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) {
160 CallSiteToFunctionMapTy::iterator C2F_I =
161 CallSiteToFunctionMap.find(Stub);
162 if (C2F_I == CallSiteToFunctionMap.end()) {
167 Function *const F = C2F_I->second;
169 void *RealStub = FunctionToLazyStubMap.lookup(F);
170 assert(RealStub == Stub &&
171 "Call-site that wasn't a stub pass in to EraseStub");
173 FunctionToLazyStubMap.erase(F);
174 CallSiteToFunctionMap.erase(C2F_I);
176 // Remove the stub from the function->call-sites map, and remove the whole
177 // entry from the map if that was the last call site.
178 FunctionToCallSitesMapTy::iterator F2C_I = FunctionToCallSitesMap.find(F);
179 assert(F2C_I != FunctionToCallSitesMap.end() &&
180 "FunctionToCallSitesMap broken");
181 bool Erased = F2C_I->second.erase(Stub);
183 assert(Erased && "FunctionToCallSitesMap broken");
184 if (F2C_I->second.empty())
185 FunctionToCallSitesMap.erase(F2C_I);
190 void EraseAllCallSites(const MutexGuard &locked, Function *F) {
191 assert(locked.holds(TheJIT->lock));
192 EraseAllCallSitesPrelocked(F);
194 void EraseAllCallSitesPrelocked(Function *F) {
195 FunctionToCallSitesMapTy::iterator F2C = FunctionToCallSitesMap.find(F);
196 if (F2C == FunctionToCallSitesMap.end())
198 for (SmallPtrSet<void*, 1>::const_iterator I = F2C->second.begin(),
199 E = F2C->second.end(); I != E; ++I) {
200 bool Erased = CallSiteToFunctionMap.erase(*I);
202 assert(Erased && "Missing call site->function mapping");
204 FunctionToCallSitesMap.erase(F2C);
208 /// JITResolver - Keep track of, and resolve, call sites for functions that
209 /// have not yet been compiled.
211 typedef JITResolverState::FunctionToLazyStubMapTy FunctionToLazyStubMapTy;
212 typedef JITResolverState::CallSiteToFunctionMapTy CallSiteToFunctionMapTy;
213 typedef JITResolverState::GlobalToIndirectSymMapTy GlobalToIndirectSymMapTy;
215 /// LazyResolverFn - The target lazy resolver function that we actually
216 /// rewrite instructions to use.
217 TargetJITInfo::LazyResolverFn LazyResolverFn;
219 JITResolverState state;
221 /// ExternalFnToStubMap - This is the equivalent of FunctionToLazyStubMap
222 /// for external functions. TODO: Of course, external functions don't need
223 /// a lazy stub. It's actually here to make it more likely that far calls
224 /// succeed, but no single stub can guarantee that. I'll remove this in a
225 /// subsequent checkin when I actually fix far calls.
226 std::map<void*, void*> ExternalFnToStubMap;
228 /// revGOTMap - map addresses to indexes in the GOT
229 std::map<void*, unsigned> revGOTMap;
230 unsigned nextGOTIndex;
234 /// Instance of JIT corresponding to this Resolver.
238 explicit JITResolver(JIT &jit, JITEmitter &je)
239 : state(&jit), nextGOTIndex(0), JE(je), TheJIT(&jit) {
240 LazyResolverFn = jit.getJITInfo().getLazyResolverFunction(JITCompilerFn);
243 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function's
244 /// lazy-compilation stub if it has already been created.
245 void *getLazyFunctionStubIfAvailable(Function *F);
247 /// getLazyFunctionStub - This returns a pointer to a function's
248 /// lazy-compilation stub, creating one on demand as needed.
249 void *getLazyFunctionStub(Function *F);
251 /// getExternalFunctionStub - Return a stub for the function at the
252 /// specified address, created lazily on demand.
253 void *getExternalFunctionStub(void *FnAddr);
255 /// getGlobalValueIndirectSym - Return an indirect symbol containing the
256 /// specified GV address.
257 void *getGlobalValueIndirectSym(GlobalValue *V, void *GVAddress);
259 void getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
260 SmallVectorImpl<void*> &Ptrs);
262 GlobalValue *invalidateStub(void *Stub);
264 /// getGOTIndexForAddress - Return a new or existing index in the GOT for
265 /// an address. This function only manages slots, it does not manage the
266 /// contents of the slots or the memory associated with the GOT.
267 unsigned getGOTIndexForAddr(void *addr);
269 /// JITCompilerFn - This function is called to resolve a stub to a compiled
270 /// address. If the LLVM Function corresponding to the stub has not yet
271 /// been compiled, this function compiles it first.
272 static void *JITCompilerFn(void *Stub);
275 class StubToResolverMapTy {
276 /// Map a stub address to a specific instance of a JITResolver so that
277 /// lazily-compiled functions can find the right resolver to use.
280 std::map<void*, JITResolver*> Map;
282 /// Guards Map from concurrent accesses.
283 mutable sys::Mutex Lock;
286 /// Registers a Stub to be resolved by Resolver.
287 void RegisterStubResolver(void *Stub, JITResolver *Resolver) {
288 MutexGuard guard(Lock);
289 Map.insert(std::make_pair(Stub, Resolver));
291 /// Unregisters the Stub when it's invalidated.
292 void UnregisterStubResolver(void *Stub) {
293 MutexGuard guard(Lock);
296 /// Returns the JITResolver instance that owns the Stub.
297 JITResolver *getResolverFromStub(void *Stub) const {
298 MutexGuard guard(Lock);
299 // The address given to us for the stub may not be exactly right, it might
300 // be a little bit after the stub. As such, use upper_bound to find it.
301 // This is the same trick as in LookupFunctionFromCallSite from
303 std::map<void*, JITResolver*>::const_iterator I = Map.upper_bound(Stub);
304 assert(I != Map.begin() && "This is not a known stub!");
309 /// This needs to be static so that a lazy call stub can access it with no
310 /// context except the address of the stub.
311 ManagedStatic<StubToResolverMapTy> StubToResolverMap;
313 /// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is
314 /// used to output functions to memory for execution.
315 class JITEmitter : public JITCodeEmitter {
316 JITMemoryManager *MemMgr;
318 // When outputting a function stub in the context of some other function, we
319 // save BufferBegin/BufferEnd/CurBufferPtr here.
320 uint8_t *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr;
322 // When reattempting to JIT a function after running out of space, we store
323 // the estimated size of the function we're trying to JIT here, so we can
324 // ask the memory manager for at least this much space. When we
325 // successfully emit the function, we reset this back to zero.
326 uintptr_t SizeEstimate;
328 /// Relocations - These are the relocations that the function needs, as
330 std::vector<MachineRelocation> Relocations;
332 /// MBBLocations - This vector is a mapping from MBB ID's to their address.
333 /// It is filled in by the StartMachineBasicBlock callback and queried by
334 /// the getMachineBasicBlockAddress callback.
335 std::vector<uintptr_t> MBBLocations;
337 /// ConstantPool - The constant pool for the current function.
339 MachineConstantPool *ConstantPool;
341 /// ConstantPoolBase - A pointer to the first entry in the constant pool.
343 void *ConstantPoolBase;
345 /// ConstPoolAddresses - Addresses of individual constant pool entries.
347 SmallVector<uintptr_t, 8> ConstPoolAddresses;
349 /// JumpTable - The jump tables for the current function.
351 MachineJumpTableInfo *JumpTable;
353 /// JumpTableBase - A pointer to the first entry in the jump table.
357 /// Resolver - This contains info about the currently resolved functions.
358 JITResolver Resolver;
360 /// DE - The dwarf emitter for the jit.
361 OwningPtr<JITDwarfEmitter> DE;
363 /// DR - The debug registerer for the jit.
364 OwningPtr<JITDebugRegisterer> DR;
366 /// LabelLocations - This vector is a mapping from Label ID's to their
368 std::vector<uintptr_t> LabelLocations;
370 /// MMI - Machine module info for exception informations
371 MachineModuleInfo* MMI;
373 // GVSet - a set to keep track of which globals have been seen
374 SmallPtrSet<const GlobalVariable*, 8> GVSet;
376 // CurFn - The llvm function being emitted. Only valid during
378 const Function *CurFn;
380 /// Information about emitted code, which is passed to the
381 /// JITEventListeners. This is reset in startFunction and used in
383 JITEvent_EmittedFunctionDetails EmissionDetails;
386 void *FunctionBody; // Beginning of the function's allocation.
387 void *Code; // The address the function's code actually starts at.
388 void *ExceptionTable;
389 EmittedCode() : FunctionBody(0), Code(0), ExceptionTable(0) {}
391 struct EmittedFunctionConfig : public ValueMapConfig<const Function*> {
392 typedef JITEmitter *ExtraData;
393 static void onDelete(JITEmitter *, const Function*);
394 static void onRAUW(JITEmitter *, const Function*, const Function*);
396 ValueMap<const Function *, EmittedCode,
397 EmittedFunctionConfig> EmittedFunctions;
399 // CurFnStubUses - For a given Function, a vector of stubs that it
400 // references. This facilitates the JIT detecting that a stub is no
401 // longer used, so that it may be deallocated.
402 DenseMap<AssertingVH<const Function>, SmallVector<void*, 1> > CurFnStubUses;
404 // StubFnRefs - For a given pointer to a stub, a set of Functions which
405 // reference the stub. When the count of a stub's references drops to zero,
406 // the stub is unused.
407 DenseMap<void *, SmallPtrSet<const Function*, 1> > StubFnRefs;
411 /// Instance of the JIT
415 JITEmitter(JIT &jit, JITMemoryManager *JMM, TargetMachine &TM)
416 : SizeEstimate(0), Resolver(jit, *this), MMI(0), CurFn(0),
417 EmittedFunctions(this), PrevDLT(NULL), TheJIT(&jit) {
418 MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager();
419 if (jit.getJITInfo().needsGOT()) {
420 MemMgr->AllocateGOT();
421 DEBUG(dbgs() << "JIT is managing a GOT\n");
424 if (DwarfExceptionHandling || JITEmitDebugInfo) {
425 DE.reset(new JITDwarfEmitter(jit));
427 if (JITEmitDebugInfo) {
428 DR.reset(new JITDebugRegisterer(TM));
435 /// classof - Methods for support type inquiry through isa, cast, and
438 static inline bool classof(const JITEmitter*) { return true; }
439 static inline bool classof(const MachineCodeEmitter*) { return true; }
441 JITResolver &getJITResolver() { return Resolver; }
443 virtual void startFunction(MachineFunction &F);
444 virtual bool finishFunction(MachineFunction &F);
446 void emitConstantPool(MachineConstantPool *MCP);
447 void initJumpTableInfo(MachineJumpTableInfo *MJTI);
448 void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
450 void startGVStub(const GlobalValue* GV,
451 unsigned StubSize, unsigned Alignment = 1);
452 void startGVStub(void *Buffer, unsigned StubSize);
454 virtual void *allocIndirectGV(const GlobalValue *GV,
455 const uint8_t *Buffer, size_t Size,
458 /// allocateSpace - Reserves space in the current block if any, or
459 /// allocate a new one of the given size.
460 virtual void *allocateSpace(uintptr_t Size, unsigned Alignment);
462 /// allocateGlobal - Allocate memory for a global. Unlike allocateSpace,
463 /// this method does not allocate memory in the current output buffer,
464 /// because a global may live longer than the current function.
465 virtual void *allocateGlobal(uintptr_t Size, unsigned Alignment);
467 virtual void addRelocation(const MachineRelocation &MR) {
468 Relocations.push_back(MR);
471 virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
472 if (MBBLocations.size() <= (unsigned)MBB->getNumber())
473 MBBLocations.resize((MBB->getNumber()+1)*2);
474 MBBLocations[MBB->getNumber()] = getCurrentPCValue();
475 DEBUG(dbgs() << "JIT: Emitting BB" << MBB->getNumber() << " at ["
476 << (void*) getCurrentPCValue() << "]\n");
479 virtual uintptr_t getConstantPoolEntryAddress(unsigned Entry) const;
480 virtual uintptr_t getJumpTableEntryAddress(unsigned Entry) const;
482 virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
483 assert(MBBLocations.size() > (unsigned)MBB->getNumber() &&
484 MBBLocations[MBB->getNumber()] && "MBB not emitted!");
485 return MBBLocations[MBB->getNumber()];
488 /// retryWithMoreMemory - Log a retry and deallocate all memory for the
489 /// given function. Increase the minimum allocation size so that we get
490 /// more memory next time.
491 void retryWithMoreMemory(MachineFunction &F);
493 /// deallocateMemForFunction - Deallocate all memory for the specified
495 void deallocateMemForFunction(const Function *F);
497 /// AddStubToCurrentFunction - Mark the current function being JIT'd as
498 /// using the stub at the specified address. Allows
499 /// deallocateMemForFunction to also remove stubs no longer referenced.
500 void AddStubToCurrentFunction(void *Stub);
502 virtual void processDebugLoc(DebugLoc DL, bool BeforePrintingInsn);
504 virtual void emitLabel(uint64_t LabelID) {
505 if (LabelLocations.size() <= LabelID)
506 LabelLocations.resize((LabelID+1)*2);
507 LabelLocations[LabelID] = getCurrentPCValue();
510 virtual uintptr_t getLabelAddress(uint64_t LabelID) const {
511 assert(LabelLocations.size() > (unsigned)LabelID &&
512 LabelLocations[LabelID] && "Label not emitted!");
513 return LabelLocations[LabelID];
516 virtual void setModuleInfo(MachineModuleInfo* Info) {
518 if (DE.get()) DE->setModuleInfo(Info);
521 void setMemoryExecutable() {
522 MemMgr->setMemoryExecutable();
525 JITMemoryManager *getMemMgr() const { return MemMgr; }
528 void *getPointerToGlobal(GlobalValue *GV, void *Reference,
529 bool MayNeedFarStub);
530 void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference);
531 unsigned addSizeOfGlobal(const GlobalVariable *GV, unsigned Size);
532 unsigned addSizeOfGlobalsInConstantVal(const Constant *C, unsigned Size);
533 unsigned addSizeOfGlobalsInInitializer(const Constant *Init, unsigned Size);
534 unsigned GetSizeOfGlobalsInBytes(MachineFunction &MF);
538 void CallSiteValueMapConfig::onDelete(JITResolverState *JRS, Function *F) {
539 JRS->EraseAllCallSitesPrelocked(F);
542 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function stub
543 /// if it has already been created.
544 void *JITResolver::getLazyFunctionStubIfAvailable(Function *F) {
545 MutexGuard locked(TheJIT->lock);
547 // If we already have a stub for this function, recycle it.
548 return state.getFunctionToLazyStubMap(locked).lookup(F);
551 /// getFunctionStub - This returns a pointer to a function stub, creating
552 /// one on demand as needed.
553 void *JITResolver::getLazyFunctionStub(Function *F) {
554 MutexGuard locked(TheJIT->lock);
556 // If we already have a lazy stub for this function, recycle it.
557 void *&Stub = state.getFunctionToLazyStubMap(locked)[F];
558 if (Stub) return Stub;
560 // Call the lazy resolver function if we are JIT'ing lazily. Otherwise we
561 // must resolve the symbol now.
562 void *Actual = TheJIT->isCompilingLazily()
563 ? (void *)(intptr_t)LazyResolverFn : (void *)0;
565 // If this is an external declaration, attempt to resolve the address now
566 // to place in the stub.
567 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage()) {
568 Actual = TheJIT->getPointerToFunction(F);
570 // If we resolved the symbol to a null address (eg. a weak external)
571 // don't emit a stub. Return a null pointer to the application.
572 if (!Actual) return 0;
575 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
576 JE.startGVStub(F, SL.Size, SL.Alignment);
577 // Codegen a new stub, calling the lazy resolver or the actual address of the
578 // external function, if it was resolved.
579 Stub = TheJIT->getJITInfo().emitFunctionStub(F, Actual, JE);
582 if (Actual != (void*)(intptr_t)LazyResolverFn) {
583 // If we are getting the stub for an external function, we really want the
584 // address of the stub in the GlobalAddressMap for the JIT, not the address
585 // of the external function.
586 TheJIT->updateGlobalMapping(F, Stub);
589 DEBUG(dbgs() << "JIT: Lazy stub emitted at [" << Stub << "] for function '"
590 << F->getName() << "'\n");
592 // Register this JITResolver as the one corresponding to this call site so
593 // JITCompilerFn will be able to find it.
594 StubToResolverMap->RegisterStubResolver(Stub, this);
596 // Finally, keep track of the stub-to-Function mapping so that the
597 // JITCompilerFn knows which function to compile!
598 state.AddCallSite(locked, Stub, F);
600 // If we are JIT'ing non-lazily but need to call a function that does not
601 // exist yet, add it to the JIT's work list so that we can fill in the stub
603 if (!Actual && !TheJIT->isCompilingLazily())
604 if (!isNonGhostDeclaration(F) && !F->hasAvailableExternallyLinkage())
605 TheJIT->addPendingFunction(F);
610 /// getGlobalValueIndirectSym - Return a lazy pointer containing the specified
612 void *JITResolver::getGlobalValueIndirectSym(GlobalValue *GV, void *GVAddress) {
613 MutexGuard locked(TheJIT->lock);
615 // If we already have a stub for this global variable, recycle it.
616 void *&IndirectSym = state.getGlobalToIndirectSymMap(locked)[GV];
617 if (IndirectSym) return IndirectSym;
619 // Otherwise, codegen a new indirect symbol.
620 IndirectSym = TheJIT->getJITInfo().emitGlobalValueIndirectSym(GV, GVAddress,
623 DEBUG(dbgs() << "JIT: Indirect symbol emitted at [" << IndirectSym
624 << "] for GV '" << GV->getName() << "'\n");
629 /// getExternalFunctionStub - Return a stub for the function at the
630 /// specified address, created lazily on demand.
631 void *JITResolver::getExternalFunctionStub(void *FnAddr) {
632 // If we already have a stub for this function, recycle it.
633 void *&Stub = ExternalFnToStubMap[FnAddr];
634 if (Stub) return Stub;
636 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
637 JE.startGVStub(0, SL.Size, SL.Alignment);
638 Stub = TheJIT->getJITInfo().emitFunctionStub(0, FnAddr, JE);
641 DEBUG(dbgs() << "JIT: Stub emitted at [" << Stub
642 << "] for external function at '" << FnAddr << "'\n");
646 unsigned JITResolver::getGOTIndexForAddr(void* addr) {
647 unsigned idx = revGOTMap[addr];
649 idx = ++nextGOTIndex;
650 revGOTMap[addr] = idx;
651 DEBUG(dbgs() << "JIT: Adding GOT entry " << idx << " for addr ["
657 void JITResolver::getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
658 SmallVectorImpl<void*> &Ptrs) {
659 MutexGuard locked(TheJIT->lock);
661 const FunctionToLazyStubMapTy &FM = state.getFunctionToLazyStubMap(locked);
662 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
664 for (FunctionToLazyStubMapTy::const_iterator i = FM.begin(), e = FM.end();
666 Function *F = i->first;
667 if (F->isDeclaration() && F->hasExternalLinkage()) {
668 GVs.push_back(i->first);
669 Ptrs.push_back(i->second);
672 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
674 GVs.push_back(i->first);
675 Ptrs.push_back(i->second);
679 GlobalValue *JITResolver::invalidateStub(void *Stub) {
680 MutexGuard locked(TheJIT->lock);
682 // Remove the stub from the StubToResolverMap.
683 StubToResolverMap->UnregisterStubResolver(Stub);
685 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
687 // Look up the cheap way first, to see if it's a function stub we are
688 // invalidating. If so, remove it from both the forward and reverse maps.
689 if (Function *F = state.EraseStub(locked, Stub)) {
693 // Otherwise, it might be an indirect symbol stub. Find it and remove it.
694 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
696 if (i->second != Stub)
698 GlobalValue *GV = i->first;
703 // Lastly, check to see if it's in the ExternalFnToStubMap.
704 for (std::map<void *, void *>::iterator i = ExternalFnToStubMap.begin(),
705 e = ExternalFnToStubMap.end(); i != e; ++i) {
706 if (i->second != Stub)
708 ExternalFnToStubMap.erase(i);
715 /// JITCompilerFn - This function is called when a lazy compilation stub has
716 /// been entered. It looks up which function this stub corresponds to, compiles
717 /// it if necessary, then returns the resultant function pointer.
718 void *JITResolver::JITCompilerFn(void *Stub) {
719 JITResolver *JR = StubToResolverMap->getResolverFromStub(Stub);
720 assert(JR && "Unable to find the corresponding JITResolver to the call site");
726 // Only lock for getting the Function. The call getPointerToFunction made
727 // in this function might trigger function materializing, which requires
728 // JIT lock to be unlocked.
729 MutexGuard locked(JR->TheJIT->lock);
731 // The address given to us for the stub may not be exactly right, it might
732 // be a little bit after the stub. As such, use upper_bound to find it.
733 pair<void*, Function*> I =
734 JR->state.LookupFunctionFromCallSite(locked, Stub);
739 // If we have already code generated the function, just return the address.
740 void *Result = JR->TheJIT->getPointerToGlobalIfAvailable(F);
743 // Otherwise we don't have it, do lazy compilation now.
745 // If lazy compilation is disabled, emit a useful error message and abort.
746 if (!JR->TheJIT->isCompilingLazily()) {
747 llvm_report_error("LLVM JIT requested to do lazy compilation of function '"
748 + F->getName() + "' when lazy compiles are disabled!");
751 DEBUG(dbgs() << "JIT: Lazily resolving function '" << F->getName()
752 << "' In stub ptr = " << Stub << " actual ptr = "
753 << ActualPtr << "\n");
755 Result = JR->TheJIT->getPointerToFunction(F);
758 // Reacquire the lock to update the GOT map.
759 MutexGuard locked(JR->TheJIT->lock);
761 // We might like to remove the call site from the CallSiteToFunction map, but
762 // we can't do that! Multiple threads could be stuck, waiting to acquire the
763 // lock above. As soon as the 1st function finishes compiling the function,
764 // the next one will be released, and needs to be able to find the function it
767 // FIXME: We could rewrite all references to this stub if we knew them.
769 // What we will do is set the compiled function address to map to the
770 // same GOT entry as the stub so that later clients may update the GOT
771 // if they see it still using the stub address.
772 // Note: this is done so the Resolver doesn't have to manage GOT memory
773 // Do this without allocating map space if the target isn't using a GOT
774 if(JR->revGOTMap.find(Stub) != JR->revGOTMap.end())
775 JR->revGOTMap[Result] = JR->revGOTMap[Stub];
780 //===----------------------------------------------------------------------===//
783 void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
784 bool MayNeedFarStub) {
785 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
786 return TheJIT->getOrEmitGlobalVariable(GV);
788 if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
789 return TheJIT->getPointerToGlobal(GA->resolveAliasedGlobal(false));
791 // If we have already compiled the function, return a pointer to its body.
792 Function *F = cast<Function>(V);
794 void *FnStub = Resolver.getLazyFunctionStubIfAvailable(F);
796 // Return the function stub if it's already created. We do this first so
797 // that we're returning the same address for the function as any previous
798 // call. TODO: Yes, this is wrong. The lazy stub isn't guaranteed to be
799 // close enough to call.
800 AddStubToCurrentFunction(FnStub);
804 // If we know the target can handle arbitrary-distance calls, try to
805 // return a direct pointer.
806 if (!MayNeedFarStub) {
807 // If we have code, go ahead and return that.
808 void *ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
809 if (ResultPtr) return ResultPtr;
811 // If this is an external function pointer, we can force the JIT to
812 // 'compile' it, which really just adds it to the map.
813 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage())
814 return TheJIT->getPointerToFunction(F);
817 // Otherwise, we may need a to emit a stub, and, conservatively, we
819 void *StubAddr = Resolver.getLazyFunctionStub(F);
821 // Add the stub to the current function's list of referenced stubs, so we can
822 // deallocate them if the current function is ever freed. It's possible to
823 // return null from getLazyFunctionStub in the case of a weak extern that
826 AddStubToCurrentFunction(StubAddr);
831 void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) {
832 // Make sure GV is emitted first, and create a stub containing the fully
834 void *GVAddress = getPointerToGlobal(V, Reference, false);
835 void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress);
837 // Add the stub to the current function's list of referenced stubs, so we can
838 // deallocate them if the current function is ever freed.
839 AddStubToCurrentFunction(StubAddr);
844 void JITEmitter::AddStubToCurrentFunction(void *StubAddr) {
845 assert(CurFn && "Stub added to current function, but current function is 0!");
847 SmallVectorImpl<void*> &StubsUsed = CurFnStubUses[CurFn];
848 StubsUsed.push_back(StubAddr);
850 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[StubAddr];
851 FnRefs.insert(CurFn);
854 void JITEmitter::processDebugLoc(DebugLoc DL, bool BeforePrintingInsn) {
855 if (!DL.isUnknown()) {
856 DILocation CurDLT = EmissionDetails.MF->getDILocation(DL);
858 if (BeforePrintingInsn) {
859 if (CurDLT.getScope().getNode() != 0
860 && PrevDLT.getNode() != CurDLT.getNode()) {
861 JITEvent_EmittedFunctionDetails::LineStart NextLine;
862 NextLine.Address = getCurrentPCValue();
864 EmissionDetails.LineStarts.push_back(NextLine);
872 static unsigned GetConstantPoolSizeInBytes(MachineConstantPool *MCP,
873 const TargetData *TD) {
874 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
875 if (Constants.empty()) return 0;
878 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
879 MachineConstantPoolEntry CPE = Constants[i];
880 unsigned AlignMask = CPE.getAlignment() - 1;
881 Size = (Size + AlignMask) & ~AlignMask;
882 const Type *Ty = CPE.getType();
883 Size += TD->getTypeAllocSize(Ty);
888 static unsigned GetJumpTableSizeInBytes(MachineJumpTableInfo *MJTI, JIT *jit) {
889 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
890 if (JT.empty()) return 0;
892 unsigned NumEntries = 0;
893 for (unsigned i = 0, e = JT.size(); i != e; ++i)
894 NumEntries += JT[i].MBBs.size();
896 return NumEntries * MJTI->getEntrySize(*jit->getTargetData());
899 static uintptr_t RoundUpToAlign(uintptr_t Size, unsigned Alignment) {
900 if (Alignment == 0) Alignment = 1;
901 // Since we do not know where the buffer will be allocated, be pessimistic.
902 return Size + Alignment;
905 /// addSizeOfGlobal - add the size of the global (plus any alignment padding)
906 /// into the running total Size.
908 unsigned JITEmitter::addSizeOfGlobal(const GlobalVariable *GV, unsigned Size) {
909 const Type *ElTy = GV->getType()->getElementType();
910 size_t GVSize = (size_t)TheJIT->getTargetData()->getTypeAllocSize(ElTy);
912 (size_t)TheJIT->getTargetData()->getPreferredAlignment(GV);
913 DEBUG(dbgs() << "JIT: Adding in size " << GVSize << " alignment " << GVAlign);
915 // Assume code section ends with worst possible alignment, so first
916 // variable needs maximal padding.
919 Size = ((Size+GVAlign-1)/GVAlign)*GVAlign;
924 /// addSizeOfGlobalsInConstantVal - find any globals that we haven't seen yet
925 /// but are referenced from the constant; put them in GVSet and add their
926 /// size into the running total Size.
928 unsigned JITEmitter::addSizeOfGlobalsInConstantVal(const Constant *C,
930 // If its undefined, return the garbage.
931 if (isa<UndefValue>(C))
934 // If the value is a ConstantExpr
935 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
936 Constant *Op0 = CE->getOperand(0);
937 switch (CE->getOpcode()) {
938 case Instruction::GetElementPtr:
939 case Instruction::Trunc:
940 case Instruction::ZExt:
941 case Instruction::SExt:
942 case Instruction::FPTrunc:
943 case Instruction::FPExt:
944 case Instruction::UIToFP:
945 case Instruction::SIToFP:
946 case Instruction::FPToUI:
947 case Instruction::FPToSI:
948 case Instruction::PtrToInt:
949 case Instruction::IntToPtr:
950 case Instruction::BitCast: {
951 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
954 case Instruction::Add:
955 case Instruction::FAdd:
956 case Instruction::Sub:
957 case Instruction::FSub:
958 case Instruction::Mul:
959 case Instruction::FMul:
960 case Instruction::UDiv:
961 case Instruction::SDiv:
962 case Instruction::URem:
963 case Instruction::SRem:
964 case Instruction::And:
965 case Instruction::Or:
966 case Instruction::Xor: {
967 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
968 Size = addSizeOfGlobalsInConstantVal(CE->getOperand(1), Size);
973 raw_string_ostream Msg(msg);
974 Msg << "ConstantExpr not handled: " << *CE;
975 llvm_report_error(Msg.str());
980 if (C->getType()->getTypeID() == Type::PointerTyID)
981 if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C))
982 if (GVSet.insert(GV))
983 Size = addSizeOfGlobal(GV, Size);
988 /// addSizeOfGLobalsInInitializer - handle any globals that we haven't seen yet
989 /// but are referenced from the given initializer.
991 unsigned JITEmitter::addSizeOfGlobalsInInitializer(const Constant *Init,
993 if (!isa<UndefValue>(Init) &&
994 !isa<ConstantVector>(Init) &&
995 !isa<ConstantAggregateZero>(Init) &&
996 !isa<ConstantArray>(Init) &&
997 !isa<ConstantStruct>(Init) &&
998 Init->getType()->isFirstClassType())
999 Size = addSizeOfGlobalsInConstantVal(Init, Size);
1003 /// GetSizeOfGlobalsInBytes - walk the code for the function, looking for
1004 /// globals; then walk the initializers of those globals looking for more.
1005 /// If their size has not been considered yet, add it into the running total
1008 unsigned JITEmitter::GetSizeOfGlobalsInBytes(MachineFunction &MF) {
1012 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
1014 for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
1016 const TargetInstrDesc &Desc = I->getDesc();
1017 const MachineInstr &MI = *I;
1018 unsigned NumOps = Desc.getNumOperands();
1019 for (unsigned CurOp = 0; CurOp < NumOps; CurOp++) {
1020 const MachineOperand &MO = MI.getOperand(CurOp);
1021 if (MO.isGlobal()) {
1022 GlobalValue* V = MO.getGlobal();
1023 const GlobalVariable *GV = dyn_cast<const GlobalVariable>(V);
1026 // If seen in previous function, it will have an entry here.
1027 if (TheJIT->getPointerToGlobalIfAvailable(GV))
1029 // If seen earlier in this function, it will have an entry here.
1030 // FIXME: it should be possible to combine these tables, by
1031 // assuming the addresses of the new globals in this module
1032 // start at 0 (or something) and adjusting them after codegen
1033 // complete. Another possibility is to grab a marker bit in GV.
1034 if (GVSet.insert(GV))
1035 // A variable as yet unseen. Add in its size.
1036 Size = addSizeOfGlobal(GV, Size);
1041 DEBUG(dbgs() << "JIT: About to look through initializers\n");
1042 // Look for more globals that are referenced only from initializers.
1043 // GVSet.end is computed each time because the set can grow as we go.
1044 for (SmallPtrSet<const GlobalVariable *, 8>::iterator I = GVSet.begin();
1045 I != GVSet.end(); I++) {
1046 const GlobalVariable* GV = *I;
1047 if (GV->hasInitializer())
1048 Size = addSizeOfGlobalsInInitializer(GV->getInitializer(), Size);
1054 void JITEmitter::startFunction(MachineFunction &F) {
1055 DEBUG(dbgs() << "JIT: Starting CodeGen of Function "
1056 << F.getFunction()->getName() << "\n");
1058 uintptr_t ActualSize = 0;
1059 // Set the memory writable, if it's not already
1060 MemMgr->setMemoryWritable();
1061 if (MemMgr->NeedsExactSize()) {
1062 DEBUG(dbgs() << "JIT: ExactSize\n");
1063 const TargetInstrInfo* TII = F.getTarget().getInstrInfo();
1064 MachineConstantPool *MCP = F.getConstantPool();
1066 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1067 ActualSize = RoundUpToAlign(ActualSize, 16);
1069 // Add the alignment of the constant pool
1070 ActualSize = RoundUpToAlign(ActualSize, MCP->getConstantPoolAlignment());
1072 // Add the constant pool size
1073 ActualSize += GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1075 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo()) {
1076 // Add the aligment of the jump table info
1077 ActualSize = RoundUpToAlign(ActualSize,
1078 MJTI->getEntryAlignment(*TheJIT->getTargetData()));
1080 // Add the jump table size
1081 ActualSize += GetJumpTableSizeInBytes(MJTI, TheJIT);
1084 // Add the alignment for the function
1085 ActualSize = RoundUpToAlign(ActualSize,
1086 std::max(F.getFunction()->getAlignment(), 8U));
1088 // Add the function size
1089 ActualSize += TII->GetFunctionSizeInBytes(F);
1091 DEBUG(dbgs() << "JIT: ActualSize before globals " << ActualSize << "\n");
1092 // Add the size of the globals that will be allocated after this function.
1093 // These are all the ones referenced from this function that were not
1094 // previously allocated.
1095 ActualSize += GetSizeOfGlobalsInBytes(F);
1096 DEBUG(dbgs() << "JIT: ActualSize after globals " << ActualSize << "\n");
1097 } else if (SizeEstimate > 0) {
1098 // SizeEstimate will be non-zero on reallocation attempts.
1099 ActualSize = SizeEstimate;
1102 BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(),
1104 BufferEnd = BufferBegin+ActualSize;
1105 EmittedFunctions[F.getFunction()].FunctionBody = BufferBegin;
1107 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1110 emitConstantPool(F.getConstantPool());
1111 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
1112 initJumpTableInfo(MJTI);
1114 // About to start emitting the machine code for the function.
1115 emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
1116 TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
1117 EmittedFunctions[F.getFunction()].Code = CurBufferPtr;
1119 MBBLocations.clear();
1121 EmissionDetails.MF = &F;
1122 EmissionDetails.LineStarts.clear();
1125 bool JITEmitter::finishFunction(MachineFunction &F) {
1126 if (CurBufferPtr == BufferEnd) {
1127 // We must call endFunctionBody before retrying, because
1128 // deallocateMemForFunction requires it.
1129 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1130 retryWithMoreMemory(F);
1134 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
1135 emitJumpTableInfo(MJTI);
1137 // FnStart is the start of the text, not the start of the constant pool and
1138 // other per-function data.
1140 (uint8_t *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
1142 // FnEnd is the end of the function's machine code.
1143 uint8_t *FnEnd = CurBufferPtr;
1145 if (!Relocations.empty()) {
1146 CurFn = F.getFunction();
1147 NumRelos += Relocations.size();
1149 // Resolve the relocations to concrete pointers.
1150 for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
1151 MachineRelocation &MR = Relocations[i];
1152 void *ResultPtr = 0;
1153 if (!MR.letTargetResolve()) {
1154 if (MR.isExternalSymbol()) {
1155 ResultPtr = TheJIT->getPointerToNamedFunction(MR.getExternalSymbol(),
1157 DEBUG(dbgs() << "JIT: Map \'" << MR.getExternalSymbol() << "\' to ["
1158 << ResultPtr << "]\n");
1160 // If the target REALLY wants a stub for this function, emit it now.
1161 if (MR.mayNeedFarStub()) {
1162 ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
1164 } else if (MR.isGlobalValue()) {
1165 ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
1166 BufferBegin+MR.getMachineCodeOffset(),
1167 MR.mayNeedFarStub());
1168 } else if (MR.isIndirectSymbol()) {
1169 ResultPtr = getPointerToGVIndirectSym(
1170 MR.getGlobalValue(), BufferBegin+MR.getMachineCodeOffset());
1171 } else if (MR.isBasicBlock()) {
1172 ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
1173 } else if (MR.isConstantPoolIndex()) {
1174 ResultPtr = (void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
1176 assert(MR.isJumpTableIndex());
1177 ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
1180 MR.setResultPointer(ResultPtr);
1183 // if we are managing the GOT and the relocation wants an index,
1185 if (MR.isGOTRelative() && MemMgr->isManagingGOT()) {
1186 unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
1187 MR.setGOTIndex(idx);
1188 if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) {
1189 DEBUG(dbgs() << "JIT: GOT was out of date for " << ResultPtr
1190 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1192 ((void**)MemMgr->getGOTBase())[idx] = ResultPtr;
1198 TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
1199 Relocations.size(), MemMgr->getGOTBase());
1202 // Update the GOT entry for F to point to the new code.
1203 if (MemMgr->isManagingGOT()) {
1204 unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
1205 if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) {
1206 DEBUG(dbgs() << "JIT: GOT was out of date for " << (void*)BufferBegin
1207 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1209 ((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin;
1213 // CurBufferPtr may have moved beyond FnEnd, due to memory allocation for
1214 // global variables that were referenced in the relocations.
1215 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1217 if (CurBufferPtr == BufferEnd) {
1218 retryWithMoreMemory(F);
1221 // Now that we've succeeded in emitting the function, reset the
1222 // SizeEstimate back down to zero.
1226 BufferBegin = CurBufferPtr = 0;
1227 NumBytes += FnEnd-FnStart;
1229 // Invalidate the icache if necessary.
1230 sys::Memory::InvalidateInstructionCache(FnStart, FnEnd-FnStart);
1232 TheJIT->NotifyFunctionEmitted(*F.getFunction(), FnStart, FnEnd-FnStart,
1235 DEBUG(dbgs() << "JIT: Finished CodeGen of [" << (void*)FnStart
1236 << "] Function: " << F.getFunction()->getName()
1237 << ": " << (FnEnd-FnStart) << " bytes of text, "
1238 << Relocations.size() << " relocations\n");
1240 Relocations.clear();
1241 ConstPoolAddresses.clear();
1243 // Mark code region readable and executable if it's not so already.
1244 MemMgr->setMemoryExecutable();
1247 if (sys::hasDisassembler()) {
1248 dbgs() << "JIT: Disassembled code:\n";
1249 dbgs() << sys::disassembleBuffer(FnStart, FnEnd-FnStart,
1250 (uintptr_t)FnStart);
1252 dbgs() << "JIT: Binary code:\n";
1253 uint8_t* q = FnStart;
1254 for (int i = 0; q < FnEnd; q += 4, ++i) {
1258 dbgs() << "JIT: " << (long)(q - FnStart) << ": ";
1260 for (int j = 3; j >= 0; --j) {
1264 dbgs() << (unsigned short)q[j];
1276 if (DwarfExceptionHandling || JITEmitDebugInfo) {
1277 uintptr_t ActualSize = 0;
1278 SavedBufferBegin = BufferBegin;
1279 SavedBufferEnd = BufferEnd;
1280 SavedCurBufferPtr = CurBufferPtr;
1282 if (MemMgr->NeedsExactSize()) {
1283 ActualSize = DE->GetDwarfTableSizeInBytes(F, *this, FnStart, FnEnd);
1286 BufferBegin = CurBufferPtr = MemMgr->startExceptionTable(F.getFunction(),
1288 BufferEnd = BufferBegin+ActualSize;
1289 EmittedFunctions[F.getFunction()].ExceptionTable = BufferBegin;
1291 uint8_t *FrameRegister = DE->EmitDwarfTable(F, *this, FnStart, FnEnd,
1293 MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr,
1295 uint8_t *EhEnd = CurBufferPtr;
1296 BufferBegin = SavedBufferBegin;
1297 BufferEnd = SavedBufferEnd;
1298 CurBufferPtr = SavedCurBufferPtr;
1300 if (DwarfExceptionHandling) {
1301 TheJIT->RegisterTable(FrameRegister);
1304 if (JITEmitDebugInfo) {
1306 I.FnStart = FnStart;
1308 I.EhStart = EhStart;
1310 DR->RegisterFunction(F.getFunction(), I);
1320 void JITEmitter::retryWithMoreMemory(MachineFunction &F) {
1321 DEBUG(dbgs() << "JIT: Ran out of space for native code. Reattempting.\n");
1322 Relocations.clear(); // Clear the old relocations or we'll reapply them.
1323 ConstPoolAddresses.clear();
1325 deallocateMemForFunction(F.getFunction());
1326 // Try again with at least twice as much free space.
1327 SizeEstimate = (uintptr_t)(2 * (BufferEnd - BufferBegin));
1330 /// deallocateMemForFunction - Deallocate all memory for the specified
1331 /// function body. Also drop any references the function has to stubs.
1332 /// May be called while the Function is being destroyed inside ~Value().
1333 void JITEmitter::deallocateMemForFunction(const Function *F) {
1334 ValueMap<const Function *, EmittedCode, EmittedFunctionConfig>::iterator
1335 Emitted = EmittedFunctions.find(F);
1336 if (Emitted != EmittedFunctions.end()) {
1337 MemMgr->deallocateFunctionBody(Emitted->second.FunctionBody);
1338 MemMgr->deallocateExceptionTable(Emitted->second.ExceptionTable);
1339 TheJIT->NotifyFreeingMachineCode(Emitted->second.Code);
1341 EmittedFunctions.erase(Emitted);
1344 // TODO: Do we need to unregister exception handling information from libgcc
1347 if (JITEmitDebugInfo) {
1348 DR->UnregisterFunction(F);
1351 // If the function did not reference any stubs, return.
1352 if (CurFnStubUses.find(F) == CurFnStubUses.end())
1355 // For each referenced stub, erase the reference to this function, and then
1356 // erase the list of referenced stubs.
1357 SmallVectorImpl<void *> &StubList = CurFnStubUses[F];
1358 for (unsigned i = 0, e = StubList.size(); i != e; ++i) {
1359 void *Stub = StubList[i];
1361 // If we already invalidated this stub for this function, continue.
1362 if (StubFnRefs.count(Stub) == 0)
1365 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[Stub];
1368 // If this function was the last reference to the stub, invalidate the stub
1369 // in the JITResolver. Were there a memory manager deallocateStub routine,
1370 // we could call that at this point too.
1371 if (FnRefs.empty()) {
1372 DEBUG(dbgs() << "\nJIT: Invalidated Stub at [" << Stub << "]\n");
1373 StubFnRefs.erase(Stub);
1375 // Invalidate the stub. If it is a GV stub, update the JIT's global
1376 // mapping for that GV to zero.
1377 GlobalValue *GV = Resolver.invalidateStub(Stub);
1379 TheJIT->updateGlobalMapping(GV, 0);
1383 CurFnStubUses.erase(F);
1387 void* JITEmitter::allocateSpace(uintptr_t Size, unsigned Alignment) {
1389 return JITCodeEmitter::allocateSpace(Size, Alignment);
1391 // create a new memory block if there is no active one.
1392 // care must be taken so that BufferBegin is invalidated when a
1394 BufferBegin = CurBufferPtr = MemMgr->allocateSpace(Size, Alignment);
1395 BufferEnd = BufferBegin+Size;
1396 return CurBufferPtr;
1399 void* JITEmitter::allocateGlobal(uintptr_t Size, unsigned Alignment) {
1400 // Delegate this call through the memory manager.
1401 return MemMgr->allocateGlobal(Size, Alignment);
1404 void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
1405 if (TheJIT->getJITInfo().hasCustomConstantPool())
1408 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
1409 if (Constants.empty()) return;
1411 unsigned Size = GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1412 unsigned Align = MCP->getConstantPoolAlignment();
1413 ConstantPoolBase = allocateSpace(Size, Align);
1416 if (ConstantPoolBase == 0) return; // Buffer overflow.
1418 DEBUG(dbgs() << "JIT: Emitted constant pool at [" << ConstantPoolBase
1419 << "] (size: " << Size << ", alignment: " << Align << ")\n");
1421 // Initialize the memory for all of the constant pool entries.
1422 unsigned Offset = 0;
1423 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
1424 MachineConstantPoolEntry CPE = Constants[i];
1425 unsigned AlignMask = CPE.getAlignment() - 1;
1426 Offset = (Offset + AlignMask) & ~AlignMask;
1428 uintptr_t CAddr = (uintptr_t)ConstantPoolBase + Offset;
1429 ConstPoolAddresses.push_back(CAddr);
1430 if (CPE.isMachineConstantPoolEntry()) {
1431 // FIXME: add support to lower machine constant pool values into bytes!
1432 llvm_report_error("Initialize memory with machine specific constant pool"
1433 "entry has not been implemented!");
1435 TheJIT->InitializeMemory(CPE.Val.ConstVal, (void*)CAddr);
1436 DEBUG(dbgs() << "JIT: CP" << i << " at [0x";
1437 dbgs().write_hex(CAddr) << "]\n");
1439 const Type *Ty = CPE.Val.ConstVal->getType();
1440 Offset += TheJIT->getTargetData()->getTypeAllocSize(Ty);
1444 void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
1445 if (TheJIT->getJITInfo().hasCustomJumpTables())
1448 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1449 if (JT.empty()) return;
1451 unsigned NumEntries = 0;
1452 for (unsigned i = 0, e = JT.size(); i != e; ++i)
1453 NumEntries += JT[i].MBBs.size();
1455 unsigned EntrySize = MJTI->getEntrySize(*TheJIT->getTargetData());
1457 // Just allocate space for all the jump tables now. We will fix up the actual
1458 // MBB entries in the tables after we emit the code for each block, since then
1459 // we will know the final locations of the MBBs in memory.
1461 JumpTableBase = allocateSpace(NumEntries * EntrySize,
1462 MJTI->getEntryAlignment(*TheJIT->getTargetData()));
1465 void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
1466 if (TheJIT->getJITInfo().hasCustomJumpTables())
1469 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1470 if (JT.empty() || JumpTableBase == 0) return;
1473 switch (MJTI->getEntryKind()) {
1474 case MachineJumpTableInfo::EK_BlockAddress: {
1475 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1477 assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == sizeof(void*) &&
1480 // For each jump table, map each target in the jump table to the address of
1481 // an emitted MachineBasicBlock.
1482 intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
1484 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1485 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1486 // Store the address of the basic block for this jump table slot in the
1487 // memory we allocated for the jump table in 'initJumpTableInfo'
1488 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
1489 *SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
1494 case MachineJumpTableInfo::EK_Custom32:
1495 case MachineJumpTableInfo::EK_GPRel32BlockAddress:
1496 case MachineJumpTableInfo::EK_LabelDifference32: {
1497 assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == 4&&"Cross JIT'ing?");
1498 // For each jump table, place the offset from the beginning of the table
1499 // to the target address.
1500 int *SlotPtr = (int*)JumpTableBase;
1502 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1503 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1504 // Store the offset of the basic block for this jump table slot in the
1505 // memory we allocated for the jump table in 'initJumpTableInfo'
1506 uintptr_t Base = (uintptr_t)SlotPtr;
1507 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) {
1508 uintptr_t MBBAddr = getMachineBasicBlockAddress(MBBs[mi]);
1509 /// FIXME: USe EntryKind instead of magic "getPICJumpTableEntry" hook.
1510 *SlotPtr++ = TheJIT->getJITInfo().getPICJumpTableEntry(MBBAddr, Base);
1518 void JITEmitter::startGVStub(const GlobalValue* GV,
1519 unsigned StubSize, unsigned Alignment) {
1520 SavedBufferBegin = BufferBegin;
1521 SavedBufferEnd = BufferEnd;
1522 SavedCurBufferPtr = CurBufferPtr;
1524 BufferBegin = CurBufferPtr = MemMgr->allocateStub(GV, StubSize, Alignment);
1525 BufferEnd = BufferBegin+StubSize+1;
1528 void JITEmitter::startGVStub(void *Buffer, unsigned StubSize) {
1529 SavedBufferBegin = BufferBegin;
1530 SavedBufferEnd = BufferEnd;
1531 SavedCurBufferPtr = CurBufferPtr;
1533 BufferBegin = CurBufferPtr = (uint8_t *)Buffer;
1534 BufferEnd = BufferBegin+StubSize+1;
1537 void JITEmitter::finishGVStub() {
1538 assert(CurBufferPtr != BufferEnd && "Stub overflowed allocated space.");
1539 NumBytes += getCurrentPCOffset();
1540 BufferBegin = SavedBufferBegin;
1541 BufferEnd = SavedBufferEnd;
1542 CurBufferPtr = SavedCurBufferPtr;
1545 void *JITEmitter::allocIndirectGV(const GlobalValue *GV,
1546 const uint8_t *Buffer, size_t Size,
1547 unsigned Alignment) {
1548 uint8_t *IndGV = MemMgr->allocateStub(GV, Size, Alignment);
1549 memcpy(IndGV, Buffer, Size);
1553 // getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
1554 // in the constant pool that was last emitted with the 'emitConstantPool'
1557 uintptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const {
1558 assert(ConstantNum < ConstantPool->getConstants().size() &&
1559 "Invalid ConstantPoolIndex!");
1560 return ConstPoolAddresses[ConstantNum];
1563 // getJumpTableEntryAddress - Return the address of the JumpTable with index
1564 // 'Index' in the jumpp table that was last initialized with 'initJumpTableInfo'
1566 uintptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
1567 const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
1568 assert(Index < JT.size() && "Invalid jump table index!");
1570 unsigned EntrySize = JumpTable->getEntrySize(*TheJIT->getTargetData());
1572 unsigned Offset = 0;
1573 for (unsigned i = 0; i < Index; ++i)
1574 Offset += JT[i].MBBs.size();
1576 Offset *= EntrySize;
1578 return (uintptr_t)((char *)JumpTableBase + Offset);
1581 void JITEmitter::EmittedFunctionConfig::onDelete(
1582 JITEmitter *Emitter, const Function *F) {
1583 Emitter->deallocateMemForFunction(F);
1585 void JITEmitter::EmittedFunctionConfig::onRAUW(
1586 JITEmitter *, const Function*, const Function*) {
1587 llvm_unreachable("The JIT doesn't know how to handle a"
1588 " RAUW on a value it has emitted.");
1592 //===----------------------------------------------------------------------===//
1593 // Public interface to this file
1594 //===----------------------------------------------------------------------===//
1596 JITCodeEmitter *JIT::createEmitter(JIT &jit, JITMemoryManager *JMM,
1597 TargetMachine &tm) {
1598 return new JITEmitter(jit, JMM, tm);
1601 // getPointerToFunctionOrStub - If the specified function has been
1602 // code-gen'd, return a pointer to the function. If not, compile it, or use
1603 // a stub to implement lazy compilation if available.
1605 void *JIT::getPointerToFunctionOrStub(Function *F) {
1606 // If we have already code generated the function, just return the address.
1607 if (void *Addr = getPointerToGlobalIfAvailable(F))
1610 // Get a stub if the target supports it.
1611 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1612 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1613 return JE->getJITResolver().getLazyFunctionStub(F);
1616 void JIT::updateFunctionStub(Function *F) {
1617 // Get the empty stub we generated earlier.
1618 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1619 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1620 void *Stub = JE->getJITResolver().getLazyFunctionStub(F);
1621 void *Addr = getPointerToGlobalIfAvailable(F);
1622 assert(Addr != Stub && "Function must have non-stub address to be updated.");
1624 // Tell the target jit info to rewrite the stub at the specified address,
1625 // rather than creating a new one.
1626 TargetJITInfo::StubLayout layout = getJITInfo().getStubLayout();
1627 JE->startGVStub(Stub, layout.Size);
1628 getJITInfo().emitFunctionStub(F, Addr, *getCodeEmitter());
1632 /// freeMachineCodeForFunction - release machine code memory for given Function.
1634 void JIT::freeMachineCodeForFunction(Function *F) {
1635 // Delete translation for this from the ExecutionEngine, so it will get
1636 // retranslated next time it is used.
1637 updateGlobalMapping(F, 0);
1639 // Free the actual memory for the function body and related stuff.
1640 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1641 cast<JITEmitter>(JCE)->deallocateMemForFunction(F);