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 /// getGOTIndexForAddress - Return a new or existing index in the GOT for
230 /// an address. This function only manages slots, it does not manage the
231 /// contents of the slots or the memory associated with the GOT.
232 unsigned getGOTIndexForAddr(void *addr);
234 /// JITCompilerFn - This function is called to resolve a stub to a compiled
235 /// address. If the LLVM Function corresponding to the stub has not yet
236 /// been compiled, this function compiles it first.
237 static void *JITCompilerFn(void *Stub);
240 class StubToResolverMapTy {
241 /// Map a stub address to a specific instance of a JITResolver so that
242 /// lazily-compiled functions can find the right resolver to use.
245 std::map<void*, JITResolver*> Map;
247 /// Guards Map from concurrent accesses.
248 mutable sys::Mutex Lock;
251 /// Registers a Stub to be resolved by Resolver.
252 void RegisterStubResolver(void *Stub, JITResolver *Resolver) {
253 MutexGuard guard(Lock);
254 Map.insert(std::make_pair(Stub, Resolver));
256 /// Unregisters the Stub when it's invalidated.
257 void UnregisterStubResolver(void *Stub) {
258 MutexGuard guard(Lock);
261 /// Returns the JITResolver instance that owns the Stub.
262 JITResolver *getResolverFromStub(void *Stub) const {
263 MutexGuard guard(Lock);
264 // The address given to us for the stub may not be exactly right, it might
265 // be a little bit after the stub. As such, use upper_bound to find it.
266 // This is the same trick as in LookupFunctionFromCallSite from
268 std::map<void*, JITResolver*>::const_iterator I = Map.upper_bound(Stub);
269 assert(I != Map.begin() && "This is not a known stub!");
273 /// True if any stubs refer to the given resolver. Only used in an assert().
275 bool ResolverHasStubs(JITResolver* Resolver) const {
276 MutexGuard guard(Lock);
277 for (std::map<void*, JITResolver*>::const_iterator I = Map.begin(),
278 E = Map.end(); I != E; ++I) {
279 if (I->second == Resolver)
285 /// This needs to be static so that a lazy call stub can access it with no
286 /// context except the address of the stub.
287 ManagedStatic<StubToResolverMapTy> StubToResolverMap;
289 /// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is
290 /// used to output functions to memory for execution.
291 class JITEmitter : public JITCodeEmitter {
292 JITMemoryManager *MemMgr;
294 // When outputting a function stub in the context of some other function, we
295 // save BufferBegin/BufferEnd/CurBufferPtr here.
296 uint8_t *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr;
298 // When reattempting to JIT a function after running out of space, we store
299 // the estimated size of the function we're trying to JIT here, so we can
300 // ask the memory manager for at least this much space. When we
301 // successfully emit the function, we reset this back to zero.
302 uintptr_t SizeEstimate;
304 /// Relocations - These are the relocations that the function needs, as
306 std::vector<MachineRelocation> Relocations;
308 /// MBBLocations - This vector is a mapping from MBB ID's to their address.
309 /// It is filled in by the StartMachineBasicBlock callback and queried by
310 /// the getMachineBasicBlockAddress callback.
311 std::vector<uintptr_t> MBBLocations;
313 /// ConstantPool - The constant pool for the current function.
315 MachineConstantPool *ConstantPool;
317 /// ConstantPoolBase - A pointer to the first entry in the constant pool.
319 void *ConstantPoolBase;
321 /// ConstPoolAddresses - Addresses of individual constant pool entries.
323 SmallVector<uintptr_t, 8> ConstPoolAddresses;
325 /// JumpTable - The jump tables for the current function.
327 MachineJumpTableInfo *JumpTable;
329 /// JumpTableBase - A pointer to the first entry in the jump table.
333 /// Resolver - This contains info about the currently resolved functions.
334 JITResolver Resolver;
336 /// DE - The dwarf emitter for the jit.
337 OwningPtr<JITDwarfEmitter> DE;
339 /// DR - The debug registerer for the jit.
340 OwningPtr<JITDebugRegisterer> DR;
342 /// LabelLocations - This vector is a mapping from Label ID's to their
344 std::vector<uintptr_t> LabelLocations;
346 /// MMI - Machine module info for exception informations
347 MachineModuleInfo* MMI;
349 // CurFn - The llvm function being emitted. Only valid during
351 const Function *CurFn;
353 /// Information about emitted code, which is passed to the
354 /// JITEventListeners. This is reset in startFunction and used in
356 JITEvent_EmittedFunctionDetails EmissionDetails;
359 void *FunctionBody; // Beginning of the function's allocation.
360 void *Code; // The address the function's code actually starts at.
361 void *ExceptionTable;
362 EmittedCode() : FunctionBody(0), Code(0), ExceptionTable(0) {}
364 struct EmittedFunctionConfig : public ValueMapConfig<const Function*> {
365 typedef JITEmitter *ExtraData;
366 static void onDelete(JITEmitter *, const Function*);
367 static void onRAUW(JITEmitter *, const Function*, const Function*);
369 ValueMap<const Function *, EmittedCode,
370 EmittedFunctionConfig> EmittedFunctions;
374 /// Instance of the JIT
378 JITEmitter(JIT &jit, JITMemoryManager *JMM, TargetMachine &TM)
379 : SizeEstimate(0), Resolver(jit, *this), MMI(0), CurFn(0),
380 EmittedFunctions(this), PrevDLT(NULL), TheJIT(&jit) {
381 MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager();
382 if (jit.getJITInfo().needsGOT()) {
383 MemMgr->AllocateGOT();
384 DEBUG(dbgs() << "JIT is managing a GOT\n");
387 if (DwarfExceptionHandling || JITEmitDebugInfo) {
388 DE.reset(new JITDwarfEmitter(jit));
390 if (JITEmitDebugInfo) {
391 DR.reset(new JITDebugRegisterer(TM));
398 /// classof - Methods for support type inquiry through isa, cast, and
401 static inline bool classof(const JITEmitter*) { return true; }
402 static inline bool classof(const MachineCodeEmitter*) { return true; }
404 JITResolver &getJITResolver() { return Resolver; }
406 virtual void startFunction(MachineFunction &F);
407 virtual bool finishFunction(MachineFunction &F);
409 void emitConstantPool(MachineConstantPool *MCP);
410 void initJumpTableInfo(MachineJumpTableInfo *MJTI);
411 void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
413 void startGVStub(const GlobalValue* GV,
414 unsigned StubSize, unsigned Alignment = 1);
415 void startGVStub(void *Buffer, unsigned StubSize);
417 virtual void *allocIndirectGV(const GlobalValue *GV,
418 const uint8_t *Buffer, size_t Size,
421 /// allocateSpace - Reserves space in the current block if any, or
422 /// allocate a new one of the given size.
423 virtual void *allocateSpace(uintptr_t Size, unsigned Alignment);
425 /// allocateGlobal - Allocate memory for a global. Unlike allocateSpace,
426 /// this method does not allocate memory in the current output buffer,
427 /// because a global may live longer than the current function.
428 virtual void *allocateGlobal(uintptr_t Size, unsigned Alignment);
430 virtual void addRelocation(const MachineRelocation &MR) {
431 Relocations.push_back(MR);
434 virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
435 if (MBBLocations.size() <= (unsigned)MBB->getNumber())
436 MBBLocations.resize((MBB->getNumber()+1)*2);
437 MBBLocations[MBB->getNumber()] = getCurrentPCValue();
438 DEBUG(dbgs() << "JIT: Emitting BB" << MBB->getNumber() << " at ["
439 << (void*) getCurrentPCValue() << "]\n");
442 virtual uintptr_t getConstantPoolEntryAddress(unsigned Entry) const;
443 virtual uintptr_t getJumpTableEntryAddress(unsigned Entry) const;
445 virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
446 assert(MBBLocations.size() > (unsigned)MBB->getNumber() &&
447 MBBLocations[MBB->getNumber()] && "MBB not emitted!");
448 return MBBLocations[MBB->getNumber()];
451 /// retryWithMoreMemory - Log a retry and deallocate all memory for the
452 /// given function. Increase the minimum allocation size so that we get
453 /// more memory next time.
454 void retryWithMoreMemory(MachineFunction &F);
456 /// deallocateMemForFunction - Deallocate all memory for the specified
458 void deallocateMemForFunction(const Function *F);
460 virtual void processDebugLoc(DebugLoc DL, bool BeforePrintingInsn);
462 virtual void emitLabel(uint64_t LabelID) {
463 if (LabelLocations.size() <= LabelID)
464 LabelLocations.resize((LabelID+1)*2);
465 LabelLocations[LabelID] = getCurrentPCValue();
468 virtual uintptr_t getLabelAddress(uint64_t LabelID) const {
469 assert(LabelLocations.size() > (unsigned)LabelID &&
470 LabelLocations[LabelID] && "Label not emitted!");
471 return LabelLocations[LabelID];
474 virtual void setModuleInfo(MachineModuleInfo* Info) {
476 if (DE.get()) DE->setModuleInfo(Info);
479 void setMemoryExecutable() {
480 MemMgr->setMemoryExecutable();
483 JITMemoryManager *getMemMgr() const { return MemMgr; }
486 void *getPointerToGlobal(GlobalValue *GV, void *Reference,
487 bool MayNeedFarStub);
488 void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference);
489 unsigned addSizeOfGlobal(const GlobalVariable *GV, unsigned Size);
490 unsigned addSizeOfGlobalsInConstantVal(
491 const Constant *C, unsigned Size,
492 SmallPtrSet<const GlobalVariable*, 8> &SeenGlobals,
493 SmallVectorImpl<const GlobalVariable*> &Worklist);
494 unsigned addSizeOfGlobalsInInitializer(
495 const Constant *Init, unsigned Size,
496 SmallPtrSet<const GlobalVariable*, 8> &SeenGlobals,
497 SmallVectorImpl<const GlobalVariable*> &Worklist);
498 unsigned GetSizeOfGlobalsInBytes(MachineFunction &MF);
502 void CallSiteValueMapConfig::onDelete(JITResolverState *JRS, Function *F) {
503 JRS->EraseAllCallSitesForPrelocked(F);
506 Function *JITResolverState::EraseStub(const MutexGuard &locked, void *Stub) {
507 CallSiteToFunctionMapTy::iterator C2F_I =
508 CallSiteToFunctionMap.find(Stub);
509 if (C2F_I == CallSiteToFunctionMap.end()) {
514 StubToResolverMap->UnregisterStubResolver(Stub);
516 Function *const F = C2F_I->second;
518 void *RealStub = FunctionToLazyStubMap.lookup(F);
519 assert(RealStub == Stub &&
520 "Call-site that wasn't a stub passed in to EraseStub");
522 FunctionToLazyStubMap.erase(F);
523 CallSiteToFunctionMap.erase(C2F_I);
525 // Remove the stub from the function->call-sites map, and remove the whole
526 // entry from the map if that was the last call site.
527 FunctionToCallSitesMapTy::iterator F2C_I = FunctionToCallSitesMap.find(F);
528 assert(F2C_I != FunctionToCallSitesMap.end() &&
529 "FunctionToCallSitesMap broken");
530 bool Erased = F2C_I->second.erase(Stub);
532 assert(Erased && "FunctionToCallSitesMap broken");
533 if (F2C_I->second.empty())
534 FunctionToCallSitesMap.erase(F2C_I);
539 void JITResolverState::EraseAllCallSitesForPrelocked(Function *F) {
540 FunctionToCallSitesMapTy::iterator F2C = FunctionToCallSitesMap.find(F);
541 if (F2C == FunctionToCallSitesMap.end())
543 StubToResolverMapTy &S2RMap = *StubToResolverMap;
544 for (SmallPtrSet<void*, 1>::const_iterator I = F2C->second.begin(),
545 E = F2C->second.end(); I != E; ++I) {
546 S2RMap.UnregisterStubResolver(*I);
547 bool Erased = CallSiteToFunctionMap.erase(*I);
549 assert(Erased && "Missing call site->function mapping");
551 FunctionToCallSitesMap.erase(F2C);
554 void JITResolverState::EraseAllCallSitesPrelocked() {
555 StubToResolverMapTy &S2RMap = *StubToResolverMap;
556 for (CallSiteToFunctionMapTy::const_iterator
557 I = CallSiteToFunctionMap.begin(),
558 E = CallSiteToFunctionMap.end(); I != E; ++I) {
559 S2RMap.UnregisterStubResolver(I->first);
561 CallSiteToFunctionMap.clear();
562 FunctionToCallSitesMap.clear();
565 JITResolver::~JITResolver() {
566 // No need to lock because we're in the destructor, and state isn't shared.
567 state.EraseAllCallSitesPrelocked();
568 assert(!StubToResolverMap->ResolverHasStubs(this) &&
569 "Resolver destroyed with stubs still alive.");
572 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function stub
573 /// if it has already been created.
574 void *JITResolver::getLazyFunctionStubIfAvailable(Function *F) {
575 MutexGuard locked(TheJIT->lock);
577 // If we already have a stub for this function, recycle it.
578 return state.getFunctionToLazyStubMap(locked).lookup(F);
581 /// getFunctionStub - This returns a pointer to a function stub, creating
582 /// one on demand as needed.
583 void *JITResolver::getLazyFunctionStub(Function *F) {
584 MutexGuard locked(TheJIT->lock);
586 // If we already have a lazy stub for this function, recycle it.
587 void *&Stub = state.getFunctionToLazyStubMap(locked)[F];
588 if (Stub) return Stub;
590 // Call the lazy resolver function if we are JIT'ing lazily. Otherwise we
591 // must resolve the symbol now.
592 void *Actual = TheJIT->isCompilingLazily()
593 ? (void *)(intptr_t)LazyResolverFn : (void *)0;
595 // If this is an external declaration, attempt to resolve the address now
596 // to place in the stub.
597 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage()) {
598 Actual = TheJIT->getPointerToFunction(F);
600 // If we resolved the symbol to a null address (eg. a weak external)
601 // don't emit a stub. Return a null pointer to the application.
602 if (!Actual) return 0;
605 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
606 JE.startGVStub(F, SL.Size, SL.Alignment);
607 // Codegen a new stub, calling the lazy resolver or the actual address of the
608 // external function, if it was resolved.
609 Stub = TheJIT->getJITInfo().emitFunctionStub(F, Actual, JE);
612 if (Actual != (void*)(intptr_t)LazyResolverFn) {
613 // If we are getting the stub for an external function, we really want the
614 // address of the stub in the GlobalAddressMap for the JIT, not the address
615 // of the external function.
616 TheJIT->updateGlobalMapping(F, Stub);
619 DEBUG(dbgs() << "JIT: Lazy stub emitted at [" << Stub << "] for function '"
620 << F->getName() << "'\n");
622 if (TheJIT->isCompilingLazily()) {
623 // Register this JITResolver as the one corresponding to this call site so
624 // JITCompilerFn will be able to find it.
625 StubToResolverMap->RegisterStubResolver(Stub, this);
627 // Finally, keep track of the stub-to-Function mapping so that the
628 // JITCompilerFn knows which function to compile!
629 state.AddCallSite(locked, Stub, F);
630 } else if (!Actual) {
631 // If we are JIT'ing non-lazily but need to call a function that does not
632 // exist yet, add it to the JIT's work list so that we can fill in the
633 // stub address later.
634 assert(!isNonGhostDeclaration(F) && !F->hasAvailableExternallyLinkage() &&
635 "'Actual' should have been set above.");
636 TheJIT->addPendingFunction(F);
642 /// getGlobalValueIndirectSym - Return a lazy pointer containing the specified
644 void *JITResolver::getGlobalValueIndirectSym(GlobalValue *GV, void *GVAddress) {
645 MutexGuard locked(TheJIT->lock);
647 // If we already have a stub for this global variable, recycle it.
648 void *&IndirectSym = state.getGlobalToIndirectSymMap(locked)[GV];
649 if (IndirectSym) return IndirectSym;
651 // Otherwise, codegen a new indirect symbol.
652 IndirectSym = TheJIT->getJITInfo().emitGlobalValueIndirectSym(GV, GVAddress,
655 DEBUG(dbgs() << "JIT: Indirect symbol emitted at [" << IndirectSym
656 << "] for GV '" << GV->getName() << "'\n");
661 /// getExternalFunctionStub - Return a stub for the function at the
662 /// specified address, created lazily on demand.
663 void *JITResolver::getExternalFunctionStub(void *FnAddr) {
664 // If we already have a stub for this function, recycle it.
665 void *&Stub = ExternalFnToStubMap[FnAddr];
666 if (Stub) return Stub;
668 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
669 JE.startGVStub(0, SL.Size, SL.Alignment);
670 Stub = TheJIT->getJITInfo().emitFunctionStub(0, FnAddr, JE);
673 DEBUG(dbgs() << "JIT: Stub emitted at [" << Stub
674 << "] for external function at '" << FnAddr << "'\n");
678 unsigned JITResolver::getGOTIndexForAddr(void* addr) {
679 unsigned idx = revGOTMap[addr];
681 idx = ++nextGOTIndex;
682 revGOTMap[addr] = idx;
683 DEBUG(dbgs() << "JIT: Adding GOT entry " << idx << " for addr ["
689 void JITResolver::getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
690 SmallVectorImpl<void*> &Ptrs) {
691 MutexGuard locked(TheJIT->lock);
693 const FunctionToLazyStubMapTy &FM = state.getFunctionToLazyStubMap(locked);
694 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
696 for (FunctionToLazyStubMapTy::const_iterator i = FM.begin(), e = FM.end();
698 Function *F = i->first;
699 if (F->isDeclaration() && F->hasExternalLinkage()) {
700 GVs.push_back(i->first);
701 Ptrs.push_back(i->second);
704 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
706 GVs.push_back(i->first);
707 Ptrs.push_back(i->second);
711 /// JITCompilerFn - This function is called when a lazy compilation stub has
712 /// been entered. It looks up which function this stub corresponds to, compiles
713 /// it if necessary, then returns the resultant function pointer.
714 void *JITResolver::JITCompilerFn(void *Stub) {
715 JITResolver *JR = StubToResolverMap->getResolverFromStub(Stub);
716 assert(JR && "Unable to find the corresponding JITResolver to the call site");
722 // Only lock for getting the Function. The call getPointerToFunction made
723 // in this function might trigger function materializing, which requires
724 // JIT lock to be unlocked.
725 MutexGuard locked(JR->TheJIT->lock);
727 // The address given to us for the stub may not be exactly right, it might
728 // be a little bit after the stub. As such, use upper_bound to find it.
729 pair<void*, Function*> I =
730 JR->state.LookupFunctionFromCallSite(locked, Stub);
735 // If we have already code generated the function, just return the address.
736 void *Result = JR->TheJIT->getPointerToGlobalIfAvailable(F);
739 // Otherwise we don't have it, do lazy compilation now.
741 // If lazy compilation is disabled, emit a useful error message and abort.
742 if (!JR->TheJIT->isCompilingLazily()) {
743 llvm_report_error("LLVM JIT requested to do lazy compilation of function '"
744 + F->getName() + "' when lazy compiles are disabled!");
747 DEBUG(dbgs() << "JIT: Lazily resolving function '" << F->getName()
748 << "' In stub ptr = " << Stub << " actual ptr = "
749 << ActualPtr << "\n");
751 Result = JR->TheJIT->getPointerToFunction(F);
754 // Reacquire the lock to update the GOT map.
755 MutexGuard locked(JR->TheJIT->lock);
757 // We might like to remove the call site from the CallSiteToFunction map, but
758 // we can't do that! Multiple threads could be stuck, waiting to acquire the
759 // lock above. As soon as the 1st function finishes compiling the function,
760 // the next one will be released, and needs to be able to find the function it
763 // FIXME: We could rewrite all references to this stub if we knew them.
765 // What we will do is set the compiled function address to map to the
766 // same GOT entry as the stub so that later clients may update the GOT
767 // if they see it still using the stub address.
768 // Note: this is done so the Resolver doesn't have to manage GOT memory
769 // Do this without allocating map space if the target isn't using a GOT
770 if(JR->revGOTMap.find(Stub) != JR->revGOTMap.end())
771 JR->revGOTMap[Result] = JR->revGOTMap[Stub];
776 //===----------------------------------------------------------------------===//
779 void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
780 bool MayNeedFarStub) {
781 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
782 return TheJIT->getOrEmitGlobalVariable(GV);
784 if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
785 return TheJIT->getPointerToGlobal(GA->resolveAliasedGlobal(false));
787 // If we have already compiled the function, return a pointer to its body.
788 Function *F = cast<Function>(V);
790 void *FnStub = Resolver.getLazyFunctionStubIfAvailable(F);
792 // Return the function stub if it's already created. We do this first so
793 // that we're returning the same address for the function as any previous
794 // call. TODO: Yes, this is wrong. The lazy stub isn't guaranteed to be
795 // close enough to call.
799 // If we know the target can handle arbitrary-distance calls, try to
800 // return a direct pointer.
801 if (!MayNeedFarStub) {
802 // If we have code, go ahead and return that.
803 void *ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
804 if (ResultPtr) return ResultPtr;
806 // If this is an external function pointer, we can force the JIT to
807 // 'compile' it, which really just adds it to the map.
808 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage())
809 return TheJIT->getPointerToFunction(F);
812 // Otherwise, we may need a to emit a stub, and, conservatively, we always do
813 // so. Note that it's possible to return null from getLazyFunctionStub in the
814 // case of a weak extern that fails to resolve.
815 return Resolver.getLazyFunctionStub(F);
818 void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) {
819 // Make sure GV is emitted first, and create a stub containing the fully
821 void *GVAddress = getPointerToGlobal(V, Reference, false);
822 void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress);
826 void JITEmitter::processDebugLoc(DebugLoc DL, bool BeforePrintingInsn) {
827 if (!DL.isUnknown()) {
828 DILocation CurDLT = EmissionDetails.MF->getDILocation(DL);
830 if (BeforePrintingInsn) {
831 if (CurDLT.getScope().getNode() != 0
832 && PrevDLT.getNode() != CurDLT.getNode()) {
833 JITEvent_EmittedFunctionDetails::LineStart NextLine;
834 NextLine.Address = getCurrentPCValue();
836 EmissionDetails.LineStarts.push_back(NextLine);
844 static unsigned GetConstantPoolSizeInBytes(MachineConstantPool *MCP,
845 const TargetData *TD) {
846 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
847 if (Constants.empty()) return 0;
850 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
851 MachineConstantPoolEntry CPE = Constants[i];
852 unsigned AlignMask = CPE.getAlignment() - 1;
853 Size = (Size + AlignMask) & ~AlignMask;
854 const Type *Ty = CPE.getType();
855 Size += TD->getTypeAllocSize(Ty);
860 static unsigned GetJumpTableSizeInBytes(MachineJumpTableInfo *MJTI, JIT *jit) {
861 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
862 if (JT.empty()) return 0;
864 unsigned NumEntries = 0;
865 for (unsigned i = 0, e = JT.size(); i != e; ++i)
866 NumEntries += JT[i].MBBs.size();
868 return NumEntries * MJTI->getEntrySize(*jit->getTargetData());
871 static uintptr_t RoundUpToAlign(uintptr_t Size, unsigned Alignment) {
872 if (Alignment == 0) Alignment = 1;
873 // Since we do not know where the buffer will be allocated, be pessimistic.
874 return Size + Alignment;
877 /// addSizeOfGlobal - add the size of the global (plus any alignment padding)
878 /// into the running total Size.
880 unsigned JITEmitter::addSizeOfGlobal(const GlobalVariable *GV, unsigned Size) {
881 const Type *ElTy = GV->getType()->getElementType();
882 size_t GVSize = (size_t)TheJIT->getTargetData()->getTypeAllocSize(ElTy);
884 (size_t)TheJIT->getTargetData()->getPreferredAlignment(GV);
885 DEBUG(dbgs() << "JIT: Adding in size " << GVSize << " alignment " << GVAlign);
887 // Assume code section ends with worst possible alignment, so first
888 // variable needs maximal padding.
891 Size = ((Size+GVAlign-1)/GVAlign)*GVAlign;
896 /// addSizeOfGlobalsInConstantVal - find any globals that we haven't seen yet
897 /// but are referenced from the constant; put them in SeenGlobals and the
898 /// Worklist, and add their size into the running total Size.
900 unsigned JITEmitter::addSizeOfGlobalsInConstantVal(
903 SmallPtrSet<const GlobalVariable*, 8> &SeenGlobals,
904 SmallVectorImpl<const GlobalVariable*> &Worklist) {
905 // If its undefined, return the garbage.
906 if (isa<UndefValue>(C))
909 // If the value is a ConstantExpr
910 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
911 Constant *Op0 = CE->getOperand(0);
912 switch (CE->getOpcode()) {
913 case Instruction::GetElementPtr:
914 case Instruction::Trunc:
915 case Instruction::ZExt:
916 case Instruction::SExt:
917 case Instruction::FPTrunc:
918 case Instruction::FPExt:
919 case Instruction::UIToFP:
920 case Instruction::SIToFP:
921 case Instruction::FPToUI:
922 case Instruction::FPToSI:
923 case Instruction::PtrToInt:
924 case Instruction::IntToPtr:
925 case Instruction::BitCast: {
926 Size = addSizeOfGlobalsInConstantVal(Op0, Size, SeenGlobals, Worklist);
929 case Instruction::Add:
930 case Instruction::FAdd:
931 case Instruction::Sub:
932 case Instruction::FSub:
933 case Instruction::Mul:
934 case Instruction::FMul:
935 case Instruction::UDiv:
936 case Instruction::SDiv:
937 case Instruction::URem:
938 case Instruction::SRem:
939 case Instruction::And:
940 case Instruction::Or:
941 case Instruction::Xor: {
942 Size = addSizeOfGlobalsInConstantVal(Op0, Size, SeenGlobals, Worklist);
943 Size = addSizeOfGlobalsInConstantVal(CE->getOperand(1), Size,
944 SeenGlobals, Worklist);
949 raw_string_ostream Msg(msg);
950 Msg << "ConstantExpr not handled: " << *CE;
951 llvm_report_error(Msg.str());
956 if (C->getType()->getTypeID() == Type::PointerTyID)
957 if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C))
958 if (SeenGlobals.insert(GV)) {
959 Worklist.push_back(GV);
960 Size = addSizeOfGlobal(GV, Size);
966 /// addSizeOfGLobalsInInitializer - handle any globals that we haven't seen yet
967 /// but are referenced from the given initializer.
969 unsigned JITEmitter::addSizeOfGlobalsInInitializer(
970 const Constant *Init,
972 SmallPtrSet<const GlobalVariable*, 8> &SeenGlobals,
973 SmallVectorImpl<const GlobalVariable*> &Worklist) {
974 if (!isa<UndefValue>(Init) &&
975 !isa<ConstantVector>(Init) &&
976 !isa<ConstantAggregateZero>(Init) &&
977 !isa<ConstantArray>(Init) &&
978 !isa<ConstantStruct>(Init) &&
979 Init->getType()->isFirstClassType())
980 Size = addSizeOfGlobalsInConstantVal(Init, Size, SeenGlobals, Worklist);
984 /// GetSizeOfGlobalsInBytes - walk the code for the function, looking for
985 /// globals; then walk the initializers of those globals looking for more.
986 /// If their size has not been considered yet, add it into the running total
989 unsigned JITEmitter::GetSizeOfGlobalsInBytes(MachineFunction &MF) {
991 SmallPtrSet<const GlobalVariable*, 8> SeenGlobals;
993 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
995 for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
997 const TargetInstrDesc &Desc = I->getDesc();
998 const MachineInstr &MI = *I;
999 unsigned NumOps = Desc.getNumOperands();
1000 for (unsigned CurOp = 0; CurOp < NumOps; CurOp++) {
1001 const MachineOperand &MO = MI.getOperand(CurOp);
1002 if (MO.isGlobal()) {
1003 GlobalValue* V = MO.getGlobal();
1004 const GlobalVariable *GV = dyn_cast<const GlobalVariable>(V);
1007 // If seen in previous function, it will have an entry here.
1008 if (TheJIT->getPointerToGlobalIfAvailable(GV))
1010 // If seen earlier in this function, it will have an entry here.
1011 // FIXME: it should be possible to combine these tables, by
1012 // assuming the addresses of the new globals in this module
1013 // start at 0 (or something) and adjusting them after codegen
1014 // complete. Another possibility is to grab a marker bit in GV.
1015 if (SeenGlobals.insert(GV))
1016 // A variable as yet unseen. Add in its size.
1017 Size = addSizeOfGlobal(GV, Size);
1022 DEBUG(dbgs() << "JIT: About to look through initializers\n");
1023 // Look for more globals that are referenced only from initializers.
1024 SmallVector<const GlobalVariable*, 8> Worklist(
1025 SeenGlobals.begin(), SeenGlobals.end());
1026 while (!Worklist.empty()) {
1027 const GlobalVariable* GV = Worklist.back();
1028 Worklist.pop_back();
1029 if (GV->hasInitializer())
1030 Size = addSizeOfGlobalsInInitializer(GV->getInitializer(), Size,
1031 SeenGlobals, Worklist);
1037 void JITEmitter::startFunction(MachineFunction &F) {
1038 DEBUG(dbgs() << "JIT: Starting CodeGen of Function "
1039 << F.getFunction()->getName() << "\n");
1041 uintptr_t ActualSize = 0;
1042 // Set the memory writable, if it's not already
1043 MemMgr->setMemoryWritable();
1044 if (MemMgr->NeedsExactSize()) {
1045 DEBUG(dbgs() << "JIT: ExactSize\n");
1046 const TargetInstrInfo* TII = F.getTarget().getInstrInfo();
1047 MachineConstantPool *MCP = F.getConstantPool();
1049 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1050 ActualSize = RoundUpToAlign(ActualSize, 16);
1052 // Add the alignment of the constant pool
1053 ActualSize = RoundUpToAlign(ActualSize, MCP->getConstantPoolAlignment());
1055 // Add the constant pool size
1056 ActualSize += GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1058 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo()) {
1059 // Add the aligment of the jump table info
1060 ActualSize = RoundUpToAlign(ActualSize,
1061 MJTI->getEntryAlignment(*TheJIT->getTargetData()));
1063 // Add the jump table size
1064 ActualSize += GetJumpTableSizeInBytes(MJTI, TheJIT);
1067 // Add the alignment for the function
1068 ActualSize = RoundUpToAlign(ActualSize,
1069 std::max(F.getFunction()->getAlignment(), 8U));
1071 // Add the function size
1072 ActualSize += TII->GetFunctionSizeInBytes(F);
1074 DEBUG(dbgs() << "JIT: ActualSize before globals " << ActualSize << "\n");
1075 // Add the size of the globals that will be allocated after this function.
1076 // These are all the ones referenced from this function that were not
1077 // previously allocated.
1078 ActualSize += GetSizeOfGlobalsInBytes(F);
1079 DEBUG(dbgs() << "JIT: ActualSize after globals " << ActualSize << "\n");
1080 } else if (SizeEstimate > 0) {
1081 // SizeEstimate will be non-zero on reallocation attempts.
1082 ActualSize = SizeEstimate;
1085 BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(),
1087 BufferEnd = BufferBegin+ActualSize;
1088 EmittedFunctions[F.getFunction()].FunctionBody = BufferBegin;
1090 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1093 emitConstantPool(F.getConstantPool());
1094 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
1095 initJumpTableInfo(MJTI);
1097 // About to start emitting the machine code for the function.
1098 emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
1099 TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
1100 EmittedFunctions[F.getFunction()].Code = CurBufferPtr;
1102 MBBLocations.clear();
1104 EmissionDetails.MF = &F;
1105 EmissionDetails.LineStarts.clear();
1108 bool JITEmitter::finishFunction(MachineFunction &F) {
1109 if (CurBufferPtr == BufferEnd) {
1110 // We must call endFunctionBody before retrying, because
1111 // deallocateMemForFunction requires it.
1112 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1113 retryWithMoreMemory(F);
1117 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
1118 emitJumpTableInfo(MJTI);
1120 // FnStart is the start of the text, not the start of the constant pool and
1121 // other per-function data.
1123 (uint8_t *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
1125 // FnEnd is the end of the function's machine code.
1126 uint8_t *FnEnd = CurBufferPtr;
1128 if (!Relocations.empty()) {
1129 CurFn = F.getFunction();
1130 NumRelos += Relocations.size();
1132 // Resolve the relocations to concrete pointers.
1133 for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
1134 MachineRelocation &MR = Relocations[i];
1135 void *ResultPtr = 0;
1136 if (!MR.letTargetResolve()) {
1137 if (MR.isExternalSymbol()) {
1138 ResultPtr = TheJIT->getPointerToNamedFunction(MR.getExternalSymbol(),
1140 DEBUG(dbgs() << "JIT: Map \'" << MR.getExternalSymbol() << "\' to ["
1141 << ResultPtr << "]\n");
1143 // If the target REALLY wants a stub for this function, emit it now.
1144 if (MR.mayNeedFarStub()) {
1145 ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
1147 } else if (MR.isGlobalValue()) {
1148 ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
1149 BufferBegin+MR.getMachineCodeOffset(),
1150 MR.mayNeedFarStub());
1151 } else if (MR.isIndirectSymbol()) {
1152 ResultPtr = getPointerToGVIndirectSym(
1153 MR.getGlobalValue(), BufferBegin+MR.getMachineCodeOffset());
1154 } else if (MR.isBasicBlock()) {
1155 ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
1156 } else if (MR.isConstantPoolIndex()) {
1157 ResultPtr = (void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
1159 assert(MR.isJumpTableIndex());
1160 ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
1163 MR.setResultPointer(ResultPtr);
1166 // if we are managing the GOT and the relocation wants an index,
1168 if (MR.isGOTRelative() && MemMgr->isManagingGOT()) {
1169 unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
1170 MR.setGOTIndex(idx);
1171 if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) {
1172 DEBUG(dbgs() << "JIT: GOT was out of date for " << ResultPtr
1173 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1175 ((void**)MemMgr->getGOTBase())[idx] = ResultPtr;
1181 TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
1182 Relocations.size(), MemMgr->getGOTBase());
1185 // Update the GOT entry for F to point to the new code.
1186 if (MemMgr->isManagingGOT()) {
1187 unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
1188 if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) {
1189 DEBUG(dbgs() << "JIT: GOT was out of date for " << (void*)BufferBegin
1190 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1192 ((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin;
1196 // CurBufferPtr may have moved beyond FnEnd, due to memory allocation for
1197 // global variables that were referenced in the relocations.
1198 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1200 if (CurBufferPtr == BufferEnd) {
1201 retryWithMoreMemory(F);
1204 // Now that we've succeeded in emitting the function, reset the
1205 // SizeEstimate back down to zero.
1209 BufferBegin = CurBufferPtr = 0;
1210 NumBytes += FnEnd-FnStart;
1212 // Invalidate the icache if necessary.
1213 sys::Memory::InvalidateInstructionCache(FnStart, FnEnd-FnStart);
1215 TheJIT->NotifyFunctionEmitted(*F.getFunction(), FnStart, FnEnd-FnStart,
1218 DEBUG(dbgs() << "JIT: Finished CodeGen of [" << (void*)FnStart
1219 << "] Function: " << F.getFunction()->getName()
1220 << ": " << (FnEnd-FnStart) << " bytes of text, "
1221 << Relocations.size() << " relocations\n");
1223 Relocations.clear();
1224 ConstPoolAddresses.clear();
1226 // Mark code region readable and executable if it's not so already.
1227 MemMgr->setMemoryExecutable();
1230 if (sys::hasDisassembler()) {
1231 dbgs() << "JIT: Disassembled code:\n";
1232 dbgs() << sys::disassembleBuffer(FnStart, FnEnd-FnStart,
1233 (uintptr_t)FnStart);
1235 dbgs() << "JIT: Binary code:\n";
1236 uint8_t* q = FnStart;
1237 for (int i = 0; q < FnEnd; q += 4, ++i) {
1241 dbgs() << "JIT: " << (long)(q - FnStart) << ": ";
1243 for (int j = 3; j >= 0; --j) {
1247 dbgs() << (unsigned short)q[j];
1259 if (DwarfExceptionHandling || JITEmitDebugInfo) {
1260 uintptr_t ActualSize = 0;
1261 SavedBufferBegin = BufferBegin;
1262 SavedBufferEnd = BufferEnd;
1263 SavedCurBufferPtr = CurBufferPtr;
1265 if (MemMgr->NeedsExactSize()) {
1266 ActualSize = DE->GetDwarfTableSizeInBytes(F, *this, FnStart, FnEnd);
1269 BufferBegin = CurBufferPtr = MemMgr->startExceptionTable(F.getFunction(),
1271 BufferEnd = BufferBegin+ActualSize;
1272 EmittedFunctions[F.getFunction()].ExceptionTable = BufferBegin;
1274 uint8_t *FrameRegister = DE->EmitDwarfTable(F, *this, FnStart, FnEnd,
1276 MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr,
1278 uint8_t *EhEnd = CurBufferPtr;
1279 BufferBegin = SavedBufferBegin;
1280 BufferEnd = SavedBufferEnd;
1281 CurBufferPtr = SavedCurBufferPtr;
1283 if (DwarfExceptionHandling) {
1284 TheJIT->RegisterTable(FrameRegister);
1287 if (JITEmitDebugInfo) {
1289 I.FnStart = FnStart;
1291 I.EhStart = EhStart;
1293 DR->RegisterFunction(F.getFunction(), I);
1303 void JITEmitter::retryWithMoreMemory(MachineFunction &F) {
1304 DEBUG(dbgs() << "JIT: Ran out of space for native code. Reattempting.\n");
1305 Relocations.clear(); // Clear the old relocations or we'll reapply them.
1306 ConstPoolAddresses.clear();
1308 deallocateMemForFunction(F.getFunction());
1309 // Try again with at least twice as much free space.
1310 SizeEstimate = (uintptr_t)(2 * (BufferEnd - BufferBegin));
1313 /// deallocateMemForFunction - Deallocate all memory for the specified
1314 /// function body. Also drop any references the function has to stubs.
1315 /// May be called while the Function is being destroyed inside ~Value().
1316 void JITEmitter::deallocateMemForFunction(const Function *F) {
1317 ValueMap<const Function *, EmittedCode, EmittedFunctionConfig>::iterator
1318 Emitted = EmittedFunctions.find(F);
1319 if (Emitted != EmittedFunctions.end()) {
1320 MemMgr->deallocateFunctionBody(Emitted->second.FunctionBody);
1321 MemMgr->deallocateExceptionTable(Emitted->second.ExceptionTable);
1322 TheJIT->NotifyFreeingMachineCode(Emitted->second.Code);
1324 EmittedFunctions.erase(Emitted);
1327 // TODO: Do we need to unregister exception handling information from libgcc
1330 if (JITEmitDebugInfo) {
1331 DR->UnregisterFunction(F);
1336 void* JITEmitter::allocateSpace(uintptr_t Size, unsigned Alignment) {
1338 return JITCodeEmitter::allocateSpace(Size, Alignment);
1340 // create a new memory block if there is no active one.
1341 // care must be taken so that BufferBegin is invalidated when a
1343 BufferBegin = CurBufferPtr = MemMgr->allocateSpace(Size, Alignment);
1344 BufferEnd = BufferBegin+Size;
1345 return CurBufferPtr;
1348 void* JITEmitter::allocateGlobal(uintptr_t Size, unsigned Alignment) {
1349 // Delegate this call through the memory manager.
1350 return MemMgr->allocateGlobal(Size, Alignment);
1353 void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
1354 if (TheJIT->getJITInfo().hasCustomConstantPool())
1357 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
1358 if (Constants.empty()) return;
1360 unsigned Size = GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1361 unsigned Align = MCP->getConstantPoolAlignment();
1362 ConstantPoolBase = allocateSpace(Size, Align);
1365 if (ConstantPoolBase == 0) return; // Buffer overflow.
1367 DEBUG(dbgs() << "JIT: Emitted constant pool at [" << ConstantPoolBase
1368 << "] (size: " << Size << ", alignment: " << Align << ")\n");
1370 // Initialize the memory for all of the constant pool entries.
1371 unsigned Offset = 0;
1372 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
1373 MachineConstantPoolEntry CPE = Constants[i];
1374 unsigned AlignMask = CPE.getAlignment() - 1;
1375 Offset = (Offset + AlignMask) & ~AlignMask;
1377 uintptr_t CAddr = (uintptr_t)ConstantPoolBase + Offset;
1378 ConstPoolAddresses.push_back(CAddr);
1379 if (CPE.isMachineConstantPoolEntry()) {
1380 // FIXME: add support to lower machine constant pool values into bytes!
1381 llvm_report_error("Initialize memory with machine specific constant pool"
1382 "entry has not been implemented!");
1384 TheJIT->InitializeMemory(CPE.Val.ConstVal, (void*)CAddr);
1385 DEBUG(dbgs() << "JIT: CP" << i << " at [0x";
1386 dbgs().write_hex(CAddr) << "]\n");
1388 const Type *Ty = CPE.Val.ConstVal->getType();
1389 Offset += TheJIT->getTargetData()->getTypeAllocSize(Ty);
1393 void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
1394 if (TheJIT->getJITInfo().hasCustomJumpTables())
1396 if (MJTI->getEntryKind() == MachineJumpTableInfo::EK_Inline)
1399 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1400 if (JT.empty()) return;
1402 unsigned NumEntries = 0;
1403 for (unsigned i = 0, e = JT.size(); i != e; ++i)
1404 NumEntries += JT[i].MBBs.size();
1406 unsigned EntrySize = MJTI->getEntrySize(*TheJIT->getTargetData());
1408 // Just allocate space for all the jump tables now. We will fix up the actual
1409 // MBB entries in the tables after we emit the code for each block, since then
1410 // we will know the final locations of the MBBs in memory.
1412 JumpTableBase = allocateSpace(NumEntries * EntrySize,
1413 MJTI->getEntryAlignment(*TheJIT->getTargetData()));
1416 void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
1417 if (TheJIT->getJITInfo().hasCustomJumpTables())
1420 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1421 if (JT.empty() || JumpTableBase == 0) return;
1424 switch (MJTI->getEntryKind()) {
1425 case MachineJumpTableInfo::EK_Inline:
1427 case MachineJumpTableInfo::EK_BlockAddress: {
1428 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1430 assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == sizeof(void*) &&
1433 // For each jump table, map each target in the jump table to the address of
1434 // an emitted MachineBasicBlock.
1435 intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
1437 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1438 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1439 // Store the address of the basic block for this jump table slot in the
1440 // memory we allocated for the jump table in 'initJumpTableInfo'
1441 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
1442 *SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
1447 case MachineJumpTableInfo::EK_Custom32:
1448 case MachineJumpTableInfo::EK_GPRel32BlockAddress:
1449 case MachineJumpTableInfo::EK_LabelDifference32: {
1450 assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == 4&&"Cross JIT'ing?");
1451 // For each jump table, place the offset from the beginning of the table
1452 // to the target address.
1453 int *SlotPtr = (int*)JumpTableBase;
1455 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1456 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1457 // Store the offset of the basic block for this jump table slot in the
1458 // memory we allocated for the jump table in 'initJumpTableInfo'
1459 uintptr_t Base = (uintptr_t)SlotPtr;
1460 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) {
1461 uintptr_t MBBAddr = getMachineBasicBlockAddress(MBBs[mi]);
1462 /// FIXME: USe EntryKind instead of magic "getPICJumpTableEntry" hook.
1463 *SlotPtr++ = TheJIT->getJITInfo().getPICJumpTableEntry(MBBAddr, Base);
1471 void JITEmitter::startGVStub(const GlobalValue* GV,
1472 unsigned StubSize, unsigned Alignment) {
1473 SavedBufferBegin = BufferBegin;
1474 SavedBufferEnd = BufferEnd;
1475 SavedCurBufferPtr = CurBufferPtr;
1477 BufferBegin = CurBufferPtr = MemMgr->allocateStub(GV, StubSize, Alignment);
1478 BufferEnd = BufferBegin+StubSize+1;
1481 void JITEmitter::startGVStub(void *Buffer, unsigned StubSize) {
1482 SavedBufferBegin = BufferBegin;
1483 SavedBufferEnd = BufferEnd;
1484 SavedCurBufferPtr = CurBufferPtr;
1486 BufferBegin = CurBufferPtr = (uint8_t *)Buffer;
1487 BufferEnd = BufferBegin+StubSize+1;
1490 void JITEmitter::finishGVStub() {
1491 assert(CurBufferPtr != BufferEnd && "Stub overflowed allocated space.");
1492 NumBytes += getCurrentPCOffset();
1493 BufferBegin = SavedBufferBegin;
1494 BufferEnd = SavedBufferEnd;
1495 CurBufferPtr = SavedCurBufferPtr;
1498 void *JITEmitter::allocIndirectGV(const GlobalValue *GV,
1499 const uint8_t *Buffer, size_t Size,
1500 unsigned Alignment) {
1501 uint8_t *IndGV = MemMgr->allocateStub(GV, Size, Alignment);
1502 memcpy(IndGV, Buffer, Size);
1506 // getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
1507 // in the constant pool that was last emitted with the 'emitConstantPool'
1510 uintptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const {
1511 assert(ConstantNum < ConstantPool->getConstants().size() &&
1512 "Invalid ConstantPoolIndex!");
1513 return ConstPoolAddresses[ConstantNum];
1516 // getJumpTableEntryAddress - Return the address of the JumpTable with index
1517 // 'Index' in the jumpp table that was last initialized with 'initJumpTableInfo'
1519 uintptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
1520 const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
1521 assert(Index < JT.size() && "Invalid jump table index!");
1523 unsigned EntrySize = JumpTable->getEntrySize(*TheJIT->getTargetData());
1525 unsigned Offset = 0;
1526 for (unsigned i = 0; i < Index; ++i)
1527 Offset += JT[i].MBBs.size();
1529 Offset *= EntrySize;
1531 return (uintptr_t)((char *)JumpTableBase + Offset);
1534 void JITEmitter::EmittedFunctionConfig::onDelete(
1535 JITEmitter *Emitter, const Function *F) {
1536 Emitter->deallocateMemForFunction(F);
1538 void JITEmitter::EmittedFunctionConfig::onRAUW(
1539 JITEmitter *, const Function*, const Function*) {
1540 llvm_unreachable("The JIT doesn't know how to handle a"
1541 " RAUW on a value it has emitted.");
1545 //===----------------------------------------------------------------------===//
1546 // Public interface to this file
1547 //===----------------------------------------------------------------------===//
1549 JITCodeEmitter *JIT::createEmitter(JIT &jit, JITMemoryManager *JMM,
1550 TargetMachine &tm) {
1551 return new JITEmitter(jit, JMM, tm);
1554 // getPointerToFunctionOrStub - If the specified function has been
1555 // code-gen'd, return a pointer to the function. If not, compile it, or use
1556 // a stub to implement lazy compilation if available.
1558 void *JIT::getPointerToFunctionOrStub(Function *F) {
1559 // If we have already code generated the function, just return the address.
1560 if (void *Addr = getPointerToGlobalIfAvailable(F))
1563 // Get a stub if the target supports it.
1564 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1565 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1566 return JE->getJITResolver().getLazyFunctionStub(F);
1569 void JIT::updateFunctionStub(Function *F) {
1570 // Get the empty stub we generated earlier.
1571 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1572 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1573 void *Stub = JE->getJITResolver().getLazyFunctionStub(F);
1574 void *Addr = getPointerToGlobalIfAvailable(F);
1575 assert(Addr != Stub && "Function must have non-stub address to be updated.");
1577 // Tell the target jit info to rewrite the stub at the specified address,
1578 // rather than creating a new one.
1579 TargetJITInfo::StubLayout layout = getJITInfo().getStubLayout();
1580 JE->startGVStub(Stub, layout.Size);
1581 getJITInfo().emitFunctionStub(F, Addr, *getCodeEmitter());
1585 /// freeMachineCodeForFunction - release machine code memory for given Function.
1587 void JIT::freeMachineCodeForFunction(Function *F) {
1588 // Delete translation for this from the ExecutionEngine, so it will get
1589 // retranslated next time it is used.
1590 updateGlobalMapping(F, 0);
1592 // Free the actual memory for the function body and related stuff.
1593 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1594 cast<JITEmitter>(JCE)->deallocateMemForFunction(F);