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 // A declaration may stop being a declaration once it's fully read from bitcode.
63 // This function returns true if F is fully read and is still a declaration.
64 static bool isNonGhostDeclaration(const Function *F) {
65 return F->isDeclaration() && !F->hasNotBeenReadFromBitcode();
68 //===----------------------------------------------------------------------===//
69 // JIT lazy compilation code.
73 class JITResolverState;
75 template<typename ValueTy>
76 struct NoRAUWValueMapConfig : public ValueMapConfig<ValueTy> {
77 typedef JITResolverState *ExtraData;
78 static void onRAUW(JITResolverState *, Value *Old, Value *New) {
79 assert(false && "The JIT doesn't know how to handle a"
80 " RAUW on a value it has emitted.");
84 struct CallSiteValueMapConfig : public NoRAUWValueMapConfig<Function*> {
85 typedef JITResolverState *ExtraData;
86 static void onDelete(JITResolverState *JRS, Function *F);
89 class JITResolverState {
91 typedef ValueMap<Function*, void*, NoRAUWValueMapConfig<Function*> >
92 FunctionToLazyStubMapTy;
93 typedef std::map<void*, AssertingVH<Function> > CallSiteToFunctionMapTy;
94 typedef ValueMap<Function *, SmallPtrSet<void*, 1>,
95 CallSiteValueMapConfig> FunctionToCallSitesMapTy;
96 typedef std::map<AssertingVH<GlobalValue>, void*> GlobalToIndirectSymMapTy;
98 /// FunctionToLazyStubMap - Keep track of the lazy stub created for a
99 /// particular function so that we can reuse them if necessary.
100 FunctionToLazyStubMapTy FunctionToLazyStubMap;
102 /// CallSiteToFunctionMap - Keep track of the function that each lazy call
103 /// site corresponds to, and vice versa.
104 CallSiteToFunctionMapTy CallSiteToFunctionMap;
105 FunctionToCallSitesMapTy FunctionToCallSitesMap;
107 /// GlobalToIndirectSymMap - Keep track of the indirect symbol created for a
108 /// particular GlobalVariable so that we can reuse them if necessary.
109 GlobalToIndirectSymMapTy GlobalToIndirectSymMap;
112 JITResolverState() : FunctionToLazyStubMap(this),
113 FunctionToCallSitesMap(this) {}
115 FunctionToLazyStubMapTy& getFunctionToLazyStubMap(
116 const MutexGuard& locked) {
117 assert(locked.holds(TheJIT->lock));
118 return FunctionToLazyStubMap;
121 GlobalToIndirectSymMapTy& getGlobalToIndirectSymMap(const MutexGuard& locked) {
122 assert(locked.holds(TheJIT->lock));
123 return GlobalToIndirectSymMap;
126 pair<void *, Function *> LookupFunctionFromCallSite(
127 const MutexGuard &locked, void *CallSite) const {
128 assert(locked.holds(TheJIT->lock));
130 // The address given to us for the stub may not be exactly right, it might be
131 // a little bit after the stub. As such, use upper_bound to find it.
132 CallSiteToFunctionMapTy::const_iterator I =
133 CallSiteToFunctionMap.upper_bound(CallSite);
134 assert(I != CallSiteToFunctionMap.begin() &&
135 "This is not a known call site!");
140 void AddCallSite(const MutexGuard &locked, void *CallSite, Function *F) {
141 assert(locked.holds(TheJIT->lock));
143 bool Inserted = CallSiteToFunctionMap.insert(
144 std::make_pair(CallSite, F)).second;
146 assert(Inserted && "Pair was already in CallSiteToFunctionMap");
147 FunctionToCallSitesMap[F].insert(CallSite);
150 // Returns the Function of the stub if a stub was erased, or NULL if there
151 // was no stub. This function uses the call-site->function map to find a
152 // relevant function, but asserts that only stubs and not other call sites
153 // will be passed in.
154 Function *EraseStub(const MutexGuard &locked, void *Stub) {
155 CallSiteToFunctionMapTy::iterator C2F_I =
156 CallSiteToFunctionMap.find(Stub);
157 if (C2F_I == CallSiteToFunctionMap.end()) {
162 Function *const F = C2F_I->second;
164 void *RealStub = FunctionToLazyStubMap.lookup(F);
165 assert(RealStub == Stub &&
166 "Call-site that wasn't a stub pass in to EraseStub");
168 FunctionToLazyStubMap.erase(F);
169 CallSiteToFunctionMap.erase(C2F_I);
171 // Remove the stub from the function->call-sites map, and remove the whole
172 // entry from the map if that was the last call site.
173 FunctionToCallSitesMapTy::iterator F2C_I = FunctionToCallSitesMap.find(F);
174 assert(F2C_I != FunctionToCallSitesMap.end() &&
175 "FunctionToCallSitesMap broken");
176 bool Erased = F2C_I->second.erase(Stub);
178 assert(Erased && "FunctionToCallSitesMap broken");
179 if (F2C_I->second.empty())
180 FunctionToCallSitesMap.erase(F2C_I);
185 void EraseAllCallSites(const MutexGuard &locked, Function *F) {
186 assert(locked.holds(TheJIT->lock));
187 EraseAllCallSitesPrelocked(F);
189 void EraseAllCallSitesPrelocked(Function *F) {
190 FunctionToCallSitesMapTy::iterator F2C = FunctionToCallSitesMap.find(F);
191 if (F2C == FunctionToCallSitesMap.end())
193 for (SmallPtrSet<void*, 1>::const_iterator I = F2C->second.begin(),
194 E = F2C->second.end(); I != E; ++I) {
195 bool Erased = CallSiteToFunctionMap.erase(*I);
197 assert(Erased && "Missing call site->function mapping");
199 FunctionToCallSitesMap.erase(F2C);
203 /// JITResolver - Keep track of, and resolve, call sites for functions that
204 /// have not yet been compiled.
206 typedef JITResolverState::FunctionToLazyStubMapTy FunctionToLazyStubMapTy;
207 typedef JITResolverState::CallSiteToFunctionMapTy CallSiteToFunctionMapTy;
208 typedef JITResolverState::GlobalToIndirectSymMapTy GlobalToIndirectSymMapTy;
210 /// LazyResolverFn - The target lazy resolver function that we actually
211 /// rewrite instructions to use.
212 TargetJITInfo::LazyResolverFn LazyResolverFn;
214 JITResolverState state;
216 /// ExternalFnToStubMap - This is the equivalent of FunctionToLazyStubMap
217 /// for external functions. TODO: Of course, external functions don't need
218 /// a lazy stub. It's actually here to make it more likely that far calls
219 /// succeed, but no single stub can guarantee that. I'll remove this in a
220 /// subsequent checkin when I actually fix far calls.
221 std::map<void*, void*> ExternalFnToStubMap;
223 /// revGOTMap - map addresses to indexes in the GOT
224 std::map<void*, unsigned> revGOTMap;
225 unsigned nextGOTIndex;
229 static JITResolver *TheJITResolver;
231 explicit JITResolver(JIT &jit, JITEmitter &je) : nextGOTIndex(0), JE(je) {
234 LazyResolverFn = jit.getJITInfo().getLazyResolverFunction(JITCompilerFn);
235 assert(TheJITResolver == 0 && "Multiple JIT resolvers?");
236 TheJITResolver = this;
243 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function's
244 /// lazy-compilation stub if it has already been created.
245 void *getLazyFunctionStubIfAvailable(Function *F);
247 /// getLazyFunctionStub - This returns a pointer to a function's
248 /// lazy-compilation stub, creating one on demand as needed.
249 void *getLazyFunctionStub(Function *F);
251 /// getExternalFunctionStub - Return a stub for the function at the
252 /// specified address, created lazily on demand.
253 void *getExternalFunctionStub(void *FnAddr);
255 /// getGlobalValueIndirectSym - Return an indirect symbol containing the
256 /// specified GV address.
257 void *getGlobalValueIndirectSym(GlobalValue *V, void *GVAddress);
259 void getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
260 SmallVectorImpl<void*> &Ptrs);
262 GlobalValue *invalidateStub(void *Stub);
264 /// getGOTIndexForAddress - Return a new or existing index in the GOT for
265 /// an address. This function only manages slots, it does not manage the
266 /// contents of the slots or the memory associated with the GOT.
267 unsigned getGOTIndexForAddr(void *addr);
269 /// JITCompilerFn - This function is called to resolve a stub to a compiled
270 /// address. If the LLVM Function corresponding to the stub has not yet
271 /// been compiled, this function compiles it first.
272 static void *JITCompilerFn(void *Stub);
275 /// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is
276 /// used to output functions to memory for execution.
277 class JITEmitter : public JITCodeEmitter {
278 JITMemoryManager *MemMgr;
280 // When outputting a function stub in the context of some other function, we
281 // save BufferBegin/BufferEnd/CurBufferPtr here.
282 uint8_t *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr;
284 // When reattempting to JIT a function after running out of space, we store
285 // the estimated size of the function we're trying to JIT here, so we can
286 // ask the memory manager for at least this much space. When we
287 // successfully emit the function, we reset this back to zero.
288 uintptr_t SizeEstimate;
290 /// Relocations - These are the relocations that the function needs, as
292 std::vector<MachineRelocation> Relocations;
294 /// MBBLocations - This vector is a mapping from MBB ID's to their address.
295 /// It is filled in by the StartMachineBasicBlock callback and queried by
296 /// the getMachineBasicBlockAddress callback.
297 std::vector<uintptr_t> MBBLocations;
299 /// ConstantPool - The constant pool for the current function.
301 MachineConstantPool *ConstantPool;
303 /// ConstantPoolBase - A pointer to the first entry in the constant pool.
305 void *ConstantPoolBase;
307 /// ConstPoolAddresses - Addresses of individual constant pool entries.
309 SmallVector<uintptr_t, 8> ConstPoolAddresses;
311 /// JumpTable - The jump tables for the current function.
313 MachineJumpTableInfo *JumpTable;
315 /// JumpTableBase - A pointer to the first entry in the jump table.
319 /// Resolver - This contains info about the currently resolved functions.
320 JITResolver Resolver;
322 /// DE - The dwarf emitter for the jit.
323 OwningPtr<JITDwarfEmitter> DE;
325 /// DR - The debug registerer for the jit.
326 OwningPtr<JITDebugRegisterer> DR;
328 /// LabelLocations - This vector is a mapping from Label ID's to their
330 std::vector<uintptr_t> LabelLocations;
332 /// MMI - Machine module info for exception informations
333 MachineModuleInfo* MMI;
335 // GVSet - a set to keep track of which globals have been seen
336 SmallPtrSet<const GlobalVariable*, 8> GVSet;
338 // CurFn - The llvm function being emitted. Only valid during
340 const Function *CurFn;
342 /// Information about emitted code, which is passed to the
343 /// JITEventListeners. This is reset in startFunction and used in
345 JITEvent_EmittedFunctionDetails EmissionDetails;
348 void *FunctionBody; // Beginning of the function's allocation.
349 void *Code; // The address the function's code actually starts at.
350 void *ExceptionTable;
351 EmittedCode() : FunctionBody(0), Code(0), ExceptionTable(0) {}
353 struct EmittedFunctionConfig : public ValueMapConfig<const Function*> {
354 typedef JITEmitter *ExtraData;
355 static void onDelete(JITEmitter *, const Function*);
356 static void onRAUW(JITEmitter *, const Function*, const Function*);
358 ValueMap<const Function *, EmittedCode,
359 EmittedFunctionConfig> EmittedFunctions;
361 // CurFnStubUses - For a given Function, a vector of stubs that it
362 // references. This facilitates the JIT detecting that a stub is no
363 // longer used, so that it may be deallocated.
364 DenseMap<AssertingVH<const Function>, SmallVector<void*, 1> > CurFnStubUses;
366 // StubFnRefs - For a given pointer to a stub, a set of Functions which
367 // reference the stub. When the count of a stub's references drops to zero,
368 // the stub is unused.
369 DenseMap<void *, SmallPtrSet<const Function*, 1> > StubFnRefs;
374 JITEmitter(JIT &jit, JITMemoryManager *JMM, TargetMachine &TM)
375 : SizeEstimate(0), Resolver(jit, *this), MMI(0), CurFn(0),
376 EmittedFunctions(this), PrevDLT(NULL) {
377 MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager();
378 if (jit.getJITInfo().needsGOT()) {
379 MemMgr->AllocateGOT();
380 DEBUG(dbgs() << "JIT is managing a GOT\n");
383 if (DwarfExceptionHandling || JITEmitDebugInfo) {
384 DE.reset(new JITDwarfEmitter(jit));
386 if (JITEmitDebugInfo) {
387 DR.reset(new JITDebugRegisterer(TM));
394 /// classof - Methods for support type inquiry through isa, cast, and
397 static inline bool classof(const JITEmitter*) { return true; }
398 static inline bool classof(const MachineCodeEmitter*) { return true; }
400 JITResolver &getJITResolver() { return Resolver; }
402 virtual void startFunction(MachineFunction &F);
403 virtual bool finishFunction(MachineFunction &F);
405 void emitConstantPool(MachineConstantPool *MCP);
406 void initJumpTableInfo(MachineJumpTableInfo *MJTI);
407 void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
409 void startGVStub(const GlobalValue* GV,
410 unsigned StubSize, unsigned Alignment = 1);
411 void startGVStub(void *Buffer, unsigned StubSize);
413 virtual void *allocIndirectGV(const GlobalValue *GV,
414 const uint8_t *Buffer, size_t Size,
417 /// allocateSpace - Reserves space in the current block if any, or
418 /// allocate a new one of the given size.
419 virtual void *allocateSpace(uintptr_t Size, unsigned Alignment);
421 /// allocateGlobal - Allocate memory for a global. Unlike allocateSpace,
422 /// this method does not allocate memory in the current output buffer,
423 /// because a global may live longer than the current function.
424 virtual void *allocateGlobal(uintptr_t Size, unsigned Alignment);
426 virtual void addRelocation(const MachineRelocation &MR) {
427 Relocations.push_back(MR);
430 virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
431 if (MBBLocations.size() <= (unsigned)MBB->getNumber())
432 MBBLocations.resize((MBB->getNumber()+1)*2);
433 MBBLocations[MBB->getNumber()] = getCurrentPCValue();
434 DEBUG(dbgs() << "JIT: Emitting BB" << MBB->getNumber() << " at ["
435 << (void*) getCurrentPCValue() << "]\n");
438 virtual uintptr_t getConstantPoolEntryAddress(unsigned Entry) const;
439 virtual uintptr_t getJumpTableEntryAddress(unsigned Entry) const;
441 virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
442 assert(MBBLocations.size() > (unsigned)MBB->getNumber() &&
443 MBBLocations[MBB->getNumber()] && "MBB not emitted!");
444 return MBBLocations[MBB->getNumber()];
447 /// retryWithMoreMemory - Log a retry and deallocate all memory for the
448 /// given function. Increase the minimum allocation size so that we get
449 /// more memory next time.
450 void retryWithMoreMemory(MachineFunction &F);
452 /// deallocateMemForFunction - Deallocate all memory for the specified
454 void deallocateMemForFunction(const Function *F);
456 /// AddStubToCurrentFunction - Mark the current function being JIT'd as
457 /// using the stub at the specified address. Allows
458 /// deallocateMemForFunction to also remove stubs no longer referenced.
459 void AddStubToCurrentFunction(void *Stub);
461 virtual void processDebugLoc(DebugLoc DL, bool BeforePrintingInsn);
463 virtual void emitLabel(uint64_t LabelID) {
464 if (LabelLocations.size() <= LabelID)
465 LabelLocations.resize((LabelID+1)*2);
466 LabelLocations[LabelID] = getCurrentPCValue();
469 virtual uintptr_t getLabelAddress(uint64_t LabelID) const {
470 assert(LabelLocations.size() > (unsigned)LabelID &&
471 LabelLocations[LabelID] && "Label not emitted!");
472 return LabelLocations[LabelID];
475 virtual void setModuleInfo(MachineModuleInfo* Info) {
477 if (DE.get()) DE->setModuleInfo(Info);
480 void setMemoryExecutable() {
481 MemMgr->setMemoryExecutable();
484 JITMemoryManager *getMemMgr() const { return MemMgr; }
487 void *getPointerToGlobal(GlobalValue *GV, void *Reference,
488 bool MayNeedFarStub);
489 void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference);
490 unsigned addSizeOfGlobal(const GlobalVariable *GV, unsigned Size);
491 unsigned addSizeOfGlobalsInConstantVal(const Constant *C, unsigned Size);
492 unsigned addSizeOfGlobalsInInitializer(const Constant *Init, unsigned Size);
493 unsigned GetSizeOfGlobalsInBytes(MachineFunction &MF);
497 JITResolver *JITResolver::TheJITResolver = 0;
499 void CallSiteValueMapConfig::onDelete(JITResolverState *JRS, Function *F) {
500 JRS->EraseAllCallSitesPrelocked(F);
503 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function stub
504 /// if it has already been created.
505 void *JITResolver::getLazyFunctionStubIfAvailable(Function *F) {
506 MutexGuard locked(TheJIT->lock);
508 // If we already have a stub for this function, recycle it.
509 return state.getFunctionToLazyStubMap(locked).lookup(F);
512 /// getFunctionStub - This returns a pointer to a function stub, creating
513 /// one on demand as needed.
514 void *JITResolver::getLazyFunctionStub(Function *F) {
515 MutexGuard locked(TheJIT->lock);
517 // If we already have a lazy stub for this function, recycle it.
518 void *&Stub = state.getFunctionToLazyStubMap(locked)[F];
519 if (Stub) return Stub;
521 // Call the lazy resolver function if we are JIT'ing lazily. Otherwise we
522 // must resolve the symbol now.
523 void *Actual = TheJIT->isCompilingLazily()
524 ? (void *)(intptr_t)LazyResolverFn : (void *)0;
526 // If this is an external declaration, attempt to resolve the address now
527 // to place in the stub.
528 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage()) {
529 Actual = TheJIT->getPointerToFunction(F);
531 // If we resolved the symbol to a null address (eg. a weak external)
532 // don't emit a stub. Return a null pointer to the application.
533 if (!Actual) return 0;
536 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
537 JE.startGVStub(F, SL.Size, SL.Alignment);
538 // Codegen a new stub, calling the lazy resolver or the actual address of the
539 // external function, if it was resolved.
540 Stub = TheJIT->getJITInfo().emitFunctionStub(F, Actual, JE);
543 if (Actual != (void*)(intptr_t)LazyResolverFn) {
544 // If we are getting the stub for an external function, we really want the
545 // address of the stub in the GlobalAddressMap for the JIT, not the address
546 // of the external function.
547 TheJIT->updateGlobalMapping(F, Stub);
550 DEBUG(dbgs() << "JIT: Lazy stub emitted at [" << Stub << "] for function '"
551 << F->getName() << "'\n");
553 // Finally, keep track of the stub-to-Function mapping so that the
554 // JITCompilerFn knows which function to compile!
555 state.AddCallSite(locked, Stub, F);
557 // If we are JIT'ing non-lazily but need to call a function that does not
558 // exist yet, add it to the JIT's work list so that we can fill in the stub
560 if (!Actual && !TheJIT->isCompilingLazily())
561 if (!isNonGhostDeclaration(F) && !F->hasAvailableExternallyLinkage())
562 TheJIT->addPendingFunction(F);
567 /// getGlobalValueIndirectSym - Return a lazy pointer containing the specified
569 void *JITResolver::getGlobalValueIndirectSym(GlobalValue *GV, void *GVAddress) {
570 MutexGuard locked(TheJIT->lock);
572 // If we already have a stub for this global variable, recycle it.
573 void *&IndirectSym = state.getGlobalToIndirectSymMap(locked)[GV];
574 if (IndirectSym) return IndirectSym;
576 // Otherwise, codegen a new indirect symbol.
577 IndirectSym = TheJIT->getJITInfo().emitGlobalValueIndirectSym(GV, GVAddress,
580 DEBUG(dbgs() << "JIT: Indirect symbol emitted at [" << IndirectSym
581 << "] for GV '" << GV->getName() << "'\n");
586 /// getExternalFunctionStub - Return a stub for the function at the
587 /// specified address, created lazily on demand.
588 void *JITResolver::getExternalFunctionStub(void *FnAddr) {
589 // If we already have a stub for this function, recycle it.
590 void *&Stub = ExternalFnToStubMap[FnAddr];
591 if (Stub) return Stub;
593 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout();
594 JE.startGVStub(0, SL.Size, SL.Alignment);
595 Stub = TheJIT->getJITInfo().emitFunctionStub(0, FnAddr, JE);
598 DEBUG(dbgs() << "JIT: Stub emitted at [" << Stub
599 << "] for external function at '" << FnAddr << "'\n");
603 unsigned JITResolver::getGOTIndexForAddr(void* addr) {
604 unsigned idx = revGOTMap[addr];
606 idx = ++nextGOTIndex;
607 revGOTMap[addr] = idx;
608 DEBUG(dbgs() << "JIT: Adding GOT entry " << idx << " for addr ["
614 void JITResolver::getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
615 SmallVectorImpl<void*> &Ptrs) {
616 MutexGuard locked(TheJIT->lock);
618 const FunctionToLazyStubMapTy &FM = state.getFunctionToLazyStubMap(locked);
619 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
621 for (FunctionToLazyStubMapTy::const_iterator i = FM.begin(), e = FM.end();
623 Function *F = i->first;
624 if (F->isDeclaration() && F->hasExternalLinkage()) {
625 GVs.push_back(i->first);
626 Ptrs.push_back(i->second);
629 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
631 GVs.push_back(i->first);
632 Ptrs.push_back(i->second);
636 GlobalValue *JITResolver::invalidateStub(void *Stub) {
637 MutexGuard locked(TheJIT->lock);
639 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
641 // Look up the cheap way first, to see if it's a function stub we are
642 // invalidating. If so, remove it from both the forward and reverse maps.
643 if (Function *F = state.EraseStub(locked, Stub)) {
647 // Otherwise, it might be an indirect symbol stub. Find it and remove it.
648 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
650 if (i->second != Stub)
652 GlobalValue *GV = i->first;
657 // Lastly, check to see if it's in the ExternalFnToStubMap.
658 for (std::map<void *, void *>::iterator i = ExternalFnToStubMap.begin(),
659 e = ExternalFnToStubMap.end(); i != e; ++i) {
660 if (i->second != Stub)
662 ExternalFnToStubMap.erase(i);
669 /// JITCompilerFn - This function is called when a lazy compilation stub has
670 /// been entered. It looks up which function this stub corresponds to, compiles
671 /// it if necessary, then returns the resultant function pointer.
672 void *JITResolver::JITCompilerFn(void *Stub) {
673 JITResolver &JR = *TheJITResolver;
679 // Only lock for getting the Function. The call getPointerToFunction made
680 // in this function might trigger function materializing, which requires
681 // JIT lock to be unlocked.
682 MutexGuard locked(TheJIT->lock);
684 // The address given to us for the stub may not be exactly right, it might
685 // be a little bit after the stub. As such, use upper_bound to find it.
686 pair<void*, Function*> I =
687 JR.state.LookupFunctionFromCallSite(locked, Stub);
692 // If we have already code generated the function, just return the address.
693 void *Result = TheJIT->getPointerToGlobalIfAvailable(F);
696 // Otherwise we don't have it, do lazy compilation now.
698 // If lazy compilation is disabled, emit a useful error message and abort.
699 if (!TheJIT->isCompilingLazily()) {
700 llvm_report_error("LLVM JIT requested to do lazy compilation of function '"
701 + F->getName() + "' when lazy compiles are disabled!");
704 DEBUG(dbgs() << "JIT: Lazily resolving function '" << F->getName()
705 << "' In stub ptr = " << Stub << " actual ptr = "
706 << ActualPtr << "\n");
708 Result = TheJIT->getPointerToFunction(F);
711 // Reacquire the lock to update the GOT map.
712 MutexGuard locked(TheJIT->lock);
714 // We might like to remove the call site from the CallSiteToFunction map, but
715 // we can't do that! Multiple threads could be stuck, waiting to acquire the
716 // lock above. As soon as the 1st function finishes compiling the function,
717 // the next one will be released, and needs to be able to find the function it
720 // FIXME: We could rewrite all references to this stub if we knew them.
722 // What we will do is set the compiled function address to map to the
723 // same GOT entry as the stub so that later clients may update the GOT
724 // if they see it still using the stub address.
725 // Note: this is done so the Resolver doesn't have to manage GOT memory
726 // Do this without allocating map space if the target isn't using a GOT
727 if(JR.revGOTMap.find(Stub) != JR.revGOTMap.end())
728 JR.revGOTMap[Result] = JR.revGOTMap[Stub];
733 //===----------------------------------------------------------------------===//
736 void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
737 bool MayNeedFarStub) {
738 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
739 return TheJIT->getOrEmitGlobalVariable(GV);
741 if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
742 return TheJIT->getPointerToGlobal(GA->resolveAliasedGlobal(false));
744 // If we have already compiled the function, return a pointer to its body.
745 Function *F = cast<Function>(V);
747 void *FnStub = Resolver.getLazyFunctionStubIfAvailable(F);
749 // Return the function stub if it's already created. We do this first so
750 // that we're returning the same address for the function as any previous
751 // call. TODO: Yes, this is wrong. The lazy stub isn't guaranteed to be
752 // close enough to call.
753 AddStubToCurrentFunction(FnStub);
757 // If we know the target can handle arbitrary-distance calls, try to
758 // return a direct pointer.
759 if (!MayNeedFarStub) {
760 // If we have code, go ahead and return that.
761 void *ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
762 if (ResultPtr) return ResultPtr;
764 // If this is an external function pointer, we can force the JIT to
765 // 'compile' it, which really just adds it to the map.
766 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage())
767 return TheJIT->getPointerToFunction(F);
770 // Otherwise, we may need a to emit a stub, and, conservatively, we
772 void *StubAddr = Resolver.getLazyFunctionStub(F);
774 // Add the stub to the current function's list of referenced stubs, so we can
775 // deallocate them if the current function is ever freed. It's possible to
776 // return null from getLazyFunctionStub in the case of a weak extern that
779 AddStubToCurrentFunction(StubAddr);
784 void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) {
785 // Make sure GV is emitted first, and create a stub containing the fully
787 void *GVAddress = getPointerToGlobal(V, Reference, false);
788 void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress);
790 // Add the stub to the current function's list of referenced stubs, so we can
791 // deallocate them if the current function is ever freed.
792 AddStubToCurrentFunction(StubAddr);
797 void JITEmitter::AddStubToCurrentFunction(void *StubAddr) {
798 assert(CurFn && "Stub added to current function, but current function is 0!");
800 SmallVectorImpl<void*> &StubsUsed = CurFnStubUses[CurFn];
801 StubsUsed.push_back(StubAddr);
803 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[StubAddr];
804 FnRefs.insert(CurFn);
807 void JITEmitter::processDebugLoc(DebugLoc DL, bool BeforePrintingInsn) {
808 if (!DL.isUnknown()) {
809 DILocation CurDLT = EmissionDetails.MF->getDILocation(DL);
811 if (BeforePrintingInsn) {
812 if (CurDLT.getScope().getNode() != 0
813 && PrevDLT.getNode() != CurDLT.getNode()) {
814 JITEvent_EmittedFunctionDetails::LineStart NextLine;
815 NextLine.Address = getCurrentPCValue();
817 EmissionDetails.LineStarts.push_back(NextLine);
825 static unsigned GetConstantPoolSizeInBytes(MachineConstantPool *MCP,
826 const TargetData *TD) {
827 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
828 if (Constants.empty()) return 0;
831 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
832 MachineConstantPoolEntry CPE = Constants[i];
833 unsigned AlignMask = CPE.getAlignment() - 1;
834 Size = (Size + AlignMask) & ~AlignMask;
835 const Type *Ty = CPE.getType();
836 Size += TD->getTypeAllocSize(Ty);
841 static unsigned GetJumpTableSizeInBytes(MachineJumpTableInfo *MJTI) {
842 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
843 if (JT.empty()) return 0;
845 unsigned NumEntries = 0;
846 for (unsigned i = 0, e = JT.size(); i != e; ++i)
847 NumEntries += JT[i].MBBs.size();
849 unsigned EntrySize = MJTI->getEntrySize();
851 return NumEntries * EntrySize;
854 static uintptr_t RoundUpToAlign(uintptr_t Size, unsigned Alignment) {
855 if (Alignment == 0) Alignment = 1;
856 // Since we do not know where the buffer will be allocated, be pessimistic.
857 return Size + Alignment;
860 /// addSizeOfGlobal - add the size of the global (plus any alignment padding)
861 /// into the running total Size.
863 unsigned JITEmitter::addSizeOfGlobal(const GlobalVariable *GV, unsigned Size) {
864 const Type *ElTy = GV->getType()->getElementType();
865 size_t GVSize = (size_t)TheJIT->getTargetData()->getTypeAllocSize(ElTy);
867 (size_t)TheJIT->getTargetData()->getPreferredAlignment(GV);
868 DEBUG(dbgs() << "JIT: Adding in size " << GVSize << " alignment " << GVAlign);
870 // Assume code section ends with worst possible alignment, so first
871 // variable needs maximal padding.
874 Size = ((Size+GVAlign-1)/GVAlign)*GVAlign;
879 /// addSizeOfGlobalsInConstantVal - find any globals that we haven't seen yet
880 /// but are referenced from the constant; put them in GVSet and add their
881 /// size into the running total Size.
883 unsigned JITEmitter::addSizeOfGlobalsInConstantVal(const Constant *C,
885 // If its undefined, return the garbage.
886 if (isa<UndefValue>(C))
889 // If the value is a ConstantExpr
890 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
891 Constant *Op0 = CE->getOperand(0);
892 switch (CE->getOpcode()) {
893 case Instruction::GetElementPtr:
894 case Instruction::Trunc:
895 case Instruction::ZExt:
896 case Instruction::SExt:
897 case Instruction::FPTrunc:
898 case Instruction::FPExt:
899 case Instruction::UIToFP:
900 case Instruction::SIToFP:
901 case Instruction::FPToUI:
902 case Instruction::FPToSI:
903 case Instruction::PtrToInt:
904 case Instruction::IntToPtr:
905 case Instruction::BitCast: {
906 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
909 case Instruction::Add:
910 case Instruction::FAdd:
911 case Instruction::Sub:
912 case Instruction::FSub:
913 case Instruction::Mul:
914 case Instruction::FMul:
915 case Instruction::UDiv:
916 case Instruction::SDiv:
917 case Instruction::URem:
918 case Instruction::SRem:
919 case Instruction::And:
920 case Instruction::Or:
921 case Instruction::Xor: {
922 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
923 Size = addSizeOfGlobalsInConstantVal(CE->getOperand(1), Size);
928 raw_string_ostream Msg(msg);
929 Msg << "ConstantExpr not handled: " << *CE;
930 llvm_report_error(Msg.str());
935 if (C->getType()->getTypeID() == Type::PointerTyID)
936 if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C))
937 if (GVSet.insert(GV))
938 Size = addSizeOfGlobal(GV, Size);
943 /// addSizeOfGLobalsInInitializer - handle any globals that we haven't seen yet
944 /// but are referenced from the given initializer.
946 unsigned JITEmitter::addSizeOfGlobalsInInitializer(const Constant *Init,
948 if (!isa<UndefValue>(Init) &&
949 !isa<ConstantVector>(Init) &&
950 !isa<ConstantAggregateZero>(Init) &&
951 !isa<ConstantArray>(Init) &&
952 !isa<ConstantStruct>(Init) &&
953 Init->getType()->isFirstClassType())
954 Size = addSizeOfGlobalsInConstantVal(Init, Size);
958 /// GetSizeOfGlobalsInBytes - walk the code for the function, looking for
959 /// globals; then walk the initializers of those globals looking for more.
960 /// If their size has not been considered yet, add it into the running total
963 unsigned JITEmitter::GetSizeOfGlobalsInBytes(MachineFunction &MF) {
967 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
969 for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
971 const TargetInstrDesc &Desc = I->getDesc();
972 const MachineInstr &MI = *I;
973 unsigned NumOps = Desc.getNumOperands();
974 for (unsigned CurOp = 0; CurOp < NumOps; CurOp++) {
975 const MachineOperand &MO = MI.getOperand(CurOp);
977 GlobalValue* V = MO.getGlobal();
978 const GlobalVariable *GV = dyn_cast<const GlobalVariable>(V);
981 // If seen in previous function, it will have an entry here.
982 if (TheJIT->getPointerToGlobalIfAvailable(GV))
984 // If seen earlier in this function, it will have an entry here.
985 // FIXME: it should be possible to combine these tables, by
986 // assuming the addresses of the new globals in this module
987 // start at 0 (or something) and adjusting them after codegen
988 // complete. Another possibility is to grab a marker bit in GV.
989 if (GVSet.insert(GV))
990 // A variable as yet unseen. Add in its size.
991 Size = addSizeOfGlobal(GV, Size);
996 DEBUG(dbgs() << "JIT: About to look through initializers\n");
997 // Look for more globals that are referenced only from initializers.
998 // GVSet.end is computed each time because the set can grow as we go.
999 for (SmallPtrSet<const GlobalVariable *, 8>::iterator I = GVSet.begin();
1000 I != GVSet.end(); I++) {
1001 const GlobalVariable* GV = *I;
1002 if (GV->hasInitializer())
1003 Size = addSizeOfGlobalsInInitializer(GV->getInitializer(), Size);
1009 void JITEmitter::startFunction(MachineFunction &F) {
1010 DEBUG(dbgs() << "JIT: Starting CodeGen of Function "
1011 << F.getFunction()->getName() << "\n");
1013 uintptr_t ActualSize = 0;
1014 // Set the memory writable, if it's not already
1015 MemMgr->setMemoryWritable();
1016 if (MemMgr->NeedsExactSize()) {
1017 DEBUG(dbgs() << "JIT: ExactSize\n");
1018 const TargetInstrInfo* TII = F.getTarget().getInstrInfo();
1019 MachineJumpTableInfo *MJTI = F.getJumpTableInfo();
1020 MachineConstantPool *MCP = F.getConstantPool();
1022 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1023 ActualSize = RoundUpToAlign(ActualSize, 16);
1025 // Add the alignment of the constant pool
1026 ActualSize = RoundUpToAlign(ActualSize, MCP->getConstantPoolAlignment());
1028 // Add the constant pool size
1029 ActualSize += GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1031 // Add the aligment of the jump table info
1032 ActualSize = RoundUpToAlign(ActualSize, MJTI->getAlignment());
1034 // Add the jump table size
1035 ActualSize += GetJumpTableSizeInBytes(MJTI);
1037 // Add the alignment for the function
1038 ActualSize = RoundUpToAlign(ActualSize,
1039 std::max(F.getFunction()->getAlignment(), 8U));
1041 // Add the function size
1042 ActualSize += TII->GetFunctionSizeInBytes(F);
1044 DEBUG(dbgs() << "JIT: ActualSize before globals " << ActualSize << "\n");
1045 // Add the size of the globals that will be allocated after this function.
1046 // These are all the ones referenced from this function that were not
1047 // previously allocated.
1048 ActualSize += GetSizeOfGlobalsInBytes(F);
1049 DEBUG(dbgs() << "JIT: ActualSize after globals " << ActualSize << "\n");
1050 } else if (SizeEstimate > 0) {
1051 // SizeEstimate will be non-zero on reallocation attempts.
1052 ActualSize = SizeEstimate;
1055 BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(),
1057 BufferEnd = BufferBegin+ActualSize;
1058 EmittedFunctions[F.getFunction()].FunctionBody = BufferBegin;
1060 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1063 emitConstantPool(F.getConstantPool());
1064 initJumpTableInfo(F.getJumpTableInfo());
1066 // About to start emitting the machine code for the function.
1067 emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
1068 TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
1069 EmittedFunctions[F.getFunction()].Code = CurBufferPtr;
1071 MBBLocations.clear();
1073 EmissionDetails.MF = &F;
1074 EmissionDetails.LineStarts.clear();
1077 bool JITEmitter::finishFunction(MachineFunction &F) {
1078 if (CurBufferPtr == BufferEnd) {
1079 // We must call endFunctionBody before retrying, because
1080 // deallocateMemForFunction requires it.
1081 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1082 retryWithMoreMemory(F);
1086 emitJumpTableInfo(F.getJumpTableInfo());
1088 // FnStart is the start of the text, not the start of the constant pool and
1089 // other per-function data.
1091 (uint8_t *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
1093 // FnEnd is the end of the function's machine code.
1094 uint8_t *FnEnd = CurBufferPtr;
1096 if (!Relocations.empty()) {
1097 CurFn = F.getFunction();
1098 NumRelos += Relocations.size();
1100 // Resolve the relocations to concrete pointers.
1101 for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
1102 MachineRelocation &MR = Relocations[i];
1103 void *ResultPtr = 0;
1104 if (!MR.letTargetResolve()) {
1105 if (MR.isExternalSymbol()) {
1106 ResultPtr = TheJIT->getPointerToNamedFunction(MR.getExternalSymbol(),
1108 DEBUG(dbgs() << "JIT: Map \'" << MR.getExternalSymbol() << "\' to ["
1109 << ResultPtr << "]\n");
1111 // If the target REALLY wants a stub for this function, emit it now.
1112 if (MR.mayNeedFarStub()) {
1113 ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
1115 } else if (MR.isGlobalValue()) {
1116 ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
1117 BufferBegin+MR.getMachineCodeOffset(),
1118 MR.mayNeedFarStub());
1119 } else if (MR.isIndirectSymbol()) {
1120 ResultPtr = getPointerToGVIndirectSym(
1121 MR.getGlobalValue(), BufferBegin+MR.getMachineCodeOffset());
1122 } else if (MR.isBasicBlock()) {
1123 ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
1124 } else if (MR.isConstantPoolIndex()) {
1125 ResultPtr = (void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
1127 assert(MR.isJumpTableIndex());
1128 ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
1131 MR.setResultPointer(ResultPtr);
1134 // if we are managing the GOT and the relocation wants an index,
1136 if (MR.isGOTRelative() && MemMgr->isManagingGOT()) {
1137 unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
1138 MR.setGOTIndex(idx);
1139 if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) {
1140 DEBUG(dbgs() << "JIT: GOT was out of date for " << ResultPtr
1141 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1143 ((void**)MemMgr->getGOTBase())[idx] = ResultPtr;
1149 TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
1150 Relocations.size(), MemMgr->getGOTBase());
1153 // Update the GOT entry for F to point to the new code.
1154 if (MemMgr->isManagingGOT()) {
1155 unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
1156 if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) {
1157 DEBUG(dbgs() << "JIT: GOT was out of date for " << (void*)BufferBegin
1158 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1160 ((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin;
1164 // CurBufferPtr may have moved beyond FnEnd, due to memory allocation for
1165 // global variables that were referenced in the relocations.
1166 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1168 if (CurBufferPtr == BufferEnd) {
1169 retryWithMoreMemory(F);
1172 // Now that we've succeeded in emitting the function, reset the
1173 // SizeEstimate back down to zero.
1177 BufferBegin = CurBufferPtr = 0;
1178 NumBytes += FnEnd-FnStart;
1180 // Invalidate the icache if necessary.
1181 sys::Memory::InvalidateInstructionCache(FnStart, FnEnd-FnStart);
1183 TheJIT->NotifyFunctionEmitted(*F.getFunction(), FnStart, FnEnd-FnStart,
1186 DEBUG(dbgs() << "JIT: Finished CodeGen of [" << (void*)FnStart
1187 << "] Function: " << F.getFunction()->getName()
1188 << ": " << (FnEnd-FnStart) << " bytes of text, "
1189 << Relocations.size() << " relocations\n");
1191 Relocations.clear();
1192 ConstPoolAddresses.clear();
1194 // Mark code region readable and executable if it's not so already.
1195 MemMgr->setMemoryExecutable();
1198 if (sys::hasDisassembler()) {
1199 dbgs() << "JIT: Disassembled code:\n";
1200 dbgs() << sys::disassembleBuffer(FnStart, FnEnd-FnStart,
1201 (uintptr_t)FnStart);
1203 dbgs() << "JIT: Binary code:\n";
1204 uint8_t* q = FnStart;
1205 for (int i = 0; q < FnEnd; q += 4, ++i) {
1209 dbgs() << "JIT: " << (long)(q - FnStart) << ": ";
1211 for (int j = 3; j >= 0; --j) {
1215 dbgs() << (unsigned short)q[j];
1227 if (DwarfExceptionHandling || JITEmitDebugInfo) {
1228 uintptr_t ActualSize = 0;
1229 SavedBufferBegin = BufferBegin;
1230 SavedBufferEnd = BufferEnd;
1231 SavedCurBufferPtr = CurBufferPtr;
1233 if (MemMgr->NeedsExactSize()) {
1234 ActualSize = DE->GetDwarfTableSizeInBytes(F, *this, FnStart, FnEnd);
1237 BufferBegin = CurBufferPtr = MemMgr->startExceptionTable(F.getFunction(),
1239 BufferEnd = BufferBegin+ActualSize;
1240 EmittedFunctions[F.getFunction()].ExceptionTable = BufferBegin;
1242 uint8_t *FrameRegister = DE->EmitDwarfTable(F, *this, FnStart, FnEnd,
1244 MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr,
1246 uint8_t *EhEnd = CurBufferPtr;
1247 BufferBegin = SavedBufferBegin;
1248 BufferEnd = SavedBufferEnd;
1249 CurBufferPtr = SavedCurBufferPtr;
1251 if (DwarfExceptionHandling) {
1252 TheJIT->RegisterTable(FrameRegister);
1255 if (JITEmitDebugInfo) {
1257 I.FnStart = FnStart;
1259 I.EhStart = EhStart;
1261 DR->RegisterFunction(F.getFunction(), I);
1271 void JITEmitter::retryWithMoreMemory(MachineFunction &F) {
1272 DEBUG(dbgs() << "JIT: Ran out of space for native code. Reattempting.\n");
1273 Relocations.clear(); // Clear the old relocations or we'll reapply them.
1274 ConstPoolAddresses.clear();
1276 deallocateMemForFunction(F.getFunction());
1277 // Try again with at least twice as much free space.
1278 SizeEstimate = (uintptr_t)(2 * (BufferEnd - BufferBegin));
1281 /// deallocateMemForFunction - Deallocate all memory for the specified
1282 /// function body. Also drop any references the function has to stubs.
1283 /// May be called while the Function is being destroyed inside ~Value().
1284 void JITEmitter::deallocateMemForFunction(const Function *F) {
1285 ValueMap<const Function *, EmittedCode, EmittedFunctionConfig>::iterator
1286 Emitted = EmittedFunctions.find(F);
1287 if (Emitted != EmittedFunctions.end()) {
1288 MemMgr->deallocateFunctionBody(Emitted->second.FunctionBody);
1289 MemMgr->deallocateExceptionTable(Emitted->second.ExceptionTable);
1290 TheJIT->NotifyFreeingMachineCode(Emitted->second.Code);
1292 EmittedFunctions.erase(Emitted);
1295 // TODO: Do we need to unregister exception handling information from libgcc
1298 if (JITEmitDebugInfo) {
1299 DR->UnregisterFunction(F);
1302 // If the function did not reference any stubs, return.
1303 if (CurFnStubUses.find(F) == CurFnStubUses.end())
1306 // For each referenced stub, erase the reference to this function, and then
1307 // erase the list of referenced stubs.
1308 SmallVectorImpl<void *> &StubList = CurFnStubUses[F];
1309 for (unsigned i = 0, e = StubList.size(); i != e; ++i) {
1310 void *Stub = StubList[i];
1312 // If we already invalidated this stub for this function, continue.
1313 if (StubFnRefs.count(Stub) == 0)
1316 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[Stub];
1319 // If this function was the last reference to the stub, invalidate the stub
1320 // in the JITResolver. Were there a memory manager deallocateStub routine,
1321 // we could call that at this point too.
1322 if (FnRefs.empty()) {
1323 DEBUG(dbgs() << "\nJIT: Invalidated Stub at [" << Stub << "]\n");
1324 StubFnRefs.erase(Stub);
1326 // Invalidate the stub. If it is a GV stub, update the JIT's global
1327 // mapping for that GV to zero.
1328 GlobalValue *GV = Resolver.invalidateStub(Stub);
1330 TheJIT->updateGlobalMapping(GV, 0);
1334 CurFnStubUses.erase(F);
1338 void* JITEmitter::allocateSpace(uintptr_t Size, unsigned Alignment) {
1340 return JITCodeEmitter::allocateSpace(Size, Alignment);
1342 // create a new memory block if there is no active one.
1343 // care must be taken so that BufferBegin is invalidated when a
1345 BufferBegin = CurBufferPtr = MemMgr->allocateSpace(Size, Alignment);
1346 BufferEnd = BufferBegin+Size;
1347 return CurBufferPtr;
1350 void* JITEmitter::allocateGlobal(uintptr_t Size, unsigned Alignment) {
1351 // Delegate this call through the memory manager.
1352 return MemMgr->allocateGlobal(Size, Alignment);
1355 void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
1356 if (TheJIT->getJITInfo().hasCustomConstantPool())
1359 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
1360 if (Constants.empty()) return;
1362 unsigned Size = GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1363 unsigned Align = MCP->getConstantPoolAlignment();
1364 ConstantPoolBase = allocateSpace(Size, Align);
1367 if (ConstantPoolBase == 0) return; // Buffer overflow.
1369 DEBUG(dbgs() << "JIT: Emitted constant pool at [" << ConstantPoolBase
1370 << "] (size: " << Size << ", alignment: " << Align << ")\n");
1372 // Initialize the memory for all of the constant pool entries.
1373 unsigned Offset = 0;
1374 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
1375 MachineConstantPoolEntry CPE = Constants[i];
1376 unsigned AlignMask = CPE.getAlignment() - 1;
1377 Offset = (Offset + AlignMask) & ~AlignMask;
1379 uintptr_t CAddr = (uintptr_t)ConstantPoolBase + Offset;
1380 ConstPoolAddresses.push_back(CAddr);
1381 if (CPE.isMachineConstantPoolEntry()) {
1382 // FIXME: add support to lower machine constant pool values into bytes!
1383 llvm_report_error("Initialize memory with machine specific constant pool"
1384 "entry has not been implemented!");
1386 TheJIT->InitializeMemory(CPE.Val.ConstVal, (void*)CAddr);
1387 DEBUG(dbgs() << "JIT: CP" << i << " at [0x";
1388 dbgs().write_hex(CAddr) << "]\n");
1390 const Type *Ty = CPE.Val.ConstVal->getType();
1391 Offset += TheJIT->getTargetData()->getTypeAllocSize(Ty);
1395 void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
1396 if (TheJIT->getJITInfo().hasCustomJumpTables())
1399 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1400 if (JT.empty()) return;
1402 unsigned NumEntries = 0;
1403 for (unsigned i = 0, e = JT.size(); i != e; ++i)
1404 NumEntries += JT[i].MBBs.size();
1406 unsigned EntrySize = MJTI->getEntrySize();
1408 // Just allocate space for all the jump tables now. We will fix up the actual
1409 // MBB entries in the tables after we emit the code for each block, since then
1410 // we will know the final locations of the MBBs in memory.
1412 JumpTableBase = allocateSpace(NumEntries * EntrySize, MJTI->getAlignment());
1415 void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
1416 if (TheJIT->getJITInfo().hasCustomJumpTables())
1419 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1420 if (JT.empty() || JumpTableBase == 0) return;
1422 if (TargetMachine::getRelocationModel() == Reloc::PIC_) {
1423 assert(MJTI->getEntrySize() == 4 && "Cross JIT'ing?");
1424 // For each jump table, place the offset from the beginning of the table
1425 // to the target address.
1426 int *SlotPtr = (int*)JumpTableBase;
1428 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1429 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1430 // Store the offset of the basic block for this jump table slot in the
1431 // memory we allocated for the jump table in 'initJumpTableInfo'
1432 uintptr_t Base = (uintptr_t)SlotPtr;
1433 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) {
1434 uintptr_t MBBAddr = getMachineBasicBlockAddress(MBBs[mi]);
1435 *SlotPtr++ = TheJIT->getJITInfo().getPICJumpTableEntry(MBBAddr, Base);
1439 assert(MJTI->getEntrySize() == sizeof(void*) && "Cross JIT'ing?");
1441 // For each jump table, map each target in the jump table to the address of
1442 // an emitted MachineBasicBlock.
1443 intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
1445 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1446 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1447 // Store the address of the basic block for this jump table slot in the
1448 // memory we allocated for the jump table in 'initJumpTableInfo'
1449 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
1450 *SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
1455 void JITEmitter::startGVStub(const GlobalValue* GV,
1456 unsigned StubSize, unsigned Alignment) {
1457 SavedBufferBegin = BufferBegin;
1458 SavedBufferEnd = BufferEnd;
1459 SavedCurBufferPtr = CurBufferPtr;
1461 BufferBegin = CurBufferPtr = MemMgr->allocateStub(GV, StubSize, Alignment);
1462 BufferEnd = BufferBegin+StubSize+1;
1465 void JITEmitter::startGVStub(void *Buffer, unsigned StubSize) {
1466 SavedBufferBegin = BufferBegin;
1467 SavedBufferEnd = BufferEnd;
1468 SavedCurBufferPtr = CurBufferPtr;
1470 BufferBegin = CurBufferPtr = (uint8_t *)Buffer;
1471 BufferEnd = BufferBegin+StubSize+1;
1474 void JITEmitter::finishGVStub() {
1475 assert(CurBufferPtr != BufferEnd && "Stub overflowed allocated space.");
1476 NumBytes += getCurrentPCOffset();
1477 BufferBegin = SavedBufferBegin;
1478 BufferEnd = SavedBufferEnd;
1479 CurBufferPtr = SavedCurBufferPtr;
1482 void *JITEmitter::allocIndirectGV(const GlobalValue *GV,
1483 const uint8_t *Buffer, size_t Size,
1484 unsigned Alignment) {
1485 uint8_t *IndGV = MemMgr->allocateStub(GV, Size, Alignment);
1486 memcpy(IndGV, Buffer, Size);
1490 // getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
1491 // in the constant pool that was last emitted with the 'emitConstantPool'
1494 uintptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const {
1495 assert(ConstantNum < ConstantPool->getConstants().size() &&
1496 "Invalid ConstantPoolIndex!");
1497 return ConstPoolAddresses[ConstantNum];
1500 // getJumpTableEntryAddress - Return the address of the JumpTable with index
1501 // 'Index' in the jumpp table that was last initialized with 'initJumpTableInfo'
1503 uintptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
1504 const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
1505 assert(Index < JT.size() && "Invalid jump table index!");
1507 unsigned Offset = 0;
1508 unsigned EntrySize = JumpTable->getEntrySize();
1510 for (unsigned i = 0; i < Index; ++i)
1511 Offset += JT[i].MBBs.size();
1513 Offset *= EntrySize;
1515 return (uintptr_t)((char *)JumpTableBase + Offset);
1518 void JITEmitter::EmittedFunctionConfig::onDelete(
1519 JITEmitter *Emitter, const Function *F) {
1520 Emitter->deallocateMemForFunction(F);
1522 void JITEmitter::EmittedFunctionConfig::onRAUW(
1523 JITEmitter *, const Function*, const Function*) {
1524 llvm_unreachable("The JIT doesn't know how to handle a"
1525 " RAUW on a value it has emitted.");
1529 //===----------------------------------------------------------------------===//
1530 // Public interface to this file
1531 //===----------------------------------------------------------------------===//
1533 JITCodeEmitter *JIT::createEmitter(JIT &jit, JITMemoryManager *JMM,
1534 TargetMachine &tm) {
1535 return new JITEmitter(jit, JMM, tm);
1538 // getPointerToNamedFunction - This function is used as a global wrapper to
1539 // JIT::getPointerToNamedFunction for the purpose of resolving symbols when
1540 // bugpoint is debugging the JIT. In that scenario, we are loading an .so and
1541 // need to resolve function(s) that are being mis-codegenerated, so we need to
1542 // resolve their addresses at runtime, and this is the way to do it.
1544 void *getPointerToNamedFunction(const char *Name) {
1545 if (Function *F = TheJIT->FindFunctionNamed(Name))
1546 return TheJIT->getPointerToFunction(F);
1547 return TheJIT->getPointerToNamedFunction(Name);
1551 // getPointerToFunctionOrStub - If the specified function has been
1552 // code-gen'd, return a pointer to the function. If not, compile it, or use
1553 // a stub to implement lazy compilation if available.
1555 void *JIT::getPointerToFunctionOrStub(Function *F) {
1556 // If we have already code generated the function, just return the address.
1557 if (void *Addr = getPointerToGlobalIfAvailable(F))
1560 // Get a stub if the target supports it.
1561 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1562 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1563 return JE->getJITResolver().getLazyFunctionStub(F);
1566 void JIT::updateFunctionStub(Function *F) {
1567 // Get the empty stub we generated earlier.
1568 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1569 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1570 void *Stub = JE->getJITResolver().getLazyFunctionStub(F);
1571 void *Addr = getPointerToGlobalIfAvailable(F);
1572 assert(Addr != Stub && "Function must have non-stub address to be updated.");
1574 // Tell the target jit info to rewrite the stub at the specified address,
1575 // rather than creating a new one.
1576 TargetJITInfo::StubLayout layout = getJITInfo().getStubLayout();
1577 JE->startGVStub(Stub, layout.Size);
1578 getJITInfo().emitFunctionStub(F, Addr, *getCodeEmitter());
1582 /// freeMachineCodeForFunction - release machine code memory for given Function.
1584 void JIT::freeMachineCodeForFunction(Function *F) {
1585 // Delete translation for this from the ExecutionEngine, so it will get
1586 // retranslated next time it is used.
1587 updateGlobalMapping(F, 0);
1589 // Free the actual memory for the function body and related stuff.
1590 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1591 cast<JITEmitter>(JCE)->deallocateMemForFunction(F);