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/CodeGen/JITCodeEmitter.h"
24 #include "llvm/CodeGen/MachineFunction.h"
25 #include "llvm/CodeGen/MachineConstantPool.h"
26 #include "llvm/CodeGen/MachineJumpTableInfo.h"
27 #include "llvm/CodeGen/MachineModuleInfo.h"
28 #include "llvm/CodeGen/MachineRelocation.h"
29 #include "llvm/ExecutionEngine/GenericValue.h"
30 #include "llvm/ExecutionEngine/JITEventListener.h"
31 #include "llvm/ExecutionEngine/JITMemoryManager.h"
32 #include "llvm/CodeGen/MachineCodeInfo.h"
33 #include "llvm/Target/TargetData.h"
34 #include "llvm/Target/TargetJITInfo.h"
35 #include "llvm/Target/TargetMachine.h"
36 #include "llvm/Target/TargetOptions.h"
37 #include "llvm/Support/Debug.h"
38 #include "llvm/Support/ErrorHandling.h"
39 #include "llvm/Support/MutexGuard.h"
40 #include "llvm/Support/ValueHandle.h"
41 #include "llvm/Support/raw_ostream.h"
42 #include "llvm/System/Disassembler.h"
43 #include "llvm/System/Memory.h"
44 #include "llvm/Target/TargetInstrInfo.h"
45 #include "llvm/ADT/DenseMap.h"
46 #include "llvm/ADT/SmallPtrSet.h"
47 #include "llvm/ADT/SmallVector.h"
48 #include "llvm/ADT/Statistic.h"
49 #include "llvm/ADT/ValueMap.h"
56 STATISTIC(NumBytes, "Number of bytes of machine code compiled");
57 STATISTIC(NumRelos, "Number of relocations applied");
58 STATISTIC(NumRetries, "Number of retries with more memory");
59 static JIT *TheJIT = 0;
62 //===----------------------------------------------------------------------===//
63 // JIT lazy compilation code.
67 class JITResolverState;
69 template<typename ValueTy>
70 struct NoRAUWValueMapConfig : public ValueMapConfig<ValueTy> {
71 typedef JITResolverState *ExtraData;
72 static void onRAUW(JITResolverState *, Value *Old, Value *New) {
73 assert(false && "The JIT doesn't know how to handle a"
74 " RAUW on a value it has emitted.");
78 struct CallSiteValueMapConfig : public NoRAUWValueMapConfig<Function*> {
79 typedef JITResolverState *ExtraData;
80 static void onDelete(JITResolverState *JRS, Function *F);
83 class JITResolverState {
85 typedef ValueMap<Function*, void*, NoRAUWValueMapConfig<Function*> >
87 typedef std::map<void*, AssertingVH<Function> > CallSiteToFunctionMapTy;
88 typedef ValueMap<Function *, SmallPtrSet<void*, 1>,
89 CallSiteValueMapConfig> FunctionToCallSitesMapTy;
90 typedef std::map<AssertingVH<GlobalValue>, void*> GlobalToIndirectSymMapTy;
92 /// FunctionToStubMap - Keep track of the stub created for a particular
93 /// function so that we can reuse them if necessary.
94 FunctionToStubMapTy FunctionToStubMap;
96 /// CallSiteToFunctionMap - Keep track of the function that each lazy call
97 /// site corresponds to, and vice versa.
98 CallSiteToFunctionMapTy CallSiteToFunctionMap;
99 FunctionToCallSitesMapTy FunctionToCallSitesMap;
101 /// GlobalToIndirectSymMap - Keep track of the indirect symbol created for a
102 /// particular GlobalVariable so that we can reuse them if necessary.
103 GlobalToIndirectSymMapTy GlobalToIndirectSymMap;
106 JITResolverState() : FunctionToStubMap(this),
107 FunctionToCallSitesMap(this) {}
109 FunctionToStubMapTy& getFunctionToStubMap(const MutexGuard& locked) {
110 assert(locked.holds(TheJIT->lock));
111 return FunctionToStubMap;
114 GlobalToIndirectSymMapTy& getGlobalToIndirectSymMap(const MutexGuard& locked) {
115 assert(locked.holds(TheJIT->lock));
116 return GlobalToIndirectSymMap;
119 pair<void *, Function *> LookupFunctionFromCallSite(
120 const MutexGuard &locked, void *CallSite) const {
121 assert(locked.holds(TheJIT->lock));
123 // The address given to us for the stub may not be exactly right, it might be
124 // a little bit after the stub. As such, use upper_bound to find it.
125 CallSiteToFunctionMapTy::const_iterator I =
126 CallSiteToFunctionMap.upper_bound(CallSite);
127 assert(I != CallSiteToFunctionMap.begin() &&
128 "This is not a known call site!");
133 void AddCallSite(const MutexGuard &locked, void *CallSite, Function *F) {
134 assert(locked.holds(TheJIT->lock));
136 bool Inserted = CallSiteToFunctionMap.insert(
137 std::make_pair(CallSite, F)).second;
139 assert(Inserted && "Pair was already in CallSiteToFunctionMap");
140 FunctionToCallSitesMap[F].insert(CallSite);
143 // Returns the Function of the stub if a stub was erased, or NULL if there
144 // was no stub. This function uses the call-site->function map to find a
145 // relevant function, but asserts that only stubs and not other call sites
146 // will be passed in.
147 Function *EraseStub(const MutexGuard &locked, void *Stub) {
148 CallSiteToFunctionMapTy::iterator C2F_I =
149 CallSiteToFunctionMap.find(Stub);
150 if (C2F_I == CallSiteToFunctionMap.end()) {
155 Function *const F = C2F_I->second;
157 void *RealStub = FunctionToStubMap.lookup(F);
158 assert(RealStub == Stub &&
159 "Call-site that wasn't a stub pass in to EraseStub");
161 FunctionToStubMap.erase(F);
162 CallSiteToFunctionMap.erase(C2F_I);
164 // Remove the stub from the function->call-sites map, and remove the whole
165 // entry from the map if that was the last call site.
166 FunctionToCallSitesMapTy::iterator F2C_I = FunctionToCallSitesMap.find(F);
167 assert(F2C_I != FunctionToCallSitesMap.end() &&
168 "FunctionToCallSitesMap broken");
169 bool Erased = F2C_I->second.erase(Stub);
171 assert(Erased && "FunctionToCallSitesMap broken");
172 if (F2C_I->second.empty())
173 FunctionToCallSitesMap.erase(F2C_I);
178 void EraseAllCallSites(const MutexGuard &locked, Function *F) {
179 assert(locked.holds(TheJIT->lock));
180 EraseAllCallSitesPrelocked(F);
182 void EraseAllCallSitesPrelocked(Function *F) {
183 FunctionToCallSitesMapTy::iterator F2C = FunctionToCallSitesMap.find(F);
184 if (F2C == FunctionToCallSitesMap.end())
186 for (SmallPtrSet<void*, 1>::const_iterator I = F2C->second.begin(),
187 E = F2C->second.end(); I != E; ++I) {
188 bool Erased = CallSiteToFunctionMap.erase(*I);
190 assert(Erased && "Missing call site->function mapping");
192 FunctionToCallSitesMap.erase(F2C);
196 /// JITResolver - Keep track of, and resolve, call sites for functions that
197 /// have not yet been compiled.
199 typedef JITResolverState::FunctionToStubMapTy FunctionToStubMapTy;
200 typedef JITResolverState::CallSiteToFunctionMapTy CallSiteToFunctionMapTy;
201 typedef JITResolverState::GlobalToIndirectSymMapTy GlobalToIndirectSymMapTy;
203 /// LazyResolverFn - The target lazy resolver function that we actually
204 /// rewrite instructions to use.
205 TargetJITInfo::LazyResolverFn LazyResolverFn;
207 JITResolverState state;
209 /// ExternalFnToStubMap - This is the equivalent of FunctionToStubMap for
210 /// external functions.
211 std::map<void*, void*> ExternalFnToStubMap;
213 /// revGOTMap - map addresses to indexes in the GOT
214 std::map<void*, unsigned> revGOTMap;
215 unsigned nextGOTIndex;
219 static JITResolver *TheJITResolver;
221 explicit JITResolver(JIT &jit, JITEmitter &je) : nextGOTIndex(0), JE(je) {
224 LazyResolverFn = jit.getJITInfo().getLazyResolverFunction(JITCompilerFn);
225 assert(TheJITResolver == 0 && "Multiple JIT resolvers?");
226 TheJITResolver = this;
233 /// getFunctionStubIfAvailable - This returns a pointer to a function stub
234 /// if it has already been created.
235 void *getFunctionStubIfAvailable(Function *F);
237 /// getFunctionStub - This returns a pointer to a function stub, creating
238 /// one on demand as needed. If empty is true, create a function stub
239 /// pointing at address 0, to be filled in later.
240 void *getFunctionStub(Function *F);
242 /// getExternalFunctionStub - Return a stub for the function at the
243 /// specified address, created lazily on demand.
244 void *getExternalFunctionStub(void *FnAddr);
246 /// getGlobalValueIndirectSym - Return an indirect symbol containing the
247 /// specified GV address.
248 void *getGlobalValueIndirectSym(GlobalValue *V, void *GVAddress);
250 void getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
251 SmallVectorImpl<void*> &Ptrs);
253 GlobalValue *invalidateStub(void *Stub);
255 /// getGOTIndexForAddress - Return a new or existing index in the GOT for
256 /// an address. This function only manages slots, it does not manage the
257 /// contents of the slots or the memory associated with the GOT.
258 unsigned getGOTIndexForAddr(void *addr);
260 /// JITCompilerFn - This function is called to resolve a stub to a compiled
261 /// address. If the LLVM Function corresponding to the stub has not yet
262 /// been compiled, this function compiles it first.
263 static void *JITCompilerFn(void *Stub);
266 /// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is
267 /// used to output functions to memory for execution.
268 class JITEmitter : public JITCodeEmitter {
269 JITMemoryManager *MemMgr;
271 // When outputting a function stub in the context of some other function, we
272 // save BufferBegin/BufferEnd/CurBufferPtr here.
273 uint8_t *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr;
275 // When reattempting to JIT a function after running out of space, we store
276 // the estimated size of the function we're trying to JIT here, so we can
277 // ask the memory manager for at least this much space. When we
278 // successfully emit the function, we reset this back to zero.
279 uintptr_t SizeEstimate;
281 /// Relocations - These are the relocations that the function needs, as
283 std::vector<MachineRelocation> Relocations;
285 /// MBBLocations - This vector is a mapping from MBB ID's to their address.
286 /// It is filled in by the StartMachineBasicBlock callback and queried by
287 /// the getMachineBasicBlockAddress callback.
288 std::vector<uintptr_t> MBBLocations;
290 /// ConstantPool - The constant pool for the current function.
292 MachineConstantPool *ConstantPool;
294 /// ConstantPoolBase - A pointer to the first entry in the constant pool.
296 void *ConstantPoolBase;
298 /// ConstPoolAddresses - Addresses of individual constant pool entries.
300 SmallVector<uintptr_t, 8> ConstPoolAddresses;
302 /// JumpTable - The jump tables for the current function.
304 MachineJumpTableInfo *JumpTable;
306 /// JumpTableBase - A pointer to the first entry in the jump table.
310 /// Resolver - This contains info about the currently resolved functions.
311 JITResolver Resolver;
313 /// DE - The dwarf emitter for the jit.
314 OwningPtr<JITDwarfEmitter> DE;
316 /// DR - The debug registerer for the jit.
317 OwningPtr<JITDebugRegisterer> DR;
319 /// LabelLocations - This vector is a mapping from Label ID's to their
321 std::vector<uintptr_t> LabelLocations;
323 /// MMI - Machine module info for exception informations
324 MachineModuleInfo* MMI;
326 // GVSet - a set to keep track of which globals have been seen
327 SmallPtrSet<const GlobalVariable*, 8> GVSet;
329 // CurFn - The llvm function being emitted. Only valid during
331 const Function *CurFn;
333 /// Information about emitted code, which is passed to the
334 /// JITEventListeners. This is reset in startFunction and used in
336 JITEvent_EmittedFunctionDetails EmissionDetails;
339 void *FunctionBody; // Beginning of the function's allocation.
340 void *Code; // The address the function's code actually starts at.
341 void *ExceptionTable;
342 EmittedCode() : FunctionBody(0), Code(0), ExceptionTable(0) {}
344 struct EmittedFunctionConfig : public ValueMapConfig<const Function*> {
345 typedef JITEmitter *ExtraData;
346 static void onDelete(JITEmitter *, const Function*);
347 static void onRAUW(JITEmitter *, const Function*, const Function*);
349 ValueMap<const Function *, EmittedCode,
350 EmittedFunctionConfig> EmittedFunctions;
352 // CurFnStubUses - For a given Function, a vector of stubs that it
353 // references. This facilitates the JIT detecting that a stub is no
354 // longer used, so that it may be deallocated.
355 DenseMap<AssertingVH<const Function>, SmallVector<void*, 1> > CurFnStubUses;
357 // StubFnRefs - For a given pointer to a stub, a set of Functions which
358 // reference the stub. When the count of a stub's references drops to zero,
359 // the stub is unused.
360 DenseMap<void *, SmallPtrSet<const Function*, 1> > StubFnRefs;
362 DebugLocTuple PrevDLT;
365 JITEmitter(JIT &jit, JITMemoryManager *JMM, TargetMachine &TM)
366 : SizeEstimate(0), Resolver(jit, *this), MMI(0), CurFn(0),
367 EmittedFunctions(this) {
368 MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager();
369 if (jit.getJITInfo().needsGOT()) {
370 MemMgr->AllocateGOT();
371 DEBUG(errs() << "JIT is managing a GOT\n");
374 if (DwarfExceptionHandling || JITEmitDebugInfo) {
375 DE.reset(new JITDwarfEmitter(jit));
377 if (JITEmitDebugInfo) {
378 DR.reset(new JITDebugRegisterer(TM));
385 /// classof - Methods for support type inquiry through isa, cast, and
388 static inline bool classof(const JITEmitter*) { return true; }
389 static inline bool classof(const MachineCodeEmitter*) { return true; }
391 JITResolver &getJITResolver() { return Resolver; }
393 virtual void startFunction(MachineFunction &F);
394 virtual bool finishFunction(MachineFunction &F);
396 void emitConstantPool(MachineConstantPool *MCP);
397 void initJumpTableInfo(MachineJumpTableInfo *MJTI);
398 void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
400 virtual void startGVStub(const GlobalValue* GV, unsigned StubSize,
401 unsigned Alignment = 1);
402 virtual void startGVStub(const GlobalValue* GV, void *Buffer,
404 virtual void* finishGVStub(const GlobalValue *GV);
406 /// allocateSpace - Reserves space in the current block if any, or
407 /// allocate a new one of the given size.
408 virtual void *allocateSpace(uintptr_t Size, unsigned Alignment);
410 /// allocateGlobal - Allocate memory for a global. Unlike allocateSpace,
411 /// this method does not allocate memory in the current output buffer,
412 /// because a global may live longer than the current function.
413 virtual void *allocateGlobal(uintptr_t Size, unsigned Alignment);
415 virtual void addRelocation(const MachineRelocation &MR) {
416 Relocations.push_back(MR);
419 virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
420 if (MBBLocations.size() <= (unsigned)MBB->getNumber())
421 MBBLocations.resize((MBB->getNumber()+1)*2);
422 MBBLocations[MBB->getNumber()] = getCurrentPCValue();
423 DEBUG(errs() << "JIT: Emitting BB" << MBB->getNumber() << " at ["
424 << (void*) getCurrentPCValue() << "]\n");
427 virtual uintptr_t getConstantPoolEntryAddress(unsigned Entry) const;
428 virtual uintptr_t getJumpTableEntryAddress(unsigned Entry) const;
430 virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
431 assert(MBBLocations.size() > (unsigned)MBB->getNumber() &&
432 MBBLocations[MBB->getNumber()] && "MBB not emitted!");
433 return MBBLocations[MBB->getNumber()];
436 /// retryWithMoreMemory - Log a retry and deallocate all memory for the
437 /// given function. Increase the minimum allocation size so that we get
438 /// more memory next time.
439 void retryWithMoreMemory(MachineFunction &F);
441 /// deallocateMemForFunction - Deallocate all memory for the specified
443 void deallocateMemForFunction(const Function *F);
445 /// AddStubToCurrentFunction - Mark the current function being JIT'd as
446 /// using the stub at the specified address. Allows
447 /// deallocateMemForFunction to also remove stubs no longer referenced.
448 void AddStubToCurrentFunction(void *Stub);
450 virtual void processDebugLoc(DebugLoc DL, bool BeforePrintingInsn);
452 virtual void emitLabel(uint64_t LabelID) {
453 if (LabelLocations.size() <= LabelID)
454 LabelLocations.resize((LabelID+1)*2);
455 LabelLocations[LabelID] = getCurrentPCValue();
458 virtual uintptr_t getLabelAddress(uint64_t LabelID) const {
459 assert(LabelLocations.size() > (unsigned)LabelID &&
460 LabelLocations[LabelID] && "Label not emitted!");
461 return LabelLocations[LabelID];
464 virtual void setModuleInfo(MachineModuleInfo* Info) {
466 if (DE.get()) DE->setModuleInfo(Info);
469 void setMemoryExecutable() {
470 MemMgr->setMemoryExecutable();
473 JITMemoryManager *getMemMgr() const { return MemMgr; }
476 void *getPointerToGlobal(GlobalValue *GV, void *Reference,
477 bool MayNeedFarStub);
478 void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference);
479 unsigned addSizeOfGlobal(const GlobalVariable *GV, unsigned Size);
480 unsigned addSizeOfGlobalsInConstantVal(const Constant *C, unsigned Size);
481 unsigned addSizeOfGlobalsInInitializer(const Constant *Init, unsigned Size);
482 unsigned GetSizeOfGlobalsInBytes(MachineFunction &MF);
486 JITResolver *JITResolver::TheJITResolver = 0;
488 void CallSiteValueMapConfig::onDelete(JITResolverState *JRS, Function *F) {
489 JRS->EraseAllCallSitesPrelocked(F);
492 /// getFunctionStubIfAvailable - This returns a pointer to a function stub
493 /// if it has already been created.
494 void *JITResolver::getFunctionStubIfAvailable(Function *F) {
495 MutexGuard locked(TheJIT->lock);
497 // If we already have a stub for this function, recycle it.
498 return state.getFunctionToStubMap(locked).lookup(F);
501 /// getFunctionStub - This returns a pointer to a function stub, creating
502 /// one on demand as needed.
503 void *JITResolver::getFunctionStub(Function *F) {
504 MutexGuard locked(TheJIT->lock);
506 // If we already have a stub for this function, recycle it.
507 void *&Stub = state.getFunctionToStubMap(locked)[F];
508 if (Stub) return Stub;
510 // Call the lazy resolver function if we are JIT'ing lazily. Otherwise we
511 // must resolve the symbol now.
512 void *Actual = TheJIT->isCompilingLazily()
513 ? (void *)(intptr_t)LazyResolverFn : (void *)0;
515 // If this is an external declaration, attempt to resolve the address now
516 // to place in the stub.
517 if (F->isDeclaration() && !F->hasNotBeenReadFromBitcode()) {
518 Actual = TheJIT->getPointerToFunction(F);
520 // If we resolved the symbol to a null address (eg. a weak external)
521 // don't emit a stub. Return a null pointer to the application.
522 if (!Actual) return 0;
525 // Codegen a new stub, calling the lazy resolver or the actual address of the
526 // external function, if it was resolved.
527 Stub = TheJIT->getJITInfo().emitFunctionStub(F, Actual, JE);
529 if (Actual != (void*)(intptr_t)LazyResolverFn) {
530 // If we are getting the stub for an external function, we really want the
531 // address of the stub in the GlobalAddressMap for the JIT, not the address
532 // of the external function.
533 TheJIT->updateGlobalMapping(F, Stub);
536 DEBUG(errs() << "JIT: Stub emitted at [" << Stub << "] for function '"
537 << F->getName() << "'\n");
539 // Finally, keep track of the stub-to-Function mapping so that the
540 // JITCompilerFn knows which function to compile!
541 state.AddCallSite(locked, Stub, F);
543 // If we are JIT'ing non-lazily but need to call a function that does not
544 // exist yet, add it to the JIT's work list so that we can fill in the stub
546 if (!Actual && !TheJIT->isCompilingLazily())
547 if (!F->isDeclaration() || F->hasNotBeenReadFromBitcode())
548 TheJIT->addPendingFunction(F);
553 /// getGlobalValueIndirectSym - Return a lazy pointer containing the specified
555 void *JITResolver::getGlobalValueIndirectSym(GlobalValue *GV, void *GVAddress) {
556 MutexGuard locked(TheJIT->lock);
558 // If we already have a stub for this global variable, recycle it.
559 void *&IndirectSym = state.getGlobalToIndirectSymMap(locked)[GV];
560 if (IndirectSym) return IndirectSym;
562 // Otherwise, codegen a new indirect symbol.
563 IndirectSym = TheJIT->getJITInfo().emitGlobalValueIndirectSym(GV, GVAddress,
566 DEBUG(errs() << "JIT: Indirect symbol emitted at [" << IndirectSym
567 << "] for GV '" << GV->getName() << "'\n");
572 /// getExternalFunctionStub - Return a stub for the function at the
573 /// specified address, created lazily on demand.
574 void *JITResolver::getExternalFunctionStub(void *FnAddr) {
575 // If we already have a stub for this function, recycle it.
576 void *&Stub = ExternalFnToStubMap[FnAddr];
577 if (Stub) return Stub;
579 Stub = TheJIT->getJITInfo().emitFunctionStub(0, FnAddr, JE);
581 DEBUG(errs() << "JIT: Stub emitted at [" << Stub
582 << "] for external function at '" << FnAddr << "'\n");
586 unsigned JITResolver::getGOTIndexForAddr(void* addr) {
587 unsigned idx = revGOTMap[addr];
589 idx = ++nextGOTIndex;
590 revGOTMap[addr] = idx;
591 DEBUG(errs() << "JIT: Adding GOT entry " << idx << " for addr ["
597 void JITResolver::getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
598 SmallVectorImpl<void*> &Ptrs) {
599 MutexGuard locked(TheJIT->lock);
601 const FunctionToStubMapTy &FM = state.getFunctionToStubMap(locked);
602 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
604 for (FunctionToStubMapTy::const_iterator i = FM.begin(), e = FM.end();
606 Function *F = i->first;
607 if (F->isDeclaration() && F->hasExternalLinkage()) {
608 GVs.push_back(i->first);
609 Ptrs.push_back(i->second);
612 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
614 GVs.push_back(i->first);
615 Ptrs.push_back(i->second);
619 GlobalValue *JITResolver::invalidateStub(void *Stub) {
620 MutexGuard locked(TheJIT->lock);
622 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
624 // Look up the cheap way first, to see if it's a function stub we are
625 // invalidating. If so, remove it from both the forward and reverse maps.
626 if (Function *F = state.EraseStub(locked, Stub)) {
630 // Otherwise, it might be an indirect symbol stub. Find it and remove it.
631 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
633 if (i->second != Stub)
635 GlobalValue *GV = i->first;
640 // Lastly, check to see if it's in the ExternalFnToStubMap.
641 for (std::map<void *, void *>::iterator i = ExternalFnToStubMap.begin(),
642 e = ExternalFnToStubMap.end(); i != e; ++i) {
643 if (i->second != Stub)
645 ExternalFnToStubMap.erase(i);
652 /// JITCompilerFn - This function is called when a lazy compilation stub has
653 /// been entered. It looks up which function this stub corresponds to, compiles
654 /// it if necessary, then returns the resultant function pointer.
655 void *JITResolver::JITCompilerFn(void *Stub) {
656 JITResolver &JR = *TheJITResolver;
662 // Only lock for getting the Function. The call getPointerToFunction made
663 // in this function might trigger function materializing, which requires
664 // JIT lock to be unlocked.
665 MutexGuard locked(TheJIT->lock);
667 // The address given to us for the stub may not be exactly right, it might
668 // be a little bit after the stub. As such, use upper_bound to find it.
669 pair<void*, Function*> I =
670 JR.state.LookupFunctionFromCallSite(locked, Stub);
675 // If we have already code generated the function, just return the address.
676 void *Result = TheJIT->getPointerToGlobalIfAvailable(F);
679 // Otherwise we don't have it, do lazy compilation now.
681 // If lazy compilation is disabled, emit a useful error message and abort.
682 if (!TheJIT->isCompilingLazily()) {
683 llvm_report_error("LLVM JIT requested to do lazy compilation of function '"
684 + F->getName() + "' when lazy compiles are disabled!");
687 DEBUG(errs() << "JIT: Lazily resolving function '" << F->getName()
688 << "' In stub ptr = " << Stub << " actual ptr = "
689 << ActualPtr << "\n");
691 Result = TheJIT->getPointerToFunction(F);
694 // Reacquire the lock to update the GOT map.
695 MutexGuard locked(TheJIT->lock);
697 // We might like to remove the call site from the CallSiteToFunction map, but
698 // we can't do that! Multiple threads could be stuck, waiting to acquire the
699 // lock above. As soon as the 1st function finishes compiling the function,
700 // the next one will be released, and needs to be able to find the function it
703 // FIXME: We could rewrite all references to this stub if we knew them.
705 // What we will do is set the compiled function address to map to the
706 // same GOT entry as the stub so that later clients may update the GOT
707 // if they see it still using the stub address.
708 // Note: this is done so the Resolver doesn't have to manage GOT memory
709 // Do this without allocating map space if the target isn't using a GOT
710 if(JR.revGOTMap.find(Stub) != JR.revGOTMap.end())
711 JR.revGOTMap[Result] = JR.revGOTMap[Stub];
716 //===----------------------------------------------------------------------===//
719 void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
720 bool MayNeedFarStub) {
721 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
722 return TheJIT->getOrEmitGlobalVariable(GV);
724 if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
725 return TheJIT->getPointerToGlobal(GA->resolveAliasedGlobal(false));
727 // If we have already compiled the function, return a pointer to its body.
728 Function *F = cast<Function>(V);
730 void *FnStub = Resolver.getFunctionStubIfAvailable(F);
732 // Return the function stub if it's already created. We do this first
733 // so that we're returning the same address for the function as any
735 AddStubToCurrentFunction(FnStub);
739 // If we know the target can handle arbitrary-distance calls, try to
740 // return a direct pointer.
741 if (!MayNeedFarStub) {
742 // If we have code, go ahead and return that.
743 void *ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
744 if (ResultPtr) return ResultPtr;
746 // If this is an external function pointer, we can force the JIT to
747 // 'compile' it, which really just adds it to the map.
748 if (F->isDeclaration() && !F->hasNotBeenReadFromBitcode())
749 return TheJIT->getPointerToFunction(F);
752 // Otherwise, we may need a to emit a stub, and, conservatively, we
754 void *StubAddr = Resolver.getFunctionStub(F);
756 // Add the stub to the current function's list of referenced stubs, so we can
757 // deallocate them if the current function is ever freed. It's possible to
758 // return null from getFunctionStub in the case of a weak extern that fails
761 AddStubToCurrentFunction(StubAddr);
766 void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) {
767 // Make sure GV is emitted first, and create a stub containing the fully
769 void *GVAddress = getPointerToGlobal(V, Reference, false);
770 void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress);
772 // Add the stub to the current function's list of referenced stubs, so we can
773 // deallocate them if the current function is ever freed.
774 AddStubToCurrentFunction(StubAddr);
779 void JITEmitter::AddStubToCurrentFunction(void *StubAddr) {
780 assert(CurFn && "Stub added to current function, but current function is 0!");
782 SmallVectorImpl<void*> &StubsUsed = CurFnStubUses[CurFn];
783 StubsUsed.push_back(StubAddr);
785 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[StubAddr];
786 FnRefs.insert(CurFn);
789 void JITEmitter::processDebugLoc(DebugLoc DL, bool BeforePrintingInsn) {
790 if (!DL.isUnknown()) {
791 DebugLocTuple CurDLT = EmissionDetails.MF->getDebugLocTuple(DL);
793 if (BeforePrintingInsn) {
794 if (CurDLT.Scope != 0 && PrevDLT != CurDLT) {
795 JITEvent_EmittedFunctionDetails::LineStart NextLine;
796 NextLine.Address = getCurrentPCValue();
798 EmissionDetails.LineStarts.push_back(NextLine);
806 static unsigned GetConstantPoolSizeInBytes(MachineConstantPool *MCP,
807 const TargetData *TD) {
808 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
809 if (Constants.empty()) return 0;
812 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
813 MachineConstantPoolEntry CPE = Constants[i];
814 unsigned AlignMask = CPE.getAlignment() - 1;
815 Size = (Size + AlignMask) & ~AlignMask;
816 const Type *Ty = CPE.getType();
817 Size += TD->getTypeAllocSize(Ty);
822 static unsigned GetJumpTableSizeInBytes(MachineJumpTableInfo *MJTI) {
823 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
824 if (JT.empty()) return 0;
826 unsigned NumEntries = 0;
827 for (unsigned i = 0, e = JT.size(); i != e; ++i)
828 NumEntries += JT[i].MBBs.size();
830 unsigned EntrySize = MJTI->getEntrySize();
832 return NumEntries * EntrySize;
835 static uintptr_t RoundUpToAlign(uintptr_t Size, unsigned Alignment) {
836 if (Alignment == 0) Alignment = 1;
837 // Since we do not know where the buffer will be allocated, be pessimistic.
838 return Size + Alignment;
841 /// addSizeOfGlobal - add the size of the global (plus any alignment padding)
842 /// into the running total Size.
844 unsigned JITEmitter::addSizeOfGlobal(const GlobalVariable *GV, unsigned Size) {
845 const Type *ElTy = GV->getType()->getElementType();
846 size_t GVSize = (size_t)TheJIT->getTargetData()->getTypeAllocSize(ElTy);
848 (size_t)TheJIT->getTargetData()->getPreferredAlignment(GV);
849 DEBUG(errs() << "JIT: Adding in size " << GVSize << " alignment " << GVAlign);
851 // Assume code section ends with worst possible alignment, so first
852 // variable needs maximal padding.
855 Size = ((Size+GVAlign-1)/GVAlign)*GVAlign;
860 /// addSizeOfGlobalsInConstantVal - find any globals that we haven't seen yet
861 /// but are referenced from the constant; put them in GVSet and add their
862 /// size into the running total Size.
864 unsigned JITEmitter::addSizeOfGlobalsInConstantVal(const Constant *C,
866 // If its undefined, return the garbage.
867 if (isa<UndefValue>(C))
870 // If the value is a ConstantExpr
871 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
872 Constant *Op0 = CE->getOperand(0);
873 switch (CE->getOpcode()) {
874 case Instruction::GetElementPtr:
875 case Instruction::Trunc:
876 case Instruction::ZExt:
877 case Instruction::SExt:
878 case Instruction::FPTrunc:
879 case Instruction::FPExt:
880 case Instruction::UIToFP:
881 case Instruction::SIToFP:
882 case Instruction::FPToUI:
883 case Instruction::FPToSI:
884 case Instruction::PtrToInt:
885 case Instruction::IntToPtr:
886 case Instruction::BitCast: {
887 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
890 case Instruction::Add:
891 case Instruction::FAdd:
892 case Instruction::Sub:
893 case Instruction::FSub:
894 case Instruction::Mul:
895 case Instruction::FMul:
896 case Instruction::UDiv:
897 case Instruction::SDiv:
898 case Instruction::URem:
899 case Instruction::SRem:
900 case Instruction::And:
901 case Instruction::Or:
902 case Instruction::Xor: {
903 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
904 Size = addSizeOfGlobalsInConstantVal(CE->getOperand(1), Size);
909 raw_string_ostream Msg(msg);
910 Msg << "ConstantExpr not handled: " << *CE;
911 llvm_report_error(Msg.str());
916 if (C->getType()->getTypeID() == Type::PointerTyID)
917 if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C))
918 if (GVSet.insert(GV))
919 Size = addSizeOfGlobal(GV, Size);
924 /// addSizeOfGLobalsInInitializer - handle any globals that we haven't seen yet
925 /// but are referenced from the given initializer.
927 unsigned JITEmitter::addSizeOfGlobalsInInitializer(const Constant *Init,
929 if (!isa<UndefValue>(Init) &&
930 !isa<ConstantVector>(Init) &&
931 !isa<ConstantAggregateZero>(Init) &&
932 !isa<ConstantArray>(Init) &&
933 !isa<ConstantStruct>(Init) &&
934 Init->getType()->isFirstClassType())
935 Size = addSizeOfGlobalsInConstantVal(Init, Size);
939 /// GetSizeOfGlobalsInBytes - walk the code for the function, looking for
940 /// globals; then walk the initializers of those globals looking for more.
941 /// If their size has not been considered yet, add it into the running total
944 unsigned JITEmitter::GetSizeOfGlobalsInBytes(MachineFunction &MF) {
948 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
950 for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
952 const TargetInstrDesc &Desc = I->getDesc();
953 const MachineInstr &MI = *I;
954 unsigned NumOps = Desc.getNumOperands();
955 for (unsigned CurOp = 0; CurOp < NumOps; CurOp++) {
956 const MachineOperand &MO = MI.getOperand(CurOp);
958 GlobalValue* V = MO.getGlobal();
959 const GlobalVariable *GV = dyn_cast<const GlobalVariable>(V);
962 // If seen in previous function, it will have an entry here.
963 if (TheJIT->getPointerToGlobalIfAvailable(GV))
965 // If seen earlier in this function, it will have an entry here.
966 // FIXME: it should be possible to combine these tables, by
967 // assuming the addresses of the new globals in this module
968 // start at 0 (or something) and adjusting them after codegen
969 // complete. Another possibility is to grab a marker bit in GV.
970 if (GVSet.insert(GV))
971 // A variable as yet unseen. Add in its size.
972 Size = addSizeOfGlobal(GV, Size);
977 DEBUG(errs() << "JIT: About to look through initializers\n");
978 // Look for more globals that are referenced only from initializers.
979 // GVSet.end is computed each time because the set can grow as we go.
980 for (SmallPtrSet<const GlobalVariable *, 8>::iterator I = GVSet.begin();
981 I != GVSet.end(); I++) {
982 const GlobalVariable* GV = *I;
983 if (GV->hasInitializer())
984 Size = addSizeOfGlobalsInInitializer(GV->getInitializer(), Size);
990 void JITEmitter::startFunction(MachineFunction &F) {
991 DEBUG(errs() << "JIT: Starting CodeGen of Function "
992 << F.getFunction()->getName() << "\n");
994 uintptr_t ActualSize = 0;
995 // Set the memory writable, if it's not already
996 MemMgr->setMemoryWritable();
997 if (MemMgr->NeedsExactSize()) {
998 DEBUG(errs() << "JIT: ExactSize\n");
999 const TargetInstrInfo* TII = F.getTarget().getInstrInfo();
1000 MachineJumpTableInfo *MJTI = F.getJumpTableInfo();
1001 MachineConstantPool *MCP = F.getConstantPool();
1003 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1004 ActualSize = RoundUpToAlign(ActualSize, 16);
1006 // Add the alignment of the constant pool
1007 ActualSize = RoundUpToAlign(ActualSize, MCP->getConstantPoolAlignment());
1009 // Add the constant pool size
1010 ActualSize += GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1012 // Add the aligment of the jump table info
1013 ActualSize = RoundUpToAlign(ActualSize, MJTI->getAlignment());
1015 // Add the jump table size
1016 ActualSize += GetJumpTableSizeInBytes(MJTI);
1018 // Add the alignment for the function
1019 ActualSize = RoundUpToAlign(ActualSize,
1020 std::max(F.getFunction()->getAlignment(), 8U));
1022 // Add the function size
1023 ActualSize += TII->GetFunctionSizeInBytes(F);
1025 DEBUG(errs() << "JIT: ActualSize before globals " << ActualSize << "\n");
1026 // Add the size of the globals that will be allocated after this function.
1027 // These are all the ones referenced from this function that were not
1028 // previously allocated.
1029 ActualSize += GetSizeOfGlobalsInBytes(F);
1030 DEBUG(errs() << "JIT: ActualSize after globals " << ActualSize << "\n");
1031 } else if (SizeEstimate > 0) {
1032 // SizeEstimate will be non-zero on reallocation attempts.
1033 ActualSize = SizeEstimate;
1036 BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(),
1038 BufferEnd = BufferBegin+ActualSize;
1039 EmittedFunctions[F.getFunction()].FunctionBody = BufferBegin;
1041 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1044 emitConstantPool(F.getConstantPool());
1045 initJumpTableInfo(F.getJumpTableInfo());
1047 // About to start emitting the machine code for the function.
1048 emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
1049 TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
1050 EmittedFunctions[F.getFunction()].Code = CurBufferPtr;
1052 MBBLocations.clear();
1054 EmissionDetails.MF = &F;
1055 EmissionDetails.LineStarts.clear();
1058 bool JITEmitter::finishFunction(MachineFunction &F) {
1059 if (CurBufferPtr == BufferEnd) {
1060 // We must call endFunctionBody before retrying, because
1061 // deallocateMemForFunction requires it.
1062 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1063 retryWithMoreMemory(F);
1067 emitJumpTableInfo(F.getJumpTableInfo());
1069 // FnStart is the start of the text, not the start of the constant pool and
1070 // other per-function data.
1072 (uint8_t *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
1074 // FnEnd is the end of the function's machine code.
1075 uint8_t *FnEnd = CurBufferPtr;
1077 if (!Relocations.empty()) {
1078 CurFn = F.getFunction();
1079 NumRelos += Relocations.size();
1081 // Resolve the relocations to concrete pointers.
1082 for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
1083 MachineRelocation &MR = Relocations[i];
1084 void *ResultPtr = 0;
1085 if (!MR.letTargetResolve()) {
1086 if (MR.isExternalSymbol()) {
1087 ResultPtr = TheJIT->getPointerToNamedFunction(MR.getExternalSymbol(),
1089 DEBUG(errs() << "JIT: Map \'" << MR.getExternalSymbol() << "\' to ["
1090 << ResultPtr << "]\n");
1092 // If the target REALLY wants a stub for this function, emit it now.
1093 if (MR.mayNeedFarStub()) {
1094 ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
1096 } else if (MR.isGlobalValue()) {
1097 ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
1098 BufferBegin+MR.getMachineCodeOffset(),
1099 MR.mayNeedFarStub());
1100 } else if (MR.isIndirectSymbol()) {
1101 ResultPtr = getPointerToGVIndirectSym(
1102 MR.getGlobalValue(), BufferBegin+MR.getMachineCodeOffset());
1103 } else if (MR.isBasicBlock()) {
1104 ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
1105 } else if (MR.isConstantPoolIndex()) {
1106 ResultPtr = (void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
1108 assert(MR.isJumpTableIndex());
1109 ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
1112 MR.setResultPointer(ResultPtr);
1115 // if we are managing the GOT and the relocation wants an index,
1117 if (MR.isGOTRelative() && MemMgr->isManagingGOT()) {
1118 unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
1119 MR.setGOTIndex(idx);
1120 if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) {
1121 DEBUG(errs() << "JIT: GOT was out of date for " << ResultPtr
1122 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1124 ((void**)MemMgr->getGOTBase())[idx] = ResultPtr;
1130 TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
1131 Relocations.size(), MemMgr->getGOTBase());
1134 // Update the GOT entry for F to point to the new code.
1135 if (MemMgr->isManagingGOT()) {
1136 unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
1137 if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) {
1138 DEBUG(errs() << "JIT: GOT was out of date for " << (void*)BufferBegin
1139 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1141 ((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin;
1145 // CurBufferPtr may have moved beyond FnEnd, due to memory allocation for
1146 // global variables that were referenced in the relocations.
1147 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1149 if (CurBufferPtr == BufferEnd) {
1150 retryWithMoreMemory(F);
1153 // Now that we've succeeded in emitting the function, reset the
1154 // SizeEstimate back down to zero.
1158 BufferBegin = CurBufferPtr = 0;
1159 NumBytes += FnEnd-FnStart;
1161 // Invalidate the icache if necessary.
1162 sys::Memory::InvalidateInstructionCache(FnStart, FnEnd-FnStart);
1164 TheJIT->NotifyFunctionEmitted(*F.getFunction(), FnStart, FnEnd-FnStart,
1167 DEBUG(errs() << "JIT: Finished CodeGen of [" << (void*)FnStart
1168 << "] Function: " << F.getFunction()->getName()
1169 << ": " << (FnEnd-FnStart) << " bytes of text, "
1170 << Relocations.size() << " relocations\n");
1172 Relocations.clear();
1173 ConstPoolAddresses.clear();
1175 // Mark code region readable and executable if it's not so already.
1176 MemMgr->setMemoryExecutable();
1179 if (sys::hasDisassembler()) {
1180 errs() << "JIT: Disassembled code:\n";
1181 errs() << sys::disassembleBuffer(FnStart, FnEnd-FnStart,
1182 (uintptr_t)FnStart);
1184 errs() << "JIT: Binary code:\n";
1185 uint8_t* q = FnStart;
1186 for (int i = 0; q < FnEnd; q += 4, ++i) {
1190 errs() << "JIT: " << (long)(q - FnStart) << ": ";
1192 for (int j = 3; j >= 0; --j) {
1196 errs() << (unsigned short)q[j];
1208 if (DwarfExceptionHandling || JITEmitDebugInfo) {
1209 uintptr_t ActualSize = 0;
1210 SavedBufferBegin = BufferBegin;
1211 SavedBufferEnd = BufferEnd;
1212 SavedCurBufferPtr = CurBufferPtr;
1214 if (MemMgr->NeedsExactSize()) {
1215 ActualSize = DE->GetDwarfTableSizeInBytes(F, *this, FnStart, FnEnd);
1218 BufferBegin = CurBufferPtr = MemMgr->startExceptionTable(F.getFunction(),
1220 BufferEnd = BufferBegin+ActualSize;
1221 EmittedFunctions[F.getFunction()].ExceptionTable = BufferBegin;
1223 uint8_t *FrameRegister = DE->EmitDwarfTable(F, *this, FnStart, FnEnd,
1225 MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr,
1227 uint8_t *EhEnd = CurBufferPtr;
1228 BufferBegin = SavedBufferBegin;
1229 BufferEnd = SavedBufferEnd;
1230 CurBufferPtr = SavedCurBufferPtr;
1232 if (DwarfExceptionHandling) {
1233 TheJIT->RegisterTable(FrameRegister);
1236 if (JITEmitDebugInfo) {
1238 I.FnStart = FnStart;
1240 I.EhStart = EhStart;
1242 DR->RegisterFunction(F.getFunction(), I);
1252 void JITEmitter::retryWithMoreMemory(MachineFunction &F) {
1253 DEBUG(errs() << "JIT: Ran out of space for native code. Reattempting.\n");
1254 Relocations.clear(); // Clear the old relocations or we'll reapply them.
1255 ConstPoolAddresses.clear();
1257 deallocateMemForFunction(F.getFunction());
1258 // Try again with at least twice as much free space.
1259 SizeEstimate = (uintptr_t)(2 * (BufferEnd - BufferBegin));
1262 /// deallocateMemForFunction - Deallocate all memory for the specified
1263 /// function body. Also drop any references the function has to stubs.
1264 /// May be called while the Function is being destroyed inside ~Value().
1265 void JITEmitter::deallocateMemForFunction(const Function *F) {
1266 ValueMap<const Function *, EmittedCode, EmittedFunctionConfig>::iterator
1267 Emitted = EmittedFunctions.find(F);
1268 if (Emitted != EmittedFunctions.end()) {
1269 MemMgr->deallocateFunctionBody(Emitted->second.FunctionBody);
1270 MemMgr->deallocateExceptionTable(Emitted->second.ExceptionTable);
1271 TheJIT->NotifyFreeingMachineCode(Emitted->second.Code);
1273 EmittedFunctions.erase(Emitted);
1276 // TODO: Do we need to unregister exception handling information from libgcc
1279 if (JITEmitDebugInfo) {
1280 DR->UnregisterFunction(F);
1283 // If the function did not reference any stubs, return.
1284 if (CurFnStubUses.find(F) == CurFnStubUses.end())
1287 // For each referenced stub, erase the reference to this function, and then
1288 // erase the list of referenced stubs.
1289 SmallVectorImpl<void *> &StubList = CurFnStubUses[F];
1290 for (unsigned i = 0, e = StubList.size(); i != e; ++i) {
1291 void *Stub = StubList[i];
1293 // If we already invalidated this stub for this function, continue.
1294 if (StubFnRefs.count(Stub) == 0)
1297 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[Stub];
1300 // If this function was the last reference to the stub, invalidate the stub
1301 // in the JITResolver. Were there a memory manager deallocateStub routine,
1302 // we could call that at this point too.
1303 if (FnRefs.empty()) {
1304 DEBUG(errs() << "\nJIT: Invalidated Stub at [" << Stub << "]\n");
1305 StubFnRefs.erase(Stub);
1307 // Invalidate the stub. If it is a GV stub, update the JIT's global
1308 // mapping for that GV to zero.
1309 GlobalValue *GV = Resolver.invalidateStub(Stub);
1311 TheJIT->updateGlobalMapping(GV, 0);
1315 CurFnStubUses.erase(F);
1319 void* JITEmitter::allocateSpace(uintptr_t Size, unsigned Alignment) {
1321 return JITCodeEmitter::allocateSpace(Size, Alignment);
1323 // create a new memory block if there is no active one.
1324 // care must be taken so that BufferBegin is invalidated when a
1326 BufferBegin = CurBufferPtr = MemMgr->allocateSpace(Size, Alignment);
1327 BufferEnd = BufferBegin+Size;
1328 return CurBufferPtr;
1331 void* JITEmitter::allocateGlobal(uintptr_t Size, unsigned Alignment) {
1332 // Delegate this call through the memory manager.
1333 return MemMgr->allocateGlobal(Size, Alignment);
1336 void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
1337 if (TheJIT->getJITInfo().hasCustomConstantPool())
1340 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
1341 if (Constants.empty()) return;
1343 unsigned Size = GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1344 unsigned Align = MCP->getConstantPoolAlignment();
1345 ConstantPoolBase = allocateSpace(Size, Align);
1348 if (ConstantPoolBase == 0) return; // Buffer overflow.
1350 DEBUG(errs() << "JIT: Emitted constant pool at [" << ConstantPoolBase
1351 << "] (size: " << Size << ", alignment: " << Align << ")\n");
1353 // Initialize the memory for all of the constant pool entries.
1354 unsigned Offset = 0;
1355 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
1356 MachineConstantPoolEntry CPE = Constants[i];
1357 unsigned AlignMask = CPE.getAlignment() - 1;
1358 Offset = (Offset + AlignMask) & ~AlignMask;
1360 uintptr_t CAddr = (uintptr_t)ConstantPoolBase + Offset;
1361 ConstPoolAddresses.push_back(CAddr);
1362 if (CPE.isMachineConstantPoolEntry()) {
1363 // FIXME: add support to lower machine constant pool values into bytes!
1364 llvm_report_error("Initialize memory with machine specific constant pool"
1365 "entry has not been implemented!");
1367 TheJIT->InitializeMemory(CPE.Val.ConstVal, (void*)CAddr);
1368 DEBUG(errs() << "JIT: CP" << i << " at [0x";
1369 errs().write_hex(CAddr) << "]\n");
1371 const Type *Ty = CPE.Val.ConstVal->getType();
1372 Offset += TheJIT->getTargetData()->getTypeAllocSize(Ty);
1376 void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
1377 if (TheJIT->getJITInfo().hasCustomJumpTables())
1380 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1381 if (JT.empty()) return;
1383 unsigned NumEntries = 0;
1384 for (unsigned i = 0, e = JT.size(); i != e; ++i)
1385 NumEntries += JT[i].MBBs.size();
1387 unsigned EntrySize = MJTI->getEntrySize();
1389 // Just allocate space for all the jump tables now. We will fix up the actual
1390 // MBB entries in the tables after we emit the code for each block, since then
1391 // we will know the final locations of the MBBs in memory.
1393 JumpTableBase = allocateSpace(NumEntries * EntrySize, MJTI->getAlignment());
1396 void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
1397 if (TheJIT->getJITInfo().hasCustomJumpTables())
1400 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1401 if (JT.empty() || JumpTableBase == 0) return;
1403 if (TargetMachine::getRelocationModel() == Reloc::PIC_) {
1404 assert(MJTI->getEntrySize() == 4 && "Cross JIT'ing?");
1405 // For each jump table, place the offset from the beginning of the table
1406 // to the target address.
1407 int *SlotPtr = (int*)JumpTableBase;
1409 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1410 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1411 // Store the offset of the basic block for this jump table slot in the
1412 // memory we allocated for the jump table in 'initJumpTableInfo'
1413 uintptr_t Base = (uintptr_t)SlotPtr;
1414 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) {
1415 uintptr_t MBBAddr = getMachineBasicBlockAddress(MBBs[mi]);
1416 *SlotPtr++ = TheJIT->getJITInfo().getPICJumpTableEntry(MBBAddr, Base);
1420 assert(MJTI->getEntrySize() == sizeof(void*) && "Cross JIT'ing?");
1422 // For each jump table, map each target in the jump table to the address of
1423 // an emitted MachineBasicBlock.
1424 intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
1426 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1427 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1428 // Store the address of the basic block for this jump table slot in the
1429 // memory we allocated for the jump table in 'initJumpTableInfo'
1430 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
1431 *SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
1436 void JITEmitter::startGVStub(const GlobalValue* GV, unsigned StubSize,
1437 unsigned Alignment) {
1438 SavedBufferBegin = BufferBegin;
1439 SavedBufferEnd = BufferEnd;
1440 SavedCurBufferPtr = CurBufferPtr;
1442 BufferBegin = CurBufferPtr = MemMgr->allocateStub(GV, StubSize, Alignment);
1443 BufferEnd = BufferBegin+StubSize+1;
1446 void JITEmitter::startGVStub(const GlobalValue* GV, void *Buffer,
1447 unsigned StubSize) {
1448 SavedBufferBegin = BufferBegin;
1449 SavedBufferEnd = BufferEnd;
1450 SavedCurBufferPtr = CurBufferPtr;
1452 BufferBegin = CurBufferPtr = (uint8_t *)Buffer;
1453 BufferEnd = BufferBegin+StubSize+1;
1456 void *JITEmitter::finishGVStub(const GlobalValue* GV) {
1457 NumBytes += getCurrentPCOffset();
1458 std::swap(SavedBufferBegin, BufferBegin);
1459 BufferEnd = SavedBufferEnd;
1460 CurBufferPtr = SavedCurBufferPtr;
1461 return SavedBufferBegin;
1464 // getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
1465 // in the constant pool that was last emitted with the 'emitConstantPool'
1468 uintptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const {
1469 assert(ConstantNum < ConstantPool->getConstants().size() &&
1470 "Invalid ConstantPoolIndex!");
1471 return ConstPoolAddresses[ConstantNum];
1474 // getJumpTableEntryAddress - Return the address of the JumpTable with index
1475 // 'Index' in the jumpp table that was last initialized with 'initJumpTableInfo'
1477 uintptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
1478 const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
1479 assert(Index < JT.size() && "Invalid jump table index!");
1481 unsigned Offset = 0;
1482 unsigned EntrySize = JumpTable->getEntrySize();
1484 for (unsigned i = 0; i < Index; ++i)
1485 Offset += JT[i].MBBs.size();
1487 Offset *= EntrySize;
1489 return (uintptr_t)((char *)JumpTableBase + Offset);
1492 void JITEmitter::EmittedFunctionConfig::onDelete(
1493 JITEmitter *Emitter, const Function *F) {
1494 Emitter->deallocateMemForFunction(F);
1496 void JITEmitter::EmittedFunctionConfig::onRAUW(
1497 JITEmitter *, const Function*, const Function*) {
1498 llvm_unreachable("The JIT doesn't know how to handle a"
1499 " RAUW on a value it has emitted.");
1503 //===----------------------------------------------------------------------===//
1504 // Public interface to this file
1505 //===----------------------------------------------------------------------===//
1507 JITCodeEmitter *JIT::createEmitter(JIT &jit, JITMemoryManager *JMM,
1508 TargetMachine &tm) {
1509 return new JITEmitter(jit, JMM, tm);
1512 // getPointerToNamedFunction - This function is used as a global wrapper to
1513 // JIT::getPointerToNamedFunction for the purpose of resolving symbols when
1514 // bugpoint is debugging the JIT. In that scenario, we are loading an .so and
1515 // need to resolve function(s) that are being mis-codegenerated, so we need to
1516 // resolve their addresses at runtime, and this is the way to do it.
1518 void *getPointerToNamedFunction(const char *Name) {
1519 if (Function *F = TheJIT->FindFunctionNamed(Name))
1520 return TheJIT->getPointerToFunction(F);
1521 return TheJIT->getPointerToNamedFunction(Name);
1525 // getPointerToFunctionOrStub - If the specified function has been
1526 // code-gen'd, return a pointer to the function. If not, compile it, or use
1527 // a stub to implement lazy compilation if available.
1529 void *JIT::getPointerToFunctionOrStub(Function *F) {
1530 // If we have already code generated the function, just return the address.
1531 if (void *Addr = getPointerToGlobalIfAvailable(F))
1534 // Get a stub if the target supports it.
1535 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1536 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1537 return JE->getJITResolver().getFunctionStub(F);
1540 void JIT::updateFunctionStub(Function *F) {
1541 // Get the empty stub we generated earlier.
1542 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1543 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1544 void *Stub = JE->getJITResolver().getFunctionStub(F);
1546 // Tell the target jit info to rewrite the stub at the specified address,
1547 // rather than creating a new one.
1548 void *Addr = getPointerToGlobalIfAvailable(F);
1549 getJITInfo().emitFunctionStubAtAddr(F, Addr, Stub, *getCodeEmitter());
1552 /// freeMachineCodeForFunction - release machine code memory for given Function.
1554 void JIT::freeMachineCodeForFunction(Function *F) {
1555 // Delete translation for this from the ExecutionEngine, so it will get
1556 // retranslated next time it is used.
1557 updateGlobalMapping(F, 0);
1559 // Free the actual memory for the function body and related stuff.
1560 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1561 cast<JITEmitter>(JCE)->deallocateMemForFunction(F);