1 //===-- JITEmitter.cpp - Write machine code to executable memory ----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines a MachineCodeEmitter object that is used by the JIT to
11 // write machine code to memory and remember where relocatable values are.
13 //===----------------------------------------------------------------------===//
15 #define DEBUG_TYPE "jit"
17 #include "JITDebugRegisterer.h"
18 #include "JITDwarfEmitter.h"
19 #include "llvm/ADT/OwningPtr.h"
20 #include "llvm/Constants.h"
21 #include "llvm/Module.h"
22 #include "llvm/DerivedTypes.h"
23 #include "llvm/CodeGen/JITCodeEmitter.h"
24 #include "llvm/CodeGen/MachineFunction.h"
25 #include "llvm/CodeGen/MachineConstantPool.h"
26 #include "llvm/CodeGen/MachineJumpTableInfo.h"
27 #include "llvm/CodeGen/MachineModuleInfo.h"
28 #include "llvm/CodeGen/MachineRelocation.h"
29 #include "llvm/ExecutionEngine/GenericValue.h"
30 #include "llvm/ExecutionEngine/JITEventListener.h"
31 #include "llvm/ExecutionEngine/JITMemoryManager.h"
32 #include "llvm/CodeGen/MachineCodeInfo.h"
33 #include "llvm/Target/TargetData.h"
34 #include "llvm/Target/TargetJITInfo.h"
35 #include "llvm/Target/TargetMachine.h"
36 #include "llvm/Target/TargetOptions.h"
37 #include "llvm/Support/Debug.h"
38 #include "llvm/Support/ErrorHandling.h"
39 #include "llvm/Support/MutexGuard.h"
40 #include "llvm/Support/ValueHandle.h"
41 #include "llvm/Support/raw_ostream.h"
42 #include "llvm/System/Disassembler.h"
43 #include "llvm/System/Memory.h"
44 #include "llvm/Target/TargetInstrInfo.h"
45 #include "llvm/ADT/DenseMap.h"
46 #include "llvm/ADT/SmallPtrSet.h"
47 #include "llvm/ADT/SmallVector.h"
48 #include "llvm/ADT/Statistic.h"
49 #include "llvm/ADT/ValueMap.h"
56 STATISTIC(NumBytes, "Number of bytes of machine code compiled");
57 STATISTIC(NumRelos, "Number of relocations applied");
58 STATISTIC(NumRetries, "Number of retries with more memory");
59 static JIT *TheJIT = 0;
62 //===----------------------------------------------------------------------===//
63 // JIT lazy compilation code.
67 class JITResolverState;
69 template<typename ValueTy>
70 struct NoRAUWValueMapConfig : public ValueMapConfig<ValueTy> {
71 typedef JITResolverState *ExtraData;
72 static void onRAUW(JITResolverState *, Value *Old, Value *New) {
73 assert(false && "The JIT doesn't know how to handle a"
74 " RAUW on a value it has emitted.");
78 struct CallSiteValueMapConfig : public NoRAUWValueMapConfig<Function*> {
79 typedef JITResolverState *ExtraData;
80 static void onDelete(JITResolverState *JRS, Function *F);
83 class JITResolverState {
85 typedef ValueMap<Function*, void*, NoRAUWValueMapConfig<Function*> >
87 typedef std::map<void*, AssertingVH<Function> > CallSiteToFunctionMapTy;
88 typedef ValueMap<Function *, SmallPtrSet<void*, 1>,
89 CallSiteValueMapConfig> FunctionToCallSitesMapTy;
90 typedef std::map<AssertingVH<GlobalValue>, void*> GlobalToIndirectSymMapTy;
92 /// FunctionToStubMap - Keep track of the stub created for a particular
93 /// function so that we can reuse them if necessary.
94 FunctionToStubMapTy FunctionToStubMap;
96 /// CallSiteToFunctionMap - Keep track of the function that each lazy call
97 /// site corresponds to, and vice versa.
98 CallSiteToFunctionMapTy CallSiteToFunctionMap;
99 FunctionToCallSitesMapTy FunctionToCallSitesMap;
101 /// GlobalToIndirectSymMap - Keep track of the indirect symbol created for a
102 /// particular GlobalVariable so that we can reuse them if necessary.
103 GlobalToIndirectSymMapTy GlobalToIndirectSymMap;
106 JITResolverState() : FunctionToStubMap(this),
107 FunctionToCallSitesMap(this) {}
109 FunctionToStubMapTy& getFunctionToStubMap(const MutexGuard& locked) {
110 assert(locked.holds(TheJIT->lock));
111 return FunctionToStubMap;
114 GlobalToIndirectSymMapTy& getGlobalToIndirectSymMap(const MutexGuard& locked) {
115 assert(locked.holds(TheJIT->lock));
116 return GlobalToIndirectSymMap;
119 pair<void *, Function *> LookupFunctionFromCallSite(
120 const MutexGuard &locked, void *CallSite) const {
121 assert(locked.holds(TheJIT->lock));
123 // The address given to us for the stub may not be exactly right, it might be
124 // a little bit after the stub. As such, use upper_bound to find it.
125 CallSiteToFunctionMapTy::const_iterator I =
126 CallSiteToFunctionMap.upper_bound(CallSite);
127 assert(I != CallSiteToFunctionMap.begin() &&
128 "This is not a known call site!");
133 void AddCallSite(const MutexGuard &locked, void *CallSite, Function *F) {
134 assert(locked.holds(TheJIT->lock));
136 bool Inserted = CallSiteToFunctionMap.insert(
137 std::make_pair(CallSite, F)).second;
139 assert(Inserted && "Pair was already in CallSiteToFunctionMap");
140 FunctionToCallSitesMap[F].insert(CallSite);
143 // Returns the Function of the stub if a stub was erased, or NULL if there
144 // was no stub. This function uses the call-site->function map to find a
145 // relevant function, but asserts that only stubs and not other call sites
146 // will be passed in.
147 Function *EraseStub(const MutexGuard &locked, void *Stub) {
148 CallSiteToFunctionMapTy::iterator C2F_I =
149 CallSiteToFunctionMap.find(Stub);
150 if (C2F_I == CallSiteToFunctionMap.end()) {
155 Function *const F = C2F_I->second;
157 void *RealStub = FunctionToStubMap.lookup(F);
158 assert(RealStub == Stub &&
159 "Call-site that wasn't a stub pass in to EraseStub");
161 FunctionToStubMap.erase(F);
162 CallSiteToFunctionMap.erase(C2F_I);
164 // Remove the stub from the function->call-sites map, and remove the whole
165 // entry from the map if that was the last call site.
166 FunctionToCallSitesMapTy::iterator F2C_I = FunctionToCallSitesMap.find(F);
167 assert(F2C_I != FunctionToCallSitesMap.end() &&
168 "FunctionToCallSitesMap broken");
169 bool Erased = F2C_I->second.erase(Stub);
171 assert(Erased && "FunctionToCallSitesMap broken");
172 if (F2C_I->second.empty())
173 FunctionToCallSitesMap.erase(F2C_I);
178 void EraseAllCallSites(const MutexGuard &locked, Function *F) {
179 assert(locked.holds(TheJIT->lock));
180 EraseAllCallSitesPrelocked(F);
182 void EraseAllCallSitesPrelocked(Function *F) {
183 FunctionToCallSitesMapTy::iterator F2C = FunctionToCallSitesMap.find(F);
184 if (F2C == FunctionToCallSitesMap.end())
186 for (SmallPtrSet<void*, 1>::const_iterator I = F2C->second.begin(),
187 E = F2C->second.end(); I != E; ++I) {
188 bool Erased = CallSiteToFunctionMap.erase(*I);
190 assert(Erased && "Missing call site->function mapping");
192 FunctionToCallSitesMap.erase(F2C);
196 /// JITResolver - Keep track of, and resolve, call sites for functions that
197 /// have not yet been compiled.
199 typedef JITResolverState::FunctionToStubMapTy FunctionToStubMapTy;
200 typedef JITResolverState::CallSiteToFunctionMapTy CallSiteToFunctionMapTy;
201 typedef JITResolverState::GlobalToIndirectSymMapTy GlobalToIndirectSymMapTy;
203 /// LazyResolverFn - The target lazy resolver function that we actually
204 /// rewrite instructions to use.
205 TargetJITInfo::LazyResolverFn LazyResolverFn;
207 JITResolverState state;
209 /// ExternalFnToStubMap - This is the equivalent of FunctionToStubMap for
210 /// external functions.
211 std::map<void*, void*> ExternalFnToStubMap;
213 /// revGOTMap - map addresses to indexes in the GOT
214 std::map<void*, unsigned> revGOTMap;
215 unsigned nextGOTIndex;
219 static JITResolver *TheJITResolver;
221 explicit JITResolver(JIT &jit, JITEmitter &je) : nextGOTIndex(0), JE(je) {
224 LazyResolverFn = jit.getJITInfo().getLazyResolverFunction(JITCompilerFn);
225 assert(TheJITResolver == 0 && "Multiple JIT resolvers?");
226 TheJITResolver = this;
233 /// getFunctionStubIfAvailable - This returns a pointer to a function stub
234 /// if it has already been created.
235 void *getFunctionStubIfAvailable(Function *F);
237 /// getFunctionStub - This returns a pointer to a function stub, creating
238 /// one on demand as needed. If empty is true, create a function stub
239 /// pointing at address 0, to be filled in later.
240 void *getFunctionStub(Function *F);
242 /// getExternalFunctionStub - Return a stub for the function at the
243 /// specified address, created lazily on demand.
244 void *getExternalFunctionStub(void *FnAddr);
246 /// getGlobalValueIndirectSym - Return an indirect symbol containing the
247 /// specified GV address.
248 void *getGlobalValueIndirectSym(GlobalValue *V, void *GVAddress);
250 void getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
251 SmallVectorImpl<void*> &Ptrs);
253 GlobalValue *invalidateStub(void *Stub);
255 /// getGOTIndexForAddress - Return a new or existing index in the GOT for
256 /// an address. This function only manages slots, it does not manage the
257 /// contents of the slots or the memory associated with the GOT.
258 unsigned getGOTIndexForAddr(void *addr);
260 /// JITCompilerFn - This function is called to resolve a stub to a compiled
261 /// address. If the LLVM Function corresponding to the stub has not yet
262 /// been compiled, this function compiles it first.
263 static void *JITCompilerFn(void *Stub);
266 /// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is
267 /// used to output functions to memory for execution.
268 class JITEmitter : public JITCodeEmitter {
269 JITMemoryManager *MemMgr;
271 // When reattempting to JIT a function after running out of space, we store
272 // the estimated size of the function we're trying to JIT here, so we can
273 // ask the memory manager for at least this much space. When we
274 // successfully emit the function, we reset this back to zero.
275 uintptr_t SizeEstimate;
277 /// Relocations - These are the relocations that the function needs, as
279 std::vector<MachineRelocation> Relocations;
281 /// MBBLocations - This vector is a mapping from MBB ID's to their address.
282 /// It is filled in by the StartMachineBasicBlock callback and queried by
283 /// the getMachineBasicBlockAddress callback.
284 std::vector<uintptr_t> MBBLocations;
286 /// ConstantPool - The constant pool for the current function.
288 MachineConstantPool *ConstantPool;
290 /// ConstantPoolBase - A pointer to the first entry in the constant pool.
292 void *ConstantPoolBase;
294 /// ConstPoolAddresses - Addresses of individual constant pool entries.
296 SmallVector<uintptr_t, 8> ConstPoolAddresses;
298 /// JumpTable - The jump tables for the current function.
300 MachineJumpTableInfo *JumpTable;
302 /// JumpTableBase - A pointer to the first entry in the jump table.
306 /// Resolver - This contains info about the currently resolved functions.
307 JITResolver Resolver;
309 /// DE - The dwarf emitter for the jit.
310 OwningPtr<JITDwarfEmitter> DE;
312 /// DR - The debug registerer for the jit.
313 OwningPtr<JITDebugRegisterer> DR;
315 /// LabelLocations - This vector is a mapping from Label ID's to their
317 std::vector<uintptr_t> LabelLocations;
319 /// MMI - Machine module info for exception informations
320 MachineModuleInfo* MMI;
322 // GVSet - a set to keep track of which globals have been seen
323 SmallPtrSet<const GlobalVariable*, 8> GVSet;
325 // CurFn - The llvm function being emitted. Only valid during
327 const Function *CurFn;
329 /// Information about emitted code, which is passed to the
330 /// JITEventListeners. This is reset in startFunction and used in
332 JITEvent_EmittedFunctionDetails EmissionDetails;
335 void *FunctionBody; // Beginning of the function's allocation.
336 void *Code; // The address the function's code actually starts at.
337 void *ExceptionTable;
338 EmittedCode() : FunctionBody(0), Code(0), ExceptionTable(0) {}
340 struct EmittedFunctionConfig : public ValueMapConfig<const Function*> {
341 typedef JITEmitter *ExtraData;
342 static void onDelete(JITEmitter *, const Function*);
343 static void onRAUW(JITEmitter *, const Function*, const Function*);
345 ValueMap<const Function *, EmittedCode,
346 EmittedFunctionConfig> EmittedFunctions;
348 // CurFnStubUses - For a given Function, a vector of stubs that it
349 // references. This facilitates the JIT detecting that a stub is no
350 // longer used, so that it may be deallocated.
351 DenseMap<AssertingVH<const Function>, SmallVector<void*, 1> > CurFnStubUses;
353 // StubFnRefs - For a given pointer to a stub, a set of Functions which
354 // reference the stub. When the count of a stub's references drops to zero,
355 // the stub is unused.
356 DenseMap<void *, SmallPtrSet<const Function*, 1> > StubFnRefs;
358 DebugLocTuple PrevDLT;
361 JITEmitter(JIT &jit, JITMemoryManager *JMM, TargetMachine &TM)
362 : SizeEstimate(0), Resolver(jit, *this), MMI(0), CurFn(0),
363 EmittedFunctions(this) {
364 MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager();
365 if (jit.getJITInfo().needsGOT()) {
366 MemMgr->AllocateGOT();
367 DEBUG(errs() << "JIT is managing a GOT\n");
370 if (DwarfExceptionHandling || JITEmitDebugInfo) {
371 DE.reset(new JITDwarfEmitter(jit));
373 if (JITEmitDebugInfo) {
374 DR.reset(new JITDebugRegisterer(TM));
381 /// classof - Methods for support type inquiry through isa, cast, and
384 static inline bool classof(const JITEmitter*) { return true; }
385 static inline bool classof(const MachineCodeEmitter*) { return true; }
387 JITResolver &getJITResolver() { return Resolver; }
389 virtual void startFunction(MachineFunction &F);
390 virtual bool finishFunction(MachineFunction &F);
392 void emitConstantPool(MachineConstantPool *MCP);
393 void initJumpTableInfo(MachineJumpTableInfo *MJTI);
394 void emitJumpTableInfo(MachineJumpTableInfo *MJTI);
396 virtual void startGVStub(BufferState &BS, const GlobalValue* GV,
397 unsigned StubSize, unsigned Alignment = 1);
398 virtual void startGVStub(BufferState &BS, void *Buffer,
400 virtual void* finishGVStub(BufferState &BS);
402 /// allocateSpace - Reserves space in the current block if any, or
403 /// allocate a new one of the given size.
404 virtual void *allocateSpace(uintptr_t Size, unsigned Alignment);
406 /// allocateGlobal - Allocate memory for a global. Unlike allocateSpace,
407 /// this method does not allocate memory in the current output buffer,
408 /// because a global may live longer than the current function.
409 virtual void *allocateGlobal(uintptr_t Size, unsigned Alignment);
411 virtual void addRelocation(const MachineRelocation &MR) {
412 Relocations.push_back(MR);
415 virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) {
416 if (MBBLocations.size() <= (unsigned)MBB->getNumber())
417 MBBLocations.resize((MBB->getNumber()+1)*2);
418 MBBLocations[MBB->getNumber()] = getCurrentPCValue();
419 DEBUG(errs() << "JIT: Emitting BB" << MBB->getNumber() << " at ["
420 << (void*) getCurrentPCValue() << "]\n");
423 virtual uintptr_t getConstantPoolEntryAddress(unsigned Entry) const;
424 virtual uintptr_t getJumpTableEntryAddress(unsigned Entry) const;
426 virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const {
427 assert(MBBLocations.size() > (unsigned)MBB->getNumber() &&
428 MBBLocations[MBB->getNumber()] && "MBB not emitted!");
429 return MBBLocations[MBB->getNumber()];
432 /// retryWithMoreMemory - Log a retry and deallocate all memory for the
433 /// given function. Increase the minimum allocation size so that we get
434 /// more memory next time.
435 void retryWithMoreMemory(MachineFunction &F);
437 /// deallocateMemForFunction - Deallocate all memory for the specified
439 void deallocateMemForFunction(const Function *F);
441 /// AddStubToCurrentFunction - Mark the current function being JIT'd as
442 /// using the stub at the specified address. Allows
443 /// deallocateMemForFunction to also remove stubs no longer referenced.
444 void AddStubToCurrentFunction(void *Stub);
446 virtual void processDebugLoc(DebugLoc DL, bool BeforePrintingInsn);
448 virtual void emitLabel(uint64_t LabelID) {
449 if (LabelLocations.size() <= LabelID)
450 LabelLocations.resize((LabelID+1)*2);
451 LabelLocations[LabelID] = getCurrentPCValue();
454 virtual uintptr_t getLabelAddress(uint64_t LabelID) const {
455 assert(LabelLocations.size() > (unsigned)LabelID &&
456 LabelLocations[LabelID] && "Label not emitted!");
457 return LabelLocations[LabelID];
460 virtual void setModuleInfo(MachineModuleInfo* Info) {
462 if (DE.get()) DE->setModuleInfo(Info);
465 void setMemoryExecutable() {
466 MemMgr->setMemoryExecutable();
469 JITMemoryManager *getMemMgr() const { return MemMgr; }
472 void *getPointerToGlobal(GlobalValue *GV, void *Reference,
473 bool MayNeedFarStub);
474 void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference);
475 unsigned addSizeOfGlobal(const GlobalVariable *GV, unsigned Size);
476 unsigned addSizeOfGlobalsInConstantVal(const Constant *C, unsigned Size);
477 unsigned addSizeOfGlobalsInInitializer(const Constant *Init, unsigned Size);
478 unsigned GetSizeOfGlobalsInBytes(MachineFunction &MF);
482 JITResolver *JITResolver::TheJITResolver = 0;
484 void CallSiteValueMapConfig::onDelete(JITResolverState *JRS, Function *F) {
485 JRS->EraseAllCallSitesPrelocked(F);
488 /// getFunctionStubIfAvailable - This returns a pointer to a function stub
489 /// if it has already been created.
490 void *JITResolver::getFunctionStubIfAvailable(Function *F) {
491 MutexGuard locked(TheJIT->lock);
493 // If we already have a stub for this function, recycle it.
494 return state.getFunctionToStubMap(locked).lookup(F);
497 /// getFunctionStub - This returns a pointer to a function stub, creating
498 /// one on demand as needed.
499 void *JITResolver::getFunctionStub(Function *F) {
500 MutexGuard locked(TheJIT->lock);
502 // If we already have a stub for this function, recycle it.
503 void *&Stub = state.getFunctionToStubMap(locked)[F];
504 if (Stub) return Stub;
506 // Call the lazy resolver function if we are JIT'ing lazily. Otherwise we
507 // must resolve the symbol now.
508 void *Actual = TheJIT->isCompilingLazily()
509 ? (void *)(intptr_t)LazyResolverFn : (void *)0;
511 // If this is an external declaration, attempt to resolve the address now
512 // to place in the stub.
513 if (F->isDeclaration() && !F->hasNotBeenReadFromBitcode()) {
514 Actual = TheJIT->getPointerToFunction(F);
516 // If we resolved the symbol to a null address (eg. a weak external)
517 // don't emit a stub. Return a null pointer to the application.
518 if (!Actual) return 0;
521 // Codegen a new stub, calling the lazy resolver or the actual address of the
522 // external function, if it was resolved.
523 Stub = TheJIT->getJITInfo().emitFunctionStub(F, Actual, JE);
525 if (Actual != (void*)(intptr_t)LazyResolverFn) {
526 // If we are getting the stub for an external function, we really want the
527 // address of the stub in the GlobalAddressMap for the JIT, not the address
528 // of the external function.
529 TheJIT->updateGlobalMapping(F, Stub);
532 DEBUG(errs() << "JIT: Stub emitted at [" << Stub << "] for function '"
533 << F->getName() << "'\n");
535 // Finally, keep track of the stub-to-Function mapping so that the
536 // JITCompilerFn knows which function to compile!
537 state.AddCallSite(locked, Stub, F);
539 // If we are JIT'ing non-lazily but need to call a function that does not
540 // exist yet, add it to the JIT's work list so that we can fill in the stub
542 if (!Actual && !TheJIT->isCompilingLazily())
543 if (!F->isDeclaration() || F->hasNotBeenReadFromBitcode())
544 TheJIT->addPendingFunction(F);
549 /// getGlobalValueIndirectSym - Return a lazy pointer containing the specified
551 void *JITResolver::getGlobalValueIndirectSym(GlobalValue *GV, void *GVAddress) {
552 MutexGuard locked(TheJIT->lock);
554 // If we already have a stub for this global variable, recycle it.
555 void *&IndirectSym = state.getGlobalToIndirectSymMap(locked)[GV];
556 if (IndirectSym) return IndirectSym;
558 // Otherwise, codegen a new indirect symbol.
559 IndirectSym = TheJIT->getJITInfo().emitGlobalValueIndirectSym(GV, GVAddress,
562 DEBUG(errs() << "JIT: Indirect symbol emitted at [" << IndirectSym
563 << "] for GV '" << GV->getName() << "'\n");
568 /// getExternalFunctionStub - Return a stub for the function at the
569 /// specified address, created lazily on demand.
570 void *JITResolver::getExternalFunctionStub(void *FnAddr) {
571 // If we already have a stub for this function, recycle it.
572 void *&Stub = ExternalFnToStubMap[FnAddr];
573 if (Stub) return Stub;
575 Stub = TheJIT->getJITInfo().emitFunctionStub(0, FnAddr, JE);
577 DEBUG(errs() << "JIT: Stub emitted at [" << Stub
578 << "] for external function at '" << FnAddr << "'\n");
582 unsigned JITResolver::getGOTIndexForAddr(void* addr) {
583 unsigned idx = revGOTMap[addr];
585 idx = ++nextGOTIndex;
586 revGOTMap[addr] = idx;
587 DEBUG(errs() << "JIT: Adding GOT entry " << idx << " for addr ["
593 void JITResolver::getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs,
594 SmallVectorImpl<void*> &Ptrs) {
595 MutexGuard locked(TheJIT->lock);
597 const FunctionToStubMapTy &FM = state.getFunctionToStubMap(locked);
598 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
600 for (FunctionToStubMapTy::const_iterator i = FM.begin(), e = FM.end();
602 Function *F = i->first;
603 if (F->isDeclaration() && F->hasExternalLinkage()) {
604 GVs.push_back(i->first);
605 Ptrs.push_back(i->second);
608 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
610 GVs.push_back(i->first);
611 Ptrs.push_back(i->second);
615 GlobalValue *JITResolver::invalidateStub(void *Stub) {
616 MutexGuard locked(TheJIT->lock);
618 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked);
620 // Look up the cheap way first, to see if it's a function stub we are
621 // invalidating. If so, remove it from both the forward and reverse maps.
622 if (Function *F = state.EraseStub(locked, Stub)) {
626 // Otherwise, it might be an indirect symbol stub. Find it and remove it.
627 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end();
629 if (i->second != Stub)
631 GlobalValue *GV = i->first;
636 // Lastly, check to see if it's in the ExternalFnToStubMap.
637 for (std::map<void *, void *>::iterator i = ExternalFnToStubMap.begin(),
638 e = ExternalFnToStubMap.end(); i != e; ++i) {
639 if (i->second != Stub)
641 ExternalFnToStubMap.erase(i);
648 /// JITCompilerFn - This function is called when a lazy compilation stub has
649 /// been entered. It looks up which function this stub corresponds to, compiles
650 /// it if necessary, then returns the resultant function pointer.
651 void *JITResolver::JITCompilerFn(void *Stub) {
652 JITResolver &JR = *TheJITResolver;
658 // Only lock for getting the Function. The call getPointerToFunction made
659 // in this function might trigger function materializing, which requires
660 // JIT lock to be unlocked.
661 MutexGuard locked(TheJIT->lock);
663 // The address given to us for the stub may not be exactly right, it might
664 // be a little bit after the stub. As such, use upper_bound to find it.
665 pair<void*, Function*> I =
666 JR.state.LookupFunctionFromCallSite(locked, Stub);
671 // If we have already code generated the function, just return the address.
672 void *Result = TheJIT->getPointerToGlobalIfAvailable(F);
675 // Otherwise we don't have it, do lazy compilation now.
677 // If lazy compilation is disabled, emit a useful error message and abort.
678 if (!TheJIT->isCompilingLazily()) {
679 llvm_report_error("LLVM JIT requested to do lazy compilation of function '"
680 + F->getName() + "' when lazy compiles are disabled!");
683 DEBUG(errs() << "JIT: Lazily resolving function '" << F->getName()
684 << "' In stub ptr = " << Stub << " actual ptr = "
685 << ActualPtr << "\n");
687 Result = TheJIT->getPointerToFunction(F);
690 // Reacquire the lock to update the GOT map.
691 MutexGuard locked(TheJIT->lock);
693 // We might like to remove the call site from the CallSiteToFunction map, but
694 // we can't do that! Multiple threads could be stuck, waiting to acquire the
695 // lock above. As soon as the 1st function finishes compiling the function,
696 // the next one will be released, and needs to be able to find the function it
699 // FIXME: We could rewrite all references to this stub if we knew them.
701 // What we will do is set the compiled function address to map to the
702 // same GOT entry as the stub so that later clients may update the GOT
703 // if they see it still using the stub address.
704 // Note: this is done so the Resolver doesn't have to manage GOT memory
705 // Do this without allocating map space if the target isn't using a GOT
706 if(JR.revGOTMap.find(Stub) != JR.revGOTMap.end())
707 JR.revGOTMap[Result] = JR.revGOTMap[Stub];
712 //===----------------------------------------------------------------------===//
715 void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference,
716 bool MayNeedFarStub) {
717 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
718 return TheJIT->getOrEmitGlobalVariable(GV);
720 if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
721 return TheJIT->getPointerToGlobal(GA->resolveAliasedGlobal(false));
723 // If we have already compiled the function, return a pointer to its body.
724 Function *F = cast<Function>(V);
726 void *FnStub = Resolver.getFunctionStubIfAvailable(F);
728 // Return the function stub if it's already created. We do this first
729 // so that we're returning the same address for the function as any
731 AddStubToCurrentFunction(FnStub);
735 // If we know the target can handle arbitrary-distance calls, try to
736 // return a direct pointer.
737 if (!MayNeedFarStub) {
738 // If we have code, go ahead and return that.
739 void *ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F);
740 if (ResultPtr) return ResultPtr;
742 // If this is an external function pointer, we can force the JIT to
743 // 'compile' it, which really just adds it to the map.
744 if (F->isDeclaration() && !F->hasNotBeenReadFromBitcode())
745 return TheJIT->getPointerToFunction(F);
748 // Otherwise, we may need a to emit a stub, and, conservatively, we
750 void *StubAddr = Resolver.getFunctionStub(F);
752 // Add the stub to the current function's list of referenced stubs, so we can
753 // deallocate them if the current function is ever freed. It's possible to
754 // return null from getFunctionStub in the case of a weak extern that fails
757 AddStubToCurrentFunction(StubAddr);
762 void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) {
763 // Make sure GV is emitted first, and create a stub containing the fully
765 void *GVAddress = getPointerToGlobal(V, Reference, false);
766 void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress);
768 // Add the stub to the current function's list of referenced stubs, so we can
769 // deallocate them if the current function is ever freed.
770 AddStubToCurrentFunction(StubAddr);
775 void JITEmitter::AddStubToCurrentFunction(void *StubAddr) {
776 assert(CurFn && "Stub added to current function, but current function is 0!");
778 SmallVectorImpl<void*> &StubsUsed = CurFnStubUses[CurFn];
779 StubsUsed.push_back(StubAddr);
781 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[StubAddr];
782 FnRefs.insert(CurFn);
785 void JITEmitter::processDebugLoc(DebugLoc DL, bool BeforePrintingInsn) {
786 if (!DL.isUnknown()) {
787 DebugLocTuple CurDLT = EmissionDetails.MF->getDebugLocTuple(DL);
789 if (BeforePrintingInsn) {
790 if (CurDLT.Scope != 0 && PrevDLT != CurDLT) {
791 JITEvent_EmittedFunctionDetails::LineStart NextLine;
792 NextLine.Address = getCurrentPCValue();
794 EmissionDetails.LineStarts.push_back(NextLine);
802 static unsigned GetConstantPoolSizeInBytes(MachineConstantPool *MCP,
803 const TargetData *TD) {
804 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
805 if (Constants.empty()) return 0;
808 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
809 MachineConstantPoolEntry CPE = Constants[i];
810 unsigned AlignMask = CPE.getAlignment() - 1;
811 Size = (Size + AlignMask) & ~AlignMask;
812 const Type *Ty = CPE.getType();
813 Size += TD->getTypeAllocSize(Ty);
818 static unsigned GetJumpTableSizeInBytes(MachineJumpTableInfo *MJTI) {
819 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
820 if (JT.empty()) return 0;
822 unsigned NumEntries = 0;
823 for (unsigned i = 0, e = JT.size(); i != e; ++i)
824 NumEntries += JT[i].MBBs.size();
826 unsigned EntrySize = MJTI->getEntrySize();
828 return NumEntries * EntrySize;
831 static uintptr_t RoundUpToAlign(uintptr_t Size, unsigned Alignment) {
832 if (Alignment == 0) Alignment = 1;
833 // Since we do not know where the buffer will be allocated, be pessimistic.
834 return Size + Alignment;
837 /// addSizeOfGlobal - add the size of the global (plus any alignment padding)
838 /// into the running total Size.
840 unsigned JITEmitter::addSizeOfGlobal(const GlobalVariable *GV, unsigned Size) {
841 const Type *ElTy = GV->getType()->getElementType();
842 size_t GVSize = (size_t)TheJIT->getTargetData()->getTypeAllocSize(ElTy);
844 (size_t)TheJIT->getTargetData()->getPreferredAlignment(GV);
845 DEBUG(errs() << "JIT: Adding in size " << GVSize << " alignment " << GVAlign);
847 // Assume code section ends with worst possible alignment, so first
848 // variable needs maximal padding.
851 Size = ((Size+GVAlign-1)/GVAlign)*GVAlign;
856 /// addSizeOfGlobalsInConstantVal - find any globals that we haven't seen yet
857 /// but are referenced from the constant; put them in GVSet and add their
858 /// size into the running total Size.
860 unsigned JITEmitter::addSizeOfGlobalsInConstantVal(const Constant *C,
862 // If its undefined, return the garbage.
863 if (isa<UndefValue>(C))
866 // If the value is a ConstantExpr
867 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
868 Constant *Op0 = CE->getOperand(0);
869 switch (CE->getOpcode()) {
870 case Instruction::GetElementPtr:
871 case Instruction::Trunc:
872 case Instruction::ZExt:
873 case Instruction::SExt:
874 case Instruction::FPTrunc:
875 case Instruction::FPExt:
876 case Instruction::UIToFP:
877 case Instruction::SIToFP:
878 case Instruction::FPToUI:
879 case Instruction::FPToSI:
880 case Instruction::PtrToInt:
881 case Instruction::IntToPtr:
882 case Instruction::BitCast: {
883 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
886 case Instruction::Add:
887 case Instruction::FAdd:
888 case Instruction::Sub:
889 case Instruction::FSub:
890 case Instruction::Mul:
891 case Instruction::FMul:
892 case Instruction::UDiv:
893 case Instruction::SDiv:
894 case Instruction::URem:
895 case Instruction::SRem:
896 case Instruction::And:
897 case Instruction::Or:
898 case Instruction::Xor: {
899 Size = addSizeOfGlobalsInConstantVal(Op0, Size);
900 Size = addSizeOfGlobalsInConstantVal(CE->getOperand(1), Size);
905 raw_string_ostream Msg(msg);
906 Msg << "ConstantExpr not handled: " << *CE;
907 llvm_report_error(Msg.str());
912 if (C->getType()->getTypeID() == Type::PointerTyID)
913 if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C))
914 if (GVSet.insert(GV))
915 Size = addSizeOfGlobal(GV, Size);
920 /// addSizeOfGLobalsInInitializer - handle any globals that we haven't seen yet
921 /// but are referenced from the given initializer.
923 unsigned JITEmitter::addSizeOfGlobalsInInitializer(const Constant *Init,
925 if (!isa<UndefValue>(Init) &&
926 !isa<ConstantVector>(Init) &&
927 !isa<ConstantAggregateZero>(Init) &&
928 !isa<ConstantArray>(Init) &&
929 !isa<ConstantStruct>(Init) &&
930 Init->getType()->isFirstClassType())
931 Size = addSizeOfGlobalsInConstantVal(Init, Size);
935 /// GetSizeOfGlobalsInBytes - walk the code for the function, looking for
936 /// globals; then walk the initializers of those globals looking for more.
937 /// If their size has not been considered yet, add it into the running total
940 unsigned JITEmitter::GetSizeOfGlobalsInBytes(MachineFunction &MF) {
944 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end();
946 for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end();
948 const TargetInstrDesc &Desc = I->getDesc();
949 const MachineInstr &MI = *I;
950 unsigned NumOps = Desc.getNumOperands();
951 for (unsigned CurOp = 0; CurOp < NumOps; CurOp++) {
952 const MachineOperand &MO = MI.getOperand(CurOp);
954 GlobalValue* V = MO.getGlobal();
955 const GlobalVariable *GV = dyn_cast<const GlobalVariable>(V);
958 // If seen in previous function, it will have an entry here.
959 if (TheJIT->getPointerToGlobalIfAvailable(GV))
961 // If seen earlier in this function, it will have an entry here.
962 // FIXME: it should be possible to combine these tables, by
963 // assuming the addresses of the new globals in this module
964 // start at 0 (or something) and adjusting them after codegen
965 // complete. Another possibility is to grab a marker bit in GV.
966 if (GVSet.insert(GV))
967 // A variable as yet unseen. Add in its size.
968 Size = addSizeOfGlobal(GV, Size);
973 DEBUG(errs() << "JIT: About to look through initializers\n");
974 // Look for more globals that are referenced only from initializers.
975 // GVSet.end is computed each time because the set can grow as we go.
976 for (SmallPtrSet<const GlobalVariable *, 8>::iterator I = GVSet.begin();
977 I != GVSet.end(); I++) {
978 const GlobalVariable* GV = *I;
979 if (GV->hasInitializer())
980 Size = addSizeOfGlobalsInInitializer(GV->getInitializer(), Size);
986 void JITEmitter::startFunction(MachineFunction &F) {
987 DEBUG(errs() << "JIT: Starting CodeGen of Function "
988 << F.getFunction()->getName() << "\n");
990 uintptr_t ActualSize = 0;
991 // Set the memory writable, if it's not already
992 MemMgr->setMemoryWritable();
993 if (MemMgr->NeedsExactSize()) {
994 DEBUG(errs() << "JIT: ExactSize\n");
995 const TargetInstrInfo* TII = F.getTarget().getInstrInfo();
996 MachineJumpTableInfo *MJTI = F.getJumpTableInfo();
997 MachineConstantPool *MCP = F.getConstantPool();
999 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1000 ActualSize = RoundUpToAlign(ActualSize, 16);
1002 // Add the alignment of the constant pool
1003 ActualSize = RoundUpToAlign(ActualSize, MCP->getConstantPoolAlignment());
1005 // Add the constant pool size
1006 ActualSize += GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1008 // Add the aligment of the jump table info
1009 ActualSize = RoundUpToAlign(ActualSize, MJTI->getAlignment());
1011 // Add the jump table size
1012 ActualSize += GetJumpTableSizeInBytes(MJTI);
1014 // Add the alignment for the function
1015 ActualSize = RoundUpToAlign(ActualSize,
1016 std::max(F.getFunction()->getAlignment(), 8U));
1018 // Add the function size
1019 ActualSize += TII->GetFunctionSizeInBytes(F);
1021 DEBUG(errs() << "JIT: ActualSize before globals " << ActualSize << "\n");
1022 // Add the size of the globals that will be allocated after this function.
1023 // These are all the ones referenced from this function that were not
1024 // previously allocated.
1025 ActualSize += GetSizeOfGlobalsInBytes(F);
1026 DEBUG(errs() << "JIT: ActualSize after globals " << ActualSize << "\n");
1027 } else if (SizeEstimate > 0) {
1028 // SizeEstimate will be non-zero on reallocation attempts.
1029 ActualSize = SizeEstimate;
1032 BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(),
1034 BufferEnd = BufferBegin+ActualSize;
1035 EmittedFunctions[F.getFunction()].FunctionBody = BufferBegin;
1037 // Ensure the constant pool/jump table info is at least 4-byte aligned.
1040 emitConstantPool(F.getConstantPool());
1041 initJumpTableInfo(F.getJumpTableInfo());
1043 // About to start emitting the machine code for the function.
1044 emitAlignment(std::max(F.getFunction()->getAlignment(), 8U));
1045 TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr);
1046 EmittedFunctions[F.getFunction()].Code = CurBufferPtr;
1048 MBBLocations.clear();
1050 EmissionDetails.MF = &F;
1051 EmissionDetails.LineStarts.clear();
1054 bool JITEmitter::finishFunction(MachineFunction &F) {
1055 if (CurBufferPtr == BufferEnd) {
1056 // We must call endFunctionBody before retrying, because
1057 // deallocateMemForFunction requires it.
1058 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1059 retryWithMoreMemory(F);
1063 emitJumpTableInfo(F.getJumpTableInfo());
1065 // FnStart is the start of the text, not the start of the constant pool and
1066 // other per-function data.
1068 (uint8_t *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction());
1070 // FnEnd is the end of the function's machine code.
1071 uint8_t *FnEnd = CurBufferPtr;
1073 if (!Relocations.empty()) {
1074 CurFn = F.getFunction();
1075 NumRelos += Relocations.size();
1077 // Resolve the relocations to concrete pointers.
1078 for (unsigned i = 0, e = Relocations.size(); i != e; ++i) {
1079 MachineRelocation &MR = Relocations[i];
1080 void *ResultPtr = 0;
1081 if (!MR.letTargetResolve()) {
1082 if (MR.isExternalSymbol()) {
1083 ResultPtr = TheJIT->getPointerToNamedFunction(MR.getExternalSymbol(),
1085 DEBUG(errs() << "JIT: Map \'" << MR.getExternalSymbol() << "\' to ["
1086 << ResultPtr << "]\n");
1088 // If the target REALLY wants a stub for this function, emit it now.
1089 if (MR.mayNeedFarStub()) {
1090 ResultPtr = Resolver.getExternalFunctionStub(ResultPtr);
1092 } else if (MR.isGlobalValue()) {
1093 ResultPtr = getPointerToGlobal(MR.getGlobalValue(),
1094 BufferBegin+MR.getMachineCodeOffset(),
1095 MR.mayNeedFarStub());
1096 } else if (MR.isIndirectSymbol()) {
1097 ResultPtr = getPointerToGVIndirectSym(
1098 MR.getGlobalValue(), BufferBegin+MR.getMachineCodeOffset());
1099 } else if (MR.isBasicBlock()) {
1100 ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock());
1101 } else if (MR.isConstantPoolIndex()) {
1102 ResultPtr = (void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex());
1104 assert(MR.isJumpTableIndex());
1105 ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex());
1108 MR.setResultPointer(ResultPtr);
1111 // if we are managing the GOT and the relocation wants an index,
1113 if (MR.isGOTRelative() && MemMgr->isManagingGOT()) {
1114 unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr);
1115 MR.setGOTIndex(idx);
1116 if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) {
1117 DEBUG(errs() << "JIT: GOT was out of date for " << ResultPtr
1118 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1120 ((void**)MemMgr->getGOTBase())[idx] = ResultPtr;
1126 TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0],
1127 Relocations.size(), MemMgr->getGOTBase());
1130 // Update the GOT entry for F to point to the new code.
1131 if (MemMgr->isManagingGOT()) {
1132 unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin);
1133 if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) {
1134 DEBUG(errs() << "JIT: GOT was out of date for " << (void*)BufferBegin
1135 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx]
1137 ((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin;
1141 // CurBufferPtr may have moved beyond FnEnd, due to memory allocation for
1142 // global variables that were referenced in the relocations.
1143 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr);
1145 if (CurBufferPtr == BufferEnd) {
1146 retryWithMoreMemory(F);
1149 // Now that we've succeeded in emitting the function, reset the
1150 // SizeEstimate back down to zero.
1154 BufferBegin = CurBufferPtr = 0;
1155 NumBytes += FnEnd-FnStart;
1157 // Invalidate the icache if necessary.
1158 sys::Memory::InvalidateInstructionCache(FnStart, FnEnd-FnStart);
1160 TheJIT->NotifyFunctionEmitted(*F.getFunction(), FnStart, FnEnd-FnStart,
1163 DEBUG(errs() << "JIT: Finished CodeGen of [" << (void*)FnStart
1164 << "] Function: " << F.getFunction()->getName()
1165 << ": " << (FnEnd-FnStart) << " bytes of text, "
1166 << Relocations.size() << " relocations\n");
1168 Relocations.clear();
1169 ConstPoolAddresses.clear();
1171 // Mark code region readable and executable if it's not so already.
1172 MemMgr->setMemoryExecutable();
1175 if (sys::hasDisassembler()) {
1176 errs() << "JIT: Disassembled code:\n";
1177 errs() << sys::disassembleBuffer(FnStart, FnEnd-FnStart,
1178 (uintptr_t)FnStart);
1180 errs() << "JIT: Binary code:\n";
1181 uint8_t* q = FnStart;
1182 for (int i = 0; q < FnEnd; q += 4, ++i) {
1186 errs() << "JIT: " << (long)(q - FnStart) << ": ";
1188 for (int j = 3; j >= 0; --j) {
1192 errs() << (unsigned short)q[j];
1204 if (DwarfExceptionHandling || JITEmitDebugInfo) {
1205 uintptr_t ActualSize = 0;
1209 if (MemMgr->NeedsExactSize()) {
1210 ActualSize = DE->GetDwarfTableSizeInBytes(F, *this, FnStart, FnEnd);
1213 BufferBegin = CurBufferPtr = MemMgr->startExceptionTable(F.getFunction(),
1215 BufferEnd = BufferBegin+ActualSize;
1216 EmittedFunctions[F.getFunction()].ExceptionTable = BufferBegin;
1218 uint8_t *FrameRegister = DE->EmitDwarfTable(F, *this, FnStart, FnEnd,
1220 MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr,
1222 uint8_t *EhEnd = CurBufferPtr;
1223 RestoreStateFrom(BS);
1225 if (DwarfExceptionHandling) {
1226 TheJIT->RegisterTable(FrameRegister);
1229 if (JITEmitDebugInfo) {
1231 I.FnStart = FnStart;
1233 I.EhStart = EhStart;
1235 DR->RegisterFunction(F.getFunction(), I);
1245 void JITEmitter::retryWithMoreMemory(MachineFunction &F) {
1246 DEBUG(errs() << "JIT: Ran out of space for native code. Reattempting.\n");
1247 Relocations.clear(); // Clear the old relocations or we'll reapply them.
1248 ConstPoolAddresses.clear();
1250 deallocateMemForFunction(F.getFunction());
1251 // Try again with at least twice as much free space.
1252 SizeEstimate = (uintptr_t)(2 * (BufferEnd - BufferBegin));
1255 /// deallocateMemForFunction - Deallocate all memory for the specified
1256 /// function body. Also drop any references the function has to stubs.
1257 /// May be called while the Function is being destroyed inside ~Value().
1258 void JITEmitter::deallocateMemForFunction(const Function *F) {
1259 ValueMap<const Function *, EmittedCode, EmittedFunctionConfig>::iterator
1260 Emitted = EmittedFunctions.find(F);
1261 if (Emitted != EmittedFunctions.end()) {
1262 MemMgr->deallocateFunctionBody(Emitted->second.FunctionBody);
1263 MemMgr->deallocateExceptionTable(Emitted->second.ExceptionTable);
1264 TheJIT->NotifyFreeingMachineCode(Emitted->second.Code);
1266 EmittedFunctions.erase(Emitted);
1269 // TODO: Do we need to unregister exception handling information from libgcc
1272 if (JITEmitDebugInfo) {
1273 DR->UnregisterFunction(F);
1276 // If the function did not reference any stubs, return.
1277 if (CurFnStubUses.find(F) == CurFnStubUses.end())
1280 // For each referenced stub, erase the reference to this function, and then
1281 // erase the list of referenced stubs.
1282 SmallVectorImpl<void *> &StubList = CurFnStubUses[F];
1283 for (unsigned i = 0, e = StubList.size(); i != e; ++i) {
1284 void *Stub = StubList[i];
1286 // If we already invalidated this stub for this function, continue.
1287 if (StubFnRefs.count(Stub) == 0)
1290 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[Stub];
1293 // If this function was the last reference to the stub, invalidate the stub
1294 // in the JITResolver. Were there a memory manager deallocateStub routine,
1295 // we could call that at this point too.
1296 if (FnRefs.empty()) {
1297 DEBUG(errs() << "\nJIT: Invalidated Stub at [" << Stub << "]\n");
1298 StubFnRefs.erase(Stub);
1300 // Invalidate the stub. If it is a GV stub, update the JIT's global
1301 // mapping for that GV to zero.
1302 GlobalValue *GV = Resolver.invalidateStub(Stub);
1304 TheJIT->updateGlobalMapping(GV, 0);
1308 CurFnStubUses.erase(F);
1312 void* JITEmitter::allocateSpace(uintptr_t Size, unsigned Alignment) {
1314 return JITCodeEmitter::allocateSpace(Size, Alignment);
1316 // create a new memory block if there is no active one.
1317 // care must be taken so that BufferBegin is invalidated when a
1319 BufferBegin = CurBufferPtr = MemMgr->allocateSpace(Size, Alignment);
1320 BufferEnd = BufferBegin+Size;
1321 return CurBufferPtr;
1324 void* JITEmitter::allocateGlobal(uintptr_t Size, unsigned Alignment) {
1325 // Delegate this call through the memory manager.
1326 return MemMgr->allocateGlobal(Size, Alignment);
1329 void JITEmitter::emitConstantPool(MachineConstantPool *MCP) {
1330 if (TheJIT->getJITInfo().hasCustomConstantPool())
1333 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants();
1334 if (Constants.empty()) return;
1336 unsigned Size = GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData());
1337 unsigned Align = MCP->getConstantPoolAlignment();
1338 ConstantPoolBase = allocateSpace(Size, Align);
1341 if (ConstantPoolBase == 0) return; // Buffer overflow.
1343 DEBUG(errs() << "JIT: Emitted constant pool at [" << ConstantPoolBase
1344 << "] (size: " << Size << ", alignment: " << Align << ")\n");
1346 // Initialize the memory for all of the constant pool entries.
1347 unsigned Offset = 0;
1348 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
1349 MachineConstantPoolEntry CPE = Constants[i];
1350 unsigned AlignMask = CPE.getAlignment() - 1;
1351 Offset = (Offset + AlignMask) & ~AlignMask;
1353 uintptr_t CAddr = (uintptr_t)ConstantPoolBase + Offset;
1354 ConstPoolAddresses.push_back(CAddr);
1355 if (CPE.isMachineConstantPoolEntry()) {
1356 // FIXME: add support to lower machine constant pool values into bytes!
1357 llvm_report_error("Initialize memory with machine specific constant pool"
1358 "entry has not been implemented!");
1360 TheJIT->InitializeMemory(CPE.Val.ConstVal, (void*)CAddr);
1361 DEBUG(errs() << "JIT: CP" << i << " at [0x";
1362 errs().write_hex(CAddr) << "]\n");
1364 const Type *Ty = CPE.Val.ConstVal->getType();
1365 Offset += TheJIT->getTargetData()->getTypeAllocSize(Ty);
1369 void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) {
1370 if (TheJIT->getJITInfo().hasCustomJumpTables())
1373 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1374 if (JT.empty()) return;
1376 unsigned NumEntries = 0;
1377 for (unsigned i = 0, e = JT.size(); i != e; ++i)
1378 NumEntries += JT[i].MBBs.size();
1380 unsigned EntrySize = MJTI->getEntrySize();
1382 // Just allocate space for all the jump tables now. We will fix up the actual
1383 // MBB entries in the tables after we emit the code for each block, since then
1384 // we will know the final locations of the MBBs in memory.
1386 JumpTableBase = allocateSpace(NumEntries * EntrySize, MJTI->getAlignment());
1389 void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) {
1390 if (TheJIT->getJITInfo().hasCustomJumpTables())
1393 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables();
1394 if (JT.empty() || JumpTableBase == 0) return;
1396 if (TargetMachine::getRelocationModel() == Reloc::PIC_) {
1397 assert(MJTI->getEntrySize() == 4 && "Cross JIT'ing?");
1398 // For each jump table, place the offset from the beginning of the table
1399 // to the target address.
1400 int *SlotPtr = (int*)JumpTableBase;
1402 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1403 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1404 // Store the offset of the basic block for this jump table slot in the
1405 // memory we allocated for the jump table in 'initJumpTableInfo'
1406 uintptr_t Base = (uintptr_t)SlotPtr;
1407 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) {
1408 uintptr_t MBBAddr = getMachineBasicBlockAddress(MBBs[mi]);
1409 *SlotPtr++ = TheJIT->getJITInfo().getPICJumpTableEntry(MBBAddr, Base);
1413 assert(MJTI->getEntrySize() == sizeof(void*) && "Cross JIT'ing?");
1415 // For each jump table, map each target in the jump table to the address of
1416 // an emitted MachineBasicBlock.
1417 intptr_t *SlotPtr = (intptr_t*)JumpTableBase;
1419 for (unsigned i = 0, e = JT.size(); i != e; ++i) {
1420 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs;
1421 // Store the address of the basic block for this jump table slot in the
1422 // memory we allocated for the jump table in 'initJumpTableInfo'
1423 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi)
1424 *SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]);
1429 void JITEmitter::startGVStub(BufferState &BS, const GlobalValue* GV,
1430 unsigned StubSize, unsigned Alignment) {
1433 BufferBegin = CurBufferPtr = MemMgr->allocateStub(GV, StubSize, Alignment);
1434 BufferEnd = BufferBegin+StubSize+1;
1437 void JITEmitter::startGVStub(BufferState &BS, void *Buffer, unsigned StubSize) {
1440 BufferBegin = CurBufferPtr = (uint8_t *)Buffer;
1441 BufferEnd = BufferBegin+StubSize+1;
1444 void *JITEmitter::finishGVStub(BufferState &BS) {
1445 NumBytes += getCurrentPCOffset();
1446 void *Result = BufferBegin;
1447 RestoreStateFrom(BS);
1451 // getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry
1452 // in the constant pool that was last emitted with the 'emitConstantPool'
1455 uintptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const {
1456 assert(ConstantNum < ConstantPool->getConstants().size() &&
1457 "Invalid ConstantPoolIndex!");
1458 return ConstPoolAddresses[ConstantNum];
1461 // getJumpTableEntryAddress - Return the address of the JumpTable with index
1462 // 'Index' in the jumpp table that was last initialized with 'initJumpTableInfo'
1464 uintptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const {
1465 const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables();
1466 assert(Index < JT.size() && "Invalid jump table index!");
1468 unsigned Offset = 0;
1469 unsigned EntrySize = JumpTable->getEntrySize();
1471 for (unsigned i = 0; i < Index; ++i)
1472 Offset += JT[i].MBBs.size();
1474 Offset *= EntrySize;
1476 return (uintptr_t)((char *)JumpTableBase + Offset);
1479 void JITEmitter::EmittedFunctionConfig::onDelete(
1480 JITEmitter *Emitter, const Function *F) {
1481 Emitter->deallocateMemForFunction(F);
1483 void JITEmitter::EmittedFunctionConfig::onRAUW(
1484 JITEmitter *, const Function*, const Function*) {
1485 llvm_unreachable("The JIT doesn't know how to handle a"
1486 " RAUW on a value it has emitted.");
1490 //===----------------------------------------------------------------------===//
1491 // Public interface to this file
1492 //===----------------------------------------------------------------------===//
1494 JITCodeEmitter *JIT::createEmitter(JIT &jit, JITMemoryManager *JMM,
1495 TargetMachine &tm) {
1496 return new JITEmitter(jit, JMM, tm);
1499 // getPointerToNamedFunction - This function is used as a global wrapper to
1500 // JIT::getPointerToNamedFunction for the purpose of resolving symbols when
1501 // bugpoint is debugging the JIT. In that scenario, we are loading an .so and
1502 // need to resolve function(s) that are being mis-codegenerated, so we need to
1503 // resolve their addresses at runtime, and this is the way to do it.
1505 void *getPointerToNamedFunction(const char *Name) {
1506 if (Function *F = TheJIT->FindFunctionNamed(Name))
1507 return TheJIT->getPointerToFunction(F);
1508 return TheJIT->getPointerToNamedFunction(Name);
1512 // getPointerToFunctionOrStub - If the specified function has been
1513 // code-gen'd, return a pointer to the function. If not, compile it, or use
1514 // a stub to implement lazy compilation if available.
1516 void *JIT::getPointerToFunctionOrStub(Function *F) {
1517 // If we have already code generated the function, just return the address.
1518 if (void *Addr = getPointerToGlobalIfAvailable(F))
1521 // Get a stub if the target supports it.
1522 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1523 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1524 return JE->getJITResolver().getFunctionStub(F);
1527 void JIT::updateFunctionStub(Function *F) {
1528 // Get the empty stub we generated earlier.
1529 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1530 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter());
1531 void *Stub = JE->getJITResolver().getFunctionStub(F);
1533 // Tell the target jit info to rewrite the stub at the specified address,
1534 // rather than creating a new one.
1535 void *Addr = getPointerToGlobalIfAvailable(F);
1536 getJITInfo().emitFunctionStubAtAddr(F, Addr, Stub, *getCodeEmitter());
1539 /// freeMachineCodeForFunction - release machine code memory for given Function.
1541 void JIT::freeMachineCodeForFunction(Function *F) {
1542 // Delete translation for this from the ExecutionEngine, so it will get
1543 // retranslated next time it is used.
1544 updateGlobalMapping(F, 0);
1546 // Free the actual memory for the function body and related stuff.
1547 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?");
1548 cast<JITEmitter>(JCE)->deallocateMemForFunction(F);