AliasSetTracker.cpp revision 6948897e478cbd66626159776a8017b3c18579b9
1//===- AliasSetTracker.cpp - Alias Sets Tracker implementation-------------===// 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 implements the AliasSetTracker and AliasSet classes. 11// 12//===----------------------------------------------------------------------===// 13 14#include "llvm/Analysis/AliasSetTracker.h" 15#include "llvm/Analysis/AliasAnalysis.h" 16#include "llvm/IR/DataLayout.h" 17#include "llvm/IR/InstIterator.h" 18#include "llvm/IR/Instructions.h" 19#include "llvm/IR/IntrinsicInst.h" 20#include "llvm/IR/LLVMContext.h" 21#include "llvm/IR/Type.h" 22#include "llvm/Pass.h" 23#include "llvm/Support/Debug.h" 24#include "llvm/Support/ErrorHandling.h" 25#include "llvm/Support/raw_ostream.h" 26using namespace llvm; 27 28/// mergeSetIn - Merge the specified alias set into this alias set. 29/// 30void AliasSet::mergeSetIn(AliasSet &AS, AliasSetTracker &AST) { 31 assert(!AS.Forward && "Alias set is already forwarding!"); 32 assert(!Forward && "This set is a forwarding set!!"); 33 34 // Update the alias and access types of this set... 35 AccessTy |= AS.AccessTy; 36 AliasTy |= AS.AliasTy; 37 Volatile |= AS.Volatile; 38 39 if (AliasTy == MustAlias) { 40 // Check that these two merged sets really are must aliases. Since both 41 // used to be must-alias sets, we can just check any pointer from each set 42 // for aliasing. 43 AliasAnalysis &AA = AST.getAliasAnalysis(); 44 PointerRec *L = getSomePointer(); 45 PointerRec *R = AS.getSomePointer(); 46 47 // If the pointers are not a must-alias pair, this set becomes a may alias. 48 if (AA.alias(AliasAnalysis::Location(L->getValue(), 49 L->getSize(), 50 L->getAAInfo()), 51 AliasAnalysis::Location(R->getValue(), 52 R->getSize(), 53 R->getAAInfo())) 54 != AliasAnalysis::MustAlias) 55 AliasTy = MayAlias; 56 } 57 58 bool ASHadUnknownInsts = !AS.UnknownInsts.empty(); 59 if (UnknownInsts.empty()) { // Merge call sites... 60 if (ASHadUnknownInsts) { 61 std::swap(UnknownInsts, AS.UnknownInsts); 62 addRef(); 63 } 64 } else if (ASHadUnknownInsts) { 65 UnknownInsts.insert(UnknownInsts.end(), AS.UnknownInsts.begin(), AS.UnknownInsts.end()); 66 AS.UnknownInsts.clear(); 67 } 68 69 AS.Forward = this; // Forward across AS now... 70 addRef(); // AS is now pointing to us... 71 72 // Merge the list of constituent pointers... 73 if (AS.PtrList) { 74 *PtrListEnd = AS.PtrList; 75 AS.PtrList->setPrevInList(PtrListEnd); 76 PtrListEnd = AS.PtrListEnd; 77 78 AS.PtrList = nullptr; 79 AS.PtrListEnd = &AS.PtrList; 80 assert(*AS.PtrListEnd == nullptr && "End of list is not null?"); 81 } 82 if (ASHadUnknownInsts) 83 AS.dropRef(AST); 84} 85 86void AliasSetTracker::removeAliasSet(AliasSet *AS) { 87 if (AliasSet *Fwd = AS->Forward) { 88 Fwd->dropRef(*this); 89 AS->Forward = nullptr; 90 } 91 AliasSets.erase(AS); 92} 93 94void AliasSet::removeFromTracker(AliasSetTracker &AST) { 95 assert(RefCount == 0 && "Cannot remove non-dead alias set from tracker!"); 96 AST.removeAliasSet(this); 97} 98 99void AliasSet::addPointer(AliasSetTracker &AST, PointerRec &Entry, 100 uint64_t Size, const AAMDNodes &AAInfo, 101 bool KnownMustAlias) { 102 assert(!Entry.hasAliasSet() && "Entry already in set!"); 103 104 // Check to see if we have to downgrade to _may_ alias. 105 if (isMustAlias() && !KnownMustAlias) 106 if (PointerRec *P = getSomePointer()) { 107 AliasAnalysis &AA = AST.getAliasAnalysis(); 108 AliasAnalysis::AliasResult Result = 109 AA.alias(AliasAnalysis::Location(P->getValue(), P->getSize(), 110 P->getAAInfo()), 111 AliasAnalysis::Location(Entry.getValue(), Size, AAInfo)); 112 if (Result != AliasAnalysis::MustAlias) 113 AliasTy = MayAlias; 114 else // First entry of must alias must have maximum size! 115 P->updateSizeAndAAInfo(Size, AAInfo); 116 assert(Result != AliasAnalysis::NoAlias && "Cannot be part of must set!"); 117 } 118 119 Entry.setAliasSet(this); 120 Entry.updateSizeAndAAInfo(Size, AAInfo); 121 122 // Add it to the end of the list... 123 assert(*PtrListEnd == nullptr && "End of list is not null?"); 124 *PtrListEnd = &Entry; 125 PtrListEnd = Entry.setPrevInList(PtrListEnd); 126 assert(*PtrListEnd == nullptr && "End of list is not null?"); 127 addRef(); // Entry points to alias set. 128} 129 130void AliasSet::addUnknownInst(Instruction *I, AliasAnalysis &AA) { 131 if (UnknownInsts.empty()) 132 addRef(); 133 UnknownInsts.emplace_back(I); 134 135 if (!I->mayWriteToMemory()) { 136 AliasTy = MayAlias; 137 AccessTy |= Refs; 138 return; 139 } 140 141 // FIXME: This should use mod/ref information to make this not suck so bad 142 AliasTy = MayAlias; 143 AccessTy = ModRef; 144} 145 146/// aliasesPointer - Return true if the specified pointer "may" (or must) 147/// alias one of the members in the set. 148/// 149bool AliasSet::aliasesPointer(const Value *Ptr, uint64_t Size, 150 const AAMDNodes &AAInfo, 151 AliasAnalysis &AA) const { 152 if (AliasTy == MustAlias) { 153 assert(UnknownInsts.empty() && "Illegal must alias set!"); 154 155 // If this is a set of MustAliases, only check to see if the pointer aliases 156 // SOME value in the set. 157 PointerRec *SomePtr = getSomePointer(); 158 assert(SomePtr && "Empty must-alias set??"); 159 return AA.alias(AliasAnalysis::Location(SomePtr->getValue(), 160 SomePtr->getSize(), 161 SomePtr->getAAInfo()), 162 AliasAnalysis::Location(Ptr, Size, AAInfo)); 163 } 164 165 // If this is a may-alias set, we have to check all of the pointers in the set 166 // to be sure it doesn't alias the set... 167 for (iterator I = begin(), E = end(); I != E; ++I) 168 if (AA.alias(AliasAnalysis::Location(Ptr, Size, AAInfo), 169 AliasAnalysis::Location(I.getPointer(), I.getSize(), 170 I.getAAInfo()))) 171 return true; 172 173 // Check the unknown instructions... 174 if (!UnknownInsts.empty()) { 175 for (unsigned i = 0, e = UnknownInsts.size(); i != e; ++i) 176 if (AA.getModRefInfo(UnknownInsts[i], 177 AliasAnalysis::Location(Ptr, Size, AAInfo)) != 178 AliasAnalysis::NoModRef) 179 return true; 180 } 181 182 return false; 183} 184 185bool AliasSet::aliasesUnknownInst(const Instruction *Inst, 186 AliasAnalysis &AA) const { 187 if (!Inst->mayReadOrWriteMemory()) 188 return false; 189 190 for (unsigned i = 0, e = UnknownInsts.size(); i != e; ++i) { 191 ImmutableCallSite C1(getUnknownInst(i)), C2(Inst); 192 if (!C1 || !C2 || 193 AA.getModRefInfo(C1, C2) != AliasAnalysis::NoModRef || 194 AA.getModRefInfo(C2, C1) != AliasAnalysis::NoModRef) 195 return true; 196 } 197 198 for (iterator I = begin(), E = end(); I != E; ++I) 199 if (AA.getModRefInfo(Inst, AliasAnalysis::Location(I.getPointer(), 200 I.getSize(), 201 I.getAAInfo())) != 202 AliasAnalysis::NoModRef) 203 return true; 204 205 return false; 206} 207 208void AliasSetTracker::clear() { 209 // Delete all the PointerRec entries. 210 for (PointerMapType::iterator I = PointerMap.begin(), E = PointerMap.end(); 211 I != E; ++I) 212 I->second->eraseFromList(); 213 214 PointerMap.clear(); 215 216 // The alias sets should all be clear now. 217 AliasSets.clear(); 218} 219 220 221/// findAliasSetForPointer - Given a pointer, find the one alias set to put the 222/// instruction referring to the pointer into. If there are multiple alias sets 223/// that may alias the pointer, merge them together and return the unified set. 224/// 225AliasSet *AliasSetTracker::findAliasSetForPointer(const Value *Ptr, 226 uint64_t Size, 227 const AAMDNodes &AAInfo) { 228 AliasSet *FoundSet = nullptr; 229 for (iterator I = begin(), E = end(); I != E;) { 230 iterator Cur = I++; 231 if (Cur->Forward || !Cur->aliasesPointer(Ptr, Size, AAInfo, AA)) continue; 232 233 if (!FoundSet) { // If this is the first alias set ptr can go into. 234 FoundSet = Cur; // Remember it. 235 } else { // Otherwise, we must merge the sets. 236 FoundSet->mergeSetIn(*Cur, *this); // Merge in contents. 237 } 238 } 239 240 return FoundSet; 241} 242 243/// containsPointer - Return true if the specified location is represented by 244/// this alias set, false otherwise. This does not modify the AST object or 245/// alias sets. 246bool AliasSetTracker::containsPointer(const Value *Ptr, uint64_t Size, 247 const AAMDNodes &AAInfo) const { 248 for (const_iterator I = begin(), E = end(); I != E; ++I) 249 if (!I->Forward && I->aliasesPointer(Ptr, Size, AAInfo, AA)) 250 return true; 251 return false; 252} 253 254bool AliasSetTracker::containsUnknown(const Instruction *Inst) const { 255 for (const_iterator I = begin(), E = end(); I != E; ++I) 256 if (!I->Forward && I->aliasesUnknownInst(Inst, AA)) 257 return true; 258 return false; 259} 260 261AliasSet *AliasSetTracker::findAliasSetForUnknownInst(Instruction *Inst) { 262 AliasSet *FoundSet = nullptr; 263 for (iterator I = begin(), E = end(); I != E;) { 264 iterator Cur = I++; 265 if (Cur->Forward || !Cur->aliasesUnknownInst(Inst, AA)) 266 continue; 267 if (!FoundSet) // If this is the first alias set ptr can go into. 268 FoundSet = Cur; // Remember it. 269 else if (!Cur->Forward) // Otherwise, we must merge the sets. 270 FoundSet->mergeSetIn(*Cur, *this); // Merge in contents. 271 } 272 return FoundSet; 273} 274 275 276 277 278/// getAliasSetForPointer - Return the alias set that the specified pointer 279/// lives in. 280AliasSet &AliasSetTracker::getAliasSetForPointer(Value *Pointer, uint64_t Size, 281 const AAMDNodes &AAInfo, 282 bool *New) { 283 AliasSet::PointerRec &Entry = getEntryFor(Pointer); 284 285 // Check to see if the pointer is already known. 286 if (Entry.hasAliasSet()) { 287 Entry.updateSizeAndAAInfo(Size, AAInfo); 288 // Return the set! 289 return *Entry.getAliasSet(*this)->getForwardedTarget(*this); 290 } 291 292 if (AliasSet *AS = findAliasSetForPointer(Pointer, Size, AAInfo)) { 293 // Add it to the alias set it aliases. 294 AS->addPointer(*this, Entry, Size, AAInfo); 295 return *AS; 296 } 297 298 if (New) *New = true; 299 // Otherwise create a new alias set to hold the loaded pointer. 300 AliasSets.push_back(new AliasSet()); 301 AliasSets.back().addPointer(*this, Entry, Size, AAInfo); 302 return AliasSets.back(); 303} 304 305bool AliasSetTracker::add(Value *Ptr, uint64_t Size, const AAMDNodes &AAInfo) { 306 bool NewPtr; 307 addPointer(Ptr, Size, AAInfo, AliasSet::NoModRef, NewPtr); 308 return NewPtr; 309} 310 311 312bool AliasSetTracker::add(LoadInst *LI) { 313 if (LI->getOrdering() > Monotonic) return addUnknown(LI); 314 315 AAMDNodes AAInfo; 316 LI->getAAMetadata(AAInfo); 317 318 AliasSet::AccessType ATy = AliasSet::Refs; 319 bool NewPtr; 320 AliasSet &AS = addPointer(LI->getOperand(0), 321 AA.getTypeStoreSize(LI->getType()), 322 AAInfo, ATy, NewPtr); 323 if (LI->isVolatile()) AS.setVolatile(); 324 return NewPtr; 325} 326 327bool AliasSetTracker::add(StoreInst *SI) { 328 if (SI->getOrdering() > Monotonic) return addUnknown(SI); 329 330 AAMDNodes AAInfo; 331 SI->getAAMetadata(AAInfo); 332 333 AliasSet::AccessType ATy = AliasSet::Mods; 334 bool NewPtr; 335 Value *Val = SI->getOperand(0); 336 AliasSet &AS = addPointer(SI->getOperand(1), 337 AA.getTypeStoreSize(Val->getType()), 338 AAInfo, ATy, NewPtr); 339 if (SI->isVolatile()) AS.setVolatile(); 340 return NewPtr; 341} 342 343bool AliasSetTracker::add(VAArgInst *VAAI) { 344 AAMDNodes AAInfo; 345 VAAI->getAAMetadata(AAInfo); 346 347 bool NewPtr; 348 addPointer(VAAI->getOperand(0), AliasAnalysis::UnknownSize, 349 AAInfo, AliasSet::ModRef, NewPtr); 350 return NewPtr; 351} 352 353 354bool AliasSetTracker::addUnknown(Instruction *Inst) { 355 if (isa<DbgInfoIntrinsic>(Inst)) 356 return true; // Ignore DbgInfo Intrinsics. 357 if (!Inst->mayReadOrWriteMemory()) 358 return true; // doesn't alias anything 359 360 AliasSet *AS = findAliasSetForUnknownInst(Inst); 361 if (AS) { 362 AS->addUnknownInst(Inst, AA); 363 return false; 364 } 365 AliasSets.push_back(new AliasSet()); 366 AS = &AliasSets.back(); 367 AS->addUnknownInst(Inst, AA); 368 return true; 369} 370 371bool AliasSetTracker::add(Instruction *I) { 372 // Dispatch to one of the other add methods. 373 if (LoadInst *LI = dyn_cast<LoadInst>(I)) 374 return add(LI); 375 if (StoreInst *SI = dyn_cast<StoreInst>(I)) 376 return add(SI); 377 if (VAArgInst *VAAI = dyn_cast<VAArgInst>(I)) 378 return add(VAAI); 379 return addUnknown(I); 380} 381 382void AliasSetTracker::add(BasicBlock &BB) { 383 for (BasicBlock::iterator I = BB.begin(), E = BB.end(); I != E; ++I) 384 add(I); 385} 386 387void AliasSetTracker::add(const AliasSetTracker &AST) { 388 assert(&AA == &AST.AA && 389 "Merging AliasSetTracker objects with different Alias Analyses!"); 390 391 // Loop over all of the alias sets in AST, adding the pointers contained 392 // therein into the current alias sets. This can cause alias sets to be 393 // merged together in the current AST. 394 for (const_iterator I = AST.begin(), E = AST.end(); I != E; ++I) { 395 if (I->Forward) continue; // Ignore forwarding alias sets 396 397 AliasSet &AS = const_cast<AliasSet&>(*I); 398 399 // If there are any call sites in the alias set, add them to this AST. 400 for (unsigned i = 0, e = AS.UnknownInsts.size(); i != e; ++i) 401 add(AS.UnknownInsts[i]); 402 403 // Loop over all of the pointers in this alias set. 404 bool X; 405 for (AliasSet::iterator ASI = AS.begin(), E = AS.end(); ASI != E; ++ASI) { 406 AliasSet &NewAS = addPointer(ASI.getPointer(), ASI.getSize(), 407 ASI.getAAInfo(), 408 (AliasSet::AccessType)AS.AccessTy, X); 409 if (AS.isVolatile()) NewAS.setVolatile(); 410 } 411 } 412} 413 414/// remove - Remove the specified (potentially non-empty) alias set from the 415/// tracker. 416void AliasSetTracker::remove(AliasSet &AS) { 417 // Drop all call sites. 418 if (!AS.UnknownInsts.empty()) 419 AS.dropRef(*this); 420 AS.UnknownInsts.clear(); 421 422 // Clear the alias set. 423 unsigned NumRefs = 0; 424 while (!AS.empty()) { 425 AliasSet::PointerRec *P = AS.PtrList; 426 427 Value *ValToRemove = P->getValue(); 428 429 // Unlink and delete entry from the list of values. 430 P->eraseFromList(); 431 432 // Remember how many references need to be dropped. 433 ++NumRefs; 434 435 // Finally, remove the entry. 436 PointerMap.erase(ValToRemove); 437 } 438 439 // Stop using the alias set, removing it. 440 AS.RefCount -= NumRefs; 441 if (AS.RefCount == 0) 442 AS.removeFromTracker(*this); 443} 444 445bool 446AliasSetTracker::remove(Value *Ptr, uint64_t Size, const AAMDNodes &AAInfo) { 447 AliasSet *AS = findAliasSetForPointer(Ptr, Size, AAInfo); 448 if (!AS) return false; 449 remove(*AS); 450 return true; 451} 452 453bool AliasSetTracker::remove(LoadInst *LI) { 454 uint64_t Size = AA.getTypeStoreSize(LI->getType()); 455 456 AAMDNodes AAInfo; 457 LI->getAAMetadata(AAInfo); 458 459 AliasSet *AS = findAliasSetForPointer(LI->getOperand(0), Size, AAInfo); 460 if (!AS) return false; 461 remove(*AS); 462 return true; 463} 464 465bool AliasSetTracker::remove(StoreInst *SI) { 466 uint64_t Size = AA.getTypeStoreSize(SI->getOperand(0)->getType()); 467 468 AAMDNodes AAInfo; 469 SI->getAAMetadata(AAInfo); 470 471 AliasSet *AS = findAliasSetForPointer(SI->getOperand(1), Size, AAInfo); 472 if (!AS) return false; 473 remove(*AS); 474 return true; 475} 476 477bool AliasSetTracker::remove(VAArgInst *VAAI) { 478 AAMDNodes AAInfo; 479 VAAI->getAAMetadata(AAInfo); 480 481 AliasSet *AS = findAliasSetForPointer(VAAI->getOperand(0), 482 AliasAnalysis::UnknownSize, AAInfo); 483 if (!AS) return false; 484 remove(*AS); 485 return true; 486} 487 488bool AliasSetTracker::removeUnknown(Instruction *I) { 489 if (!I->mayReadOrWriteMemory()) 490 return false; // doesn't alias anything 491 492 AliasSet *AS = findAliasSetForUnknownInst(I); 493 if (!AS) return false; 494 remove(*AS); 495 return true; 496} 497 498bool AliasSetTracker::remove(Instruction *I) { 499 // Dispatch to one of the other remove methods... 500 if (LoadInst *LI = dyn_cast<LoadInst>(I)) 501 return remove(LI); 502 if (StoreInst *SI = dyn_cast<StoreInst>(I)) 503 return remove(SI); 504 if (VAArgInst *VAAI = dyn_cast<VAArgInst>(I)) 505 return remove(VAAI); 506 return removeUnknown(I); 507} 508 509 510// deleteValue method - This method is used to remove a pointer value from the 511// AliasSetTracker entirely. It should be used when an instruction is deleted 512// from the program to update the AST. If you don't use this, you would have 513// dangling pointers to deleted instructions. 514// 515void AliasSetTracker::deleteValue(Value *PtrVal) { 516 // Notify the alias analysis implementation that this value is gone. 517 AA.deleteValue(PtrVal); 518 519 // If this is a call instruction, remove the callsite from the appropriate 520 // AliasSet (if present). 521 if (Instruction *Inst = dyn_cast<Instruction>(PtrVal)) { 522 if (Inst->mayReadOrWriteMemory()) { 523 // Scan all the alias sets to see if this call site is contained. 524 for (iterator I = begin(), E = end(); I != E;) { 525 iterator Cur = I++; 526 if (!Cur->Forward) 527 Cur->removeUnknownInst(*this, Inst); 528 } 529 } 530 } 531 532 // First, look up the PointerRec for this pointer. 533 PointerMapType::iterator I = PointerMap.find_as(PtrVal); 534 if (I == PointerMap.end()) return; // Noop 535 536 // If we found one, remove the pointer from the alias set it is in. 537 AliasSet::PointerRec *PtrValEnt = I->second; 538 AliasSet *AS = PtrValEnt->getAliasSet(*this); 539 540 // Unlink and delete from the list of values. 541 PtrValEnt->eraseFromList(); 542 543 // Stop using the alias set. 544 AS->dropRef(*this); 545 546 PointerMap.erase(I); 547} 548 549// copyValue - This method should be used whenever a preexisting value in the 550// program is copied or cloned, introducing a new value. Note that it is ok for 551// clients that use this method to introduce the same value multiple times: if 552// the tracker already knows about a value, it will ignore the request. 553// 554void AliasSetTracker::copyValue(Value *From, Value *To) { 555 // Notify the alias analysis implementation that this value is copied. 556 AA.copyValue(From, To); 557 558 // First, look up the PointerRec for this pointer. 559 PointerMapType::iterator I = PointerMap.find_as(From); 560 if (I == PointerMap.end()) 561 return; // Noop 562 assert(I->second->hasAliasSet() && "Dead entry?"); 563 564 AliasSet::PointerRec &Entry = getEntryFor(To); 565 if (Entry.hasAliasSet()) return; // Already in the tracker! 566 567 // Add it to the alias set it aliases... 568 I = PointerMap.find_as(From); 569 AliasSet *AS = I->second->getAliasSet(*this); 570 AS->addPointer(*this, Entry, I->second->getSize(), 571 I->second->getAAInfo(), 572 true); 573} 574 575 576 577//===----------------------------------------------------------------------===// 578// AliasSet/AliasSetTracker Printing Support 579//===----------------------------------------------------------------------===// 580 581void AliasSet::print(raw_ostream &OS) const { 582 OS << " AliasSet[" << (const void*)this << ", " << RefCount << "] "; 583 OS << (AliasTy == MustAlias ? "must" : "may") << " alias, "; 584 switch (AccessTy) { 585 case NoModRef: OS << "No access "; break; 586 case Refs : OS << "Ref "; break; 587 case Mods : OS << "Mod "; break; 588 case ModRef : OS << "Mod/Ref "; break; 589 default: llvm_unreachable("Bad value for AccessTy!"); 590 } 591 if (isVolatile()) OS << "[volatile] "; 592 if (Forward) 593 OS << " forwarding to " << (void*)Forward; 594 595 596 if (!empty()) { 597 OS << "Pointers: "; 598 for (iterator I = begin(), E = end(); I != E; ++I) { 599 if (I != begin()) OS << ", "; 600 I.getPointer()->printAsOperand(OS << "("); 601 OS << ", " << I.getSize() << ")"; 602 } 603 } 604 if (!UnknownInsts.empty()) { 605 OS << "\n " << UnknownInsts.size() << " Unknown instructions: "; 606 for (unsigned i = 0, e = UnknownInsts.size(); i != e; ++i) { 607 if (i) OS << ", "; 608 UnknownInsts[i]->printAsOperand(OS); 609 } 610 } 611 OS << "\n"; 612} 613 614void AliasSetTracker::print(raw_ostream &OS) const { 615 OS << "Alias Set Tracker: " << AliasSets.size() << " alias sets for " 616 << PointerMap.size() << " pointer values.\n"; 617 for (const_iterator I = begin(), E = end(); I != E; ++I) 618 I->print(OS); 619 OS << "\n"; 620} 621 622#if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP) 623void AliasSet::dump() const { print(dbgs()); } 624void AliasSetTracker::dump() const { print(dbgs()); } 625#endif 626 627//===----------------------------------------------------------------------===// 628// ASTCallbackVH Class Implementation 629//===----------------------------------------------------------------------===// 630 631void AliasSetTracker::ASTCallbackVH::deleted() { 632 assert(AST && "ASTCallbackVH called with a null AliasSetTracker!"); 633 AST->deleteValue(getValPtr()); 634 // this now dangles! 635} 636 637void AliasSetTracker::ASTCallbackVH::allUsesReplacedWith(Value *V) { 638 AST->copyValue(getValPtr(), V); 639} 640 641AliasSetTracker::ASTCallbackVH::ASTCallbackVH(Value *V, AliasSetTracker *ast) 642 : CallbackVH(V), AST(ast) {} 643 644AliasSetTracker::ASTCallbackVH & 645AliasSetTracker::ASTCallbackVH::operator=(Value *V) { 646 return *this = ASTCallbackVH(V, AST); 647} 648 649//===----------------------------------------------------------------------===// 650// AliasSetPrinter Pass 651//===----------------------------------------------------------------------===// 652 653namespace { 654 class AliasSetPrinter : public FunctionPass { 655 AliasSetTracker *Tracker; 656 public: 657 static char ID; // Pass identification, replacement for typeid 658 AliasSetPrinter() : FunctionPass(ID) { 659 initializeAliasSetPrinterPass(*PassRegistry::getPassRegistry()); 660 } 661 662 void getAnalysisUsage(AnalysisUsage &AU) const override { 663 AU.setPreservesAll(); 664 AU.addRequired<AliasAnalysis>(); 665 } 666 667 bool runOnFunction(Function &F) override { 668 Tracker = new AliasSetTracker(getAnalysis<AliasAnalysis>()); 669 670 for (inst_iterator I = inst_begin(F), E = inst_end(F); I != E; ++I) 671 Tracker->add(&*I); 672 Tracker->print(errs()); 673 delete Tracker; 674 return false; 675 } 676 }; 677} 678 679char AliasSetPrinter::ID = 0; 680INITIALIZE_PASS_BEGIN(AliasSetPrinter, "print-alias-sets", 681 "Alias Set Printer", false, true) 682INITIALIZE_AG_DEPENDENCY(AliasAnalysis) 683INITIALIZE_PASS_END(AliasSetPrinter, "print-alias-sets", 684 "Alias Set Printer", false, true) 685