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 /// AddCallbackAtLocation - If the target is capable of rewriting an
251 /// instruction without the use of a stub, record the location of the use so
252 /// we know which function is being used at the location.
253 void *AddCallbackAtLocation(Function *F, void *Location) {
254 MutexGuard locked(TheJIT->lock);
255 /// Get the target-specific JIT resolver function.
256 state.AddCallSite(locked, Location, F);
257 return (void*)(intptr_t)LazyResolverFn;
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;
372 DebugLocTuple PrevDLT;
375 JITEmitter(JIT &jit, JITMemoryManager *JMM, TargetMachine &TM)
376 : SizeEstimate(0), Resolver(jit, *this), MMI(0), CurFn(0),
377 EmittedFunctions(this) {
378 MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager();
379 if (jit.getJITInfo().needsGOT()) {
380 MemMgr->AllocateGOT();
381 DEBUG(errs() << "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 virtual void startGVStub(const GlobalValue* GV, unsigned StubSize,
411 unsigned Alignment = 1);
412 virtual void startGVStub(const GlobalValue* GV, void *Buffer,
414 virtual void* finishGVStub(const GlobalValue *GV);
416 /// allocateSpace - Reserves space in the current block if any, or
417 /// allocate a new one of the given size.
418 virtual void *allocateSpace(uintptr_t Size, unsigned Alignment);
420 /// allocateGlobal - Allocate memory for a global. Unlike allocateSpace,
421 /// this method does not allocate memory in the current output buffer,
422 /// because a global may live longer than the current function.
423 virtual void *allocateGlobal(uintptr_t Size, unsigned Alignment);
425 virtual void addRelocation(const MachineRelocation &MR) {
426 Relocations.push_back(MR);
429 virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
430 if (MBBLocations.size() <= (unsigned)MBB->getNumber())
431 MBBLocations.resize((MBB->getNumber()+1)*2);
432 MBBLocations[MBB->getNumber()] = getCurrentPCValue();
433 DEBUG(errs() << "JIT: Emitting BB" << MBB->getNumber() << " at ["
434 << (void*) getCurrentPCValue() << "]\n");
437 virtual uintptr_t getConstantPoolEntryAddress(unsigned Entry) const;
438 virtual uintptr_t getJumpTableEntryAddress(unsigned Entry) const;
440 virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
441 assert(MBBLocations.size() > (unsigned)MBB->getNumber() &&
442 MBBLocations[MBB->getNumber()] && "MBB not emitted!");
443 return MBBLocations[MBB->getNumber()];
446 /// retryWithMoreMemory - Log a retry and deallocate all memory for the
447 /// given function. Increase the minimum allocation size so that we get
448 /// more memory next time.
449 void retryWithMoreMemory(MachineFunction &F);
451 /// deallocateMemForFunction - Deallocate all memory for the specified
453 void deallocateMemForFunction(const Function *F);
455 /// AddStubToCurrentFunction - Mark the current function being JIT'd as
456 /// using the stub at the specified address. Allows
457 /// deallocateMemForFunction to also remove stubs no longer referenced.
458 void AddStubToCurrentFunction(void *Stub);
460 virtual void processDebugLoc(DebugLoc DL, bool BeforePrintingInsn);
462 virtual void emitLabel(uint64_t LabelID) {
463 if (LabelLocations.size() <= LabelID)
464 LabelLocations.resize((LabelID+1)*2);
465 LabelLocations[LabelID] = getCurrentPCValue();
468 virtual uintptr_t getLabelAddress(uint64_t LabelID) const {
469 assert(LabelLocations.size() > (unsigned)LabelID &&
470 LabelLocations[LabelID] && "Label not emitted!");
471 return LabelLocations[LabelID];
474 virtual void setModuleInfo(MachineModuleInfo* Info) {
476 if (DE.get()) DE->setModuleInfo(Info);
479 void setMemoryExecutable() {
480 MemMgr->setMemoryExecutable();
483 JITMemoryManager *getMemMgr() const { return MemMgr; }
486 void *getPointerToGlobal(GlobalValue *GV, void *Reference,
487 bool MayNeedFarStub);
488 void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference);
489 unsigned addSizeOfGlobal(const GlobalVariable *GV, unsigned Size);
490 unsigned addSizeOfGlobalsInConstantVal(const Constant *C, unsigned Size);
491 unsigned addSizeOfGlobalsInInitializer(const Constant *Init, unsigned Size);
492 unsigned GetSizeOfGlobalsInBytes(MachineFunction &MF);
496 JITResolver *JITResolver::TheJITResolver = 0;
498 void CallSiteValueMapConfig::onDelete(JITResolverState *JRS, Function *F) {
499 JRS->EraseAllCallSitesPrelocked(F);
502 /// getFunctionStubIfAvailable - This returns a pointer to a function stub
503 /// if it has already been created.
504 void *JITResolver::getFunctionStubIfAvailable(Function *F) {
505 MutexGuard locked(TheJIT->lock);
507 // If we already have a stub for this function, recycle it.
508 return state.getFunctionToStubMap(locked).lookup(F);
511 /// getFunctionStub - This returns a pointer to a function stub, creating
512 /// one on demand as needed.
513 void *JITResolver::getFunctionStub(Function *F) {
514 MutexGuard locked(TheJIT->lock);
516 // If we already have a stub for this function, recycle it.
517 void *&Stub = state.getFunctionToStubMap(locked)[F];
518 if (Stub) return Stub;
520 // Call the lazy resolver function if we are JIT'ing lazily. Otherwise we
521 // must resolve the symbol now.
522 void *Actual = TheJIT->isCompilingLazily()
523 ? (void *)(intptr_t)LazyResolverFn : (void *)0;
525 // If this is an external declaration, attempt to resolve the address now
526 // to place in the stub.
527 if (F->isDeclaration() && !F->hasNotBeenReadFromBitcode()) {
528 Actual = TheJIT->getPointerToFunction(F);
530 // If we resolved the symbol to a null address (eg. a weak external)
531 // don't emit a stub. Return a null pointer to the application.
532 if (!Actual) return 0;
535 // Codegen a new stub, calling the lazy resolver or the actual address of the
536 // external function, if it was resolved.
537 Stub = TheJIT->getJITInfo().emitFunctionStub(F, Actual, JE);
539 if (Actual != (void*)(intptr_t)LazyResolverFn) {
540 // If we are getting the stub for an external function, we really want the
541 // address of the stub in the GlobalAddressMap for the JIT, not the address
542 // of the external function.
543 TheJIT->updateGlobalMapping(F, Stub);
546 DEBUG(errs() << "JIT: Stub emitted at [" << Stub << "] for function '"
547 << F->getName() << "'\n");
549 // Finally, keep track of the stub-to-Function mapping so that the
550 // JITCompilerFn knows which function to compile!
551 state.AddCallSite(locked, Stub, F);
553 // If we are JIT'ing non-lazily but need to call a function that does not
554 // exist yet, add it to the JIT's work list so that we can fill in the stub
556 if (!Actual && !TheJIT->isCompilingLazily())
557 if (!F->isDeclaration() || F->hasNotBeenReadFromBitcode())
558 TheJIT->addPendingFunction(F);
563 /// getGlobalValueIndirectSym - Return a lazy pointer containing the specified
565 void *JITResolver::getGlobalValueIndirectSym(GlobalValue *GV, void *GVAddress) {
566 MutexGuard locked(TheJIT->lock);
568 // If we already have a stub for this global variable, recycle it.
569 void *&IndirectSym = state.getGlobalToIndirectSymMap(locked)[GV];
570 if (IndirectSym) return IndirectSym;
572 // Otherwise, codegen a new indirect symbol.
573 IndirectSym = TheJIT->getJITInfo().emitGlobalValueIndirectSym(GV, GVAddress,
576 DEBUG(errs() << "JIT: Indirect symbol emitted at [" << IndirectSym
577 << "] for GV '" << GV->getName() << "'\n");
582 /// getExternalFunctionStub - Return a stub for the function at the
583 /// specified address, created lazily on demand.
584 void *JITResolver::getExternalFunctionStub(void *FnAddr) {
585 // If we already have a stub for this function, recycle it.
586 void *&Stub = ExternalFnToStubMap[FnAddr];
587 if (Stub) return Stub;
589 Stub = TheJIT->getJITInfo().emitFunctionStub(0, FnAddr, JE);
591 DEBUG(errs() << "JIT: Stub emitted at [" << Stub
592 << "] for external function at '" << FnAddr << "'\n");
596 unsigned JITResolver::getGOTIndexForAddr(void* addr) {
597 unsigned idx = revGOTMap[addr];
599 idx = ++nextGOTIndex;
600 revGOTMap[addr] = idx;
601 DEBUG(errs() << "JIT: Adding GOT entry " << idx << " for addr ["
607 void JITResolver::getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
608 SmallVectorImpl<void*> &Ptrs) {
609 MutexGuard locked(TheJIT->lock);
611 const FunctionToStubMapTy &FM = state.getFunctionToStubMap(locked);
612 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
614 for (FunctionToStubMapTy::const_iterator i = FM.begin(), e = FM.end();
616 Function *F = i->first;
617 if (F->isDeclaration() && F->hasExternalLinkage()) {
618 GVs.push_back(i->first);
619 Ptrs.push_back(i->second);
622 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
624 GVs.push_back(i->first);
625 Ptrs.push_back(i->second);
629 GlobalValue *JITResolver::invalidateStub(void *Stub) {
630 MutexGuard locked(TheJIT->lock);
632 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
634 // Look up the cheap way first, to see if it's a function stub we are
635 // invalidating. If so, remove it from both the forward and reverse maps.
636 if (Function *F = state.EraseStub(locked, Stub)) {
640 // Otherwise, it might be an indirect symbol stub. Find it and remove it.
641 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
643 if (i->second != Stub)
645 GlobalValue *GV = i->first;
650 // Lastly, check to see if it's in the ExternalFnToStubMap.
651 for (std::map<void *, void *>::iterator i = ExternalFnToStubMap.begin(),
652 e = ExternalFnToStubMap.end(); i != e; ++i) {
653 if (i->second != Stub)
655 ExternalFnToStubMap.erase(i);
662 /// JITCompilerFn - This function is called when a lazy compilation stub has
663 /// been entered. It looks up which function this stub corresponds to, compiles
664 /// it if necessary, then returns the resultant function pointer.
665 void *JITResolver::JITCompilerFn(void *Stub) {
666 JITResolver &JR = *TheJITResolver;
672 // Only lock for getting the Function. The call getPointerToFunction made
673 // in this function might trigger function materializing, which requires
674 // JIT lock to be unlocked.
675 MutexGuard locked(TheJIT->lock);
677 // The address given to us for the stub may not be exactly right, it might
678 // be a little bit after the stub. As such, use upper_bound to find it.
679 pair<void*, Function*> I =
680 JR.state.LookupFunctionFromCallSite(locked, Stub);
685 // If we have already code generated the function, just return the address.
686 void *Result = TheJIT->getPointerToGlobalIfAvailable(F);
689 // Otherwise we don't have it, do lazy compilation now.
691 // If lazy compilation is disabled, emit a useful error message and abort.
692 if (!TheJIT->isCompilingLazily()) {
693 llvm_report_error("LLVM JIT requested to do lazy compilation of function '"
694 + F->getName() + "' when lazy compiles are disabled!");
697 DEBUG(errs() << "JIT: Lazily resolving function '" << F->getName()
698 << "' In stub ptr = " << Stub << " actual ptr = "
699 << ActualPtr << "\n");
701 Result = TheJIT->getPointerToFunction(F);
704 // Reacquire the lock to update the GOT map.
705 MutexGuard locked(TheJIT->lock);
707 // We might like to remove the call site from the CallSiteToFunction map, but
708 // we can't do that! Multiple threads could be stuck, waiting to acquire the
709 // lock above. As soon as the 1st function finishes compiling the function,
710 // the next one will be released, and needs to be able to find the function it
713 // FIXME: We could rewrite all references to this stub if we knew them.
715 // What we will do is set the compiled function address to map to the
716 // same GOT entry as the stub so that later clients may update the GOT
717 // if they see it still using the stub address.
718 // Note: this is done so the Resolver doesn't have to manage GOT memory
719 // Do this without allocating map space if the target isn't using a GOT
720 if(JR.revGOTMap.find(Stub) != JR.revGOTMap.end())
721 JR.revGOTMap[Result] = JR.revGOTMap[Stub];
726 //===----------------------------------------------------------------------===//
729 void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
730 bool MayNeedFarStub) {
731 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
732 return TheJIT->getOrEmitGlobalVariable(GV);
734 if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
735 return TheJIT->getPointerToGlobal(GA->resolveAliasedGlobal(false));
737 // If we have already compiled the function, return a pointer to its body.
738 Function *F = cast<Function>(V);
740 if (MayNeedFarStub) {
741 // Return the function stub if it's already created.
742 ResultPtr = Resolver.getFunctionStubIfAvailable(F);
744 AddStubToCurrentFunction(ResultPtr);
746 ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
748 if (ResultPtr) return ResultPtr;
750 // If this is an external function pointer, we can force the JIT to
751 // 'compile' it, which really just adds it to the map.
752 if (F->isDeclaration() && !F->hasNotBeenReadFromBitcode() &&
754 return TheJIT->getPointerToFunction(F);
756 // Okay, the function has not been compiled yet, if the target callback
757 // mechanism is capable of rewriting the instruction directly, prefer to do
758 // that instead of emitting a stub. This uses the lazy resolver, so is not
759 // legal if lazy compilation is disabled.
760 if (!MayNeedFarStub && TheJIT->isCompilingLazily())
761 return Resolver.AddCallbackAtLocation(F, Reference);
763 // Otherwise, we have to emit a stub.
764 void *StubAddr = Resolver.getFunctionStub(F);
766 // Add the stub to the current function's list of referenced stubs, so we can
767 // deallocate them if the current function is ever freed. It's possible to
768 // return null from getFunctionStub in the case of a weak extern that fails
771 AddStubToCurrentFunction(StubAddr);
776 void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) {
777 // Make sure GV is emitted first, and create a stub containing the fully
779 void *GVAddress = getPointerToGlobal(V, Reference, false);
780 void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress);
782 // Add the stub to the current function's list of referenced stubs, so we can
783 // deallocate them if the current function is ever freed.
784 AddStubToCurrentFunction(StubAddr);
789 void JITEmitter::AddStubToCurrentFunction(void *StubAddr) {
790 assert(CurFn && "Stub added to current function, but current function is 0!");
792 SmallVectorImpl<void*> &StubsUsed = CurFnStubUses[CurFn];
793 StubsUsed.push_back(StubAddr);
795 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[StubAddr];
796 FnRefs.insert(CurFn);
799 void JITEmitter::processDebugLoc(DebugLoc DL, bool BeforePrintingInsn) {
800 if (!DL.isUnknown()) {
801 DebugLocTuple CurDLT = EmissionDetails.MF->getDebugLocTuple(DL);
803 if (BeforePrintingInsn) {
804 if (CurDLT.Scope != 0 && PrevDLT != CurDLT) {
805 JITEvent_EmittedFunctionDetails::LineStart NextLine;
806 NextLine.Address = getCurrentPCValue();
808 EmissionDetails.LineStarts.push_back(NextLine);
816 static unsigned GetConstantPoolSizeInBytes(MachineConstantPool *MCP,
817 const TargetData *TD) {
818 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
819 if (Constants.empty()) return 0;
822 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
823 MachineConstantPoolEntry CPE = Constants[i];
824 unsigned AlignMask = CPE.getAlignment() - 1;
825 Size = (Size + AlignMask) & ~AlignMask;
826 const Type *Ty = CPE.getType();
827 Size += TD->getTypeAllocSize(Ty);
832 static unsigned GetJumpTableSizeInBytes(MachineJumpTableInfo *MJTI) {
833 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
834 if (JT.empty()) return 0;
836 unsigned NumEntries = 0;
837 for (unsigned i = 0, e = JT.size(); i != e; ++i)
838 NumEntries += JT[i].MBBs.size();
840 unsigned EntrySize = MJTI->getEntrySize();
842 return NumEntries * EntrySize;
845 static uintptr_t RoundUpToAlign(uintptr_t Size, unsigned Alignment) {
846 if (Alignment == 0) Alignment = 1;
847 // Since we do not know where the buffer will be allocated, be pessimistic.
848 return Size + Alignment;
851 /// addSizeOfGlobal - add the size of the global (plus any alignment padding)
852 /// into the running total Size.
854 unsigned JITEmitter::addSizeOfGlobal(const GlobalVariable *GV, unsigned Size) {
855 const Type *ElTy = GV->getType()->getElementType();
856 size_t GVSize = (size_t)TheJIT->getTargetData()->getTypeAllocSize(ElTy);
858 (size_t)TheJIT->getTargetData()->getPreferredAlignment(GV);
859 DEBUG(errs() << "JIT: Adding in size " << GVSize << " alignment " << GVAlign);
861 // Assume code section ends with worst possible alignment, so first
862 // variable needs maximal padding.
865 Size = ((Size+GVAlign-1)/GVAlign)*GVAlign;
870 /// addSizeOfGlobalsInConstantVal - find any globals that we haven't seen yet
871 /// but are referenced from the constant; put them in GVSet and add their
872 /// size into the running total Size.
874 unsigned JITEmitter::addSizeOfGlobalsInConstantVal(const Constant *C,
876 // If its undefined, return the garbage.
877 if (isa<UndefValue>(C))
880 // If the value is a ConstantExpr
881 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
882 Constant *Op0 = CE->getOperand(0);
883 switch (CE->getOpcode()) {
884 case Instruction::GetElementPtr:
885 case Instruction::Trunc:
886 case Instruction::ZExt:
887 case Instruction::SExt:
888 case Instruction::FPTrunc:
889 case Instruction::FPExt:
890 case Instruction::UIToFP:
891 case Instruction::SIToFP:
892 case Instruction::FPToUI:
893 case Instruction::FPToSI:
894 case Instruction::PtrToInt:
895 case Instruction::IntToPtr:
896 case Instruction::BitCast: {
897 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
900 case Instruction::Add:
901 case Instruction::FAdd:
902 case Instruction::Sub:
903 case Instruction::FSub:
904 case Instruction::Mul:
905 case Instruction::FMul:
906 case Instruction::UDiv:
907 case Instruction::SDiv:
908 case Instruction::URem:
909 case Instruction::SRem:
910 case Instruction::And:
911 case Instruction::Or:
912 case Instruction::Xor: {
913 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
914 Size = addSizeOfGlobalsInConstantVal(CE->getOperand(1), Size);
919 raw_string_ostream Msg(msg);
920 Msg << "ConstantExpr not handled: " << *CE;
921 llvm_report_error(Msg.str());
926 if (C->getType()->getTypeID() == Type::PointerTyID)
927 if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C))
928 if (GVSet.insert(GV))
929 Size = addSizeOfGlobal(GV, Size);
934 /// addSizeOfGLobalsInInitializer - handle any globals that we haven't seen yet
935 /// but are referenced from the given initializer.
937 unsigned JITEmitter::addSizeOfGlobalsInInitializer(const Constant *Init,
939 if (!isa<UndefValue>(Init) &&
940 !isa<ConstantVector>(Init) &&
941 !isa<ConstantAggregateZero>(Init) &&
942 !isa<ConstantArray>(Init) &&
943 !isa<ConstantStruct>(Init) &&
944 Init->getType()->isFirstClassType())
945 Size = addSizeOfGlobalsInConstantVal(Init, Size);
949 /// GetSizeOfGlobalsInBytes - walk the code for the function, looking for
950 /// globals; then walk the initializers of those globals looking for more.
951 /// If their size has not been considered yet, add it into the running total
954 unsigned JITEmitter::GetSizeOfGlobalsInBytes(MachineFunction &MF) {
958 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
960 for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
962 const TargetInstrDesc &Desc = I->getDesc();
963 const MachineInstr &MI = *I;
964 unsigned NumOps = Desc.getNumOperands();
965 for (unsigned CurOp = 0; CurOp < NumOps; CurOp++) {
966 const MachineOperand &MO = MI.getOperand(CurOp);
968 GlobalValue* V = MO.getGlobal();
969 const GlobalVariable *GV = dyn_cast<const GlobalVariable>(V);
972 // If seen in previous function, it will have an entry here.
973 if (TheJIT->getPointerToGlobalIfAvailable(GV))
975 // If seen earlier in this function, it will have an entry here.
976 // FIXME: it should be possible to combine these tables, by
977 // assuming the addresses of the new globals in this module
978 // start at 0 (or something) and adjusting them after codegen
979 // complete. Another possibility is to grab a marker bit in GV.
980 if (GVSet.insert(GV))
981 // A variable as yet unseen. Add in its size.
982 Size = addSizeOfGlobal(GV, Size);
987 DEBUG(errs() << "JIT: About to look through initializers\n");
988 // Look for more globals that are referenced only from initializers.
989 // GVSet.end is computed each time because the set can grow as we go.
990 for (SmallPtrSet<const GlobalVariable *, 8>::iterator I = GVSet.begin();
991 I != GVSet.end(); I++) {
992 const GlobalVariable* GV = *I;
993 if (GV->hasInitializer())
994 Size = addSizeOfGlobalsInInitializer(GV->getInitializer(), Size);
1000 void JITEmitter::startFunction(MachineFunction &F) {
1001 DEBUG(errs() << "JIT: Starting CodeGen of Function "
1002 << F.getFunction()->getName() << "\n");
1004 uintptr_t ActualSize = 0;
1005 // Set the memory writable, if it's not already
1006 MemMgr->setMemoryWritable();
1007 if (MemMgr->NeedsExactSize()) {
1008 DEBUG(errs() << "JIT: ExactSize\n");
1009 const TargetInstrInfo* TII = F.getTarget().getInstrInfo();
1010 MachineJumpTableInfo *MJTI = F.getJumpTableInfo();
1011 MachineConstantPool *MCP = F.getConstantPool();
1013 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1014 ActualSize = RoundUpToAlign(ActualSize, 16);
1016 // Add the alignment of the constant pool
1017 ActualSize = RoundUpToAlign(ActualSize, MCP->getConstantPoolAlignment());
1019 // Add the constant pool size
1020 ActualSize += GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1022 // Add the aligment of the jump table info
1023 ActualSize = RoundUpToAlign(ActualSize, MJTI->getAlignment());
1025 // Add the jump table size
1026 ActualSize += GetJumpTableSizeInBytes(MJTI);
1028 // Add the alignment for the function
1029 ActualSize = RoundUpToAlign(ActualSize,
1030 std::max(F.getFunction()->getAlignment(), 8U));
1032 // Add the function size
1033 ActualSize += TII->GetFunctionSizeInBytes(F);
1035 DEBUG(errs() << "JIT: ActualSize before globals " << ActualSize << "\n");
1036 // Add the size of the globals that will be allocated after this function.
1037 // These are all the ones referenced from this function that were not
1038 // previously allocated.
1039 ActualSize += GetSizeOfGlobalsInBytes(F);
1040 DEBUG(errs() << "JIT: ActualSize after globals " << ActualSize << "\n");
1041 } else if (SizeEstimate > 0) {
1042 // SizeEstimate will be non-zero on reallocation attempts.
1043 ActualSize = SizeEstimate;
1046 BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(),
1048 BufferEnd = BufferBegin+ActualSize;
1049 EmittedFunctions[F.getFunction()].FunctionBody = BufferBegin;
1051 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1054 emitConstantPool(F.getConstantPool());
1055 initJumpTableInfo(F.getJumpTableInfo());
1057 // About to start emitting the machine code for the function.
1058 emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
1059 TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
1060 EmittedFunctions[F.getFunction()].Code = CurBufferPtr;
1062 MBBLocations.clear();
1064 EmissionDetails.MF = &F;
1065 EmissionDetails.LineStarts.clear();
1068 bool JITEmitter::finishFunction(MachineFunction &F) {
1069 if (CurBufferPtr == BufferEnd) {
1070 // We must call endFunctionBody before retrying, because
1071 // deallocateMemForFunction requires it.
1072 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1073 retryWithMoreMemory(F);
1077 emitJumpTableInfo(F.getJumpTableInfo());
1079 // FnStart is the start of the text, not the start of the constant pool and
1080 // other per-function data.
1082 (uint8_t *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
1084 // FnEnd is the end of the function's machine code.
1085 uint8_t *FnEnd = CurBufferPtr;
1087 if (!Relocations.empty()) {
1088 CurFn = F.getFunction();
1089 NumRelos += Relocations.size();
1091 // Resolve the relocations to concrete pointers.
1092 for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
1093 MachineRelocation &MR = Relocations[i];
1094 void *ResultPtr = 0;
1095 if (!MR.letTargetResolve()) {
1096 if (MR.isExternalSymbol()) {
1097 ResultPtr = TheJIT->getPointerToNamedFunction(MR.getExternalSymbol(),
1099 DEBUG(errs() << "JIT: Map \'" << MR.getExternalSymbol() << "\' to ["
1100 << ResultPtr << "]\n");
1102 // If the target REALLY wants a stub for this function, emit it now.
1103 if (MR.mayNeedFarStub()) {
1104 ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
1106 } else if (MR.isGlobalValue()) {
1107 ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
1108 BufferBegin+MR.getMachineCodeOffset(),
1109 MR.mayNeedFarStub());
1110 } else if (MR.isIndirectSymbol()) {
1111 ResultPtr = getPointerToGVIndirectSym(
1112 MR.getGlobalValue(), BufferBegin+MR.getMachineCodeOffset());
1113 } else if (MR.isBasicBlock()) {
1114 ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
1115 } else if (MR.isConstantPoolIndex()) {
1116 ResultPtr = (void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
1118 assert(MR.isJumpTableIndex());
1119 ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
1122 MR.setResultPointer(ResultPtr);
1125 // if we are managing the GOT and the relocation wants an index,
1127 if (MR.isGOTRelative() && MemMgr->isManagingGOT()) {
1128 unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
1129 MR.setGOTIndex(idx);
1130 if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) {
1131 DEBUG(errs() << "JIT: GOT was out of date for " << ResultPtr
1132 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1134 ((void**)MemMgr->getGOTBase())[idx] = ResultPtr;
1140 TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
1141 Relocations.size(), MemMgr->getGOTBase());
1144 // Update the GOT entry for F to point to the new code.
1145 if (MemMgr->isManagingGOT()) {
1146 unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
1147 if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) {
1148 DEBUG(errs() << "JIT: GOT was out of date for " << (void*)BufferBegin
1149 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1151 ((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin;
1155 // CurBufferPtr may have moved beyond FnEnd, due to memory allocation for
1156 // global variables that were referenced in the relocations.
1157 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1159 if (CurBufferPtr == BufferEnd) {
1160 retryWithMoreMemory(F);
1163 // Now that we've succeeded in emitting the function, reset the
1164 // SizeEstimate back down to zero.
1168 BufferBegin = CurBufferPtr = 0;
1169 NumBytes += FnEnd-FnStart;
1171 // Invalidate the icache if necessary.
1172 sys::Memory::InvalidateInstructionCache(FnStart, FnEnd-FnStart);
1174 TheJIT->NotifyFunctionEmitted(*F.getFunction(), FnStart, FnEnd-FnStart,
1177 DEBUG(errs() << "JIT: Finished CodeGen of [" << (void*)FnStart
1178 << "] Function: " << F.getFunction()->getName()
1179 << ": " << (FnEnd-FnStart) << " bytes of text, "
1180 << Relocations.size() << " relocations\n");
1182 Relocations.clear();
1183 ConstPoolAddresses.clear();
1185 // Mark code region readable and executable if it's not so already.
1186 MemMgr->setMemoryExecutable();
1189 if (sys::hasDisassembler()) {
1190 errs() << "JIT: Disassembled code:\n";
1191 errs() << sys::disassembleBuffer(FnStart, FnEnd-FnStart,
1192 (uintptr_t)FnStart);
1194 errs() << "JIT: Binary code:\n";
1195 uint8_t* q = FnStart;
1196 for (int i = 0; q < FnEnd; q += 4, ++i) {
1200 errs() << "JIT: " << (long)(q - FnStart) << ": ";
1202 for (int j = 3; j >= 0; --j) {
1206 errs() << (unsigned short)q[j];
1218 if (DwarfExceptionHandling || JITEmitDebugInfo) {
1219 uintptr_t ActualSize = 0;
1220 SavedBufferBegin = BufferBegin;
1221 SavedBufferEnd = BufferEnd;
1222 SavedCurBufferPtr = CurBufferPtr;
1224 if (MemMgr->NeedsExactSize()) {
1225 ActualSize = DE->GetDwarfTableSizeInBytes(F, *this, FnStart, FnEnd);
1228 BufferBegin = CurBufferPtr = MemMgr->startExceptionTable(F.getFunction(),
1230 BufferEnd = BufferBegin+ActualSize;
1231 EmittedFunctions[F.getFunction()].ExceptionTable = BufferBegin;
1233 uint8_t *FrameRegister = DE->EmitDwarfTable(F, *this, FnStart, FnEnd,
1235 MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr,
1237 uint8_t *EhEnd = CurBufferPtr;
1238 BufferBegin = SavedBufferBegin;
1239 BufferEnd = SavedBufferEnd;
1240 CurBufferPtr = SavedCurBufferPtr;
1242 if (DwarfExceptionHandling) {
1243 TheJIT->RegisterTable(FrameRegister);
1246 if (JITEmitDebugInfo) {
1248 I.FnStart = FnStart;
1250 I.EhStart = EhStart;
1252 DR->RegisterFunction(F.getFunction(), I);
1262 void JITEmitter::retryWithMoreMemory(MachineFunction &F) {
1263 DEBUG(errs() << "JIT: Ran out of space for native code. Reattempting.\n");
1264 Relocations.clear(); // Clear the old relocations or we'll reapply them.
1265 ConstPoolAddresses.clear();
1267 deallocateMemForFunction(F.getFunction());
1268 // Try again with at least twice as much free space.
1269 SizeEstimate = (uintptr_t)(2 * (BufferEnd - BufferBegin));
1272 /// deallocateMemForFunction - Deallocate all memory for the specified
1273 /// function body. Also drop any references the function has to stubs.
1274 /// May be called while the Function is being destroyed inside ~Value().
1275 void JITEmitter::deallocateMemForFunction(const Function *F) {
1276 ValueMap<const Function *, EmittedCode, EmittedFunctionConfig>::iterator
1277 Emitted = EmittedFunctions.find(F);
1278 if (Emitted != EmittedFunctions.end()) {
1279 MemMgr->deallocateFunctionBody(Emitted->second.FunctionBody);
1280 MemMgr->deallocateExceptionTable(Emitted->second.ExceptionTable);
1281 TheJIT->NotifyFreeingMachineCode(Emitted->second.Code);
1283 EmittedFunctions.erase(Emitted);
1286 // TODO: Do we need to unregister exception handling information from libgcc
1289 if (JITEmitDebugInfo) {
1290 DR->UnregisterFunction(F);
1293 // If the function did not reference any stubs, return.
1294 if (CurFnStubUses.find(F) == CurFnStubUses.end())
1297 // For each referenced stub, erase the reference to this function, and then
1298 // erase the list of referenced stubs.
1299 SmallVectorImpl<void *> &StubList = CurFnStubUses[F];
1300 for (unsigned i = 0, e = StubList.size(); i != e; ++i) {
1301 void *Stub = StubList[i];
1303 // If we already invalidated this stub for this function, continue.
1304 if (StubFnRefs.count(Stub) == 0)
1307 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[Stub];
1310 // If this function was the last reference to the stub, invalidate the stub
1311 // in the JITResolver. Were there a memory manager deallocateStub routine,
1312 // we could call that at this point too.
1313 if (FnRefs.empty()) {
1314 DEBUG(errs() << "\nJIT: Invalidated Stub at [" << Stub << "]\n");
1315 StubFnRefs.erase(Stub);
1317 // Invalidate the stub. If it is a GV stub, update the JIT's global
1318 // mapping for that GV to zero.
1319 GlobalValue *GV = Resolver.invalidateStub(Stub);
1321 TheJIT->updateGlobalMapping(GV, 0);
1325 CurFnStubUses.erase(F);
1329 void* JITEmitter::allocateSpace(uintptr_t Size, unsigned Alignment) {
1331 return JITCodeEmitter::allocateSpace(Size, Alignment);
1333 // create a new memory block if there is no active one.
1334 // care must be taken so that BufferBegin is invalidated when a
1336 BufferBegin = CurBufferPtr = MemMgr->allocateSpace(Size, Alignment);
1337 BufferEnd = BufferBegin+Size;
1338 return CurBufferPtr;
1341 void* JITEmitter::allocateGlobal(uintptr_t Size, unsigned Alignment) {
1342 // Delegate this call through the memory manager.
1343 return MemMgr->allocateGlobal(Size, Alignment);
1346 void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
1347 if (TheJIT->getJITInfo().hasCustomConstantPool())
1350 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
1351 if (Constants.empty()) return;
1353 unsigned Size = GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1354 unsigned Align = MCP->getConstantPoolAlignment();
1355 ConstantPoolBase = allocateSpace(Size, Align);
1358 if (ConstantPoolBase == 0) return; // Buffer overflow.
1360 DEBUG(errs() << "JIT: Emitted constant pool at [" << ConstantPoolBase
1361 << "] (size: " << Size << ", alignment: " << Align << ")\n");
1363 // Initialize the memory for all of the constant pool entries.
1364 unsigned Offset = 0;
1365 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
1366 MachineConstantPoolEntry CPE = Constants[i];
1367 unsigned AlignMask = CPE.getAlignment() - 1;
1368 Offset = (Offset + AlignMask) & ~AlignMask;
1370 uintptr_t CAddr = (uintptr_t)ConstantPoolBase + Offset;
1371 ConstPoolAddresses.push_back(CAddr);
1372 if (CPE.isMachineConstantPoolEntry()) {
1373 // FIXME: add support to lower machine constant pool values into bytes!
1374 llvm_report_error("Initialize memory with machine specific constant pool"
1375 "entry has not been implemented!");
1377 TheJIT->InitializeMemory(CPE.Val.ConstVal, (void*)CAddr);
1378 DEBUG(errs() << "JIT: CP" << i << " at [0x";
1379 errs().write_hex(CAddr) << "]\n");
1381 const Type *Ty = CPE.Val.ConstVal->getType();
1382 Offset += TheJIT->getTargetData()->getTypeAllocSize(Ty);
1386 void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
1387 if (TheJIT->getJITInfo().hasCustomJumpTables())
1390 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1391 if (JT.empty()) return;
1393 unsigned NumEntries = 0;
1394 for (unsigned i = 0, e = JT.size(); i != e; ++i)
1395 NumEntries += JT[i].MBBs.size();
1397 unsigned EntrySize = MJTI->getEntrySize();
1399 // Just allocate space for all the jump tables now. We will fix up the actual
1400 // MBB entries in the tables after we emit the code for each block, since then
1401 // we will know the final locations of the MBBs in memory.
1403 JumpTableBase = allocateSpace(NumEntries * EntrySize, MJTI->getAlignment());
1406 void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
1407 if (TheJIT->getJITInfo().hasCustomJumpTables())
1410 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1411 if (JT.empty() || JumpTableBase == 0) return;
1413 if (TargetMachine::getRelocationModel() == Reloc::PIC_) {
1414 assert(MJTI->getEntrySize() == 4 && "Cross JIT'ing?");
1415 // For each jump table, place the offset from the beginning of the table
1416 // to the target address.
1417 int *SlotPtr = (int*)JumpTableBase;
1419 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1420 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1421 // Store the offset of the basic block for this jump table slot in the
1422 // memory we allocated for the jump table in 'initJumpTableInfo'
1423 uintptr_t Base = (uintptr_t)SlotPtr;
1424 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) {
1425 uintptr_t MBBAddr = getMachineBasicBlockAddress(MBBs[mi]);
1426 *SlotPtr++ = TheJIT->getJITInfo().getPICJumpTableEntry(MBBAddr, Base);
1430 assert(MJTI->getEntrySize() == sizeof(void*) && "Cross JIT'ing?");
1432 // For each jump table, map each target in the jump table to the address of
1433 // an emitted MachineBasicBlock.
1434 intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
1436 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1437 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1438 // Store the address of the basic block for this jump table slot in the
1439 // memory we allocated for the jump table in 'initJumpTableInfo'
1440 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
1441 *SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
1446 void JITEmitter::startGVStub(const GlobalValue* GV, unsigned StubSize,
1447 unsigned Alignment) {
1448 SavedBufferBegin = BufferBegin;
1449 SavedBufferEnd = BufferEnd;
1450 SavedCurBufferPtr = CurBufferPtr;
1452 BufferBegin = CurBufferPtr = MemMgr->allocateStub(GV, StubSize, Alignment);
1453 BufferEnd = BufferBegin+StubSize+1;
1456 void JITEmitter::startGVStub(const GlobalValue* GV, void *Buffer,
1457 unsigned StubSize) {
1458 SavedBufferBegin = BufferBegin;
1459 SavedBufferEnd = BufferEnd;
1460 SavedCurBufferPtr = CurBufferPtr;
1462 BufferBegin = CurBufferPtr = (uint8_t *)Buffer;
1463 BufferEnd = BufferBegin+StubSize+1;
1466 void *JITEmitter::finishGVStub(const GlobalValue* GV) {
1467 NumBytes += getCurrentPCOffset();
1468 std::swap(SavedBufferBegin, BufferBegin);
1469 BufferEnd = SavedBufferEnd;
1470 CurBufferPtr = SavedCurBufferPtr;
1471 return SavedBufferBegin;
1474 // getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
1475 // in the constant pool that was last emitted with the 'emitConstantPool'
1478 uintptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const {
1479 assert(ConstantNum < ConstantPool->getConstants().size() &&
1480 "Invalid ConstantPoolIndex!");
1481 return ConstPoolAddresses[ConstantNum];
1484 // getJumpTableEntryAddress - Return the address of the JumpTable with index
1485 // 'Index' in the jumpp table that was last initialized with 'initJumpTableInfo'
1487 uintptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
1488 const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
1489 assert(Index < JT.size() && "Invalid jump table index!");
1491 unsigned Offset = 0;
1492 unsigned EntrySize = JumpTable->getEntrySize();
1494 for (unsigned i = 0; i < Index; ++i)
1495 Offset += JT[i].MBBs.size();
1497 Offset *= EntrySize;
1499 return (uintptr_t)((char *)JumpTableBase + Offset);
1502 void JITEmitter::EmittedFunctionConfig::onDelete(
1503 JITEmitter *Emitter, const Function *F) {
1504 Emitter->deallocateMemForFunction(F);
1506 void JITEmitter::EmittedFunctionConfig::onRAUW(
1507 JITEmitter *, const Function*, const Function*) {
1508 llvm_unreachable("The JIT doesn't know how to handle a"
1509 " RAUW on a value it has emitted.");
1513 //===----------------------------------------------------------------------===//
1514 // Public interface to this file
1515 //===----------------------------------------------------------------------===//
1517 JITCodeEmitter *JIT::createEmitter(JIT &jit, JITMemoryManager *JMM,
1518 TargetMachine &tm) {
1519 return new JITEmitter(jit, JMM, tm);
1522 // getPointerToNamedFunction - This function is used as a global wrapper to
1523 // JIT::getPointerToNamedFunction for the purpose of resolving symbols when
1524 // bugpoint is debugging the JIT. In that scenario, we are loading an .so and
1525 // need to resolve function(s) that are being mis-codegenerated, so we need to
1526 // resolve their addresses at runtime, and this is the way to do it.
1528 void *getPointerToNamedFunction(const char *Name) {
1529 if (Function *F = TheJIT->FindFunctionNamed(Name))
1530 return TheJIT->getPointerToFunction(F);
1531 return TheJIT->getPointerToNamedFunction(Name);
1535 // getPointerToFunctionOrStub - If the specified function has been
1536 // code-gen'd, return a pointer to the function. If not, compile it, or use
1537 // a stub to implement lazy compilation if available.
1539 void *JIT::getPointerToFunctionOrStub(Function *F) {
1540 // If we have already code generated the function, just return the address.
1541 if (void *Addr = getPointerToGlobalIfAvailable(F))
1544 // Get a stub if the target supports it.
1545 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1546 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1547 return JE->getJITResolver().getFunctionStub(F);
1550 void JIT::updateFunctionStub(Function *F) {
1551 // Get the empty stub we generated earlier.
1552 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1553 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1554 void *Stub = JE->getJITResolver().getFunctionStub(F);
1556 // Tell the target jit info to rewrite the stub at the specified address,
1557 // rather than creating a new one.
1558 void *Addr = getPointerToGlobalIfAvailable(F);
1559 getJITInfo().emitFunctionStubAtAddr(F, Addr, Stub, *getCodeEmitter());
1562 /// freeMachineCodeForFunction - release machine code memory for given Function.
1564 void JIT::freeMachineCodeForFunction(Function *F) {
1565 // Delete translation for this from the ExecutionEngine, so it will get
1566 // retranslated next time it is used.
1567 updateGlobalMapping(F, 0);
1569 // Free the actual memory for the function body and related stuff.
1570 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1571 cast<JITEmitter>(JCE)->deallocateMemForFunction(F);