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/MutexGuard.h"
41 #include "llvm/Support/ValueHandle.h"
42 #include "llvm/Support/raw_ostream.h"
43 #include "llvm/System/Disassembler.h"
44 #include "llvm/System/Memory.h"
45 #include "llvm/Target/TargetInstrInfo.h"
46 #include "llvm/ADT/DenseMap.h"
47 #include "llvm/ADT/SmallPtrSet.h"
48 #include "llvm/ADT/SmallVector.h"
49 #include "llvm/ADT/Statistic.h"
50 #include "llvm/ADT/ValueMap.h"
57 STATISTIC(NumBytes, "Number of bytes of machine code compiled");
58 STATISTIC(NumRelos, "Number of relocations applied");
59 STATISTIC(NumRetries, "Number of retries with more memory");
60 static JIT *TheJIT = 0;
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->hasNotBeenReadFromBitcode();
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;
113 JITResolverState() : FunctionToLazyStubMap(this),
114 FunctionToCallSitesMap(this) {}
116 FunctionToLazyStubMapTy& getFunctionToLazyStubMap(
117 const MutexGuard& locked) {
118 assert(locked.holds(TheJIT->lock));
119 return FunctionToLazyStubMap;
122 GlobalToIndirectSymMapTy& getGlobalToIndirectSymMap(const MutexGuard& locked) {
123 assert(locked.holds(TheJIT->lock));
124 return GlobalToIndirectSymMap;
127 pair<void *, Function *> LookupFunctionFromCallSite(
128 const MutexGuard &locked, void *CallSite) const {
129 assert(locked.holds(TheJIT->lock));
131 // The address given to us for the stub may not be exactly right, it might be
132 // a little bit after the stub. As such, use upper_bound to find it.
133 CallSiteToFunctionMapTy::const_iterator I =
134 CallSiteToFunctionMap.upper_bound(CallSite);
135 assert(I != CallSiteToFunctionMap.begin() &&
136 "This is not a known call site!");
141 void AddCallSite(const MutexGuard &locked, void *CallSite, Function *F) {
142 assert(locked.holds(TheJIT->lock));
144 bool Inserted = CallSiteToFunctionMap.insert(
145 std::make_pair(CallSite, F)).second;
147 assert(Inserted && "Pair was already in CallSiteToFunctionMap");
148 FunctionToCallSitesMap[F].insert(CallSite);
151 // Returns the Function of the stub if a stub was erased, or NULL if there
152 // was no stub. This function uses the call-site->function map to find a
153 // relevant function, but asserts that only stubs and not other call sites
154 // will be passed in.
155 Function *EraseStub(const MutexGuard &locked, void *Stub) {
156 CallSiteToFunctionMapTy::iterator C2F_I =
157 CallSiteToFunctionMap.find(Stub);
158 if (C2F_I == CallSiteToFunctionMap.end()) {
163 Function *const F = C2F_I->second;
165 void *RealStub = FunctionToLazyStubMap.lookup(F);
166 assert(RealStub == Stub &&
167 "Call-site that wasn't a stub pass in to EraseStub");
169 FunctionToLazyStubMap.erase(F);
170 CallSiteToFunctionMap.erase(C2F_I);
172 // Remove the stub from the function->call-sites map, and remove the whole
173 // entry from the map if that was the last call site.
174 FunctionToCallSitesMapTy::iterator F2C_I = FunctionToCallSitesMap.find(F);
175 assert(F2C_I != FunctionToCallSitesMap.end() &&
176 "FunctionToCallSitesMap broken");
177 bool Erased = F2C_I->second.erase(Stub);
179 assert(Erased && "FunctionToCallSitesMap broken");
180 if (F2C_I->second.empty())
181 FunctionToCallSitesMap.erase(F2C_I);
186 void EraseAllCallSites(const MutexGuard &locked, Function *F) {
187 assert(locked.holds(TheJIT->lock));
188 EraseAllCallSitesPrelocked(F);
190 void EraseAllCallSitesPrelocked(Function *F) {
191 FunctionToCallSitesMapTy::iterator F2C = FunctionToCallSitesMap.find(F);
192 if (F2C == FunctionToCallSitesMap.end())
194 for (SmallPtrSet<void*, 1>::const_iterator I = F2C->second.begin(),
195 E = F2C->second.end(); I != E; ++I) {
196 bool Erased = CallSiteToFunctionMap.erase(*I);
198 assert(Erased && "Missing call site->function mapping");
200 FunctionToCallSitesMap.erase(F2C);
204 /// JITResolver - Keep track of, and resolve, call sites for functions that
205 /// have not yet been compiled.
207 typedef JITResolverState::FunctionToLazyStubMapTy FunctionToLazyStubMapTy;
208 typedef JITResolverState::CallSiteToFunctionMapTy CallSiteToFunctionMapTy;
209 typedef JITResolverState::GlobalToIndirectSymMapTy GlobalToIndirectSymMapTy;
211 /// LazyResolverFn - The target lazy resolver function that we actually
212 /// rewrite instructions to use.
213 TargetJITInfo::LazyResolverFn LazyResolverFn;
215 JITResolverState state;
217 /// ExternalFnToStubMap - This is the equivalent of FunctionToLazyStubMap
218 /// for external functions. TODO: Of course, external functions don't need
219 /// a lazy stub. It's actually here to make it more likely that far calls
220 /// succeed, but no single stub can guarantee that. I'll remove this in a
221 /// subsequent checkin when I actually fix far calls.
222 std::map<void*, void*> ExternalFnToStubMap;
224 /// revGOTMap - map addresses to indexes in the GOT
225 std::map<void*, unsigned> revGOTMap;
226 unsigned nextGOTIndex;
230 static JITResolver *TheJITResolver;
232 explicit JITResolver(JIT &jit, JITEmitter &je) : nextGOTIndex(0), JE(je) {
235 LazyResolverFn = jit.getJITInfo().getLazyResolverFunction(JITCompilerFn);
236 assert(TheJITResolver == 0 && "Multiple JIT resolvers?");
237 TheJITResolver = this;
244 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function's
245 /// lazy-compilation stub if it has already been created.
246 void *getLazyFunctionStubIfAvailable(Function *F);
248 /// getLazyFunctionStub - This returns a pointer to a function's
249 /// lazy-compilation stub, creating one on demand as needed.
250 void *getLazyFunctionStub(Function *F);
252 /// getExternalFunctionStub - Return a stub for the function at the
253 /// specified address, created lazily on demand.
254 void *getExternalFunctionStub(void *FnAddr);
256 /// getGlobalValueIndirectSym - Return an indirect symbol containing the
257 /// specified GV address.
258 void *getGlobalValueIndirectSym(GlobalValue *V, void *GVAddress);
260 void getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
261 SmallVectorImpl<void*> &Ptrs);
263 GlobalValue *invalidateStub(void *Stub);
265 /// getGOTIndexForAddress - Return a new or existing index in the GOT for
266 /// an address. This function only manages slots, it does not manage the
267 /// contents of the slots or the memory associated with the GOT.
268 unsigned getGOTIndexForAddr(void *addr);
270 /// JITCompilerFn - This function is called to resolve a stub to a compiled
271 /// address. If the LLVM Function corresponding to the stub has not yet
272 /// been compiled, this function compiles it first.
273 static void *JITCompilerFn(void *Stub);
276 /// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is
277 /// used to output functions to memory for execution.
278 class JITEmitter : public JITCodeEmitter {
279 JITMemoryManager *MemMgr;
281 // When outputting a function stub in the context of some other function, we
282 // save BufferBegin/BufferEnd/CurBufferPtr here.
283 uint8_t *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr;
285 // When reattempting to JIT a function after running out of space, we store
286 // the estimated size of the function we're trying to JIT here, so we can
287 // ask the memory manager for at least this much space. When we
288 // successfully emit the function, we reset this back to zero.
289 uintptr_t SizeEstimate;
291 /// Relocations - These are the relocations that the function needs, as
293 std::vector<MachineRelocation> Relocations;
295 /// MBBLocations - This vector is a mapping from MBB ID's to their address.
296 /// It is filled in by the StartMachineBasicBlock callback and queried by
297 /// the getMachineBasicBlockAddress callback.
298 std::vector<uintptr_t> MBBLocations;
300 /// ConstantPool - The constant pool for the current function.
302 MachineConstantPool *ConstantPool;
304 /// ConstantPoolBase - A pointer to the first entry in the constant pool.
306 void *ConstantPoolBase;
308 /// ConstPoolAddresses - Addresses of individual constant pool entries.
310 SmallVector<uintptr_t, 8> ConstPoolAddresses;
312 /// JumpTable - The jump tables for the current function.
314 MachineJumpTableInfo *JumpTable;
316 /// JumpTableBase - A pointer to the first entry in the jump table.
320 /// Resolver - This contains info about the currently resolved functions.
321 JITResolver Resolver;
323 /// DE - The dwarf emitter for the jit.
324 OwningPtr<JITDwarfEmitter> DE;
326 /// DR - The debug registerer for the jit.
327 OwningPtr<JITDebugRegisterer> DR;
329 /// LabelLocations - This vector is a mapping from Label ID's to their
331 std::vector<uintptr_t> LabelLocations;
333 /// MMI - Machine module info for exception informations
334 MachineModuleInfo* MMI;
336 // GVSet - a set to keep track of which globals have been seen
337 SmallPtrSet<const GlobalVariable*, 8> GVSet;
339 // CurFn - The llvm function being emitted. Only valid during
341 const Function *CurFn;
343 /// Information about emitted code, which is passed to the
344 /// JITEventListeners. This is reset in startFunction and used in
346 JITEvent_EmittedFunctionDetails EmissionDetails;
349 void *FunctionBody; // Beginning of the function's allocation.
350 void *Code; // The address the function's code actually starts at.
351 void *ExceptionTable;
352 EmittedCode() : FunctionBody(0), Code(0), ExceptionTable(0) {}
354 struct EmittedFunctionConfig : public ValueMapConfig<const Function*> {
355 typedef JITEmitter *ExtraData;
356 static void onDelete(JITEmitter *, const Function*);
357 static void onRAUW(JITEmitter *, const Function*, const Function*);
359 ValueMap<const Function *, EmittedCode,
360 EmittedFunctionConfig> EmittedFunctions;
362 // CurFnStubUses - For a given Function, a vector of stubs that it
363 // references. This facilitates the JIT detecting that a stub is no
364 // longer used, so that it may be deallocated.
365 DenseMap<AssertingVH<const Function>, SmallVector<void*, 1> > CurFnStubUses;
367 // StubFnRefs - For a given pointer to a stub, a set of Functions which
368 // reference the stub. When the count of a stub's references drops to zero,
369 // the stub is unused.
370 DenseMap<void *, SmallPtrSet<const Function*, 1> > StubFnRefs;
375 JITEmitter(JIT &jit, JITMemoryManager *JMM, TargetMachine &TM)
376 : SizeEstimate(0), Resolver(jit, *this), MMI(0), CurFn(0),
377 EmittedFunctions(this), PrevDLT(NULL) {
378 MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager();
379 if (jit.getJITInfo().needsGOT()) {
380 MemMgr->AllocateGOT();
381 DEBUG(dbgs() << "JIT is managing a GOT\n");
384 if (DwarfExceptionHandling || JITEmitDebugInfo) {
385 DE.reset(new JITDwarfEmitter(jit));
387 if (JITEmitDebugInfo) {
388 DR.reset(new JITDebugRegisterer(TM));
395 /// classof - Methods for support type inquiry through isa, cast, and
398 static inline bool classof(const JITEmitter*) { return true; }
399 static inline bool classof(const MachineCodeEmitter*) { return true; }
401 JITResolver &getJITResolver() { return Resolver; }
403 virtual void startFunction(MachineFunction &F);
404 virtual bool finishFunction(MachineFunction &F);
406 void emitConstantPool(MachineConstantPool *MCP);
407 void initJumpTableInfo(MachineJumpTableInfo *MJTI);
408 void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
410 void startGVStub(const GlobalValue* GV,
411 unsigned StubSize, unsigned Alignment = 1);
412 void startGVStub(void *Buffer, unsigned StubSize);
414 virtual void *allocIndirectGV(const GlobalValue *GV,
415 const uint8_t *Buffer, size_t Size,
418 /// allocateSpace - Reserves space in the current block if any, or
419 /// allocate a new one of the given size.
420 virtual void *allocateSpace(uintptr_t Size, unsigned Alignment);
422 /// allocateGlobal - Allocate memory for a global. Unlike allocateSpace,
423 /// this method does not allocate memory in the current output buffer,
424 /// because a global may live longer than the current function.
425 virtual void *allocateGlobal(uintptr_t Size, unsigned Alignment);
427 virtual void addRelocation(const MachineRelocation &MR) {
428 Relocations.push_back(MR);
431 virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
432 if (MBBLocations.size() <= (unsigned)MBB->getNumber())
433 MBBLocations.resize((MBB->getNumber()+1)*2);
434 MBBLocations[MBB->getNumber()] = getCurrentPCValue();
435 DEBUG(dbgs() << "JIT: Emitting BB" << MBB->getNumber() << " at ["
436 << (void*) getCurrentPCValue() << "]\n");
439 virtual uintptr_t getConstantPoolEntryAddress(unsigned Entry) const;
440 virtual uintptr_t getJumpTableEntryAddress(unsigned Entry) const;
442 virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
443 assert(MBBLocations.size() > (unsigned)MBB->getNumber() &&
444 MBBLocations[MBB->getNumber()] && "MBB not emitted!");
445 return MBBLocations[MBB->getNumber()];
448 /// retryWithMoreMemory - Log a retry and deallocate all memory for the
449 /// given function. Increase the minimum allocation size so that we get
450 /// more memory next time.
451 void retryWithMoreMemory(MachineFunction &F);
453 /// deallocateMemForFunction - Deallocate all memory for the specified
455 void deallocateMemForFunction(const Function *F);
457 /// AddStubToCurrentFunction - Mark the current function being JIT'd as
458 /// using the stub at the specified address. Allows
459 /// deallocateMemForFunction to also remove stubs no longer referenced.
460 void AddStubToCurrentFunction(void *Stub);
462 virtual void processDebugLoc(DebugLoc DL, bool BeforePrintingInsn);
464 virtual void emitLabel(uint64_t LabelID) {
465 if (LabelLocations.size() <= LabelID)
466 LabelLocations.resize((LabelID+1)*2);
467 LabelLocations[LabelID] = getCurrentPCValue();
470 virtual uintptr_t getLabelAddress(uint64_t LabelID) const {
471 assert(LabelLocations.size() > (unsigned)LabelID &&
472 LabelLocations[LabelID] && "Label not emitted!");
473 return LabelLocations[LabelID];
476 virtual void setModuleInfo(MachineModuleInfo* Info) {
478 if (DE.get()) DE->setModuleInfo(Info);
481 void setMemoryExecutable() {
482 MemMgr->setMemoryExecutable();
485 JITMemoryManager *getMemMgr() const { return MemMgr; }
488 void *getPointerToGlobal(GlobalValue *GV, void *Reference,
489 bool MayNeedFarStub);
490 void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference);
491 unsigned addSizeOfGlobal(const GlobalVariable *GV, unsigned Size);
492 unsigned addSizeOfGlobalsInConstantVal(const Constant *C, unsigned Size);
493 unsigned addSizeOfGlobalsInInitializer(const Constant *Init, unsigned Size);
494 unsigned GetSizeOfGlobalsInBytes(MachineFunction &MF);
498 JITResolver *JITResolver::TheJITResolver = 0;
500 void CallSiteValueMapConfig::onDelete(JITResolverState *JRS, Function *F) {
501 JRS->EraseAllCallSitesPrelocked(F);
504 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function stub
505 /// if it has already been created.
506 void *JITResolver::getLazyFunctionStubIfAvailable(Function *F) {
507 MutexGuard locked(TheJIT->lock);
509 // If we already have a stub for this function, recycle it.
510 return state.getFunctionToLazyStubMap(locked).lookup(F);
513 /// getFunctionStub - This returns a pointer to a function stub, creating
514 /// one on demand as needed.
515 void *JITResolver::getLazyFunctionStub(Function *F) {
516 MutexGuard locked(TheJIT->lock);
518 // If we already have a lazy stub for this function, recycle it.
519 void *&Stub = state.getFunctionToLazyStubMap(locked)[F];
520 if (Stub) return Stub;
522 // Call the lazy resolver function if we are JIT'ing lazily. Otherwise we
523 // must resolve the symbol now.
524 void *Actual = TheJIT->isCompilingLazily()
525 ? (void *)(intptr_t)LazyResolverFn : (void *)0;
527 // If this is an external declaration, attempt to resolve the address now
528 // to place in the stub.
529 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage()) {
530 Actual = TheJIT->getPointerToFunction(F);
532 // If we resolved the symbol to a null address (eg. a weak external)
533 // don't emit a stub. Return a null pointer to the application.
534 if (!Actual) return 0;
537 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
538 JE.startGVStub(F, SL.Size, SL.Alignment);
539 // Codegen a new stub, calling the lazy resolver or the actual address of the
540 // external function, if it was resolved.
541 Stub = TheJIT->getJITInfo().emitFunctionStub(F, Actual, JE);
544 if (Actual != (void*)(intptr_t)LazyResolverFn) {
545 // If we are getting the stub for an external function, we really want the
546 // address of the stub in the GlobalAddressMap for the JIT, not the address
547 // of the external function.
548 TheJIT->updateGlobalMapping(F, Stub);
551 DEBUG(dbgs() << "JIT: Lazy stub emitted at [" << Stub << "] for function '"
552 << F->getName() << "'\n");
554 // Finally, keep track of the stub-to-Function mapping so that the
555 // JITCompilerFn knows which function to compile!
556 state.AddCallSite(locked, Stub, F);
558 // If we are JIT'ing non-lazily but need to call a function that does not
559 // exist yet, add it to the JIT's work list so that we can fill in the stub
561 if (!Actual && !TheJIT->isCompilingLazily())
562 if (!isNonGhostDeclaration(F) && !F->hasAvailableExternallyLinkage())
563 TheJIT->addPendingFunction(F);
568 /// getGlobalValueIndirectSym - Return a lazy pointer containing the specified
570 void *JITResolver::getGlobalValueIndirectSym(GlobalValue *GV, void *GVAddress) {
571 MutexGuard locked(TheJIT->lock);
573 // If we already have a stub for this global variable, recycle it.
574 void *&IndirectSym = state.getGlobalToIndirectSymMap(locked)[GV];
575 if (IndirectSym) return IndirectSym;
577 // Otherwise, codegen a new indirect symbol.
578 IndirectSym = TheJIT->getJITInfo().emitGlobalValueIndirectSym(GV, GVAddress,
581 DEBUG(dbgs() << "JIT: Indirect symbol emitted at [" << IndirectSym
582 << "] for GV '" << GV->getName() << "'\n");
587 /// getExternalFunctionStub - Return a stub for the function at the
588 /// specified address, created lazily on demand.
589 void *JITResolver::getExternalFunctionStub(void *FnAddr) {
590 // If we already have a stub for this function, recycle it.
591 void *&Stub = ExternalFnToStubMap[FnAddr];
592 if (Stub) return Stub;
594 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
595 JE.startGVStub(0, SL.Size, SL.Alignment);
596 Stub = TheJIT->getJITInfo().emitFunctionStub(0, FnAddr, JE);
599 DEBUG(dbgs() << "JIT: Stub emitted at [" << Stub
600 << "] for external function at '" << FnAddr << "'\n");
604 unsigned JITResolver::getGOTIndexForAddr(void* addr) {
605 unsigned idx = revGOTMap[addr];
607 idx = ++nextGOTIndex;
608 revGOTMap[addr] = idx;
609 DEBUG(dbgs() << "JIT: Adding GOT entry " << idx << " for addr ["
615 void JITResolver::getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
616 SmallVectorImpl<void*> &Ptrs) {
617 MutexGuard locked(TheJIT->lock);
619 const FunctionToLazyStubMapTy &FM = state.getFunctionToLazyStubMap(locked);
620 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
622 for (FunctionToLazyStubMapTy::const_iterator i = FM.begin(), e = FM.end();
624 Function *F = i->first;
625 if (F->isDeclaration() && F->hasExternalLinkage()) {
626 GVs.push_back(i->first);
627 Ptrs.push_back(i->second);
630 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
632 GVs.push_back(i->first);
633 Ptrs.push_back(i->second);
637 GlobalValue *JITResolver::invalidateStub(void *Stub) {
638 MutexGuard locked(TheJIT->lock);
640 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
642 // Look up the cheap way first, to see if it's a function stub we are
643 // invalidating. If so, remove it from both the forward and reverse maps.
644 if (Function *F = state.EraseStub(locked, Stub)) {
648 // Otherwise, it might be an indirect symbol stub. Find it and remove it.
649 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
651 if (i->second != Stub)
653 GlobalValue *GV = i->first;
658 // Lastly, check to see if it's in the ExternalFnToStubMap.
659 for (std::map<void *, void *>::iterator i = ExternalFnToStubMap.begin(),
660 e = ExternalFnToStubMap.end(); i != e; ++i) {
661 if (i->second != Stub)
663 ExternalFnToStubMap.erase(i);
670 /// JITCompilerFn - This function is called when a lazy compilation stub has
671 /// been entered. It looks up which function this stub corresponds to, compiles
672 /// it if necessary, then returns the resultant function pointer.
673 void *JITResolver::JITCompilerFn(void *Stub) {
674 JITResolver &JR = *TheJITResolver;
680 // Only lock for getting the Function. The call getPointerToFunction made
681 // in this function might trigger function materializing, which requires
682 // JIT lock to be unlocked.
683 MutexGuard locked(TheJIT->lock);
685 // The address given to us for the stub may not be exactly right, it might
686 // be a little bit after the stub. As such, use upper_bound to find it.
687 pair<void*, Function*> I =
688 JR.state.LookupFunctionFromCallSite(locked, Stub);
693 // If we have already code generated the function, just return the address.
694 void *Result = TheJIT->getPointerToGlobalIfAvailable(F);
697 // Otherwise we don't have it, do lazy compilation now.
699 // If lazy compilation is disabled, emit a useful error message and abort.
700 if (!TheJIT->isCompilingLazily()) {
701 llvm_report_error("LLVM JIT requested to do lazy compilation of function '"
702 + F->getName() + "' when lazy compiles are disabled!");
705 DEBUG(dbgs() << "JIT: Lazily resolving function '" << F->getName()
706 << "' In stub ptr = " << Stub << " actual ptr = "
707 << ActualPtr << "\n");
709 Result = TheJIT->getPointerToFunction(F);
712 // Reacquire the lock to update the GOT map.
713 MutexGuard locked(TheJIT->lock);
715 // We might like to remove the call site from the CallSiteToFunction map, but
716 // we can't do that! Multiple threads could be stuck, waiting to acquire the
717 // lock above. As soon as the 1st function finishes compiling the function,
718 // the next one will be released, and needs to be able to find the function it
721 // FIXME: We could rewrite all references to this stub if we knew them.
723 // What we will do is set the compiled function address to map to the
724 // same GOT entry as the stub so that later clients may update the GOT
725 // if they see it still using the stub address.
726 // Note: this is done so the Resolver doesn't have to manage GOT memory
727 // Do this without allocating map space if the target isn't using a GOT
728 if(JR.revGOTMap.find(Stub) != JR.revGOTMap.end())
729 JR.revGOTMap[Result] = JR.revGOTMap[Stub];
734 //===----------------------------------------------------------------------===//
737 void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
738 bool MayNeedFarStub) {
739 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
740 return TheJIT->getOrEmitGlobalVariable(GV);
742 if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
743 return TheJIT->getPointerToGlobal(GA->resolveAliasedGlobal(false));
745 // If we have already compiled the function, return a pointer to its body.
746 Function *F = cast<Function>(V);
748 void *FnStub = Resolver.getLazyFunctionStubIfAvailable(F);
750 // Return the function stub if it's already created. We do this first so
751 // that we're returning the same address for the function as any previous
752 // call. TODO: Yes, this is wrong. The lazy stub isn't guaranteed to be
753 // close enough to call.
754 AddStubToCurrentFunction(FnStub);
758 // If we know the target can handle arbitrary-distance calls, try to
759 // return a direct pointer.
760 if (!MayNeedFarStub) {
761 // If we have code, go ahead and return that.
762 void *ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
763 if (ResultPtr) return ResultPtr;
765 // If this is an external function pointer, we can force the JIT to
766 // 'compile' it, which really just adds it to the map.
767 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage())
768 return TheJIT->getPointerToFunction(F);
771 // Otherwise, we may need a to emit a stub, and, conservatively, we
773 void *StubAddr = Resolver.getLazyFunctionStub(F);
775 // Add the stub to the current function's list of referenced stubs, so we can
776 // deallocate them if the current function is ever freed. It's possible to
777 // return null from getLazyFunctionStub in the case of a weak extern that
780 AddStubToCurrentFunction(StubAddr);
785 void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) {
786 // Make sure GV is emitted first, and create a stub containing the fully
788 void *GVAddress = getPointerToGlobal(V, Reference, false);
789 void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress);
791 // Add the stub to the current function's list of referenced stubs, so we can
792 // deallocate them if the current function is ever freed.
793 AddStubToCurrentFunction(StubAddr);
798 void JITEmitter::AddStubToCurrentFunction(void *StubAddr) {
799 assert(CurFn && "Stub added to current function, but current function is 0!");
801 SmallVectorImpl<void*> &StubsUsed = CurFnStubUses[CurFn];
802 StubsUsed.push_back(StubAddr);
804 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[StubAddr];
805 FnRefs.insert(CurFn);
808 void JITEmitter::processDebugLoc(DebugLoc DL, bool BeforePrintingInsn) {
809 if (!DL.isUnknown()) {
810 DILocation CurDLT = EmissionDetails.MF->getDILocation(DL);
812 if (BeforePrintingInsn) {
813 if (CurDLT.getScope().getNode() != 0
814 && PrevDLT.getNode() != CurDLT.getNode()) {
815 JITEvent_EmittedFunctionDetails::LineStart NextLine;
816 NextLine.Address = getCurrentPCValue();
818 EmissionDetails.LineStarts.push_back(NextLine);
826 static unsigned GetConstantPoolSizeInBytes(MachineConstantPool *MCP,
827 const TargetData *TD) {
828 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
829 if (Constants.empty()) return 0;
832 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
833 MachineConstantPoolEntry CPE = Constants[i];
834 unsigned AlignMask = CPE.getAlignment() - 1;
835 Size = (Size + AlignMask) & ~AlignMask;
836 const Type *Ty = CPE.getType();
837 Size += TD->getTypeAllocSize(Ty);
842 static unsigned GetJumpTableSizeInBytes(MachineJumpTableInfo *MJTI) {
843 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
844 if (JT.empty()) return 0;
846 unsigned NumEntries = 0;
847 for (unsigned i = 0, e = JT.size(); i != e; ++i)
848 NumEntries += JT[i].MBBs.size();
850 return NumEntries * MJTI->getEntrySize(*TheJIT->getTargetData());
853 static uintptr_t RoundUpToAlign(uintptr_t Size, unsigned Alignment) {
854 if (Alignment == 0) Alignment = 1;
855 // Since we do not know where the buffer will be allocated, be pessimistic.
856 return Size + Alignment;
859 /// addSizeOfGlobal - add the size of the global (plus any alignment padding)
860 /// into the running total Size.
862 unsigned JITEmitter::addSizeOfGlobal(const GlobalVariable *GV, unsigned Size) {
863 const Type *ElTy = GV->getType()->getElementType();
864 size_t GVSize = (size_t)TheJIT->getTargetData()->getTypeAllocSize(ElTy);
866 (size_t)TheJIT->getTargetData()->getPreferredAlignment(GV);
867 DEBUG(dbgs() << "JIT: Adding in size " << GVSize << " alignment " << GVAlign);
869 // Assume code section ends with worst possible alignment, so first
870 // variable needs maximal padding.
873 Size = ((Size+GVAlign-1)/GVAlign)*GVAlign;
878 /// addSizeOfGlobalsInConstantVal - find any globals that we haven't seen yet
879 /// but are referenced from the constant; put them in GVSet and add their
880 /// size into the running total Size.
882 unsigned JITEmitter::addSizeOfGlobalsInConstantVal(const Constant *C,
884 // If its undefined, return the garbage.
885 if (isa<UndefValue>(C))
888 // If the value is a ConstantExpr
889 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
890 Constant *Op0 = CE->getOperand(0);
891 switch (CE->getOpcode()) {
892 case Instruction::GetElementPtr:
893 case Instruction::Trunc:
894 case Instruction::ZExt:
895 case Instruction::SExt:
896 case Instruction::FPTrunc:
897 case Instruction::FPExt:
898 case Instruction::UIToFP:
899 case Instruction::SIToFP:
900 case Instruction::FPToUI:
901 case Instruction::FPToSI:
902 case Instruction::PtrToInt:
903 case Instruction::IntToPtr:
904 case Instruction::BitCast: {
905 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
908 case Instruction::Add:
909 case Instruction::FAdd:
910 case Instruction::Sub:
911 case Instruction::FSub:
912 case Instruction::Mul:
913 case Instruction::FMul:
914 case Instruction::UDiv:
915 case Instruction::SDiv:
916 case Instruction::URem:
917 case Instruction::SRem:
918 case Instruction::And:
919 case Instruction::Or:
920 case Instruction::Xor: {
921 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
922 Size = addSizeOfGlobalsInConstantVal(CE->getOperand(1), Size);
927 raw_string_ostream Msg(msg);
928 Msg << "ConstantExpr not handled: " << *CE;
929 llvm_report_error(Msg.str());
934 if (C->getType()->getTypeID() == Type::PointerTyID)
935 if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C))
936 if (GVSet.insert(GV))
937 Size = addSizeOfGlobal(GV, Size);
942 /// addSizeOfGLobalsInInitializer - handle any globals that we haven't seen yet
943 /// but are referenced from the given initializer.
945 unsigned JITEmitter::addSizeOfGlobalsInInitializer(const Constant *Init,
947 if (!isa<UndefValue>(Init) &&
948 !isa<ConstantVector>(Init) &&
949 !isa<ConstantAggregateZero>(Init) &&
950 !isa<ConstantArray>(Init) &&
951 !isa<ConstantStruct>(Init) &&
952 Init->getType()->isFirstClassType())
953 Size = addSizeOfGlobalsInConstantVal(Init, Size);
957 /// GetSizeOfGlobalsInBytes - walk the code for the function, looking for
958 /// globals; then walk the initializers of those globals looking for more.
959 /// If their size has not been considered yet, add it into the running total
962 unsigned JITEmitter::GetSizeOfGlobalsInBytes(MachineFunction &MF) {
966 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
968 for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
970 const TargetInstrDesc &Desc = I->getDesc();
971 const MachineInstr &MI = *I;
972 unsigned NumOps = Desc.getNumOperands();
973 for (unsigned CurOp = 0; CurOp < NumOps; CurOp++) {
974 const MachineOperand &MO = MI.getOperand(CurOp);
976 GlobalValue* V = MO.getGlobal();
977 const GlobalVariable *GV = dyn_cast<const GlobalVariable>(V);
980 // If seen in previous function, it will have an entry here.
981 if (TheJIT->getPointerToGlobalIfAvailable(GV))
983 // If seen earlier in this function, it will have an entry here.
984 // FIXME: it should be possible to combine these tables, by
985 // assuming the addresses of the new globals in this module
986 // start at 0 (or something) and adjusting them after codegen
987 // complete. Another possibility is to grab a marker bit in GV.
988 if (GVSet.insert(GV))
989 // A variable as yet unseen. Add in its size.
990 Size = addSizeOfGlobal(GV, Size);
995 DEBUG(dbgs() << "JIT: About to look through initializers\n");
996 // Look for more globals that are referenced only from initializers.
997 // GVSet.end is computed each time because the set can grow as we go.
998 for (SmallPtrSet<const GlobalVariable *, 8>::iterator I = GVSet.begin();
999 I != GVSet.end(); I++) {
1000 const GlobalVariable* GV = *I;
1001 if (GV->hasInitializer())
1002 Size = addSizeOfGlobalsInInitializer(GV->getInitializer(), Size);
1008 void JITEmitter::startFunction(MachineFunction &F) {
1009 DEBUG(dbgs() << "JIT: Starting CodeGen of Function "
1010 << F.getFunction()->getName() << "\n");
1012 uintptr_t ActualSize = 0;
1013 // Set the memory writable, if it's not already
1014 MemMgr->setMemoryWritable();
1015 if (MemMgr->NeedsExactSize()) {
1016 DEBUG(dbgs() << "JIT: ExactSize\n");
1017 const TargetInstrInfo* TII = F.getTarget().getInstrInfo();
1018 MachineConstantPool *MCP = F.getConstantPool();
1020 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1021 ActualSize = RoundUpToAlign(ActualSize, 16);
1023 // Add the alignment of the constant pool
1024 ActualSize = RoundUpToAlign(ActualSize, MCP->getConstantPoolAlignment());
1026 // Add the constant pool size
1027 ActualSize += GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1029 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo()) {
1030 // Add the aligment of the jump table info
1031 ActualSize = RoundUpToAlign(ActualSize,
1032 MJTI->getEntryAlignment(*TheJIT->getTargetData()));
1034 // Add the jump table size
1035 ActualSize += GetJumpTableSizeInBytes(MJTI);
1038 // Add the alignment for the function
1039 ActualSize = RoundUpToAlign(ActualSize,
1040 std::max(F.getFunction()->getAlignment(), 8U));
1042 // Add the function size
1043 ActualSize += TII->GetFunctionSizeInBytes(F);
1045 DEBUG(dbgs() << "JIT: ActualSize before globals " << ActualSize << "\n");
1046 // Add the size of the globals that will be allocated after this function.
1047 // These are all the ones referenced from this function that were not
1048 // previously allocated.
1049 ActualSize += GetSizeOfGlobalsInBytes(F);
1050 DEBUG(dbgs() << "JIT: ActualSize after globals " << ActualSize << "\n");
1051 } else if (SizeEstimate > 0) {
1052 // SizeEstimate will be non-zero on reallocation attempts.
1053 ActualSize = SizeEstimate;
1056 BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(),
1058 BufferEnd = BufferBegin+ActualSize;
1059 EmittedFunctions[F.getFunction()].FunctionBody = BufferBegin;
1061 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1064 emitConstantPool(F.getConstantPool());
1065 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
1066 initJumpTableInfo(MJTI);
1068 // About to start emitting the machine code for the function.
1069 emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
1070 TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
1071 EmittedFunctions[F.getFunction()].Code = CurBufferPtr;
1073 MBBLocations.clear();
1075 EmissionDetails.MF = &F;
1076 EmissionDetails.LineStarts.clear();
1079 bool JITEmitter::finishFunction(MachineFunction &F) {
1080 if (CurBufferPtr == BufferEnd) {
1081 // We must call endFunctionBody before retrying, because
1082 // deallocateMemForFunction requires it.
1083 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1084 retryWithMoreMemory(F);
1088 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo())
1089 emitJumpTableInfo(MJTI);
1091 // FnStart is the start of the text, not the start of the constant pool and
1092 // other per-function data.
1094 (uint8_t *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
1096 // FnEnd is the end of the function's machine code.
1097 uint8_t *FnEnd = CurBufferPtr;
1099 if (!Relocations.empty()) {
1100 CurFn = F.getFunction();
1101 NumRelos += Relocations.size();
1103 // Resolve the relocations to concrete pointers.
1104 for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
1105 MachineRelocation &MR = Relocations[i];
1106 void *ResultPtr = 0;
1107 if (!MR.letTargetResolve()) {
1108 if (MR.isExternalSymbol()) {
1109 ResultPtr = TheJIT->getPointerToNamedFunction(MR.getExternalSymbol(),
1111 DEBUG(dbgs() << "JIT: Map \'" << MR.getExternalSymbol() << "\' to ["
1112 << ResultPtr << "]\n");
1114 // If the target REALLY wants a stub for this function, emit it now.
1115 if (MR.mayNeedFarStub()) {
1116 ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
1118 } else if (MR.isGlobalValue()) {
1119 ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
1120 BufferBegin+MR.getMachineCodeOffset(),
1121 MR.mayNeedFarStub());
1122 } else if (MR.isIndirectSymbol()) {
1123 ResultPtr = getPointerToGVIndirectSym(
1124 MR.getGlobalValue(), BufferBegin+MR.getMachineCodeOffset());
1125 } else if (MR.isBasicBlock()) {
1126 ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
1127 } else if (MR.isConstantPoolIndex()) {
1128 ResultPtr = (void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
1130 assert(MR.isJumpTableIndex());
1131 ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
1134 MR.setResultPointer(ResultPtr);
1137 // if we are managing the GOT and the relocation wants an index,
1139 if (MR.isGOTRelative() && MemMgr->isManagingGOT()) {
1140 unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
1141 MR.setGOTIndex(idx);
1142 if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) {
1143 DEBUG(dbgs() << "JIT: GOT was out of date for " << ResultPtr
1144 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1146 ((void**)MemMgr->getGOTBase())[idx] = ResultPtr;
1152 TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
1153 Relocations.size(), MemMgr->getGOTBase());
1156 // Update the GOT entry for F to point to the new code.
1157 if (MemMgr->isManagingGOT()) {
1158 unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
1159 if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) {
1160 DEBUG(dbgs() << "JIT: GOT was out of date for " << (void*)BufferBegin
1161 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1163 ((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin;
1167 // CurBufferPtr may have moved beyond FnEnd, due to memory allocation for
1168 // global variables that were referenced in the relocations.
1169 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1171 if (CurBufferPtr == BufferEnd) {
1172 retryWithMoreMemory(F);
1175 // Now that we've succeeded in emitting the function, reset the
1176 // SizeEstimate back down to zero.
1180 BufferBegin = CurBufferPtr = 0;
1181 NumBytes += FnEnd-FnStart;
1183 // Invalidate the icache if necessary.
1184 sys::Memory::InvalidateInstructionCache(FnStart, FnEnd-FnStart);
1186 TheJIT->NotifyFunctionEmitted(*F.getFunction(), FnStart, FnEnd-FnStart,
1189 DEBUG(dbgs() << "JIT: Finished CodeGen of [" << (void*)FnStart
1190 << "] Function: " << F.getFunction()->getName()
1191 << ": " << (FnEnd-FnStart) << " bytes of text, "
1192 << Relocations.size() << " relocations\n");
1194 Relocations.clear();
1195 ConstPoolAddresses.clear();
1197 // Mark code region readable and executable if it's not so already.
1198 MemMgr->setMemoryExecutable();
1201 if (sys::hasDisassembler()) {
1202 dbgs() << "JIT: Disassembled code:\n";
1203 dbgs() << sys::disassembleBuffer(FnStart, FnEnd-FnStart,
1204 (uintptr_t)FnStart);
1206 dbgs() << "JIT: Binary code:\n";
1207 uint8_t* q = FnStart;
1208 for (int i = 0; q < FnEnd; q += 4, ++i) {
1212 dbgs() << "JIT: " << (long)(q - FnStart) << ": ";
1214 for (int j = 3; j >= 0; --j) {
1218 dbgs() << (unsigned short)q[j];
1230 if (DwarfExceptionHandling || JITEmitDebugInfo) {
1231 uintptr_t ActualSize = 0;
1232 SavedBufferBegin = BufferBegin;
1233 SavedBufferEnd = BufferEnd;
1234 SavedCurBufferPtr = CurBufferPtr;
1236 if (MemMgr->NeedsExactSize()) {
1237 ActualSize = DE->GetDwarfTableSizeInBytes(F, *this, FnStart, FnEnd);
1240 BufferBegin = CurBufferPtr = MemMgr->startExceptionTable(F.getFunction(),
1242 BufferEnd = BufferBegin+ActualSize;
1243 EmittedFunctions[F.getFunction()].ExceptionTable = BufferBegin;
1245 uint8_t *FrameRegister = DE->EmitDwarfTable(F, *this, FnStart, FnEnd,
1247 MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr,
1249 uint8_t *EhEnd = CurBufferPtr;
1250 BufferBegin = SavedBufferBegin;
1251 BufferEnd = SavedBufferEnd;
1252 CurBufferPtr = SavedCurBufferPtr;
1254 if (DwarfExceptionHandling) {
1255 TheJIT->RegisterTable(FrameRegister);
1258 if (JITEmitDebugInfo) {
1260 I.FnStart = FnStart;
1262 I.EhStart = EhStart;
1264 DR->RegisterFunction(F.getFunction(), I);
1274 void JITEmitter::retryWithMoreMemory(MachineFunction &F) {
1275 DEBUG(dbgs() << "JIT: Ran out of space for native code. Reattempting.\n");
1276 Relocations.clear(); // Clear the old relocations or we'll reapply them.
1277 ConstPoolAddresses.clear();
1279 deallocateMemForFunction(F.getFunction());
1280 // Try again with at least twice as much free space.
1281 SizeEstimate = (uintptr_t)(2 * (BufferEnd - BufferBegin));
1284 /// deallocateMemForFunction - Deallocate all memory for the specified
1285 /// function body. Also drop any references the function has to stubs.
1286 /// May be called while the Function is being destroyed inside ~Value().
1287 void JITEmitter::deallocateMemForFunction(const Function *F) {
1288 ValueMap<const Function *, EmittedCode, EmittedFunctionConfig>::iterator
1289 Emitted = EmittedFunctions.find(F);
1290 if (Emitted != EmittedFunctions.end()) {
1291 MemMgr->deallocateFunctionBody(Emitted->second.FunctionBody);
1292 MemMgr->deallocateExceptionTable(Emitted->second.ExceptionTable);
1293 TheJIT->NotifyFreeingMachineCode(Emitted->second.Code);
1295 EmittedFunctions.erase(Emitted);
1298 // TODO: Do we need to unregister exception handling information from libgcc
1301 if (JITEmitDebugInfo) {
1302 DR->UnregisterFunction(F);
1305 // If the function did not reference any stubs, return.
1306 if (CurFnStubUses.find(F) == CurFnStubUses.end())
1309 // For each referenced stub, erase the reference to this function, and then
1310 // erase the list of referenced stubs.
1311 SmallVectorImpl<void *> &StubList = CurFnStubUses[F];
1312 for (unsigned i = 0, e = StubList.size(); i != e; ++i) {
1313 void *Stub = StubList[i];
1315 // If we already invalidated this stub for this function, continue.
1316 if (StubFnRefs.count(Stub) == 0)
1319 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[Stub];
1322 // If this function was the last reference to the stub, invalidate the stub
1323 // in the JITResolver. Were there a memory manager deallocateStub routine,
1324 // we could call that at this point too.
1325 if (FnRefs.empty()) {
1326 DEBUG(dbgs() << "\nJIT: Invalidated Stub at [" << Stub << "]\n");
1327 StubFnRefs.erase(Stub);
1329 // Invalidate the stub. If it is a GV stub, update the JIT's global
1330 // mapping for that GV to zero.
1331 GlobalValue *GV = Resolver.invalidateStub(Stub);
1333 TheJIT->updateGlobalMapping(GV, 0);
1337 CurFnStubUses.erase(F);
1341 void* JITEmitter::allocateSpace(uintptr_t Size, unsigned Alignment) {
1343 return JITCodeEmitter::allocateSpace(Size, Alignment);
1345 // create a new memory block if there is no active one.
1346 // care must be taken so that BufferBegin is invalidated when a
1348 BufferBegin = CurBufferPtr = MemMgr->allocateSpace(Size, Alignment);
1349 BufferEnd = BufferBegin+Size;
1350 return CurBufferPtr;
1353 void* JITEmitter::allocateGlobal(uintptr_t Size, unsigned Alignment) {
1354 // Delegate this call through the memory manager.
1355 return MemMgr->allocateGlobal(Size, Alignment);
1358 void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
1359 if (TheJIT->getJITInfo().hasCustomConstantPool())
1362 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
1363 if (Constants.empty()) return;
1365 unsigned Size = GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1366 unsigned Align = MCP->getConstantPoolAlignment();
1367 ConstantPoolBase = allocateSpace(Size, Align);
1370 if (ConstantPoolBase == 0) return; // Buffer overflow.
1372 DEBUG(dbgs() << "JIT: Emitted constant pool at [" << ConstantPoolBase
1373 << "] (size: " << Size << ", alignment: " << Align << ")\n");
1375 // Initialize the memory for all of the constant pool entries.
1376 unsigned Offset = 0;
1377 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
1378 MachineConstantPoolEntry CPE = Constants[i];
1379 unsigned AlignMask = CPE.getAlignment() - 1;
1380 Offset = (Offset + AlignMask) & ~AlignMask;
1382 uintptr_t CAddr = (uintptr_t)ConstantPoolBase + Offset;
1383 ConstPoolAddresses.push_back(CAddr);
1384 if (CPE.isMachineConstantPoolEntry()) {
1385 // FIXME: add support to lower machine constant pool values into bytes!
1386 llvm_report_error("Initialize memory with machine specific constant pool"
1387 "entry has not been implemented!");
1389 TheJIT->InitializeMemory(CPE.Val.ConstVal, (void*)CAddr);
1390 DEBUG(dbgs() << "JIT: CP" << i << " at [0x";
1391 dbgs().write_hex(CAddr) << "]\n");
1393 const Type *Ty = CPE.Val.ConstVal->getType();
1394 Offset += TheJIT->getTargetData()->getTypeAllocSize(Ty);
1398 void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
1399 if (TheJIT->getJITInfo().hasCustomJumpTables())
1402 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1403 if (JT.empty()) return;
1405 unsigned NumEntries = 0;
1406 for (unsigned i = 0, e = JT.size(); i != e; ++i)
1407 NumEntries += JT[i].MBBs.size();
1409 unsigned EntrySize = MJTI->getEntrySize(*TheJIT->getTargetData());
1411 // Just allocate space for all the jump tables now. We will fix up the actual
1412 // MBB entries in the tables after we emit the code for each block, since then
1413 // we will know the final locations of the MBBs in memory.
1415 JumpTableBase = allocateSpace(NumEntries * EntrySize,
1416 MJTI->getEntryAlignment(*TheJIT->getTargetData()));
1419 void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
1420 if (TheJIT->getJITInfo().hasCustomJumpTables())
1423 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1424 if (JT.empty() || JumpTableBase == 0) return;
1427 switch (MJTI->getEntryKind()) {
1428 case MachineJumpTableInfo::EK_BlockAddress: {
1429 // EK_BlockAddress - Each entry is a plain address of block, e.g.:
1431 assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == sizeof(void*) &&
1434 // For each jump table, map each target in the jump table to the address of
1435 // an emitted MachineBasicBlock.
1436 intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
1438 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1439 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1440 // Store the address of the basic block for this jump table slot in the
1441 // memory we allocated for the jump table in 'initJumpTableInfo'
1442 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
1443 *SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
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 // getPointerToNamedFunction - This function is used as a global wrapper to
1555 // JIT::getPointerToNamedFunction for the purpose of resolving symbols when
1556 // bugpoint is debugging the JIT. In that scenario, we are loading an .so and
1557 // need to resolve function(s) that are being mis-codegenerated, so we need to
1558 // resolve their addresses at runtime, and this is the way to do it.
1560 void *getPointerToNamedFunction(const char *Name) {
1561 if (Function *F = TheJIT->FindFunctionNamed(Name))
1562 return TheJIT->getPointerToFunction(F);
1563 return TheJIT->getPointerToNamedFunction(Name);
1567 // getPointerToFunctionOrStub - If the specified function has been
1568 // code-gen'd, return a pointer to the function. If not, compile it, or use
1569 // a stub to implement lazy compilation if available.
1571 void *JIT::getPointerToFunctionOrStub(Function *F) {
1572 // If we have already code generated the function, just return the address.
1573 if (void *Addr = getPointerToGlobalIfAvailable(F))
1576 // Get a stub if the target supports it.
1577 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1578 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1579 return JE->getJITResolver().getLazyFunctionStub(F);
1582 void JIT::updateFunctionStub(Function *F) {
1583 // Get the empty stub we generated earlier.
1584 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1585 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1586 void *Stub = JE->getJITResolver().getLazyFunctionStub(F);
1587 void *Addr = getPointerToGlobalIfAvailable(F);
1588 assert(Addr != Stub && "Function must have non-stub address to be updated.");
1590 // Tell the target jit info to rewrite the stub at the specified address,
1591 // rather than creating a new one.
1592 TargetJITInfo::StubLayout layout = getJITInfo().getStubLayout();
1593 JE->startGVStub(Stub, layout.Size);
1594 getJITInfo().emitFunctionStub(F, Addr, *getCodeEmitter());
1598 /// freeMachineCodeForFunction - release machine code memory for given Function.
1600 void JIT::freeMachineCodeForFunction(Function *F) {
1601 // Delete translation for this from the ExecutionEngine, so it will get
1602 // retranslated next time it is used.
1603 updateGlobalMapping(F, 0);
1605 // Free the actual memory for the function body and related stuff.
1606 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1607 cast<JITEmitter>(JCE)->deallocateMemForFunction(F);