JITEmitter.cpp revision 13af11acbf23664d61f73ddac54bc05a9733c051
1//===-- JITEmitter.cpp - Write machine code to executable memory ----------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 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. 12// 13//===----------------------------------------------------------------------===// 14 15#define DEBUG_TYPE "jit" 16#include "JIT.h" 17#include "JITDebugRegisterer.h" 18#include "JITDwarfEmitter.h" 19#include "llvm/ADT/OwningPtr.h" 20#include "llvm/Constants.h" 21#include "llvm/Module.h" 22#include "llvm/DerivedTypes.h" 23#include "llvm/Analysis/DebugInfo.h" 24#include "llvm/CodeGen/JITCodeEmitter.h" 25#include "llvm/CodeGen/MachineFunction.h" 26#include "llvm/CodeGen/MachineConstantPool.h" 27#include "llvm/CodeGen/MachineJumpTableInfo.h" 28#include "llvm/CodeGen/MachineModuleInfo.h" 29#include "llvm/CodeGen/MachineRelocation.h" 30#include "llvm/ExecutionEngine/GenericValue.h" 31#include "llvm/ExecutionEngine/JITEventListener.h" 32#include "llvm/ExecutionEngine/JITMemoryManager.h" 33#include "llvm/CodeGen/MachineCodeInfo.h" 34#include "llvm/Target/TargetData.h" 35#include "llvm/Target/TargetJITInfo.h" 36#include "llvm/Target/TargetMachine.h" 37#include "llvm/Target/TargetOptions.h" 38#include "llvm/Support/Debug.h" 39#include "llvm/Support/ErrorHandling.h" 40#include "llvm/Support/MutexGuard.h" 41#include "llvm/Support/ValueHandle.h" 42#include "llvm/Support/raw_ostream.h" 43#include "llvm/System/Disassembler.h" 44#include "llvm/System/Memory.h" 45#include "llvm/Target/TargetInstrInfo.h" 46#include "llvm/ADT/DenseMap.h" 47#include "llvm/ADT/SmallPtrSet.h" 48#include "llvm/ADT/SmallVector.h" 49#include "llvm/ADT/Statistic.h" 50#include "llvm/ADT/ValueMap.h" 51#include <algorithm> 52#ifndef NDEBUG 53#include <iomanip> 54#endif 55using namespace llvm; 56 57STATISTIC(NumBytes, "Number of bytes of machine code compiled"); 58STATISTIC(NumRelos, "Number of relocations applied"); 59STATISTIC(NumRetries, "Number of retries with more memory"); 60static JIT *TheJIT = 0; 61 62 63// A declaration may stop being a declaration once it's fully read from bitcode. 64// This function returns true if F is fully read and is still a declaration. 65static bool isNonGhostDeclaration(const Function *F) { 66 return F->isDeclaration() && !F->hasNotBeenReadFromBitcode(); 67} 68 69//===----------------------------------------------------------------------===// 70// JIT lazy compilation code. 71// 72namespace { 73 class JITEmitter; 74 class JITResolverState; 75 76 template<typename ValueTy> 77 struct NoRAUWValueMapConfig : public ValueMapConfig<ValueTy> { 78 typedef JITResolverState *ExtraData; 79 static void onRAUW(JITResolverState *, Value *Old, Value *New) { 80 assert(false && "The JIT doesn't know how to handle a" 81 " RAUW on a value it has emitted."); 82 } 83 }; 84 85 struct CallSiteValueMapConfig : public NoRAUWValueMapConfig<Function*> { 86 typedef JITResolverState *ExtraData; 87 static void onDelete(JITResolverState *JRS, Function *F); 88 }; 89 90 class JITResolverState { 91 public: 92 typedef ValueMap<Function*, void*, NoRAUWValueMapConfig<Function*> > 93 FunctionToLazyStubMapTy; 94 typedef std::map<void*, AssertingVH<Function> > CallSiteToFunctionMapTy; 95 typedef ValueMap<Function *, SmallPtrSet<void*, 1>, 96 CallSiteValueMapConfig> FunctionToCallSitesMapTy; 97 typedef std::map<AssertingVH<GlobalValue>, void*> GlobalToIndirectSymMapTy; 98 private: 99 /// FunctionToLazyStubMap - Keep track of the lazy stub created for a 100 /// particular function so that we can reuse them if necessary. 101 FunctionToLazyStubMapTy FunctionToLazyStubMap; 102 103 /// CallSiteToFunctionMap - Keep track of the function that each lazy call 104 /// site corresponds to, and vice versa. 105 CallSiteToFunctionMapTy CallSiteToFunctionMap; 106 FunctionToCallSitesMapTy FunctionToCallSitesMap; 107 108 /// GlobalToIndirectSymMap - Keep track of the indirect symbol created for a 109 /// particular GlobalVariable so that we can reuse them if necessary. 110 GlobalToIndirectSymMapTy GlobalToIndirectSymMap; 111 112 public: 113 JITResolverState() : FunctionToLazyStubMap(this), 114 FunctionToCallSitesMap(this) {} 115 116 FunctionToLazyStubMapTy& getFunctionToLazyStubMap( 117 const MutexGuard& locked) { 118 assert(locked.holds(TheJIT->lock)); 119 return FunctionToLazyStubMap; 120 } 121 122 GlobalToIndirectSymMapTy& getGlobalToIndirectSymMap(const MutexGuard& locked) { 123 assert(locked.holds(TheJIT->lock)); 124 return GlobalToIndirectSymMap; 125 } 126 127 pair<void *, Function *> LookupFunctionFromCallSite( 128 const MutexGuard &locked, void *CallSite) const { 129 assert(locked.holds(TheJIT->lock)); 130 131 // The address given to us for the stub may not be exactly right, it might be 132 // a little bit after the stub. As such, use upper_bound to find it. 133 CallSiteToFunctionMapTy::const_iterator I = 134 CallSiteToFunctionMap.upper_bound(CallSite); 135 assert(I != CallSiteToFunctionMap.begin() && 136 "This is not a known call site!"); 137 --I; 138 return *I; 139 } 140 141 void AddCallSite(const MutexGuard &locked, void *CallSite, Function *F) { 142 assert(locked.holds(TheJIT->lock)); 143 144 bool Inserted = CallSiteToFunctionMap.insert( 145 std::make_pair(CallSite, F)).second; 146 (void)Inserted; 147 assert(Inserted && "Pair was already in CallSiteToFunctionMap"); 148 FunctionToCallSitesMap[F].insert(CallSite); 149 } 150 151 // Returns the Function of the stub if a stub was erased, or NULL if there 152 // was no stub. This function uses the call-site->function map to find a 153 // relevant function, but asserts that only stubs and not other call sites 154 // will be passed in. 155 Function *EraseStub(const MutexGuard &locked, void *Stub) { 156 CallSiteToFunctionMapTy::iterator C2F_I = 157 CallSiteToFunctionMap.find(Stub); 158 if (C2F_I == CallSiteToFunctionMap.end()) { 159 // Not a stub. 160 return NULL; 161 } 162 163 Function *const F = C2F_I->second; 164#ifndef NDEBUG 165 void *RealStub = FunctionToLazyStubMap.lookup(F); 166 assert(RealStub == Stub && 167 "Call-site that wasn't a stub pass in to EraseStub"); 168#endif 169 FunctionToLazyStubMap.erase(F); 170 CallSiteToFunctionMap.erase(C2F_I); 171 172 // Remove the stub from the function->call-sites map, and remove the whole 173 // entry from the map if that was the last call site. 174 FunctionToCallSitesMapTy::iterator F2C_I = FunctionToCallSitesMap.find(F); 175 assert(F2C_I != FunctionToCallSitesMap.end() && 176 "FunctionToCallSitesMap broken"); 177 bool Erased = F2C_I->second.erase(Stub); 178 (void)Erased; 179 assert(Erased && "FunctionToCallSitesMap broken"); 180 if (F2C_I->second.empty()) 181 FunctionToCallSitesMap.erase(F2C_I); 182 183 return F; 184 } 185 186 void EraseAllCallSites(const MutexGuard &locked, Function *F) { 187 assert(locked.holds(TheJIT->lock)); 188 EraseAllCallSitesPrelocked(F); 189 } 190 void EraseAllCallSitesPrelocked(Function *F) { 191 FunctionToCallSitesMapTy::iterator F2C = FunctionToCallSitesMap.find(F); 192 if (F2C == FunctionToCallSitesMap.end()) 193 return; 194 for (SmallPtrSet<void*, 1>::const_iterator I = F2C->second.begin(), 195 E = F2C->second.end(); I != E; ++I) { 196 bool Erased = CallSiteToFunctionMap.erase(*I); 197 (void)Erased; 198 assert(Erased && "Missing call site->function mapping"); 199 } 200 FunctionToCallSitesMap.erase(F2C); 201 } 202 }; 203 204 /// JITResolver - Keep track of, and resolve, call sites for functions that 205 /// have not yet been compiled. 206 class JITResolver { 207 typedef JITResolverState::FunctionToLazyStubMapTy FunctionToLazyStubMapTy; 208 typedef JITResolverState::CallSiteToFunctionMapTy CallSiteToFunctionMapTy; 209 typedef JITResolverState::GlobalToIndirectSymMapTy GlobalToIndirectSymMapTy; 210 211 /// LazyResolverFn - The target lazy resolver function that we actually 212 /// rewrite instructions to use. 213 TargetJITInfo::LazyResolverFn LazyResolverFn; 214 215 JITResolverState state; 216 217 /// ExternalFnToStubMap - This is the equivalent of FunctionToLazyStubMap 218 /// for external functions. TODO: Of course, external functions don't need 219 /// a lazy stub. It's actually here to make it more likely that far calls 220 /// succeed, but no single stub can guarantee that. I'll remove this in a 221 /// subsequent checkin when I actually fix far calls. 222 std::map<void*, void*> ExternalFnToStubMap; 223 224 /// revGOTMap - map addresses to indexes in the GOT 225 std::map<void*, unsigned> revGOTMap; 226 unsigned nextGOTIndex; 227 228 JITEmitter &JE; 229 230 static JITResolver *TheJITResolver; 231 public: 232 explicit JITResolver(JIT &jit, JITEmitter &je) : nextGOTIndex(0), JE(je) { 233 TheJIT = &jit; 234 235 LazyResolverFn = jit.getJITInfo().getLazyResolverFunction(JITCompilerFn); 236 assert(TheJITResolver == 0 && "Multiple JIT resolvers?"); 237 TheJITResolver = this; 238 } 239 240 ~JITResolver() { 241 TheJITResolver = 0; 242 } 243 244 /// getLazyFunctionStubIfAvailable - This returns a pointer to a function's 245 /// lazy-compilation stub if it has already been created. 246 void *getLazyFunctionStubIfAvailable(Function *F); 247 248 /// getLazyFunctionStub - This returns a pointer to a function's 249 /// lazy-compilation stub, creating one on demand as needed. 250 void *getLazyFunctionStub(Function *F); 251 252 /// getExternalFunctionStub - Return a stub for the function at the 253 /// specified address, created lazily on demand. 254 void *getExternalFunctionStub(void *FnAddr); 255 256 /// getGlobalValueIndirectSym - Return an indirect symbol containing the 257 /// specified GV address. 258 void *getGlobalValueIndirectSym(GlobalValue *V, void *GVAddress); 259 260 void getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs, 261 SmallVectorImpl<void*> &Ptrs); 262 263 GlobalValue *invalidateStub(void *Stub); 264 265 /// getGOTIndexForAddress - Return a new or existing index in the GOT for 266 /// an address. This function only manages slots, it does not manage the 267 /// contents of the slots or the memory associated with the GOT. 268 unsigned getGOTIndexForAddr(void *addr); 269 270 /// JITCompilerFn - This function is called to resolve a stub to a compiled 271 /// address. If the LLVM Function corresponding to the stub has not yet 272 /// been compiled, this function compiles it first. 273 static void *JITCompilerFn(void *Stub); 274 }; 275 276 /// JITEmitter - The JIT implementation of the MachineCodeEmitter, which is 277 /// used to output functions to memory for execution. 278 class JITEmitter : public JITCodeEmitter { 279 JITMemoryManager *MemMgr; 280 281 // When outputting a function stub in the context of some other function, we 282 // save BufferBegin/BufferEnd/CurBufferPtr here. 283 uint8_t *SavedBufferBegin, *SavedBufferEnd, *SavedCurBufferPtr; 284 285 // When reattempting to JIT a function after running out of space, we store 286 // the estimated size of the function we're trying to JIT here, so we can 287 // ask the memory manager for at least this much space. When we 288 // successfully emit the function, we reset this back to zero. 289 uintptr_t SizeEstimate; 290 291 /// Relocations - These are the relocations that the function needs, as 292 /// emitted. 293 std::vector<MachineRelocation> Relocations; 294 295 /// MBBLocations - This vector is a mapping from MBB ID's to their address. 296 /// It is filled in by the StartMachineBasicBlock callback and queried by 297 /// the getMachineBasicBlockAddress callback. 298 std::vector<uintptr_t> MBBLocations; 299 300 /// ConstantPool - The constant pool for the current function. 301 /// 302 MachineConstantPool *ConstantPool; 303 304 /// ConstantPoolBase - A pointer to the first entry in the constant pool. 305 /// 306 void *ConstantPoolBase; 307 308 /// ConstPoolAddresses - Addresses of individual constant pool entries. 309 /// 310 SmallVector<uintptr_t, 8> ConstPoolAddresses; 311 312 /// JumpTable - The jump tables for the current function. 313 /// 314 MachineJumpTableInfo *JumpTable; 315 316 /// JumpTableBase - A pointer to the first entry in the jump table. 317 /// 318 void *JumpTableBase; 319 320 /// Resolver - This contains info about the currently resolved functions. 321 JITResolver Resolver; 322 323 /// DE - The dwarf emitter for the jit. 324 OwningPtr<JITDwarfEmitter> DE; 325 326 /// DR - The debug registerer for the jit. 327 OwningPtr<JITDebugRegisterer> DR; 328 329 /// LabelLocations - This vector is a mapping from Label ID's to their 330 /// address. 331 std::vector<uintptr_t> LabelLocations; 332 333 /// MMI - Machine module info for exception informations 334 MachineModuleInfo* MMI; 335 336 // GVSet - a set to keep track of which globals have been seen 337 SmallPtrSet<const GlobalVariable*, 8> GVSet; 338 339 // CurFn - The llvm function being emitted. Only valid during 340 // finishFunction(). 341 const Function *CurFn; 342 343 /// Information about emitted code, which is passed to the 344 /// JITEventListeners. This is reset in startFunction and used in 345 /// finishFunction. 346 JITEvent_EmittedFunctionDetails EmissionDetails; 347 348 struct EmittedCode { 349 void *FunctionBody; // Beginning of the function's allocation. 350 void *Code; // The address the function's code actually starts at. 351 void *ExceptionTable; 352 EmittedCode() : FunctionBody(0), Code(0), ExceptionTable(0) {} 353 }; 354 struct EmittedFunctionConfig : public ValueMapConfig<const Function*> { 355 typedef JITEmitter *ExtraData; 356 static void onDelete(JITEmitter *, const Function*); 357 static void onRAUW(JITEmitter *, const Function*, const Function*); 358 }; 359 ValueMap<const Function *, EmittedCode, 360 EmittedFunctionConfig> EmittedFunctions; 361 362 // CurFnStubUses - For a given Function, a vector of stubs that it 363 // references. This facilitates the JIT detecting that a stub is no 364 // longer used, so that it may be deallocated. 365 DenseMap<AssertingVH<const Function>, SmallVector<void*, 1> > CurFnStubUses; 366 367 // StubFnRefs - For a given pointer to a stub, a set of Functions which 368 // reference the stub. When the count of a stub's references drops to zero, 369 // the stub is unused. 370 DenseMap<void *, SmallPtrSet<const Function*, 1> > StubFnRefs; 371 372 DILocation PrevDLT; 373 374 public: 375 JITEmitter(JIT &jit, JITMemoryManager *JMM, TargetMachine &TM) 376 : SizeEstimate(0), Resolver(jit, *this), MMI(0), CurFn(0), 377 EmittedFunctions(this), PrevDLT(NULL) { 378 MemMgr = JMM ? JMM : JITMemoryManager::CreateDefaultMemManager(); 379 if (jit.getJITInfo().needsGOT()) { 380 MemMgr->AllocateGOT(); 381 DEBUG(dbgs() << "JIT is managing a GOT\n"); 382 } 383 384 if (DwarfExceptionHandling || JITEmitDebugInfo) { 385 DE.reset(new JITDwarfEmitter(jit)); 386 } 387 if (JITEmitDebugInfo) { 388 DR.reset(new JITDebugRegisterer(TM)); 389 } 390 } 391 ~JITEmitter() { 392 delete MemMgr; 393 } 394 395 /// classof - Methods for support type inquiry through isa, cast, and 396 /// dyn_cast: 397 /// 398 static inline bool classof(const JITEmitter*) { return true; } 399 static inline bool classof(const MachineCodeEmitter*) { return true; } 400 401 JITResolver &getJITResolver() { return Resolver; } 402 403 virtual void startFunction(MachineFunction &F); 404 virtual bool finishFunction(MachineFunction &F); 405 406 void emitConstantPool(MachineConstantPool *MCP); 407 void initJumpTableInfo(MachineJumpTableInfo *MJTI); 408 void emitJumpTableInfo(MachineJumpTableInfo *MJTI); 409 410 void startGVStub(const GlobalValue* GV, 411 unsigned StubSize, unsigned Alignment = 1); 412 void startGVStub(void *Buffer, unsigned StubSize); 413 void finishGVStub(); 414 virtual void *allocIndirectGV(const GlobalValue *GV, 415 const uint8_t *Buffer, size_t Size, 416 unsigned Alignment); 417 418 /// allocateSpace - Reserves space in the current block if any, or 419 /// allocate a new one of the given size. 420 virtual void *allocateSpace(uintptr_t Size, unsigned Alignment); 421 422 /// allocateGlobal - Allocate memory for a global. Unlike allocateSpace, 423 /// this method does not allocate memory in the current output buffer, 424 /// because a global may live longer than the current function. 425 virtual void *allocateGlobal(uintptr_t Size, unsigned Alignment); 426 427 virtual void addRelocation(const MachineRelocation &MR) { 428 Relocations.push_back(MR); 429 } 430 431 virtual void StartMachineBasicBlock(MachineBasicBlock *MBB) { 432 if (MBBLocations.size() <= (unsigned)MBB->getNumber()) 433 MBBLocations.resize((MBB->getNumber()+1)*2); 434 MBBLocations[MBB->getNumber()] = getCurrentPCValue(); 435 DEBUG(dbgs() << "JIT: Emitting BB" << MBB->getNumber() << " at [" 436 << (void*) getCurrentPCValue() << "]\n"); 437 } 438 439 virtual uintptr_t getConstantPoolEntryAddress(unsigned Entry) const; 440 virtual uintptr_t getJumpTableEntryAddress(unsigned Entry) const; 441 442 virtual uintptr_t getMachineBasicBlockAddress(MachineBasicBlock *MBB) const { 443 assert(MBBLocations.size() > (unsigned)MBB->getNumber() && 444 MBBLocations[MBB->getNumber()] && "MBB not emitted!"); 445 return MBBLocations[MBB->getNumber()]; 446 } 447 448 /// retryWithMoreMemory - Log a retry and deallocate all memory for the 449 /// given function. Increase the minimum allocation size so that we get 450 /// more memory next time. 451 void retryWithMoreMemory(MachineFunction &F); 452 453 /// deallocateMemForFunction - Deallocate all memory for the specified 454 /// function body. 455 void deallocateMemForFunction(const Function *F); 456 457 /// AddStubToCurrentFunction - Mark the current function being JIT'd as 458 /// using the stub at the specified address. Allows 459 /// deallocateMemForFunction to also remove stubs no longer referenced. 460 void AddStubToCurrentFunction(void *Stub); 461 462 virtual void processDebugLoc(DebugLoc DL, bool BeforePrintingInsn); 463 464 virtual void emitLabel(uint64_t LabelID) { 465 if (LabelLocations.size() <= LabelID) 466 LabelLocations.resize((LabelID+1)*2); 467 LabelLocations[LabelID] = getCurrentPCValue(); 468 } 469 470 virtual uintptr_t getLabelAddress(uint64_t LabelID) const { 471 assert(LabelLocations.size() > (unsigned)LabelID && 472 LabelLocations[LabelID] && "Label not emitted!"); 473 return LabelLocations[LabelID]; 474 } 475 476 virtual void setModuleInfo(MachineModuleInfo* Info) { 477 MMI = Info; 478 if (DE.get()) DE->setModuleInfo(Info); 479 } 480 481 void setMemoryExecutable() { 482 MemMgr->setMemoryExecutable(); 483 } 484 485 JITMemoryManager *getMemMgr() const { return MemMgr; } 486 487 private: 488 void *getPointerToGlobal(GlobalValue *GV, void *Reference, 489 bool MayNeedFarStub); 490 void *getPointerToGVIndirectSym(GlobalValue *V, void *Reference); 491 unsigned addSizeOfGlobal(const GlobalVariable *GV, unsigned Size); 492 unsigned addSizeOfGlobalsInConstantVal(const Constant *C, unsigned Size); 493 unsigned addSizeOfGlobalsInInitializer(const Constant *Init, unsigned Size); 494 unsigned GetSizeOfGlobalsInBytes(MachineFunction &MF); 495 }; 496} 497 498JITResolver *JITResolver::TheJITResolver = 0; 499 500void CallSiteValueMapConfig::onDelete(JITResolverState *JRS, Function *F) { 501 JRS->EraseAllCallSitesPrelocked(F); 502} 503 504/// getLazyFunctionStubIfAvailable - This returns a pointer to a function stub 505/// if it has already been created. 506void *JITResolver::getLazyFunctionStubIfAvailable(Function *F) { 507 MutexGuard locked(TheJIT->lock); 508 509 // If we already have a stub for this function, recycle it. 510 return state.getFunctionToLazyStubMap(locked).lookup(F); 511} 512 513/// getFunctionStub - This returns a pointer to a function stub, creating 514/// one on demand as needed. 515void *JITResolver::getLazyFunctionStub(Function *F) { 516 MutexGuard locked(TheJIT->lock); 517 518 // If we already have a lazy stub for this function, recycle it. 519 void *&Stub = state.getFunctionToLazyStubMap(locked)[F]; 520 if (Stub) return Stub; 521 522 // Call the lazy resolver function if we are JIT'ing lazily. Otherwise we 523 // must resolve the symbol now. 524 void *Actual = TheJIT->isCompilingLazily() 525 ? (void *)(intptr_t)LazyResolverFn : (void *)0; 526 527 // If this is an external declaration, attempt to resolve the address now 528 // to place in the stub. 529 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage()) { 530 Actual = TheJIT->getPointerToFunction(F); 531 532 // If we resolved the symbol to a null address (eg. a weak external) 533 // don't emit a stub. Return a null pointer to the application. 534 if (!Actual) return 0; 535 } 536 537 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout(); 538 JE.startGVStub(F, SL.Size, SL.Alignment); 539 // Codegen a new stub, calling the lazy resolver or the actual address of the 540 // external function, if it was resolved. 541 Stub = TheJIT->getJITInfo().emitFunctionStub(F, Actual, JE); 542 JE.finishGVStub(); 543 544 if (Actual != (void*)(intptr_t)LazyResolverFn) { 545 // If we are getting the stub for an external function, we really want the 546 // address of the stub in the GlobalAddressMap for the JIT, not the address 547 // of the external function. 548 TheJIT->updateGlobalMapping(F, Stub); 549 } 550 551 DEBUG(dbgs() << "JIT: Lazy stub emitted at [" << Stub << "] for function '" 552 << F->getName() << "'\n"); 553 554 // Finally, keep track of the stub-to-Function mapping so that the 555 // JITCompilerFn knows which function to compile! 556 state.AddCallSite(locked, Stub, F); 557 558 // If we are JIT'ing non-lazily but need to call a function that does not 559 // exist yet, add it to the JIT's work list so that we can fill in the stub 560 // address later. 561 if (!Actual && !TheJIT->isCompilingLazily()) 562 if (!isNonGhostDeclaration(F) && !F->hasAvailableExternallyLinkage()) 563 TheJIT->addPendingFunction(F); 564 565 return Stub; 566} 567 568/// getGlobalValueIndirectSym - Return a lazy pointer containing the specified 569/// GV address. 570void *JITResolver::getGlobalValueIndirectSym(GlobalValue *GV, void *GVAddress) { 571 MutexGuard locked(TheJIT->lock); 572 573 // If we already have a stub for this global variable, recycle it. 574 void *&IndirectSym = state.getGlobalToIndirectSymMap(locked)[GV]; 575 if (IndirectSym) return IndirectSym; 576 577 // Otherwise, codegen a new indirect symbol. 578 IndirectSym = TheJIT->getJITInfo().emitGlobalValueIndirectSym(GV, GVAddress, 579 JE); 580 581 DEBUG(dbgs() << "JIT: Indirect symbol emitted at [" << IndirectSym 582 << "] for GV '" << GV->getName() << "'\n"); 583 584 return IndirectSym; 585} 586 587/// getExternalFunctionStub - Return a stub for the function at the 588/// specified address, created lazily on demand. 589void *JITResolver::getExternalFunctionStub(void *FnAddr) { 590 // If we already have a stub for this function, recycle it. 591 void *&Stub = ExternalFnToStubMap[FnAddr]; 592 if (Stub) return Stub; 593 594 TargetJITInfo::StubLayout SL = TheJIT->getJITInfo().getStubLayout(); 595 JE.startGVStub(0, SL.Size, SL.Alignment); 596 Stub = TheJIT->getJITInfo().emitFunctionStub(0, FnAddr, JE); 597 JE.finishGVStub(); 598 599 DEBUG(dbgs() << "JIT: Stub emitted at [" << Stub 600 << "] for external function at '" << FnAddr << "'\n"); 601 return Stub; 602} 603 604unsigned JITResolver::getGOTIndexForAddr(void* addr) { 605 unsigned idx = revGOTMap[addr]; 606 if (!idx) { 607 idx = ++nextGOTIndex; 608 revGOTMap[addr] = idx; 609 DEBUG(dbgs() << "JIT: Adding GOT entry " << idx << " for addr [" 610 << addr << "]\n"); 611 } 612 return idx; 613} 614 615void JITResolver::getRelocatableGVs(SmallVectorImpl<GlobalValue*> &GVs, 616 SmallVectorImpl<void*> &Ptrs) { 617 MutexGuard locked(TheJIT->lock); 618 619 const FunctionToLazyStubMapTy &FM = state.getFunctionToLazyStubMap(locked); 620 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked); 621 622 for (FunctionToLazyStubMapTy::const_iterator i = FM.begin(), e = FM.end(); 623 i != e; ++i){ 624 Function *F = i->first; 625 if (F->isDeclaration() && F->hasExternalLinkage()) { 626 GVs.push_back(i->first); 627 Ptrs.push_back(i->second); 628 } 629 } 630 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end(); 631 i != e; ++i) { 632 GVs.push_back(i->first); 633 Ptrs.push_back(i->second); 634 } 635} 636 637GlobalValue *JITResolver::invalidateStub(void *Stub) { 638 MutexGuard locked(TheJIT->lock); 639 640 GlobalToIndirectSymMapTy &GM = state.getGlobalToIndirectSymMap(locked); 641 642 // Look up the cheap way first, to see if it's a function stub we are 643 // invalidating. If so, remove it from both the forward and reverse maps. 644 if (Function *F = state.EraseStub(locked, Stub)) { 645 return F; 646 } 647 648 // Otherwise, it might be an indirect symbol stub. Find it and remove it. 649 for (GlobalToIndirectSymMapTy::iterator i = GM.begin(), e = GM.end(); 650 i != e; ++i) { 651 if (i->second != Stub) 652 continue; 653 GlobalValue *GV = i->first; 654 GM.erase(i); 655 return GV; 656 } 657 658 // Lastly, check to see if it's in the ExternalFnToStubMap. 659 for (std::map<void *, void *>::iterator i = ExternalFnToStubMap.begin(), 660 e = ExternalFnToStubMap.end(); i != e; ++i) { 661 if (i->second != Stub) 662 continue; 663 ExternalFnToStubMap.erase(i); 664 break; 665 } 666 667 return 0; 668} 669 670/// JITCompilerFn - This function is called when a lazy compilation stub has 671/// been entered. It looks up which function this stub corresponds to, compiles 672/// it if necessary, then returns the resultant function pointer. 673void *JITResolver::JITCompilerFn(void *Stub) { 674 JITResolver &JR = *TheJITResolver; 675 676 Function* F = 0; 677 void* ActualPtr = 0; 678 679 { 680 // Only lock for getting the Function. The call getPointerToFunction made 681 // in this function might trigger function materializing, which requires 682 // JIT lock to be unlocked. 683 MutexGuard locked(TheJIT->lock); 684 685 // The address given to us for the stub may not be exactly right, it might 686 // be a little bit after the stub. As such, use upper_bound to find it. 687 pair<void*, Function*> I = 688 JR.state.LookupFunctionFromCallSite(locked, Stub); 689 F = I.second; 690 ActualPtr = I.first; 691 } 692 693 // If we have already code generated the function, just return the address. 694 void *Result = TheJIT->getPointerToGlobalIfAvailable(F); 695 696 if (!Result) { 697 // Otherwise we don't have it, do lazy compilation now. 698 699 // If lazy compilation is disabled, emit a useful error message and abort. 700 if (!TheJIT->isCompilingLazily()) { 701 llvm_report_error("LLVM JIT requested to do lazy compilation of function '" 702 + F->getName() + "' when lazy compiles are disabled!"); 703 } 704 705 DEBUG(dbgs() << "JIT: Lazily resolving function '" << F->getName() 706 << "' In stub ptr = " << Stub << " actual ptr = " 707 << ActualPtr << "\n"); 708 709 Result = TheJIT->getPointerToFunction(F); 710 } 711 712 // Reacquire the lock to update the GOT map. 713 MutexGuard locked(TheJIT->lock); 714 715 // We might like to remove the call site from the CallSiteToFunction map, but 716 // we can't do that! Multiple threads could be stuck, waiting to acquire the 717 // lock above. As soon as the 1st function finishes compiling the function, 718 // the next one will be released, and needs to be able to find the function it 719 // needs to call. 720 721 // FIXME: We could rewrite all references to this stub if we knew them. 722 723 // What we will do is set the compiled function address to map to the 724 // same GOT entry as the stub so that later clients may update the GOT 725 // if they see it still using the stub address. 726 // Note: this is done so the Resolver doesn't have to manage GOT memory 727 // Do this without allocating map space if the target isn't using a GOT 728 if(JR.revGOTMap.find(Stub) != JR.revGOTMap.end()) 729 JR.revGOTMap[Result] = JR.revGOTMap[Stub]; 730 731 return Result; 732} 733 734//===----------------------------------------------------------------------===// 735// JITEmitter code. 736// 737void *JITEmitter::getPointerToGlobal(GlobalValue *V, void *Reference, 738 bool MayNeedFarStub) { 739 if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) 740 return TheJIT->getOrEmitGlobalVariable(GV); 741 742 if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V)) 743 return TheJIT->getPointerToGlobal(GA->resolveAliasedGlobal(false)); 744 745 // If we have already compiled the function, return a pointer to its body. 746 Function *F = cast<Function>(V); 747 748 void *FnStub = Resolver.getLazyFunctionStubIfAvailable(F); 749 if (FnStub) { 750 // Return the function stub if it's already created. We do this first so 751 // that we're returning the same address for the function as any previous 752 // call. TODO: Yes, this is wrong. The lazy stub isn't guaranteed to be 753 // close enough to call. 754 AddStubToCurrentFunction(FnStub); 755 return FnStub; 756 } 757 758 // If we know the target can handle arbitrary-distance calls, try to 759 // return a direct pointer. 760 if (!MayNeedFarStub) { 761 // If we have code, go ahead and return that. 762 void *ResultPtr = TheJIT->getPointerToGlobalIfAvailable(F); 763 if (ResultPtr) return ResultPtr; 764 765 // If this is an external function pointer, we can force the JIT to 766 // 'compile' it, which really just adds it to the map. 767 if (isNonGhostDeclaration(F) || F->hasAvailableExternallyLinkage()) 768 return TheJIT->getPointerToFunction(F); 769 } 770 771 // Otherwise, we may need a to emit a stub, and, conservatively, we 772 // always do so. 773 void *StubAddr = Resolver.getLazyFunctionStub(F); 774 775 // Add the stub to the current function's list of referenced stubs, so we can 776 // deallocate them if the current function is ever freed. It's possible to 777 // return null from getLazyFunctionStub in the case of a weak extern that 778 // fails to resolve. 779 if (StubAddr) 780 AddStubToCurrentFunction(StubAddr); 781 782 return StubAddr; 783} 784 785void *JITEmitter::getPointerToGVIndirectSym(GlobalValue *V, void *Reference) { 786 // Make sure GV is emitted first, and create a stub containing the fully 787 // resolved address. 788 void *GVAddress = getPointerToGlobal(V, Reference, false); 789 void *StubAddr = Resolver.getGlobalValueIndirectSym(V, GVAddress); 790 791 // Add the stub to the current function's list of referenced stubs, so we can 792 // deallocate them if the current function is ever freed. 793 AddStubToCurrentFunction(StubAddr); 794 795 return StubAddr; 796} 797 798void JITEmitter::AddStubToCurrentFunction(void *StubAddr) { 799 assert(CurFn && "Stub added to current function, but current function is 0!"); 800 801 SmallVectorImpl<void*> &StubsUsed = CurFnStubUses[CurFn]; 802 StubsUsed.push_back(StubAddr); 803 804 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[StubAddr]; 805 FnRefs.insert(CurFn); 806} 807 808void JITEmitter::processDebugLoc(DebugLoc DL, bool BeforePrintingInsn) { 809 if (!DL.isUnknown()) { 810 DILocation CurDLT = EmissionDetails.MF->getDILocation(DL); 811 812 if (BeforePrintingInsn) { 813 if (CurDLT.getScope().getNode() != 0 814 && PrevDLT.getNode() != CurDLT.getNode()) { 815 JITEvent_EmittedFunctionDetails::LineStart NextLine; 816 NextLine.Address = getCurrentPCValue(); 817 NextLine.Loc = DL; 818 EmissionDetails.LineStarts.push_back(NextLine); 819 } 820 821 PrevDLT = CurDLT; 822 } 823 } 824} 825 826static unsigned GetConstantPoolSizeInBytes(MachineConstantPool *MCP, 827 const TargetData *TD) { 828 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants(); 829 if (Constants.empty()) return 0; 830 831 unsigned Size = 0; 832 for (unsigned i = 0, e = Constants.size(); i != e; ++i) { 833 MachineConstantPoolEntry CPE = Constants[i]; 834 unsigned AlignMask = CPE.getAlignment() - 1; 835 Size = (Size + AlignMask) & ~AlignMask; 836 const Type *Ty = CPE.getType(); 837 Size += TD->getTypeAllocSize(Ty); 838 } 839 return Size; 840} 841 842static unsigned GetJumpTableSizeInBytes(MachineJumpTableInfo *MJTI) { 843 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 844 if (JT.empty()) return 0; 845 846 unsigned NumEntries = 0; 847 for (unsigned i = 0, e = JT.size(); i != e; ++i) 848 NumEntries += JT[i].MBBs.size(); 849 850 return NumEntries * MJTI->getEntrySize(*TheJIT->getTargetData()); 851} 852 853static uintptr_t RoundUpToAlign(uintptr_t Size, unsigned Alignment) { 854 if (Alignment == 0) Alignment = 1; 855 // Since we do not know where the buffer will be allocated, be pessimistic. 856 return Size + Alignment; 857} 858 859/// addSizeOfGlobal - add the size of the global (plus any alignment padding) 860/// into the running total Size. 861 862unsigned JITEmitter::addSizeOfGlobal(const GlobalVariable *GV, unsigned Size) { 863 const Type *ElTy = GV->getType()->getElementType(); 864 size_t GVSize = (size_t)TheJIT->getTargetData()->getTypeAllocSize(ElTy); 865 size_t GVAlign = 866 (size_t)TheJIT->getTargetData()->getPreferredAlignment(GV); 867 DEBUG(dbgs() << "JIT: Adding in size " << GVSize << " alignment " << GVAlign); 868 DEBUG(GV->dump()); 869 // Assume code section ends with worst possible alignment, so first 870 // variable needs maximal padding. 871 if (Size==0) 872 Size = 1; 873 Size = ((Size+GVAlign-1)/GVAlign)*GVAlign; 874 Size += GVSize; 875 return Size; 876} 877 878/// addSizeOfGlobalsInConstantVal - find any globals that we haven't seen yet 879/// but are referenced from the constant; put them in GVSet and add their 880/// size into the running total Size. 881 882unsigned JITEmitter::addSizeOfGlobalsInConstantVal(const Constant *C, 883 unsigned Size) { 884 // If its undefined, return the garbage. 885 if (isa<UndefValue>(C)) 886 return Size; 887 888 // If the value is a ConstantExpr 889 if (const ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) { 890 Constant *Op0 = CE->getOperand(0); 891 switch (CE->getOpcode()) { 892 case Instruction::GetElementPtr: 893 case Instruction::Trunc: 894 case Instruction::ZExt: 895 case Instruction::SExt: 896 case Instruction::FPTrunc: 897 case Instruction::FPExt: 898 case Instruction::UIToFP: 899 case Instruction::SIToFP: 900 case Instruction::FPToUI: 901 case Instruction::FPToSI: 902 case Instruction::PtrToInt: 903 case Instruction::IntToPtr: 904 case Instruction::BitCast: { 905 Size = addSizeOfGlobalsInConstantVal(Op0, Size); 906 break; 907 } 908 case Instruction::Add: 909 case Instruction::FAdd: 910 case Instruction::Sub: 911 case Instruction::FSub: 912 case Instruction::Mul: 913 case Instruction::FMul: 914 case Instruction::UDiv: 915 case Instruction::SDiv: 916 case Instruction::URem: 917 case Instruction::SRem: 918 case Instruction::And: 919 case Instruction::Or: 920 case Instruction::Xor: { 921 Size = addSizeOfGlobalsInConstantVal(Op0, Size); 922 Size = addSizeOfGlobalsInConstantVal(CE->getOperand(1), Size); 923 break; 924 } 925 default: { 926 std::string msg; 927 raw_string_ostream Msg(msg); 928 Msg << "ConstantExpr not handled: " << *CE; 929 llvm_report_error(Msg.str()); 930 } 931 } 932 } 933 934 if (C->getType()->getTypeID() == Type::PointerTyID) 935 if (const GlobalVariable* GV = dyn_cast<GlobalVariable>(C)) 936 if (GVSet.insert(GV)) 937 Size = addSizeOfGlobal(GV, Size); 938 939 return Size; 940} 941 942/// addSizeOfGLobalsInInitializer - handle any globals that we haven't seen yet 943/// but are referenced from the given initializer. 944 945unsigned JITEmitter::addSizeOfGlobalsInInitializer(const Constant *Init, 946 unsigned Size) { 947 if (!isa<UndefValue>(Init) && 948 !isa<ConstantVector>(Init) && 949 !isa<ConstantAggregateZero>(Init) && 950 !isa<ConstantArray>(Init) && 951 !isa<ConstantStruct>(Init) && 952 Init->getType()->isFirstClassType()) 953 Size = addSizeOfGlobalsInConstantVal(Init, Size); 954 return Size; 955} 956 957/// GetSizeOfGlobalsInBytes - walk the code for the function, looking for 958/// globals; then walk the initializers of those globals looking for more. 959/// If their size has not been considered yet, add it into the running total 960/// Size. 961 962unsigned JITEmitter::GetSizeOfGlobalsInBytes(MachineFunction &MF) { 963 unsigned Size = 0; 964 GVSet.clear(); 965 966 for (MachineFunction::iterator MBB = MF.begin(), E = MF.end(); 967 MBB != E; ++MBB) { 968 for (MachineBasicBlock::const_iterator I = MBB->begin(), E = MBB->end(); 969 I != E; ++I) { 970 const TargetInstrDesc &Desc = I->getDesc(); 971 const MachineInstr &MI = *I; 972 unsigned NumOps = Desc.getNumOperands(); 973 for (unsigned CurOp = 0; CurOp < NumOps; CurOp++) { 974 const MachineOperand &MO = MI.getOperand(CurOp); 975 if (MO.isGlobal()) { 976 GlobalValue* V = MO.getGlobal(); 977 const GlobalVariable *GV = dyn_cast<const GlobalVariable>(V); 978 if (!GV) 979 continue; 980 // If seen in previous function, it will have an entry here. 981 if (TheJIT->getPointerToGlobalIfAvailable(GV)) 982 continue; 983 // If seen earlier in this function, it will have an entry here. 984 // FIXME: it should be possible to combine these tables, by 985 // assuming the addresses of the new globals in this module 986 // start at 0 (or something) and adjusting them after codegen 987 // complete. Another possibility is to grab a marker bit in GV. 988 if (GVSet.insert(GV)) 989 // A variable as yet unseen. Add in its size. 990 Size = addSizeOfGlobal(GV, Size); 991 } 992 } 993 } 994 } 995 DEBUG(dbgs() << "JIT: About to look through initializers\n"); 996 // Look for more globals that are referenced only from initializers. 997 // GVSet.end is computed each time because the set can grow as we go. 998 for (SmallPtrSet<const GlobalVariable *, 8>::iterator I = GVSet.begin(); 999 I != GVSet.end(); I++) { 1000 const GlobalVariable* GV = *I; 1001 if (GV->hasInitializer()) 1002 Size = addSizeOfGlobalsInInitializer(GV->getInitializer(), Size); 1003 } 1004 1005 return Size; 1006} 1007 1008void JITEmitter::startFunction(MachineFunction &F) { 1009 DEBUG(dbgs() << "JIT: Starting CodeGen of Function " 1010 << F.getFunction()->getName() << "\n"); 1011 1012 uintptr_t ActualSize = 0; 1013 // Set the memory writable, if it's not already 1014 MemMgr->setMemoryWritable(); 1015 if (MemMgr->NeedsExactSize()) { 1016 DEBUG(dbgs() << "JIT: ExactSize\n"); 1017 const TargetInstrInfo* TII = F.getTarget().getInstrInfo(); 1018 MachineConstantPool *MCP = F.getConstantPool(); 1019 1020 // Ensure the constant pool/jump table info is at least 4-byte aligned. 1021 ActualSize = RoundUpToAlign(ActualSize, 16); 1022 1023 // Add the alignment of the constant pool 1024 ActualSize = RoundUpToAlign(ActualSize, MCP->getConstantPoolAlignment()); 1025 1026 // Add the constant pool size 1027 ActualSize += GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData()); 1028 1029 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo()) { 1030 // Add the aligment of the jump table info 1031 ActualSize = RoundUpToAlign(ActualSize, 1032 MJTI->getEntryAlignment(*TheJIT->getTargetData())); 1033 1034 // Add the jump table size 1035 ActualSize += GetJumpTableSizeInBytes(MJTI); 1036 } 1037 1038 // Add the alignment for the function 1039 ActualSize = RoundUpToAlign(ActualSize, 1040 std::max(F.getFunction()->getAlignment(), 8U)); 1041 1042 // Add the function size 1043 ActualSize += TII->GetFunctionSizeInBytes(F); 1044 1045 DEBUG(dbgs() << "JIT: ActualSize before globals " << ActualSize << "\n"); 1046 // Add the size of the globals that will be allocated after this function. 1047 // These are all the ones referenced from this function that were not 1048 // previously allocated. 1049 ActualSize += GetSizeOfGlobalsInBytes(F); 1050 DEBUG(dbgs() << "JIT: ActualSize after globals " << ActualSize << "\n"); 1051 } else if (SizeEstimate > 0) { 1052 // SizeEstimate will be non-zero on reallocation attempts. 1053 ActualSize = SizeEstimate; 1054 } 1055 1056 BufferBegin = CurBufferPtr = MemMgr->startFunctionBody(F.getFunction(), 1057 ActualSize); 1058 BufferEnd = BufferBegin+ActualSize; 1059 EmittedFunctions[F.getFunction()].FunctionBody = BufferBegin; 1060 1061 // Ensure the constant pool/jump table info is at least 4-byte aligned. 1062 emitAlignment(16); 1063 1064 emitConstantPool(F.getConstantPool()); 1065 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo()) 1066 initJumpTableInfo(MJTI); 1067 1068 // About to start emitting the machine code for the function. 1069 emitAlignment(std::max(F.getFunction()->getAlignment(), 8U)); 1070 TheJIT->updateGlobalMapping(F.getFunction(), CurBufferPtr); 1071 EmittedFunctions[F.getFunction()].Code = CurBufferPtr; 1072 1073 MBBLocations.clear(); 1074 1075 EmissionDetails.MF = &F; 1076 EmissionDetails.LineStarts.clear(); 1077} 1078 1079bool JITEmitter::finishFunction(MachineFunction &F) { 1080 if (CurBufferPtr == BufferEnd) { 1081 // We must call endFunctionBody before retrying, because 1082 // deallocateMemForFunction requires it. 1083 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr); 1084 retryWithMoreMemory(F); 1085 return true; 1086 } 1087 1088 if (MachineJumpTableInfo *MJTI = F.getJumpTableInfo()) 1089 emitJumpTableInfo(MJTI); 1090 1091 // FnStart is the start of the text, not the start of the constant pool and 1092 // other per-function data. 1093 uint8_t *FnStart = 1094 (uint8_t *)TheJIT->getPointerToGlobalIfAvailable(F.getFunction()); 1095 1096 // FnEnd is the end of the function's machine code. 1097 uint8_t *FnEnd = CurBufferPtr; 1098 1099 if (!Relocations.empty()) { 1100 CurFn = F.getFunction(); 1101 NumRelos += Relocations.size(); 1102 1103 // Resolve the relocations to concrete pointers. 1104 for (unsigned i = 0, e = Relocations.size(); i != e; ++i) { 1105 MachineRelocation &MR = Relocations[i]; 1106 void *ResultPtr = 0; 1107 if (!MR.letTargetResolve()) { 1108 if (MR.isExternalSymbol()) { 1109 ResultPtr = TheJIT->getPointerToNamedFunction(MR.getExternalSymbol(), 1110 false); 1111 DEBUG(dbgs() << "JIT: Map \'" << MR.getExternalSymbol() << "\' to [" 1112 << ResultPtr << "]\n"); 1113 1114 // If the target REALLY wants a stub for this function, emit it now. 1115 if (MR.mayNeedFarStub()) { 1116 ResultPtr = Resolver.getExternalFunctionStub(ResultPtr); 1117 } 1118 } else if (MR.isGlobalValue()) { 1119 ResultPtr = getPointerToGlobal(MR.getGlobalValue(), 1120 BufferBegin+MR.getMachineCodeOffset(), 1121 MR.mayNeedFarStub()); 1122 } else if (MR.isIndirectSymbol()) { 1123 ResultPtr = getPointerToGVIndirectSym( 1124 MR.getGlobalValue(), BufferBegin+MR.getMachineCodeOffset()); 1125 } else if (MR.isBasicBlock()) { 1126 ResultPtr = (void*)getMachineBasicBlockAddress(MR.getBasicBlock()); 1127 } else if (MR.isConstantPoolIndex()) { 1128 ResultPtr = (void*)getConstantPoolEntryAddress(MR.getConstantPoolIndex()); 1129 } else { 1130 assert(MR.isJumpTableIndex()); 1131 ResultPtr=(void*)getJumpTableEntryAddress(MR.getJumpTableIndex()); 1132 } 1133 1134 MR.setResultPointer(ResultPtr); 1135 } 1136 1137 // if we are managing the GOT and the relocation wants an index, 1138 // give it one 1139 if (MR.isGOTRelative() && MemMgr->isManagingGOT()) { 1140 unsigned idx = Resolver.getGOTIndexForAddr(ResultPtr); 1141 MR.setGOTIndex(idx); 1142 if (((void**)MemMgr->getGOTBase())[idx] != ResultPtr) { 1143 DEBUG(dbgs() << "JIT: GOT was out of date for " << ResultPtr 1144 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx] 1145 << "\n"); 1146 ((void**)MemMgr->getGOTBase())[idx] = ResultPtr; 1147 } 1148 } 1149 } 1150 1151 CurFn = 0; 1152 TheJIT->getJITInfo().relocate(BufferBegin, &Relocations[0], 1153 Relocations.size(), MemMgr->getGOTBase()); 1154 } 1155 1156 // Update the GOT entry for F to point to the new code. 1157 if (MemMgr->isManagingGOT()) { 1158 unsigned idx = Resolver.getGOTIndexForAddr((void*)BufferBegin); 1159 if (((void**)MemMgr->getGOTBase())[idx] != (void*)BufferBegin) { 1160 DEBUG(dbgs() << "JIT: GOT was out of date for " << (void*)BufferBegin 1161 << " pointing at " << ((void**)MemMgr->getGOTBase())[idx] 1162 << "\n"); 1163 ((void**)MemMgr->getGOTBase())[idx] = (void*)BufferBegin; 1164 } 1165 } 1166 1167 // CurBufferPtr may have moved beyond FnEnd, due to memory allocation for 1168 // global variables that were referenced in the relocations. 1169 MemMgr->endFunctionBody(F.getFunction(), BufferBegin, CurBufferPtr); 1170 1171 if (CurBufferPtr == BufferEnd) { 1172 retryWithMoreMemory(F); 1173 return true; 1174 } else { 1175 // Now that we've succeeded in emitting the function, reset the 1176 // SizeEstimate back down to zero. 1177 SizeEstimate = 0; 1178 } 1179 1180 BufferBegin = CurBufferPtr = 0; 1181 NumBytes += FnEnd-FnStart; 1182 1183 // Invalidate the icache if necessary. 1184 sys::Memory::InvalidateInstructionCache(FnStart, FnEnd-FnStart); 1185 1186 TheJIT->NotifyFunctionEmitted(*F.getFunction(), FnStart, FnEnd-FnStart, 1187 EmissionDetails); 1188 1189 DEBUG(dbgs() << "JIT: Finished CodeGen of [" << (void*)FnStart 1190 << "] Function: " << F.getFunction()->getName() 1191 << ": " << (FnEnd-FnStart) << " bytes of text, " 1192 << Relocations.size() << " relocations\n"); 1193 1194 Relocations.clear(); 1195 ConstPoolAddresses.clear(); 1196 1197 // Mark code region readable and executable if it's not so already. 1198 MemMgr->setMemoryExecutable(); 1199 1200 DEBUG( 1201 if (sys::hasDisassembler()) { 1202 dbgs() << "JIT: Disassembled code:\n"; 1203 dbgs() << sys::disassembleBuffer(FnStart, FnEnd-FnStart, 1204 (uintptr_t)FnStart); 1205 } else { 1206 dbgs() << "JIT: Binary code:\n"; 1207 uint8_t* q = FnStart; 1208 for (int i = 0; q < FnEnd; q += 4, ++i) { 1209 if (i == 4) 1210 i = 0; 1211 if (i == 0) 1212 dbgs() << "JIT: " << (long)(q - FnStart) << ": "; 1213 bool Done = false; 1214 for (int j = 3; j >= 0; --j) { 1215 if (q + j >= FnEnd) 1216 Done = true; 1217 else 1218 dbgs() << (unsigned short)q[j]; 1219 } 1220 if (Done) 1221 break; 1222 dbgs() << ' '; 1223 if (i == 3) 1224 dbgs() << '\n'; 1225 } 1226 dbgs()<< '\n'; 1227 } 1228 ); 1229 1230 if (DwarfExceptionHandling || JITEmitDebugInfo) { 1231 uintptr_t ActualSize = 0; 1232 SavedBufferBegin = BufferBegin; 1233 SavedBufferEnd = BufferEnd; 1234 SavedCurBufferPtr = CurBufferPtr; 1235 1236 if (MemMgr->NeedsExactSize()) { 1237 ActualSize = DE->GetDwarfTableSizeInBytes(F, *this, FnStart, FnEnd); 1238 } 1239 1240 BufferBegin = CurBufferPtr = MemMgr->startExceptionTable(F.getFunction(), 1241 ActualSize); 1242 BufferEnd = BufferBegin+ActualSize; 1243 EmittedFunctions[F.getFunction()].ExceptionTable = BufferBegin; 1244 uint8_t *EhStart; 1245 uint8_t *FrameRegister = DE->EmitDwarfTable(F, *this, FnStart, FnEnd, 1246 EhStart); 1247 MemMgr->endExceptionTable(F.getFunction(), BufferBegin, CurBufferPtr, 1248 FrameRegister); 1249 uint8_t *EhEnd = CurBufferPtr; 1250 BufferBegin = SavedBufferBegin; 1251 BufferEnd = SavedBufferEnd; 1252 CurBufferPtr = SavedCurBufferPtr; 1253 1254 if (DwarfExceptionHandling) { 1255 TheJIT->RegisterTable(FrameRegister); 1256 } 1257 1258 if (JITEmitDebugInfo) { 1259 DebugInfo I; 1260 I.FnStart = FnStart; 1261 I.FnEnd = FnEnd; 1262 I.EhStart = EhStart; 1263 I.EhEnd = EhEnd; 1264 DR->RegisterFunction(F.getFunction(), I); 1265 } 1266 } 1267 1268 if (MMI) 1269 MMI->EndFunction(); 1270 1271 return false; 1272} 1273 1274void JITEmitter::retryWithMoreMemory(MachineFunction &F) { 1275 DEBUG(dbgs() << "JIT: Ran out of space for native code. Reattempting.\n"); 1276 Relocations.clear(); // Clear the old relocations or we'll reapply them. 1277 ConstPoolAddresses.clear(); 1278 ++NumRetries; 1279 deallocateMemForFunction(F.getFunction()); 1280 // Try again with at least twice as much free space. 1281 SizeEstimate = (uintptr_t)(2 * (BufferEnd - BufferBegin)); 1282} 1283 1284/// deallocateMemForFunction - Deallocate all memory for the specified 1285/// function body. Also drop any references the function has to stubs. 1286/// May be called while the Function is being destroyed inside ~Value(). 1287void JITEmitter::deallocateMemForFunction(const Function *F) { 1288 ValueMap<const Function *, EmittedCode, EmittedFunctionConfig>::iterator 1289 Emitted = EmittedFunctions.find(F); 1290 if (Emitted != EmittedFunctions.end()) { 1291 MemMgr->deallocateFunctionBody(Emitted->second.FunctionBody); 1292 MemMgr->deallocateExceptionTable(Emitted->second.ExceptionTable); 1293 TheJIT->NotifyFreeingMachineCode(Emitted->second.Code); 1294 1295 EmittedFunctions.erase(Emitted); 1296 } 1297 1298 // TODO: Do we need to unregister exception handling information from libgcc 1299 // here? 1300 1301 if (JITEmitDebugInfo) { 1302 DR->UnregisterFunction(F); 1303 } 1304 1305 // If the function did not reference any stubs, return. 1306 if (CurFnStubUses.find(F) == CurFnStubUses.end()) 1307 return; 1308 1309 // For each referenced stub, erase the reference to this function, and then 1310 // erase the list of referenced stubs. 1311 SmallVectorImpl<void *> &StubList = CurFnStubUses[F]; 1312 for (unsigned i = 0, e = StubList.size(); i != e; ++i) { 1313 void *Stub = StubList[i]; 1314 1315 // If we already invalidated this stub for this function, continue. 1316 if (StubFnRefs.count(Stub) == 0) 1317 continue; 1318 1319 SmallPtrSet<const Function *, 1> &FnRefs = StubFnRefs[Stub]; 1320 FnRefs.erase(F); 1321 1322 // If this function was the last reference to the stub, invalidate the stub 1323 // in the JITResolver. Were there a memory manager deallocateStub routine, 1324 // we could call that at this point too. 1325 if (FnRefs.empty()) { 1326 DEBUG(dbgs() << "\nJIT: Invalidated Stub at [" << Stub << "]\n"); 1327 StubFnRefs.erase(Stub); 1328 1329 // Invalidate the stub. If it is a GV stub, update the JIT's global 1330 // mapping for that GV to zero. 1331 GlobalValue *GV = Resolver.invalidateStub(Stub); 1332 if (GV) { 1333 TheJIT->updateGlobalMapping(GV, 0); 1334 } 1335 } 1336 } 1337 CurFnStubUses.erase(F); 1338} 1339 1340 1341void* JITEmitter::allocateSpace(uintptr_t Size, unsigned Alignment) { 1342 if (BufferBegin) 1343 return JITCodeEmitter::allocateSpace(Size, Alignment); 1344 1345 // create a new memory block if there is no active one. 1346 // care must be taken so that BufferBegin is invalidated when a 1347 // block is trimmed 1348 BufferBegin = CurBufferPtr = MemMgr->allocateSpace(Size, Alignment); 1349 BufferEnd = BufferBegin+Size; 1350 return CurBufferPtr; 1351} 1352 1353void* JITEmitter::allocateGlobal(uintptr_t Size, unsigned Alignment) { 1354 // Delegate this call through the memory manager. 1355 return MemMgr->allocateGlobal(Size, Alignment); 1356} 1357 1358void JITEmitter::emitConstantPool(MachineConstantPool *MCP) { 1359 if (TheJIT->getJITInfo().hasCustomConstantPool()) 1360 return; 1361 1362 const std::vector<MachineConstantPoolEntry> &Constants = MCP->getConstants(); 1363 if (Constants.empty()) return; 1364 1365 unsigned Size = GetConstantPoolSizeInBytes(MCP, TheJIT->getTargetData()); 1366 unsigned Align = MCP->getConstantPoolAlignment(); 1367 ConstantPoolBase = allocateSpace(Size, Align); 1368 ConstantPool = MCP; 1369 1370 if (ConstantPoolBase == 0) return; // Buffer overflow. 1371 1372 DEBUG(dbgs() << "JIT: Emitted constant pool at [" << ConstantPoolBase 1373 << "] (size: " << Size << ", alignment: " << Align << ")\n"); 1374 1375 // Initialize the memory for all of the constant pool entries. 1376 unsigned Offset = 0; 1377 for (unsigned i = 0, e = Constants.size(); i != e; ++i) { 1378 MachineConstantPoolEntry CPE = Constants[i]; 1379 unsigned AlignMask = CPE.getAlignment() - 1; 1380 Offset = (Offset + AlignMask) & ~AlignMask; 1381 1382 uintptr_t CAddr = (uintptr_t)ConstantPoolBase + Offset; 1383 ConstPoolAddresses.push_back(CAddr); 1384 if (CPE.isMachineConstantPoolEntry()) { 1385 // FIXME: add support to lower machine constant pool values into bytes! 1386 llvm_report_error("Initialize memory with machine specific constant pool" 1387 "entry has not been implemented!"); 1388 } 1389 TheJIT->InitializeMemory(CPE.Val.ConstVal, (void*)CAddr); 1390 DEBUG(dbgs() << "JIT: CP" << i << " at [0x"; 1391 dbgs().write_hex(CAddr) << "]\n"); 1392 1393 const Type *Ty = CPE.Val.ConstVal->getType(); 1394 Offset += TheJIT->getTargetData()->getTypeAllocSize(Ty); 1395 } 1396} 1397 1398void JITEmitter::initJumpTableInfo(MachineJumpTableInfo *MJTI) { 1399 if (TheJIT->getJITInfo().hasCustomJumpTables()) 1400 return; 1401 1402 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 1403 if (JT.empty()) return; 1404 1405 unsigned NumEntries = 0; 1406 for (unsigned i = 0, e = JT.size(); i != e; ++i) 1407 NumEntries += JT[i].MBBs.size(); 1408 1409 unsigned EntrySize = MJTI->getEntrySize(*TheJIT->getTargetData()); 1410 1411 // Just allocate space for all the jump tables now. We will fix up the actual 1412 // MBB entries in the tables after we emit the code for each block, since then 1413 // we will know the final locations of the MBBs in memory. 1414 JumpTable = MJTI; 1415 JumpTableBase = allocateSpace(NumEntries * EntrySize, 1416 MJTI->getEntryAlignment(*TheJIT->getTargetData())); 1417} 1418 1419void JITEmitter::emitJumpTableInfo(MachineJumpTableInfo *MJTI) { 1420 if (TheJIT->getJITInfo().hasCustomJumpTables()) 1421 return; 1422 1423 const std::vector<MachineJumpTableEntry> &JT = MJTI->getJumpTables(); 1424 if (JT.empty() || JumpTableBase == 0) return; 1425 1426 1427 switch (MJTI->getEntryKind()) { 1428 case MachineJumpTableInfo::EK_BlockAddress: { 1429 // EK_BlockAddress - Each entry is a plain address of block, e.g.: 1430 // .word LBB123 1431 assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == sizeof(void*) && 1432 "Cross JIT'ing?"); 1433 1434 // For each jump table, map each target in the jump table to the address of 1435 // an emitted MachineBasicBlock. 1436 intptr_t *SlotPtr = (intptr_t*)JumpTableBase; 1437 1438 for (unsigned i = 0, e = JT.size(); i != e; ++i) { 1439 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs; 1440 // Store the address of the basic block for this jump table slot in the 1441 // memory we allocated for the jump table in 'initJumpTableInfo' 1442 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) 1443 *SlotPtr++ = getMachineBasicBlockAddress(MBBs[mi]); 1444 } 1445 break; 1446 } 1447 1448 case MachineJumpTableInfo::EK_GPRel32BlockAddress: 1449 case MachineJumpTableInfo::EK_LabelDifference32: { 1450 assert(MJTI->getEntrySize(*TheJIT->getTargetData()) == 4&&"Cross JIT'ing?"); 1451 // For each jump table, place the offset from the beginning of the table 1452 // to the target address. 1453 int *SlotPtr = (int*)JumpTableBase; 1454 1455 for (unsigned i = 0, e = JT.size(); i != e; ++i) { 1456 const std::vector<MachineBasicBlock*> &MBBs = JT[i].MBBs; 1457 // Store the offset of the basic block for this jump table slot in the 1458 // memory we allocated for the jump table in 'initJumpTableInfo' 1459 uintptr_t Base = (uintptr_t)SlotPtr; 1460 for (unsigned mi = 0, me = MBBs.size(); mi != me; ++mi) { 1461 uintptr_t MBBAddr = getMachineBasicBlockAddress(MBBs[mi]); 1462 /// FIXME: USe EntryKind instead of magic "getPICJumpTableEntry" hook. 1463 *SlotPtr++ = TheJIT->getJITInfo().getPICJumpTableEntry(MBBAddr, Base); 1464 } 1465 } 1466 break; 1467 } 1468 } 1469} 1470 1471void JITEmitter::startGVStub(const GlobalValue* GV, 1472 unsigned StubSize, unsigned Alignment) { 1473 SavedBufferBegin = BufferBegin; 1474 SavedBufferEnd = BufferEnd; 1475 SavedCurBufferPtr = CurBufferPtr; 1476 1477 BufferBegin = CurBufferPtr = MemMgr->allocateStub(GV, StubSize, Alignment); 1478 BufferEnd = BufferBegin+StubSize+1; 1479} 1480 1481void JITEmitter::startGVStub(void *Buffer, unsigned StubSize) { 1482 SavedBufferBegin = BufferBegin; 1483 SavedBufferEnd = BufferEnd; 1484 SavedCurBufferPtr = CurBufferPtr; 1485 1486 BufferBegin = CurBufferPtr = (uint8_t *)Buffer; 1487 BufferEnd = BufferBegin+StubSize+1; 1488} 1489 1490void JITEmitter::finishGVStub() { 1491 assert(CurBufferPtr != BufferEnd && "Stub overflowed allocated space."); 1492 NumBytes += getCurrentPCOffset(); 1493 BufferBegin = SavedBufferBegin; 1494 BufferEnd = SavedBufferEnd; 1495 CurBufferPtr = SavedCurBufferPtr; 1496} 1497 1498void *JITEmitter::allocIndirectGV(const GlobalValue *GV, 1499 const uint8_t *Buffer, size_t Size, 1500 unsigned Alignment) { 1501 uint8_t *IndGV = MemMgr->allocateStub(GV, Size, Alignment); 1502 memcpy(IndGV, Buffer, Size); 1503 return IndGV; 1504} 1505 1506// getConstantPoolEntryAddress - Return the address of the 'ConstantNum' entry 1507// in the constant pool that was last emitted with the 'emitConstantPool' 1508// method. 1509// 1510uintptr_t JITEmitter::getConstantPoolEntryAddress(unsigned ConstantNum) const { 1511 assert(ConstantNum < ConstantPool->getConstants().size() && 1512 "Invalid ConstantPoolIndex!"); 1513 return ConstPoolAddresses[ConstantNum]; 1514} 1515 1516// getJumpTableEntryAddress - Return the address of the JumpTable with index 1517// 'Index' in the jumpp table that was last initialized with 'initJumpTableInfo' 1518// 1519uintptr_t JITEmitter::getJumpTableEntryAddress(unsigned Index) const { 1520 const std::vector<MachineJumpTableEntry> &JT = JumpTable->getJumpTables(); 1521 assert(Index < JT.size() && "Invalid jump table index!"); 1522 1523 unsigned EntrySize = JumpTable->getEntrySize(*TheJIT->getTargetData()); 1524 1525 unsigned Offset = 0; 1526 for (unsigned i = 0; i < Index; ++i) 1527 Offset += JT[i].MBBs.size(); 1528 1529 Offset *= EntrySize; 1530 1531 return (uintptr_t)((char *)JumpTableBase + Offset); 1532} 1533 1534void JITEmitter::EmittedFunctionConfig::onDelete( 1535 JITEmitter *Emitter, const Function *F) { 1536 Emitter->deallocateMemForFunction(F); 1537} 1538void JITEmitter::EmittedFunctionConfig::onRAUW( 1539 JITEmitter *, const Function*, const Function*) { 1540 llvm_unreachable("The JIT doesn't know how to handle a" 1541 " RAUW on a value it has emitted."); 1542} 1543 1544 1545//===----------------------------------------------------------------------===// 1546// Public interface to this file 1547//===----------------------------------------------------------------------===// 1548 1549JITCodeEmitter *JIT::createEmitter(JIT &jit, JITMemoryManager *JMM, 1550 TargetMachine &tm) { 1551 return new JITEmitter(jit, JMM, tm); 1552} 1553 1554// getPointerToNamedFunction - This function is used as a global wrapper to 1555// JIT::getPointerToNamedFunction for the purpose of resolving symbols when 1556// bugpoint is debugging the JIT. In that scenario, we are loading an .so and 1557// need to resolve function(s) that are being mis-codegenerated, so we need to 1558// resolve their addresses at runtime, and this is the way to do it. 1559extern "C" { 1560 void *getPointerToNamedFunction(const char *Name) { 1561 if (Function *F = TheJIT->FindFunctionNamed(Name)) 1562 return TheJIT->getPointerToFunction(F); 1563 return TheJIT->getPointerToNamedFunction(Name); 1564 } 1565} 1566 1567// getPointerToFunctionOrStub - If the specified function has been 1568// code-gen'd, return a pointer to the function. If not, compile it, or use 1569// a stub to implement lazy compilation if available. 1570// 1571void *JIT::getPointerToFunctionOrStub(Function *F) { 1572 // If we have already code generated the function, just return the address. 1573 if (void *Addr = getPointerToGlobalIfAvailable(F)) 1574 return Addr; 1575 1576 // Get a stub if the target supports it. 1577 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?"); 1578 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter()); 1579 return JE->getJITResolver().getLazyFunctionStub(F); 1580} 1581 1582void JIT::updateFunctionStub(Function *F) { 1583 // Get the empty stub we generated earlier. 1584 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?"); 1585 JITEmitter *JE = cast<JITEmitter>(getCodeEmitter()); 1586 void *Stub = JE->getJITResolver().getLazyFunctionStub(F); 1587 void *Addr = getPointerToGlobalIfAvailable(F); 1588 assert(Addr != Stub && "Function must have non-stub address to be updated."); 1589 1590 // Tell the target jit info to rewrite the stub at the specified address, 1591 // rather than creating a new one. 1592 TargetJITInfo::StubLayout layout = getJITInfo().getStubLayout(); 1593 JE->startGVStub(Stub, layout.Size); 1594 getJITInfo().emitFunctionStub(F, Addr, *getCodeEmitter()); 1595 JE->finishGVStub(); 1596} 1597 1598/// freeMachineCodeForFunction - release machine code memory for given Function. 1599/// 1600void JIT::freeMachineCodeForFunction(Function *F) { 1601 // Delete translation for this from the ExecutionEngine, so it will get 1602 // retranslated next time it is used. 1603 updateGlobalMapping(F, 0); 1604 1605 // Free the actual memory for the function body and related stuff. 1606 assert(isa<JITEmitter>(JCE) && "Unexpected MCE?"); 1607 cast<JITEmitter>(JCE)->deallocateMemForFunction(F); 1608} 1609