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/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/CodeGen/MachineCodeInfo.h"
34 #include "llvm/Target/TargetData.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/System/Disassembler.h"
45 #include "llvm/System/Memory.h"
46 #include "llvm/Target/TargetInstrInfo.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 // Returns the Function of the stub if a stub was erased, or NULL if there
156 // was no stub. This function uses the call-site->function map to find a
157 // relevant function, but asserts that only stubs and not other call sites
158 // will be passed in.
159 Function *EraseStub(const MutexGuard &locked, void *Stub);
161 void EraseAllCallSitesFor(const MutexGuard &locked, Function *F) {
162 assert(locked.holds(TheJIT->lock));
163 EraseAllCallSitesForPrelocked(F);
165 void EraseAllCallSitesForPrelocked(Function *F);
167 // Erases _all_ call sites regardless of their function. This is used to
168 // unregister the stub addresses from the StubToResolverMap in
170 void EraseAllCallSitesPrelocked();
173 /// JITResolver - Keep track of, and resolve, call sites for functions that
174 /// have not yet been compiled.
176 typedef JITResolverState::FunctionToLazyStubMapTy FunctionToLazyStubMapTy;
177 typedef JITResolverState::CallSiteToFunctionMapTy CallSiteToFunctionMapTy;
178 typedef JITResolverState::GlobalToIndirectSymMapTy GlobalToIndirectSymMapTy;
180 /// LazyResolverFn - The target lazy resolver function that we actually
181 /// rewrite instructions to use.
182 TargetJITInfo::LazyResolverFn LazyResolverFn;
184 JITResolverState state;
186 /// ExternalFnToStubMap - This is the equivalent of FunctionToLazyStubMap
187 /// for external functions. TODO: Of course, external functions don't need
188 /// a lazy stub. It's actually here to make it more likely that far calls
189 /// succeed, but no single stub can guarantee that. I'll remove this in a
190 /// subsequent checkin when I actually fix far calls.
191 std::map<void*, void*> ExternalFnToStubMap;
193 /// revGOTMap - map addresses to indexes in the GOT
194 std::map<void*, unsigned> revGOTMap;
195 unsigned nextGOTIndex;
199 /// Instance of JIT corresponding to this Resolver.
203 explicit JITResolver(JIT &jit, JITEmitter &je)
204 : state(&jit), nextGOTIndex(0), JE(je), TheJIT(&jit) {
205 LazyResolverFn = jit.getJITInfo().getLazyResolverFunction(JITCompilerFn);
210 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function's
211 /// lazy-compilation stub if it has already been created.
212 void *getLazyFunctionStubIfAvailable(Function *F);
214 /// getLazyFunctionStub - This returns a pointer to a function's
215 /// lazy-compilation stub, creating one on demand as needed.
216 void *getLazyFunctionStub(Function *F);
218 /// getExternalFunctionStub - Return a stub for the function at the
219 /// specified address, created lazily on demand.
220 void *getExternalFunctionStub(void *FnAddr);
222 /// getGlobalValueIndirectSym - Return an indirect symbol containing the
223 /// specified GV address.
224 void *getGlobalValueIndirectSym(GlobalValue *V, void *GVAddress);
226 void getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
227 SmallVectorImpl<void*> &Ptrs);
229 GlobalValue *invalidateStub(void *Stub);
231 /// getGOTIndexForAddress - Return a new or existing index in the GOT for
232 /// an address. This function only manages slots, it does not manage the
233 /// contents of the slots or the memory associated with the GOT.
234 unsigned getGOTIndexForAddr(void *addr);
236 /// JITCompilerFn - This function is called to resolve a stub to a compiled
237 /// address. If the LLVM Function corresponding to the stub has not yet
238 /// been compiled, this function compiles it first.
239 static void *JITCompilerFn(void *Stub);
242 class StubToResolverMapTy {
243 /// Map a stub address to a specific instance of a JITResolver so that
244 /// lazily-compiled functions can find the right resolver to use.
247 std::map<void*, JITResolver*> Map;
249 /// Guards Map from concurrent accesses.
250 mutable sys::Mutex Lock;
253 /// Registers a Stub to be resolved by Resolver.
254 void RegisterStubResolver(void *Stub, JITResolver *Resolver) {
255 MutexGuard guard(Lock);
256 Map.insert(std::make_pair(Stub, Resolver));
258 /// Unregisters the Stub when it's invalidated.
259 void UnregisterStubResolver(void *Stub) {
260 MutexGuard guard(Lock);
263 /// Returns the JITResolver instance that owns the Stub.
264 JITResolver *getResolverFromStub(void *Stub) const {
265 MutexGuard guard(Lock);
266 // The address given to us for the stub may not be exactly right, it might
267 // be a little bit after the stub. As such, use upper_bound to find it.
268 // This is the same trick as in LookupFunctionFromCallSite from
270 std::map<void*, JITResolver*>::const_iterator I = Map.upper_bound(Stub);
271 assert(I != Map.begin() && "This is not a known stub!");
275 /// True if any stubs refer to the given resolver. Only used in an assert().
277 bool ResolverHasStubs(JITResolver* Resolver) const {
278 MutexGuard guard(Lock);
279 for (std::map<void*, JITResolver*>::const_iterator I = Map.begin(),
280 E = Map.end(); I != E; ++I) {
281 if (I->second == Resolver)
287 /// This needs to be static so that a lazy call stub can access it with no
288 /// context except the address of the stub.
289 ManagedStatic<StubToResolverMapTy> StubToResolverMap;
291 /// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is
292 /// used to output functions to memory for execution.
293 class JITEmitter : public JITCodeEmitter {
294 JITMemoryManager *MemMgr;
296 // When outputting a function stub in the context of some other function, we
297 // save BufferBegin/BufferEnd/CurBufferPtr here.
298 uint8_t *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr;
300 // When reattempting to JIT a function after running out of space, we store
301 // the estimated size of the function we're trying to JIT here, so we can
302 // ask the memory manager for at least this much space. When we
303 // successfully emit the function, we reset this back to zero.
304 uintptr_t SizeEstimate;
306 /// Relocations - These are the relocations that the function needs, as
308 std::vector<MachineRelocation> Relocations;
310 /// MBBLocations - This vector is a mapping from MBB ID's to their address.
311 /// It is filled in by the StartMachineBasicBlock callback and queried by
312 /// the getMachineBasicBlockAddress callback.
313 std::vector<uintptr_t> MBBLocations;
315 /// ConstantPool - The constant pool for the current function.
317 MachineConstantPool *ConstantPool;
319 /// ConstantPoolBase - A pointer to the first entry in the constant pool.
321 void *ConstantPoolBase;
323 /// ConstPoolAddresses - Addresses of individual constant pool entries.
325 SmallVector<uintptr_t, 8> ConstPoolAddresses;
327 /// JumpTable - The jump tables for the current function.
329 MachineJumpTableInfo *JumpTable;
331 /// JumpTableBase - A pointer to the first entry in the jump table.
335 /// Resolver - This contains info about the currently resolved functions.
336 JITResolver Resolver;
338 /// DE - The dwarf emitter for the jit.
339 OwningPtr<JITDwarfEmitter> DE;
341 /// DR - The debug registerer for the jit.
342 OwningPtr<JITDebugRegisterer> DR;
344 /// LabelLocations - This vector is a mapping from Label ID's to their
346 std::vector<uintptr_t> LabelLocations;
348 /// MMI - Machine module info for exception informations
349 MachineModuleInfo* MMI;
351 // GVSet - a set to keep track of which globals have been seen
352 SmallPtrSet<const GlobalVariable*, 8> GVSet;
354 // CurFn - The llvm function being emitted. Only valid during
356 const Function *CurFn;
358 /// Information about emitted code, which is passed to the
359 /// JITEventListeners. This is reset in startFunction and used in
361 JITEvent_EmittedFunctionDetails EmissionDetails;
364 void *FunctionBody; // Beginning of the function's allocation.
365 void *Code; // The address the function's code actually starts at.
366 void *ExceptionTable;
367 EmittedCode() : FunctionBody(0), Code(0), ExceptionTable(0) {}
369 struct EmittedFunctionConfig : public ValueMapConfig<const Function*> {
370 typedef JITEmitter *ExtraData;
371 static void onDelete(JITEmitter *, const Function*);
372 static void onRAUW(JITEmitter *, const Function*, const Function*);
374 ValueMap<const Function *, EmittedCode,
375 EmittedFunctionConfig> EmittedFunctions;
377 // CurFnStubUses - For a given Function, a vector of stubs that it
378 // references. This facilitates the JIT detecting that a stub is no
379 // longer used, so that it may be deallocated.
380 DenseMap<AssertingVH<const Function>, SmallVector<void*, 1> > CurFnStubUses;
382 // StubFnRefs - For a given pointer to a stub, a set of Functions which
383 // reference the stub. When the count of a stub's references drops to zero,
384 // the stub is unused.
385 DenseMap<void *, SmallPtrSet<const Function*, 1> > StubFnRefs;
389 /// Instance of the JIT
393 JITEmitter(JIT &jit, JITMemoryManager *JMM, TargetMachine &TM)
394 : SizeEstimate(0), Resolver(jit, *this), MMI(0), CurFn(0),
395 EmittedFunctions(this), PrevDLT(NULL), TheJIT(&jit) {
396 MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager();
397 if (jit.getJITInfo().needsGOT()) {
398 MemMgr->AllocateGOT();
399 DEBUG(dbgs() << "JIT is managing a GOT\n");
402 if (DwarfExceptionHandling || JITEmitDebugInfo) {
403 DE.reset(new JITDwarfEmitter(jit));
405 if (JITEmitDebugInfo) {
406 DR.reset(new JITDebugRegisterer(TM));
413 /// classof - Methods for support type inquiry through isa, cast, and
416 static inline bool classof(const JITEmitter*) { return true; }
417 static inline bool classof(const MachineCodeEmitter*) { return true; }
419 JITResolver &getJITResolver() { return Resolver; }
421 virtual void startFunction(MachineFunction &F);
422 virtual bool finishFunction(MachineFunction &F);
424 void emitConstantPool(MachineConstantPool *MCP);
425 void initJumpTableInfo(MachineJumpTableInfo *MJTI);
426 void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
428 void startGVStub(const GlobalValue* GV,
429 unsigned StubSize, unsigned Alignment = 1);
430 void startGVStub(void *Buffer, unsigned StubSize);
432 virtual void *allocIndirectGV(const GlobalValue *GV,
433 const uint8_t *Buffer, size_t Size,
436 /// allocateSpace - Reserves space in the current block if any, or
437 /// allocate a new one of the given size.
438 virtual void *allocateSpace(uintptr_t Size, unsigned Alignment);
440 /// allocateGlobal - Allocate memory for a global. Unlike allocateSpace,
441 /// this method does not allocate memory in the current output buffer,
442 /// because a global may live longer than the current function.
443 virtual void *allocateGlobal(uintptr_t Size, unsigned Alignment);
445 virtual void addRelocation(const MachineRelocation &MR) {
446 Relocations.push_back(MR);
449 virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
450 if (MBBLocations.size() <= (unsigned)MBB->getNumber())
451 MBBLocations.resize((MBB->getNumber()+1)*2);
452 MBBLocations[MBB->getNumber()] = getCurrentPCValue();
453 DEBUG(dbgs() << "JIT: Emitting BB" << MBB->getNumber() << " at ["
454 << (void*) getCurrentPCValue() << "]\n");
457 virtual uintptr_t getConstantPoolEntryAddress(unsigned Entry) const;
458 virtual uintptr_t getJumpTableEntryAddress(unsigned Entry) const;
460 virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
461 assert(MBBLocations.size() > (unsigned)MBB->getNumber() &&
462 MBBLocations[MBB->getNumber()] && "MBB not emitted!");
463 return MBBLocations[MBB->getNumber()];
466 /// retryWithMoreMemory - Log a retry and deallocate all memory for the
467 /// given function. Increase the minimum allocation size so that we get
468 /// more memory next time.
469 void retryWithMoreMemory(MachineFunction &F);
471 /// deallocateMemForFunction - Deallocate all memory for the specified
473 void deallocateMemForFunction(const Function *F);
475 /// AddStubToCurrentFunction - Mark the current function being JIT'd as
476 /// using the stub at the specified address. Allows
477 /// deallocateMemForFunction to also remove stubs no longer referenced.
478 void AddStubToCurrentFunction(void *Stub);
480 virtual void processDebugLoc(DebugLoc DL, bool BeforePrintingInsn);
482 virtual void emitLabel(uint64_t LabelID) {
483 if (LabelLocations.size() <= LabelID)
484 LabelLocations.resize((LabelID+1)*2);
485 LabelLocations[LabelID] = getCurrentPCValue();
488 virtual uintptr_t getLabelAddress(uint64_t LabelID) const {
489 assert(LabelLocations.size() > (unsigned)LabelID &&
490 LabelLocations[LabelID] && "Label not emitted!");
491 return LabelLocations[LabelID];
494 virtual void setModuleInfo(MachineModuleInfo* Info) {
496 if (DE.get()) DE->setModuleInfo(Info);
499 void setMemoryExecutable() {
500 MemMgr->setMemoryExecutable();
503 JITMemoryManager *getMemMgr() const { return MemMgr; }
506 void *getPointerToGlobal(GlobalValue *GV, void *Reference,
507 bool MayNeedFarStub);
508 void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference);
509 unsigned addSizeOfGlobal(const GlobalVariable *GV, unsigned Size);
510 unsigned addSizeOfGlobalsInConstantVal(const Constant *C, unsigned Size);
511 unsigned addSizeOfGlobalsInInitializer(const Constant *Init, unsigned Size);
512 unsigned GetSizeOfGlobalsInBytes(MachineFunction &MF);
516 void CallSiteValueMapConfig::onDelete(JITResolverState *JRS, Function *F) {
517 JRS->EraseAllCallSitesForPrelocked(F);
520 Function *JITResolverState::EraseStub(const MutexGuard &locked, void *Stub) {
521 CallSiteToFunctionMapTy::iterator C2F_I =
522 CallSiteToFunctionMap.find(Stub);
523 if (C2F_I == CallSiteToFunctionMap.end()) {
528 StubToResolverMap->UnregisterStubResolver(Stub);
530 Function *const F = C2F_I->second;
532 void *RealStub = FunctionToLazyStubMap.lookup(F);
533 assert(RealStub == Stub &&
534 "Call-site that wasn't a stub passed in to EraseStub");
536 FunctionToLazyStubMap.erase(F);
537 CallSiteToFunctionMap.erase(C2F_I);
539 // Remove the stub from the function->call-sites map, and remove the whole
540 // entry from the map if that was the last call site.
541 FunctionToCallSitesMapTy::iterator F2C_I = FunctionToCallSitesMap.find(F);
542 assert(F2C_I != FunctionToCallSitesMap.end() &&
543 "FunctionToCallSitesMap broken");
544 bool Erased = F2C_I->second.erase(Stub);
546 assert(Erased && "FunctionToCallSitesMap broken");
547 if (F2C_I->second.empty())
548 FunctionToCallSitesMap.erase(F2C_I);
553 void JITResolverState::EraseAllCallSitesForPrelocked(Function *F) {
554 FunctionToCallSitesMapTy::iterator F2C = FunctionToCallSitesMap.find(F);
555 if (F2C == FunctionToCallSitesMap.end())
557 StubToResolverMapTy &S2RMap = *StubToResolverMap;
558 for (SmallPtrSet<void*, 1>::const_iterator I = F2C->second.begin(),
559 E = F2C->second.end(); I != E; ++I) {
560 S2RMap.UnregisterStubResolver(*I);
561 bool Erased = CallSiteToFunctionMap.erase(*I);
563 assert(Erased && "Missing call site->function mapping");
565 FunctionToCallSitesMap.erase(F2C);
568 void JITResolverState::EraseAllCallSitesPrelocked() {
569 StubToResolverMapTy &S2RMap = *StubToResolverMap;
570 for (CallSiteToFunctionMapTy::const_iterator
571 I = CallSiteToFunctionMap.begin(),
572 E = CallSiteToFunctionMap.end(); I != E; ++I) {
573 S2RMap.UnregisterStubResolver(I->first);
575 CallSiteToFunctionMap.clear();
576 FunctionToCallSitesMap.clear();
579 JITResolver::~JITResolver() {
580 // No need to lock because we're in the destructor, and state isn't shared.
581 state.EraseAllCallSitesPrelocked();
582 assert(!StubToResolverMap->ResolverHasStubs(this) &&
583 "Resolver destroyed with stubs still alive.");
586 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function stub
587 /// if it has already been created.
588 void *JITResolver::getLazyFunctionStubIfAvailable(Function *F) {
589 MutexGuard locked(TheJIT->lock);
591 // If we already have a stub for this function, recycle it.
592 return state.getFunctionToLazyStubMap(locked).lookup(F);
595 /// getFunctionStub - This returns a pointer to a function stub, creating
596 /// one on demand as needed.
597 void *JITResolver::getLazyFunctionStub(Function *F) {
598 MutexGuard locked(TheJIT->lock);
600 // If we already have a lazy stub for this function, recycle it.
601 void *&Stub = state.getFunctionToLazyStubMap(locked)[F];
602 if (Stub) return Stub;
604 // Call the lazy resolver function if we are JIT'ing lazily. Otherwise we
605 // must resolve the symbol now.
606 void *Actual = TheJIT->isCompilingLazily()
607 ? (void *)(intptr_t)LazyResolverFn : (void *)0;
609 // If this is an external declaration, attempt to resolve the address now
610 // to place in the stub.
611 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage()) {
612 Actual = TheJIT->getPointerToFunction(F);
614 // If we resolved the symbol to a null address (eg. a weak external)
615 // don't emit a stub. Return a null pointer to the application.
616 if (!Actual) return 0;
619 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
620 JE.startGVStub(F, SL.Size, SL.Alignment);
621 // Codegen a new stub, calling the lazy resolver or the actual address of the
622 // external function, if it was resolved.
623 Stub = TheJIT->getJITInfo().emitFunctionStub(F, Actual, JE);
626 if (Actual != (void*)(intptr_t)LazyResolverFn) {
627 // If we are getting the stub for an external function, we really want the
628 // address of the stub in the GlobalAddressMap for the JIT, not the address
629 // of the external function.
630 TheJIT->updateGlobalMapping(F, Stub);
633 DEBUG(dbgs() << "JIT: Lazy stub emitted at [" << Stub << "] for function '"
634 << F->getName() << "'\n");
636 if (TheJIT->isCompilingLazily()) {
637 // Register this JITResolver as the one corresponding to this call site so
638 // JITCompilerFn will be able to find it.
639 StubToResolverMap->RegisterStubResolver(Stub, this);
641 // Finally, keep track of the stub-to-Function mapping so that the
642 // JITCompilerFn knows which function to compile!
643 state.AddCallSite(locked, Stub, F);
644 } else if (!Actual) {
645 // If we are JIT'ing non-lazily but need to call a function that does not
646 // exist yet, add it to the JIT's work list so that we can fill in the
647 // stub address later.
648 assert(!isNonGhostDeclaration(F) && !F->hasAvailableExternallyLinkage() &&
649 "'Actual' should have been set above.");
650 TheJIT->addPendingFunction(F);
656 /// getGlobalValueIndirectSym - Return a lazy pointer containing the specified
658 void *JITResolver::getGlobalValueIndirectSym(GlobalValue *GV, void *GVAddress) {
659 MutexGuard locked(TheJIT->lock);
661 // If we already have a stub for this global variable, recycle it.
662 void *&IndirectSym = state.getGlobalToIndirectSymMap(locked)[GV];
663 if (IndirectSym) return IndirectSym;
665 // Otherwise, codegen a new indirect symbol.
666 IndirectSym = TheJIT->getJITInfo().emitGlobalValueIndirectSym(GV, GVAddress,
669 DEBUG(dbgs() << "JIT: Indirect symbol emitted at [" << IndirectSym
670 << "] for GV '" << GV->getName() << "'\n");
675 /// getExternalFunctionStub - Return a stub for the function at the
676 /// specified address, created lazily on demand.
677 void *JITResolver::getExternalFunctionStub(void *FnAddr) {
678 // If we already have a stub for this function, recycle it.
679 void *&Stub = ExternalFnToStubMap[FnAddr];
680 if (Stub) return Stub;
682 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
683 JE.startGVStub(0, SL.Size, SL.Alignment);
684 Stub = TheJIT->getJITInfo().emitFunctionStub(0, FnAddr, JE);
687 DEBUG(dbgs() << "JIT: Stub emitted at [" << Stub
688 << "] for external function at '" << FnAddr << "'\n");
692 unsigned JITResolver::getGOTIndexForAddr(void* addr) {
693 unsigned idx = revGOTMap[addr];
695 idx = ++nextGOTIndex;
696 revGOTMap[addr] = idx;
697 DEBUG(dbgs() << "JIT: Adding GOT entry " << idx << " for addr ["
703 void JITResolver::getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
704 SmallVectorImpl<void*> &Ptrs) {
705 MutexGuard locked(TheJIT->lock);
707 const FunctionToLazyStubMapTy &FM = state.getFunctionToLazyStubMap(locked);
708 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
710 for (FunctionToLazyStubMapTy::const_iterator i = FM.begin(), e = FM.end();
712 Function *F = i->first;
713 if (F->isDeclaration() && F->hasExternalLinkage()) {
714 GVs.push_back(i->first);
715 Ptrs.push_back(i->second);
718 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
720 GVs.push_back(i->first);
721 Ptrs.push_back(i->second);
725 GlobalValue *JITResolver::invalidateStub(void *Stub) {
726 MutexGuard locked(TheJIT->lock);
728 // Remove the stub from the StubToResolverMap.
729 StubToResolverMap->UnregisterStubResolver(Stub);
731 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
733 // Look up the cheap way first, to see if it's a function stub we are
734 // invalidating. If so, remove it from both the forward and reverse maps.
735 if (Function *F = state.EraseStub(locked, Stub)) {
739 // Otherwise, it might be an indirect symbol stub. Find it and remove it.
740 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
742 if (i->second != Stub)
744 GlobalValue *GV = i->first;
749 // Lastly, check to see if it's in the ExternalFnToStubMap.
750 for (std::map<void *, void *>::iterator i = ExternalFnToStubMap.begin(),
751 e = ExternalFnToStubMap.end(); i != e; ++i) {
752 if (i->second != Stub)
754 ExternalFnToStubMap.erase(i);
761 /// JITCompilerFn - This function is called when a lazy compilation stub has
762 /// been entered. It looks up which function this stub corresponds to, compiles
763 /// it if necessary, then returns the resultant function pointer.
764 void *JITResolver::JITCompilerFn(void *Stub) {
765 JITResolver *JR = StubToResolverMap->getResolverFromStub(Stub);
766 assert(JR && "Unable to find the corresponding JITResolver to the call site");
772 // Only lock for getting the Function. The call getPointerToFunction made
773 // in this function might trigger function materializing, which requires
774 // JIT lock to be unlocked.
775 MutexGuard locked(JR->TheJIT->lock);
777 // The address given to us for the stub may not be exactly right, it might
778 // be a little bit after the stub. As such, use upper_bound to find it.
779 pair<void*, Function*> I =
780 JR->state.LookupFunctionFromCallSite(locked, Stub);
785 // If we have already code generated the function, just return the address.
786 void *Result = JR->TheJIT->getPointerToGlobalIfAvailable(F);
789 // Otherwise we don't have it, do lazy compilation now.
791 // If lazy compilation is disabled, emit a useful error message and abort.
792 if (!JR->TheJIT->isCompilingLazily()) {
793 llvm_report_error("LLVM JIT requested to do lazy compilation of function '"
794 + F->getName() + "' when lazy compiles are disabled!");
797 DEBUG(dbgs() << "JIT: Lazily resolving function '" << F->getName()
798 << "' In stub ptr = " << Stub << " actual ptr = "
799 << ActualPtr << "\n");
801 Result = JR->TheJIT->getPointerToFunction(F);
804 // Reacquire the lock to update the GOT map.
805 MutexGuard locked(JR->TheJIT->lock);
807 // We might like to remove the call site from the CallSiteToFunction map, but
808 // we can't do that! Multiple threads could be stuck, waiting to acquire the
809 // lock above. As soon as the 1st function finishes compiling the function,
810 // the next one will be released, and needs to be able to find the function it
813 // FIXME: We could rewrite all references to this stub if we knew them.
815 // What we will do is set the compiled function address to map to the
816 // same GOT entry as the stub so that later clients may update the GOT
817 // if they see it still using the stub address.
818 // Note: this is done so the Resolver doesn't have to manage GOT memory
819 // Do this without allocating map space if the target isn't using a GOT
820 if(JR->revGOTMap.find(Stub) != JR->revGOTMap.end())
821 JR->revGOTMap[Result] = JR->revGOTMap[Stub];
826 //===----------------------------------------------------------------------===//
829 void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
830 bool MayNeedFarStub) {
831 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
832 return TheJIT->getOrEmitGlobalVariable(GV);
834 if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
835 return TheJIT->getPointerToGlobal(GA->resolveAliasedGlobal(false));
837 // If we have already compiled the function, return a pointer to its body.
838 Function *F = cast<Function>(V);
840 void *FnStub = Resolver.getLazyFunctionStubIfAvailable(F);
842 // Return the function stub if it's already created. We do this first so
843 // that we're returning the same address for the function as any previous
844 // call. TODO: Yes, this is wrong. The lazy stub isn't guaranteed to be
845 // close enough to call.
846 AddStubToCurrentFunction(FnStub);
850 // If we know the target can handle arbitrary-distance calls, try to
851 // return a direct pointer.
852 if (!MayNeedFarStub) {
853 // If we have code, go ahead and return that.
854 void *ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
855 if (ResultPtr) return ResultPtr;
857 // If this is an external function pointer, we can force the JIT to
858 // 'compile' it, which really just adds it to the map.
859 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage())
860 return TheJIT->getPointerToFunction(F);
863 // Otherwise, we may need a to emit a stub, and, conservatively, we
865 void *StubAddr = Resolver.getLazyFunctionStub(F);
867 // Add the stub to the current function's list of referenced stubs, so we can
868 // deallocate them if the current function is ever freed. It's possible to
869 // return null from getLazyFunctionStub in the case of a weak extern that
872 AddStubToCurrentFunction(StubAddr);
877 void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) {
878 // Make sure GV is emitted first, and create a stub containing the fully
880 void *GVAddress = getPointerToGlobal(V, Reference, false);
881 void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress);
883 // Add the stub to the current function's list of referenced stubs, so we can
884 // deallocate them if the current function is ever freed.
885 AddStubToCurrentFunction(StubAddr);
890 void JITEmitter::AddStubToCurrentFunction(void *StubAddr) {
891 assert(CurFn && "Stub added to current function, but current function is 0!");
893 SmallVectorImpl<void*> &StubsUsed = CurFnStubUses[CurFn];
894 StubsUsed.push_back(StubAddr);
896 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[StubAddr];
897 FnRefs.insert(CurFn);
900 void JITEmitter::processDebugLoc(DebugLoc DL, bool BeforePrintingInsn) {
901 if (!DL.isUnknown()) {
902 DILocation CurDLT = EmissionDetails.MF->getDILocation(DL);
904 if (BeforePrintingInsn) {
905 if (CurDLT.getScope().getNode() != 0
906 && PrevDLT.getNode() != CurDLT.getNode()) {
907 JITEvent_EmittedFunctionDetails::LineStart NextLine;
908 NextLine.Address = getCurrentPCValue();
910 EmissionDetails.LineStarts.push_back(NextLine);
918 static unsigned GetConstantPoolSizeInBytes(MachineConstantPool *MCP,
919 const TargetData *TD) {
920 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
921 if (Constants.empty()) return 0;
924 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
925 MachineConstantPoolEntry CPE = Constants[i];
926 unsigned AlignMask = CPE.getAlignment() - 1;
927 Size = (Size + AlignMask) & ~AlignMask;
928 const Type *Ty = CPE.getType();
929 Size += TD->getTypeAllocSize(Ty);
934 static unsigned GetJumpTableSizeInBytes(MachineJumpTableInfo *MJTI, JIT *jit) {
935 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
936 if (JT.empty()) return 0;
938 unsigned NumEntries = 0;
939 for (unsigned i = 0, e = JT.size(); i != e; ++i)
940 NumEntries += JT[i].MBBs.size();
942 return NumEntries * MJTI->getEntrySize(*jit->getTargetData());
945 static uintptr_t RoundUpToAlign(uintptr_t Size, unsigned Alignment) {
946 if (Alignment == 0) Alignment = 1;
947 // Since we do not know where the buffer will be allocated, be pessimistic.
948 return Size + Alignment;
951 /// addSizeOfGlobal - add the size of the global (plus any alignment padding)
952 /// into the running total Size.
954 unsigned JITEmitter::addSizeOfGlobal(const GlobalVariable *GV, unsigned Size) {
955 const Type *ElTy = GV->getType()->getElementType();
956 size_t GVSize = (size_t)TheJIT->getTargetData()->getTypeAllocSize(ElTy);
958 (size_t)TheJIT->getTargetData()->getPreferredAlignment(GV);
959 DEBUG(dbgs() << "JIT: Adding in size " << GVSize << " alignment " << GVAlign);
961 // Assume code section ends with worst possible alignment, so first
962 // variable needs maximal padding.
965 Size = ((Size+GVAlign-1)/GVAlign)*GVAlign;
970 /// addSizeOfGlobalsInConstantVal - find any globals that we haven't seen yet
971 /// but are referenced from the constant; put them in GVSet and add their
972 /// size into the running total Size.
974 unsigned JITEmitter::addSizeOfGlobalsInConstantVal(const Constant *C,
976 // If its undefined, return the garbage.
977 if (isa<UndefValue>(C))
980 // If the value is a ConstantExpr
981 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
982 Constant *Op0 = CE->getOperand(0);
983 switch (CE->getOpcode()) {
984 case Instruction::GetElementPtr:
985 case Instruction::Trunc:
986 case Instruction::ZExt:
987 case Instruction::SExt:
988 case Instruction::FPTrunc:
989 case Instruction::FPExt:
990 case Instruction::UIToFP:
991 case Instruction::SIToFP:
992 case Instruction::FPToUI:
993 case Instruction::FPToSI:
994 case Instruction::PtrToInt:
995 case Instruction::IntToPtr:
996 case Instruction::BitCast: {
997 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
1000 case Instruction::Add:
1001 case Instruction::FAdd:
1002 case Instruction::Sub:
1003 case Instruction::FSub:
1004 case Instruction::Mul:
1005 case Instruction::FMul:
1006 case Instruction::UDiv:
1007 case Instruction::SDiv:
1008 case Instruction::URem:
1009 case Instruction::SRem:
1010 case Instruction::And:
1011 case Instruction::Or:
1012 case Instruction::Xor: {
1013 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
1014 Size = addSizeOfGlobalsInConstantVal(CE->getOperand(1), Size);
1019 raw_string_ostream Msg(msg);
1020 Msg << "ConstantExpr not handled: " << *CE;
1021 llvm_report_error(Msg.str());
1026 if (C->getType()->getTypeID() == Type::PointerTyID)
1027 if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C))
1028 if (GVSet.insert(GV))
1029 Size = addSizeOfGlobal(GV, Size);
1034 /// addSizeOfGLobalsInInitializer - handle any globals that we haven't seen yet
1035 /// but are referenced from the given initializer.
1037 unsigned JITEmitter::addSizeOfGlobalsInInitializer(const Constant *Init,
1039 if (!isa<UndefValue>(Init) &&
1040 !isa<ConstantVector>(Init) &&
1041 !isa<ConstantAggregateZero>(Init) &&
1042 !isa<ConstantArray>(Init) &&
1043 !isa<ConstantStruct>(Init) &&
1044 Init->getType()->isFirstClassType())
1045 Size = addSizeOfGlobalsInConstantVal(Init, Size);
1049 /// GetSizeOfGlobalsInBytes - walk the code for the function, looking for
1050 /// globals; then walk the initializers of those globals looking for more.
1051 /// If their size has not been considered yet, add it into the running total
1054 unsigned JITEmitter::GetSizeOfGlobalsInBytes(MachineFunction &MF) {
1058 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
1060 for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
1062 const TargetInstrDesc &Desc = I->getDesc();
1063 const MachineInstr &MI = *I;
1064 unsigned NumOps = Desc.getNumOperands();
1065 for (unsigned CurOp = 0; CurOp < NumOps; CurOp++) {
1066 const MachineOperand &MO = MI.getOperand(CurOp);
1067 if (MO.isGlobal()) {
1068 GlobalValue* V = MO.getGlobal();
1069 const GlobalVariable *GV = dyn_cast<const GlobalVariable>(V);
1072 // If seen in previous function, it will have an entry here.
1073 if (TheJIT->getPointerToGlobalIfAvailable(GV))
1075 // If seen earlier in this function, it will have an entry here.
1076 // FIXME: it should be possible to combine these tables, by
1077 // assuming the addresses of the new globals in this module
1078 // start at 0 (or something) and adjusting them after codegen
1079 // complete. Another possibility is to grab a marker bit in GV.
1080 if (GVSet.insert(GV))
1081 // A variable as yet unseen. Add in its size.
1082 Size = addSizeOfGlobal(GV, Size);
1087 DEBUG(dbgs() << "JIT: About to look through initializers\n");
1088 // Look for more globals that are referenced only from initializers.
1089 // GVSet.end is computed each time because the set can grow as we go.
1090 for (SmallPtrSet<const GlobalVariable *, 8>::iterator I = GVSet.begin();
1091 I != GVSet.end(); I++) {
1092 const GlobalVariable* GV = *I;
1093 if (GV->hasInitializer())
1094 Size = addSizeOfGlobalsInInitializer(GV->getInitializer(), Size);
1100 void JITEmitter::startFunction(MachineFunction &F) {
1101 DEBUG(dbgs() << "JIT: Starting CodeGen of Function "
1102 << F.getFunction()->getName() << "\n");
1104 uintptr_t ActualSize = 0;
1105 // Set the memory writable, if it's not already
1106 MemMgr->setMemoryWritable();
1107 if (MemMgr->NeedsExactSize()) {
1108 DEBUG(dbgs() << "JIT: ExactSize\n");
1109 const TargetInstrInfo* TII = F.getTarget().getInstrInfo();
1110 MachineConstantPool *MCP = F.getConstantPool();
1112 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1113 ActualSize = RoundUpToAlign(ActualSize, 16);
1115 // Add the alignment of the constant pool
1116 ActualSize = RoundUpToAlign(ActualSize, MCP->getConstantPoolAlignment());
1118 // Add the constant pool size
1119 ActualSize += GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1121 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo()) {
1122 // Add the aligment of the jump table info
1123 ActualSize = RoundUpToAlign(ActualSize,
1124 MJTI->getEntryAlignment(*TheJIT->getTargetData()));
1126 // Add the jump table size
1127 ActualSize += GetJumpTableSizeInBytes(MJTI, TheJIT);
1130 // Add the alignment for the function
1131 ActualSize = RoundUpToAlign(ActualSize,
1132 std::max(F.getFunction()->getAlignment(), 8U));
1134 // Add the function size
1135 ActualSize += TII->GetFunctionSizeInBytes(F);
1137 DEBUG(dbgs() << "JIT: ActualSize before globals " << ActualSize << "\n");
1138 // Add the size of the globals that will be allocated after this function.
1139 // These are all the ones referenced from this function that were not
1140 // previously allocated.
1141 ActualSize += GetSizeOfGlobalsInBytes(F);
1142 DEBUG(dbgs() << "JIT: ActualSize after globals " << ActualSize << "\n");
1143 } else if (SizeEstimate > 0) {
1144 // SizeEstimate will be non-zero on reallocation attempts.
1145 ActualSize = SizeEstimate;
1148 BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(),
1150 BufferEnd = BufferBegin+ActualSize;
1151 EmittedFunctions[F.getFunction()].FunctionBody = BufferBegin;
1153 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1156 emitConstantPool(F.getConstantPool());
1157 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
1158 initJumpTableInfo(MJTI);
1160 // About to start emitting the machine code for the function.
1161 emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
1162 TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
1163 EmittedFunctions[F.getFunction()].Code = CurBufferPtr;
1165 MBBLocations.clear();
1167 EmissionDetails.MF = &F;
1168 EmissionDetails.LineStarts.clear();
1171 bool JITEmitter::finishFunction(MachineFunction &F) {
1172 if (CurBufferPtr == BufferEnd) {
1173 // We must call endFunctionBody before retrying, because
1174 // deallocateMemForFunction requires it.
1175 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1176 retryWithMoreMemory(F);
1180 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
1181 emitJumpTableInfo(MJTI);
1183 // FnStart is the start of the text, not the start of the constant pool and
1184 // other per-function data.
1186 (uint8_t *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
1188 // FnEnd is the end of the function's machine code.
1189 uint8_t *FnEnd = CurBufferPtr;
1191 if (!Relocations.empty()) {
1192 CurFn = F.getFunction();
1193 NumRelos += Relocations.size();
1195 // Resolve the relocations to concrete pointers.
1196 for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
1197 MachineRelocation &MR = Relocations[i];
1198 void *ResultPtr = 0;
1199 if (!MR.letTargetResolve()) {
1200 if (MR.isExternalSymbol()) {
1201 ResultPtr = TheJIT->getPointerToNamedFunction(MR.getExternalSymbol(),
1203 DEBUG(dbgs() << "JIT: Map \'" << MR.getExternalSymbol() << "\' to ["
1204 << ResultPtr << "]\n");
1206 // If the target REALLY wants a stub for this function, emit it now.
1207 if (MR.mayNeedFarStub()) {
1208 ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
1210 } else if (MR.isGlobalValue()) {
1211 ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
1212 BufferBegin+MR.getMachineCodeOffset(),
1213 MR.mayNeedFarStub());
1214 } else if (MR.isIndirectSymbol()) {
1215 ResultPtr = getPointerToGVIndirectSym(
1216 MR.getGlobalValue(), BufferBegin+MR.getMachineCodeOffset());
1217 } else if (MR.isBasicBlock()) {
1218 ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
1219 } else if (MR.isConstantPoolIndex()) {
1220 ResultPtr = (void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
1222 assert(MR.isJumpTableIndex());
1223 ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
1226 MR.setResultPointer(ResultPtr);
1229 // if we are managing the GOT and the relocation wants an index,
1231 if (MR.isGOTRelative() && MemMgr->isManagingGOT()) {
1232 unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
1233 MR.setGOTIndex(idx);
1234 if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) {
1235 DEBUG(dbgs() << "JIT: GOT was out of date for " << ResultPtr
1236 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1238 ((void**)MemMgr->getGOTBase())[idx] = ResultPtr;
1244 TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
1245 Relocations.size(), MemMgr->getGOTBase());
1248 // Update the GOT entry for F to point to the new code.
1249 if (MemMgr->isManagingGOT()) {
1250 unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
1251 if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) {
1252 DEBUG(dbgs() << "JIT: GOT was out of date for " << (void*)BufferBegin
1253 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1255 ((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin;
1259 // CurBufferPtr may have moved beyond FnEnd, due to memory allocation for
1260 // global variables that were referenced in the relocations.
1261 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1263 if (CurBufferPtr == BufferEnd) {
1264 retryWithMoreMemory(F);
1267 // Now that we've succeeded in emitting the function, reset the
1268 // SizeEstimate back down to zero.
1272 BufferBegin = CurBufferPtr = 0;
1273 NumBytes += FnEnd-FnStart;
1275 // Invalidate the icache if necessary.
1276 sys::Memory::InvalidateInstructionCache(FnStart, FnEnd-FnStart);
1278 TheJIT->NotifyFunctionEmitted(*F.getFunction(), FnStart, FnEnd-FnStart,
1281 DEBUG(dbgs() << "JIT: Finished CodeGen of [" << (void*)FnStart
1282 << "] Function: " << F.getFunction()->getName()
1283 << ": " << (FnEnd-FnStart) << " bytes of text, "
1284 << Relocations.size() << " relocations\n");
1286 Relocations.clear();
1287 ConstPoolAddresses.clear();
1289 // Mark code region readable and executable if it's not so already.
1290 MemMgr->setMemoryExecutable();
1293 if (sys::hasDisassembler()) {
1294 dbgs() << "JIT: Disassembled code:\n";
1295 dbgs() << sys::disassembleBuffer(FnStart, FnEnd-FnStart,
1296 (uintptr_t)FnStart);
1298 dbgs() << "JIT: Binary code:\n";
1299 uint8_t* q = FnStart;
1300 for (int i = 0; q < FnEnd; q += 4, ++i) {
1304 dbgs() << "JIT: " << (long)(q - FnStart) << ": ";
1306 for (int j = 3; j >= 0; --j) {
1310 dbgs() << (unsigned short)q[j];
1322 if (DwarfExceptionHandling || JITEmitDebugInfo) {
1323 uintptr_t ActualSize = 0;
1324 SavedBufferBegin = BufferBegin;
1325 SavedBufferEnd = BufferEnd;
1326 SavedCurBufferPtr = CurBufferPtr;
1328 if (MemMgr->NeedsExactSize()) {
1329 ActualSize = DE->GetDwarfTableSizeInBytes(F, *this, FnStart, FnEnd);
1332 BufferBegin = CurBufferPtr = MemMgr->startExceptionTable(F.getFunction(),
1334 BufferEnd = BufferBegin+ActualSize;
1335 EmittedFunctions[F.getFunction()].ExceptionTable = BufferBegin;
1337 uint8_t *FrameRegister = DE->EmitDwarfTable(F, *this, FnStart, FnEnd,
1339 MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr,
1341 uint8_t *EhEnd = CurBufferPtr;
1342 BufferBegin = SavedBufferBegin;
1343 BufferEnd = SavedBufferEnd;
1344 CurBufferPtr = SavedCurBufferPtr;
1346 if (DwarfExceptionHandling) {
1347 TheJIT->RegisterTable(FrameRegister);
1350 if (JITEmitDebugInfo) {
1352 I.FnStart = FnStart;
1354 I.EhStart = EhStart;
1356 DR->RegisterFunction(F.getFunction(), I);
1366 void JITEmitter::retryWithMoreMemory(MachineFunction &F) {
1367 DEBUG(dbgs() << "JIT: Ran out of space for native code. Reattempting.\n");
1368 Relocations.clear(); // Clear the old relocations or we'll reapply them.
1369 ConstPoolAddresses.clear();
1371 deallocateMemForFunction(F.getFunction());
1372 // Try again with at least twice as much free space.
1373 SizeEstimate = (uintptr_t)(2 * (BufferEnd - BufferBegin));
1376 /// deallocateMemForFunction - Deallocate all memory for the specified
1377 /// function body. Also drop any references the function has to stubs.
1378 /// May be called while the Function is being destroyed inside ~Value().
1379 void JITEmitter::deallocateMemForFunction(const Function *F) {
1380 ValueMap<const Function *, EmittedCode, EmittedFunctionConfig>::iterator
1381 Emitted = EmittedFunctions.find(F);
1382 if (Emitted != EmittedFunctions.end()) {
1383 MemMgr->deallocateFunctionBody(Emitted->second.FunctionBody);
1384 MemMgr->deallocateExceptionTable(Emitted->second.ExceptionTable);
1385 TheJIT->NotifyFreeingMachineCode(Emitted->second.Code);
1387 EmittedFunctions.erase(Emitted);
1390 // TODO: Do we need to unregister exception handling information from libgcc
1393 if (JITEmitDebugInfo) {
1394 DR->UnregisterFunction(F);
1397 // If the function did not reference any stubs, return.
1398 if (CurFnStubUses.find(F) == CurFnStubUses.end())
1401 // For each referenced stub, erase the reference to this function, and then
1402 // erase the list of referenced stubs.
1403 SmallVectorImpl<void *> &StubList = CurFnStubUses[F];
1404 for (unsigned i = 0, e = StubList.size(); i != e; ++i) {
1405 void *Stub = StubList[i];
1407 // If we already invalidated this stub for this function, continue.
1408 if (StubFnRefs.count(Stub) == 0)
1411 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[Stub];
1414 // If this function was the last reference to the stub, invalidate the stub
1415 // in the JITResolver. Were there a memory manager deallocateStub routine,
1416 // we could call that at this point too.
1417 if (FnRefs.empty()) {
1418 DEBUG(dbgs() << "\nJIT: Invalidated Stub at [" << Stub << "]\n");
1419 StubFnRefs.erase(Stub);
1421 // Invalidate the stub. If it is a GV stub, update the JIT's global
1422 // mapping for that GV to zero.
1423 GlobalValue *GV = Resolver.invalidateStub(Stub);
1425 TheJIT->updateGlobalMapping(GV, 0);
1429 CurFnStubUses.erase(F);
1433 void* JITEmitter::allocateSpace(uintptr_t Size, unsigned Alignment) {
1435 return JITCodeEmitter::allocateSpace(Size, Alignment);
1437 // create a new memory block if there is no active one.
1438 // care must be taken so that BufferBegin is invalidated when a
1440 BufferBegin = CurBufferPtr = MemMgr->allocateSpace(Size, Alignment);
1441 BufferEnd = BufferBegin+Size;
1442 return CurBufferPtr;
1445 void* JITEmitter::allocateGlobal(uintptr_t Size, unsigned Alignment) {
1446 // Delegate this call through the memory manager.
1447 return MemMgr->allocateGlobal(Size, Alignment);
1450 void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
1451 if (TheJIT->getJITInfo().hasCustomConstantPool())
1454 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
1455 if (Constants.empty()) return;
1457 unsigned Size = GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1458 unsigned Align = MCP->getConstantPoolAlignment();
1459 ConstantPoolBase = allocateSpace(Size, Align);
1462 if (ConstantPoolBase == 0) return; // Buffer overflow.
1464 DEBUG(dbgs() << "JIT: Emitted constant pool at [" << ConstantPoolBase
1465 << "] (size: " << Size << ", alignment: " << Align << ")\n");
1467 // Initialize the memory for all of the constant pool entries.
1468 unsigned Offset = 0;
1469 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
1470 MachineConstantPoolEntry CPE = Constants[i];
1471 unsigned AlignMask = CPE.getAlignment() - 1;
1472 Offset = (Offset + AlignMask) & ~AlignMask;
1474 uintptr_t CAddr = (uintptr_t)ConstantPoolBase + Offset;
1475 ConstPoolAddresses.push_back(CAddr);
1476 if (CPE.isMachineConstantPoolEntry()) {
1477 // FIXME: add support to lower machine constant pool values into bytes!
1478 llvm_report_error("Initialize memory with machine specific constant pool"
1479 "entry has not been implemented!");
1481 TheJIT->InitializeMemory(CPE.Val.ConstVal, (void*)CAddr);
1482 DEBUG(dbgs() << "JIT: CP" << i << " at [0x";
1483 dbgs().write_hex(CAddr) << "]\n");
1485 const Type *Ty = CPE.Val.ConstVal->getType();
1486 Offset += TheJIT->getTargetData()->getTypeAllocSize(Ty);
1490 void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
1491 if (TheJIT->getJITInfo().hasCustomJumpTables())
1494 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1495 if (JT.empty()) return;
1497 unsigned NumEntries = 0;
1498 for (unsigned i = 0, e = JT.size(); i != e; ++i)
1499 NumEntries += JT[i].MBBs.size();
1501 unsigned EntrySize = MJTI->getEntrySize(*TheJIT->getTargetData());
1503 // Just allocate space for all the jump tables now. We will fix up the actual
1504 // MBB entries in the tables after we emit the code for each block, since then
1505 // we will know the final locations of the MBBs in memory.
1507 JumpTableBase = allocateSpace(NumEntries * EntrySize,
1508 MJTI->getEntryAlignment(*TheJIT->getTargetData()));
1511 void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
1512 if (TheJIT->getJITInfo().hasCustomJumpTables())
1515 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1516 if (JT.empty() || JumpTableBase == 0) return;
1519 switch (MJTI->getEntryKind()) {
1520 case MachineJumpTableInfo::EK_BlockAddress: {
1521 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1523 assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == sizeof(void*) &&
1526 // For each jump table, map each target in the jump table to the address of
1527 // an emitted MachineBasicBlock.
1528 intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
1530 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1531 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1532 // Store the address of the basic block for this jump table slot in the
1533 // memory we allocated for the jump table in 'initJumpTableInfo'
1534 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
1535 *SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
1540 case MachineJumpTableInfo::EK_Custom32:
1541 case MachineJumpTableInfo::EK_GPRel32BlockAddress:
1542 case MachineJumpTableInfo::EK_LabelDifference32: {
1543 assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == 4&&"Cross JIT'ing?");
1544 // For each jump table, place the offset from the beginning of the table
1545 // to the target address.
1546 int *SlotPtr = (int*)JumpTableBase;
1548 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1549 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1550 // Store the offset of the basic block for this jump table slot in the
1551 // memory we allocated for the jump table in 'initJumpTableInfo'
1552 uintptr_t Base = (uintptr_t)SlotPtr;
1553 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) {
1554 uintptr_t MBBAddr = getMachineBasicBlockAddress(MBBs[mi]);
1555 /// FIXME: USe EntryKind instead of magic "getPICJumpTableEntry" hook.
1556 *SlotPtr++ = TheJIT->getJITInfo().getPICJumpTableEntry(MBBAddr, Base);
1564 void JITEmitter::startGVStub(const GlobalValue* GV,
1565 unsigned StubSize, unsigned Alignment) {
1566 SavedBufferBegin = BufferBegin;
1567 SavedBufferEnd = BufferEnd;
1568 SavedCurBufferPtr = CurBufferPtr;
1570 BufferBegin = CurBufferPtr = MemMgr->allocateStub(GV, StubSize, Alignment);
1571 BufferEnd = BufferBegin+StubSize+1;
1574 void JITEmitter::startGVStub(void *Buffer, unsigned StubSize) {
1575 SavedBufferBegin = BufferBegin;
1576 SavedBufferEnd = BufferEnd;
1577 SavedCurBufferPtr = CurBufferPtr;
1579 BufferBegin = CurBufferPtr = (uint8_t *)Buffer;
1580 BufferEnd = BufferBegin+StubSize+1;
1583 void JITEmitter::finishGVStub() {
1584 assert(CurBufferPtr != BufferEnd && "Stub overflowed allocated space.");
1585 NumBytes += getCurrentPCOffset();
1586 BufferBegin = SavedBufferBegin;
1587 BufferEnd = SavedBufferEnd;
1588 CurBufferPtr = SavedCurBufferPtr;
1591 void *JITEmitter::allocIndirectGV(const GlobalValue *GV,
1592 const uint8_t *Buffer, size_t Size,
1593 unsigned Alignment) {
1594 uint8_t *IndGV = MemMgr->allocateStub(GV, Size, Alignment);
1595 memcpy(IndGV, Buffer, Size);
1599 // getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
1600 // in the constant pool that was last emitted with the 'emitConstantPool'
1603 uintptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const {
1604 assert(ConstantNum < ConstantPool->getConstants().size() &&
1605 "Invalid ConstantPoolIndex!");
1606 return ConstPoolAddresses[ConstantNum];
1609 // getJumpTableEntryAddress - Return the address of the JumpTable with index
1610 // 'Index' in the jumpp table that was last initialized with 'initJumpTableInfo'
1612 uintptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
1613 const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
1614 assert(Index < JT.size() && "Invalid jump table index!");
1616 unsigned EntrySize = JumpTable->getEntrySize(*TheJIT->getTargetData());
1618 unsigned Offset = 0;
1619 for (unsigned i = 0; i < Index; ++i)
1620 Offset += JT[i].MBBs.size();
1622 Offset *= EntrySize;
1624 return (uintptr_t)((char *)JumpTableBase + Offset);
1627 void JITEmitter::EmittedFunctionConfig::onDelete(
1628 JITEmitter *Emitter, const Function *F) {
1629 Emitter->deallocateMemForFunction(F);
1631 void JITEmitter::EmittedFunctionConfig::onRAUW(
1632 JITEmitter *, const Function*, const Function*) {
1633 llvm_unreachable("The JIT doesn't know how to handle a"
1634 " RAUW on a value it has emitted.");
1638 //===----------------------------------------------------------------------===//
1639 // Public interface to this file
1640 //===----------------------------------------------------------------------===//
1642 JITCodeEmitter *JIT::createEmitter(JIT &jit, JITMemoryManager *JMM,
1643 TargetMachine &tm) {
1644 return new JITEmitter(jit, JMM, tm);
1647 // getPointerToFunctionOrStub - If the specified function has been
1648 // code-gen'd, return a pointer to the function. If not, compile it, or use
1649 // a stub to implement lazy compilation if available.
1651 void *JIT::getPointerToFunctionOrStub(Function *F) {
1652 // If we have already code generated the function, just return the address.
1653 if (void *Addr = getPointerToGlobalIfAvailable(F))
1656 // Get a stub if the target supports it.
1657 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1658 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1659 return JE->getJITResolver().getLazyFunctionStub(F);
1662 void JIT::updateFunctionStub(Function *F) {
1663 // Get the empty stub we generated earlier.
1664 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1665 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1666 void *Stub = JE->getJITResolver().getLazyFunctionStub(F);
1667 void *Addr = getPointerToGlobalIfAvailable(F);
1668 assert(Addr != Stub && "Function must have non-stub address to be updated.");
1670 // Tell the target jit info to rewrite the stub at the specified address,
1671 // rather than creating a new one.
1672 TargetJITInfo::StubLayout layout = getJITInfo().getStubLayout();
1673 JE->startGVStub(Stub, layout.Size);
1674 getJITInfo().emitFunctionStub(F, Addr, *getCodeEmitter());
1678 /// freeMachineCodeForFunction - release machine code memory for given Function.
1680 void JIT::freeMachineCodeForFunction(Function *F) {
1681 // Delete translation for this from the ExecutionEngine, so it will get
1682 // retranslated next time it is used.
1683 updateGlobalMapping(F, 0);
1685 // Free the actual memory for the function body and related stuff.
1686 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1687 cast<JITEmitter>(JCE)->deallocateMemForFunction(F);