,
1209 const uint8_t *Buffer, size_t Size,
1210 unsigned Alignment) {
1211 uint8_t *IndGV = MemMgr->allocateStub(GV, Size, Alignment);
1212 memcpy(IndGV, Buffer, Size);
1216 // getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
1217 // in the constant pool that was last emitted with the 'emitConstantPool'
1220 uintptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const {
1221 assert(ConstantNum < ConstantPool->getConstants().size() &&
1222 "Invalid ConstantPoolIndex!");
1223 return ConstPoolAddresses[ConstantNum];
1226 // getJumpTableEntryAddress - Return the address of the JumpTable with index
1227 // 'Index' in the jumpp table that was last initialized with 'initJumpTableInfo'
1229 uintptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
1230 const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
1231 assert(Index < JT.size() && "Invalid jump table index!");
1233 unsigned EntrySize = JumpTable->getEntrySize(*TheJIT->getTargetData());
1235 unsigned Offset = 0;
1236 for (unsigned i = 0; i < Index; ++i)
1237 Offset += JT[i].MBBs.size();
1239 Offset *= EntrySize;
1241 return (uintptr_t)((char *)JumpTableBase + Offset);
1244 void JITEmitter::EmittedFunctionConfig::onDelete(
1245 JITEmitter *Emitter, const Function *F) {
1246 Emitter->deallocateMemForFunction(F);
1248 void JITEmitter::EmittedFunctionConfig::onRAUW(
1249 JITEmitter *, const Function*, const Function*) {
1250 llvm_unreachable("The JIT doesn't know how to handle a"
1251 " RAUW on a value it has emitted.");
1255 //===----------------------------------------------------------------------===//
1256 // Public interface to this file
1257 //===----------------------------------------------------------------------===//
1259 JITCodeEmitter *JIT::createEmitter(JIT &jit, JITMemoryManager *JMM,
1260 TargetMachine &tm) {
1261 return new JITEmitter(jit, JMM, tm);
1264 // getPointerToFunctionOrStub - If the specified function has been
1265 // code-gen'd, return a pointer to the function. If not, compile it, or use
1266 // a stub to implement lazy compilation if available.
1268 void *JIT::getPointerToFunctionOrStub(Function *F) {
1269 // If we have already code generated the function, just return the address.
1270 if (void *Addr = getPointerToGlobalIfAvailable(F))
1273 // Get a stub if the target supports it.
1274 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1275 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1276 return JE->getJITResolver().getLazyFunctionStub(F);
1279 void JIT::updateFunctionStub(Function *F) {
1280 // Get the empty stub we generated earlier.
1281 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1282 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1283 void *Stub = JE->getJITResolver().getLazyFunctionStub(F);
1284 void *Addr = getPointerToGlobalIfAvailable(F);
1285 assert(Addr != Stub && "Function must have non-stub address to be updated.");
1287 // Tell the target jit info to rewrite the stub at the specified address,
1288 // rather than creating a new one.
1289 TargetJITInfo::StubLayout layout = getJITInfo().getStubLayout();
1290 JE->startGVStub(Stub, layout.Size);
1291 getJITInfo().emitFunctionStub(F, Addr, *getCodeEmitter());
1295 /// freeMachineCodeForFunction - release machine code memory for given Function.
1297 void JIT::freeMachineCodeForFunction(Function *F) {
1298 // Delete translation for this from the ExecutionEngine, so it will get
1299 // retranslated next time it is used.
1300 updateGlobalMapping(F, 0);
1302 // Free the actual memory for the function body and related stuff.
1303 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1304 cast<JITEmitter>(JCE)->deallocateMemForFunction(F);