1 //==- AliasAnalysis.cpp - Generic Alias Analysis Interface Implementation --==//
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 implements the generic AliasAnalysis interface which is used as the
11 // common interface used by all clients and implementations of alias analysis.
13 // This file also implements the default version of the AliasAnalysis interface
14 // that is to be used when no other implementation is specified. This does some
15 // simple tests that detect obvious cases: two different global pointers cannot
16 // alias, a global cannot alias a malloc, two different mallocs cannot alias,
19 // This alias analysis implementation really isn't very good for anything, but
20 // it is very fast, and makes a nice clean default implementation. Because it
21 // handles lots of little corner cases, other, more complex, alias analysis
22 // implementations may choose to rely on this pass to resolve these simple and
25 //===----------------------------------------------------------------------===//
27 #include "llvm/Analysis/AliasAnalysis.h"
28 #include "llvm/Analysis/BasicAliasAnalysis.h"
29 #include "llvm/Analysis/CFLAndersAliasAnalysis.h"
30 #include "llvm/Analysis/CFLSteensAliasAnalysis.h"
31 #include "llvm/Analysis/CaptureTracking.h"
32 #include "llvm/Analysis/GlobalsModRef.h"
33 #include "llvm/Analysis/MemoryLocation.h"
34 #include "llvm/Analysis/ObjCARCAliasAnalysis.h"
35 #include "llvm/Analysis/ScalarEvolutionAliasAnalysis.h"
36 #include "llvm/Analysis/ScopedNoAliasAA.h"
37 #include "llvm/Analysis/TargetLibraryInfo.h"
38 #include "llvm/Analysis/TypeBasedAliasAnalysis.h"
39 #include "llvm/Analysis/ValueTracking.h"
40 #include "llvm/IR/Argument.h"
41 #include "llvm/IR/Attributes.h"
42 #include "llvm/IR/BasicBlock.h"
43 #include "llvm/IR/CallSite.h"
44 #include "llvm/IR/Instruction.h"
45 #include "llvm/IR/Instructions.h"
46 #include "llvm/IR/Module.h"
47 #include "llvm/IR/Type.h"
48 #include "llvm/IR/Value.h"
49 #include "llvm/Pass.h"
50 #include "llvm/Support/AtomicOrdering.h"
51 #include "llvm/Support/Casting.h"
52 #include "llvm/Support/CommandLine.h"
60 /// Allow disabling BasicAA from the AA results. This is particularly useful
61 /// when testing to isolate a single AA implementation.
62 static cl::opt<bool> DisableBasicAA("disable-basicaa", cl::Hidden,
65 AAResults::AAResults(AAResults &&Arg)
66 : TLI(Arg.TLI), AAs(std::move(Arg.AAs)), AADeps(std::move(Arg.AADeps)) {
68 AA->setAAResults(this);
71 AAResults::~AAResults() {
72 // FIXME; It would be nice to at least clear out the pointers back to this
73 // aggregation here, but we end up with non-nesting lifetimes in the legacy
74 // pass manager that prevent this from working. In the legacy pass manager
75 // we'll end up with dangling references here in some cases.
78 AA->setAAResults(nullptr);
82 bool AAResults::invalidate(Function &F, const PreservedAnalyses &PA,
83 FunctionAnalysisManager::Invalidator &Inv) {
84 // Check if the AA manager itself has been invalidated.
85 auto PAC = PA.getChecker<AAManager>();
86 if (!PAC.preserved() && !PAC.preservedSet<AllAnalysesOn<Function>>())
87 return true; // The manager needs to be blown away, clear everything.
89 // Check all of the dependencies registered.
90 for (AnalysisKey *ID : AADeps)
91 if (Inv.invalidate(ID, F, PA))
94 // Everything we depend on is still fine, so are we. Nothing to invalidate.
98 //===----------------------------------------------------------------------===//
99 // Default chaining methods
100 //===----------------------------------------------------------------------===//
102 AliasResult AAResults::alias(const MemoryLocation &LocA,
103 const MemoryLocation &LocB) {
104 for (const auto &AA : AAs) {
105 auto Result = AA->alias(LocA, LocB);
106 if (Result != MayAlias)
112 bool AAResults::pointsToConstantMemory(const MemoryLocation &Loc,
114 for (const auto &AA : AAs)
115 if (AA->pointsToConstantMemory(Loc, OrLocal))
121 ModRefInfo AAResults::getArgModRefInfo(ImmutableCallSite CS, unsigned ArgIdx) {
122 ModRefInfo Result = ModRefInfo::ModRef;
124 for (const auto &AA : AAs) {
125 Result = intersectModRef(Result, AA->getArgModRefInfo(CS, ArgIdx));
127 // Early-exit the moment we reach the bottom of the lattice.
128 if (isNoModRef(Result))
135 ModRefInfo AAResults::getModRefInfo(Instruction *I, ImmutableCallSite Call) {
136 // We may have two calls
137 if (auto CS = ImmutableCallSite(I)) {
138 // Check if the two calls modify the same memory
139 return getModRefInfo(CS, Call);
140 } else if (I->isFenceLike()) {
141 // If this is a fence, just return ModRef.
142 return ModRefInfo::ModRef;
144 // Otherwise, check if the call modifies or references the
145 // location this memory access defines. The best we can say
146 // is that if the call references what this instruction
147 // defines, it must be clobbered by this location.
148 const MemoryLocation DefLoc = MemoryLocation::get(I);
149 ModRefInfo MR = getModRefInfo(Call, DefLoc);
150 if (isModOrRefSet(MR))
151 return setModAndRef(MR);
153 return ModRefInfo::NoModRef;
156 ModRefInfo AAResults::getModRefInfo(ImmutableCallSite CS,
157 const MemoryLocation &Loc) {
158 ModRefInfo Result = ModRefInfo::ModRef;
160 for (const auto &AA : AAs) {
161 Result = intersectModRef(Result, AA->getModRefInfo(CS, Loc));
163 // Early-exit the moment we reach the bottom of the lattice.
164 if (isNoModRef(Result))
168 // Try to refine the mod-ref info further using other API entry points to the
169 // aggregate set of AA results.
170 auto MRB = getModRefBehavior(CS);
171 if (MRB == FMRB_DoesNotAccessMemory ||
172 MRB == FMRB_OnlyAccessesInaccessibleMem)
173 return ModRefInfo::NoModRef;
175 if (onlyReadsMemory(MRB))
176 Result = clearMod(Result);
177 else if (doesNotReadMemory(MRB))
178 Result = clearRef(Result);
180 if (onlyAccessesArgPointees(MRB) || onlyAccessesInaccessibleOrArgMem(MRB)) {
181 bool DoesAlias = false;
182 ModRefInfo AllArgsMask = ModRefInfo::NoModRef;
183 if (doesAccessArgPointees(MRB)) {
184 for (auto AI = CS.arg_begin(), AE = CS.arg_end(); AI != AE; ++AI) {
185 const Value *Arg = *AI;
186 if (!Arg->getType()->isPointerTy())
188 unsigned ArgIdx = std::distance(CS.arg_begin(), AI);
189 MemoryLocation ArgLoc = MemoryLocation::getForArgument(CS, ArgIdx, TLI);
190 AliasResult ArgAlias = alias(ArgLoc, Loc);
191 if (ArgAlias != NoAlias) {
192 ModRefInfo ArgMask = getArgModRefInfo(CS, ArgIdx);
194 AllArgsMask = unionModRef(AllArgsMask, ArgMask);
198 // Return NoModRef if no alias found with any argument.
200 return ModRefInfo::NoModRef;
201 // Logical & between other AA analyses and argument analysis.
202 Result = intersectModRef(Result, AllArgsMask);
205 // If Loc is a constant memory location, the call definitely could not
206 // modify the memory location.
207 if (isModSet(Result) && pointsToConstantMemory(Loc, /*OrLocal*/ false))
208 Result = clearMod(Result);
213 ModRefInfo AAResults::getModRefInfo(ImmutableCallSite CS1,
214 ImmutableCallSite CS2) {
215 ModRefInfo Result = ModRefInfo::ModRef;
217 for (const auto &AA : AAs) {
218 Result = intersectModRef(Result, AA->getModRefInfo(CS1, CS2));
220 // Early-exit the moment we reach the bottom of the lattice.
221 if (isNoModRef(Result))
225 // Try to refine the mod-ref info further using other API entry points to the
226 // aggregate set of AA results.
228 // If CS1 or CS2 are readnone, they don't interact.
229 auto CS1B = getModRefBehavior(CS1);
230 if (CS1B == FMRB_DoesNotAccessMemory)
231 return ModRefInfo::NoModRef;
233 auto CS2B = getModRefBehavior(CS2);
234 if (CS2B == FMRB_DoesNotAccessMemory)
235 return ModRefInfo::NoModRef;
237 // If they both only read from memory, there is no dependence.
238 if (onlyReadsMemory(CS1B) && onlyReadsMemory(CS2B))
239 return ModRefInfo::NoModRef;
241 // If CS1 only reads memory, the only dependence on CS2 can be
242 // from CS1 reading memory written by CS2.
243 if (onlyReadsMemory(CS1B))
244 Result = clearMod(Result);
245 else if (doesNotReadMemory(CS1B))
246 Result = clearRef(Result);
248 // If CS2 only access memory through arguments, accumulate the mod/ref
249 // information from CS1's references to the memory referenced by
251 if (onlyAccessesArgPointees(CS2B)) {
252 ModRefInfo R = ModRefInfo::NoModRef;
253 if (doesAccessArgPointees(CS2B)) {
254 for (auto I = CS2.arg_begin(), E = CS2.arg_end(); I != E; ++I) {
255 const Value *Arg = *I;
256 if (!Arg->getType()->isPointerTy())
258 unsigned CS2ArgIdx = std::distance(CS2.arg_begin(), I);
259 auto CS2ArgLoc = MemoryLocation::getForArgument(CS2, CS2ArgIdx, TLI);
261 // ArgModRefCS2 indicates what CS2 might do to CS2ArgLoc, and the
262 // dependence of CS1 on that location is the inverse:
263 // - If CS2 modifies location, dependence exists if CS1 reads or writes.
264 // - If CS2 only reads location, dependence exists if CS1 writes.
265 ModRefInfo ArgModRefCS2 = getArgModRefInfo(CS2, CS2ArgIdx);
266 ModRefInfo ArgMask = ModRefInfo::NoModRef;
267 if (isModSet(ArgModRefCS2))
268 ArgMask = ModRefInfo::ModRef;
269 else if (isRefSet(ArgModRefCS2))
270 ArgMask = ModRefInfo::Mod;
272 // ModRefCS1 indicates what CS1 might do to CS2ArgLoc, and we use
273 // above ArgMask to update dependence info.
274 ModRefInfo ModRefCS1 = getModRefInfo(CS1, CS2ArgLoc);
275 ArgMask = intersectModRef(ArgMask, ModRefCS1);
277 R = intersectModRef(unionModRef(R, ArgMask), Result);
285 // If CS1 only accesses memory through arguments, check if CS2 references
286 // any of the memory referenced by CS1's arguments. If not, return NoModRef.
287 if (onlyAccessesArgPointees(CS1B)) {
288 ModRefInfo R = ModRefInfo::NoModRef;
289 if (doesAccessArgPointees(CS1B)) {
290 for (auto I = CS1.arg_begin(), E = CS1.arg_end(); I != E; ++I) {
291 const Value *Arg = *I;
292 if (!Arg->getType()->isPointerTy())
294 unsigned CS1ArgIdx = std::distance(CS1.arg_begin(), I);
295 auto CS1ArgLoc = MemoryLocation::getForArgument(CS1, CS1ArgIdx, TLI);
297 // ArgModRefCS1 indicates what CS1 might do to CS1ArgLoc; if CS1 might
298 // Mod CS1ArgLoc, then we care about either a Mod or a Ref by CS2. If
299 // CS1 might Ref, then we care only about a Mod by CS2.
300 ModRefInfo ArgModRefCS1 = getArgModRefInfo(CS1, CS1ArgIdx);
301 ModRefInfo ModRefCS2 = getModRefInfo(CS2, CS1ArgLoc);
302 if ((isModSet(ArgModRefCS1) && isModOrRefSet(ModRefCS2)) ||
303 (isRefSet(ArgModRefCS1) && isModSet(ModRefCS2)))
304 R = intersectModRef(unionModRef(R, ArgModRefCS1), Result);
316 FunctionModRefBehavior AAResults::getModRefBehavior(ImmutableCallSite CS) {
317 FunctionModRefBehavior Result = FMRB_UnknownModRefBehavior;
319 for (const auto &AA : AAs) {
320 Result = FunctionModRefBehavior(Result & AA->getModRefBehavior(CS));
322 // Early-exit the moment we reach the bottom of the lattice.
323 if (Result == FMRB_DoesNotAccessMemory)
330 FunctionModRefBehavior AAResults::getModRefBehavior(const Function *F) {
331 FunctionModRefBehavior Result = FMRB_UnknownModRefBehavior;
333 for (const auto &AA : AAs) {
334 Result = FunctionModRefBehavior(Result & AA->getModRefBehavior(F));
336 // Early-exit the moment we reach the bottom of the lattice.
337 if (Result == FMRB_DoesNotAccessMemory)
344 //===----------------------------------------------------------------------===//
345 // Helper method implementation
346 //===----------------------------------------------------------------------===//
348 ModRefInfo AAResults::getModRefInfo(const LoadInst *L,
349 const MemoryLocation &Loc) {
350 // Be conservative in the face of atomic.
351 if (isStrongerThan(L->getOrdering(), AtomicOrdering::Unordered))
352 return ModRefInfo::ModRef;
354 // If the load address doesn't alias the given address, it doesn't read
355 // or write the specified memory.
356 if (Loc.Ptr && !alias(MemoryLocation::get(L), Loc))
357 return ModRefInfo::NoModRef;
359 // Otherwise, a load just reads.
360 return ModRefInfo::Ref;
363 ModRefInfo AAResults::getModRefInfo(const StoreInst *S,
364 const MemoryLocation &Loc) {
365 // Be conservative in the face of atomic.
366 if (isStrongerThan(S->getOrdering(), AtomicOrdering::Unordered))
367 return ModRefInfo::ModRef;
370 // If the store address cannot alias the pointer in question, then the
371 // specified memory cannot be modified by the store.
372 if (!alias(MemoryLocation::get(S), Loc))
373 return ModRefInfo::NoModRef;
375 // If the pointer is a pointer to constant memory, then it could not have
376 // been modified by this store.
377 if (pointsToConstantMemory(Loc))
378 return ModRefInfo::NoModRef;
381 // Otherwise, a store just writes.
382 return ModRefInfo::Mod;
385 ModRefInfo AAResults::getModRefInfo(const FenceInst *S, const MemoryLocation &Loc) {
386 // If we know that the location is a constant memory location, the fence
387 // cannot modify this location.
388 if (Loc.Ptr && pointsToConstantMemory(Loc))
389 return ModRefInfo::Ref;
390 return ModRefInfo::ModRef;
393 ModRefInfo AAResults::getModRefInfo(const VAArgInst *V,
394 const MemoryLocation &Loc) {
396 // If the va_arg address cannot alias the pointer in question, then the
397 // specified memory cannot be accessed by the va_arg.
398 if (!alias(MemoryLocation::get(V), Loc))
399 return ModRefInfo::NoModRef;
401 // If the pointer is a pointer to constant memory, then it could not have
402 // been modified by this va_arg.
403 if (pointsToConstantMemory(Loc))
404 return ModRefInfo::NoModRef;
407 // Otherwise, a va_arg reads and writes.
408 return ModRefInfo::ModRef;
411 ModRefInfo AAResults::getModRefInfo(const CatchPadInst *CatchPad,
412 const MemoryLocation &Loc) {
414 // If the pointer is a pointer to constant memory,
415 // then it could not have been modified by this catchpad.
416 if (pointsToConstantMemory(Loc))
417 return ModRefInfo::NoModRef;
420 // Otherwise, a catchpad reads and writes.
421 return ModRefInfo::ModRef;
424 ModRefInfo AAResults::getModRefInfo(const CatchReturnInst *CatchRet,
425 const MemoryLocation &Loc) {
427 // If the pointer is a pointer to constant memory,
428 // then it could not have been modified by this catchpad.
429 if (pointsToConstantMemory(Loc))
430 return ModRefInfo::NoModRef;
433 // Otherwise, a catchret reads and writes.
434 return ModRefInfo::ModRef;
437 ModRefInfo AAResults::getModRefInfo(const AtomicCmpXchgInst *CX,
438 const MemoryLocation &Loc) {
439 // Acquire/Release cmpxchg has properties that matter for arbitrary addresses.
440 if (isStrongerThanMonotonic(CX->getSuccessOrdering()))
441 return ModRefInfo::ModRef;
443 // If the cmpxchg address does not alias the location, it does not access it.
444 if (Loc.Ptr && !alias(MemoryLocation::get(CX), Loc))
445 return ModRefInfo::NoModRef;
447 return ModRefInfo::ModRef;
450 ModRefInfo AAResults::getModRefInfo(const AtomicRMWInst *RMW,
451 const MemoryLocation &Loc) {
452 // Acquire/Release atomicrmw has properties that matter for arbitrary addresses.
453 if (isStrongerThanMonotonic(RMW->getOrdering()))
454 return ModRefInfo::ModRef;
456 // If the atomicrmw address does not alias the location, it does not access it.
457 if (Loc.Ptr && !alias(MemoryLocation::get(RMW), Loc))
458 return ModRefInfo::NoModRef;
460 return ModRefInfo::ModRef;
463 /// \brief Return information about whether a particular call site modifies
464 /// or reads the specified memory location \p MemLoc before instruction \p I
465 /// in a BasicBlock. An ordered basic block \p OBB can be used to speed up
466 /// instruction-ordering queries inside the BasicBlock containing \p I.
467 /// FIXME: this is really just shoring-up a deficiency in alias analysis.
468 /// BasicAA isn't willing to spend linear time determining whether an alloca
469 /// was captured before or after this particular call, while we are. However,
470 /// with a smarter AA in place, this test is just wasting compile time.
471 ModRefInfo AAResults::callCapturesBefore(const Instruction *I,
472 const MemoryLocation &MemLoc,
474 OrderedBasicBlock *OBB) {
476 return ModRefInfo::ModRef;
478 const Value *Object =
479 GetUnderlyingObject(MemLoc.Ptr, I->getModule()->getDataLayout());
480 if (!isIdentifiedObject(Object) || isa<GlobalValue>(Object) ||
481 isa<Constant>(Object))
482 return ModRefInfo::ModRef;
484 ImmutableCallSite CS(I);
485 if (!CS.getInstruction() || CS.getInstruction() == Object)
486 return ModRefInfo::ModRef;
488 if (PointerMayBeCapturedBefore(Object, /* ReturnCaptures */ true,
489 /* StoreCaptures */ true, I, DT,
490 /* include Object */ true,
491 /* OrderedBasicBlock */ OBB))
492 return ModRefInfo::ModRef;
495 ModRefInfo R = ModRefInfo::NoModRef;
496 for (auto CI = CS.data_operands_begin(), CE = CS.data_operands_end();
497 CI != CE; ++CI, ++ArgNo) {
498 // Only look at the no-capture or byval pointer arguments. If this
499 // pointer were passed to arguments that were neither of these, then it
500 // couldn't be no-capture.
501 if (!(*CI)->getType()->isPointerTy() ||
502 (!CS.doesNotCapture(ArgNo) &&
503 ArgNo < CS.getNumArgOperands() && !CS.isByValArgument(ArgNo)))
506 // If this is a no-capture pointer argument, see if we can tell that it
507 // is impossible to alias the pointer we're checking. If not, we have to
508 // assume that the call could touch the pointer, even though it doesn't
510 if (isNoAlias(MemoryLocation(*CI), MemoryLocation(Object)))
512 if (CS.doesNotAccessMemory(ArgNo))
514 if (CS.onlyReadsMemory(ArgNo)) {
518 return ModRefInfo::ModRef;
523 /// canBasicBlockModify - Return true if it is possible for execution of the
524 /// specified basic block to modify the location Loc.
526 bool AAResults::canBasicBlockModify(const BasicBlock &BB,
527 const MemoryLocation &Loc) {
528 return canInstructionRangeModRef(BB.front(), BB.back(), Loc, ModRefInfo::Mod);
531 /// canInstructionRangeModRef - Return true if it is possible for the
532 /// execution of the specified instructions to mod\ref (according to the
533 /// mode) the location Loc. The instructions to consider are all
534 /// of the instructions in the range of [I1,I2] INCLUSIVE.
535 /// I1 and I2 must be in the same basic block.
536 bool AAResults::canInstructionRangeModRef(const Instruction &I1,
537 const Instruction &I2,
538 const MemoryLocation &Loc,
539 const ModRefInfo Mode) {
540 assert(I1.getParent() == I2.getParent() &&
541 "Instructions not in same basic block!");
542 BasicBlock::const_iterator I = I1.getIterator();
543 BasicBlock::const_iterator E = I2.getIterator();
544 ++E; // Convert from inclusive to exclusive range.
546 for (; I != E; ++I) // Check every instruction in range
547 if (isModOrRefSet(intersectModRef(getModRefInfo(&*I, Loc), Mode)))
552 // Provide a definition for the root virtual destructor.
553 AAResults::Concept::~Concept() = default;
555 // Provide a definition for the static object used to identify passes.
556 AnalysisKey AAManager::Key;
560 /// A wrapper pass for external alias analyses. This just squirrels away the
561 /// callback used to run any analyses and register their results.
562 struct ExternalAAWrapperPass : ImmutablePass {
563 using CallbackT = std::function<void(Pass &, Function &, AAResults &)>;
569 ExternalAAWrapperPass() : ImmutablePass(ID) {
570 initializeExternalAAWrapperPassPass(*PassRegistry::getPassRegistry());
573 explicit ExternalAAWrapperPass(CallbackT CB)
574 : ImmutablePass(ID), CB(std::move(CB)) {
575 initializeExternalAAWrapperPassPass(*PassRegistry::getPassRegistry());
578 void getAnalysisUsage(AnalysisUsage &AU) const override {
579 AU.setPreservesAll();
583 } // end anonymous namespace
585 char ExternalAAWrapperPass::ID = 0;
587 INITIALIZE_PASS(ExternalAAWrapperPass, "external-aa", "External Alias Analysis",
591 llvm::createExternalAAWrapperPass(ExternalAAWrapperPass::CallbackT Callback) {
592 return new ExternalAAWrapperPass(std::move(Callback));
595 AAResultsWrapperPass::AAResultsWrapperPass() : FunctionPass(ID) {
596 initializeAAResultsWrapperPassPass(*PassRegistry::getPassRegistry());
599 char AAResultsWrapperPass::ID = 0;
601 INITIALIZE_PASS_BEGIN(AAResultsWrapperPass, "aa",
602 "Function Alias Analysis Results", false, true)
603 INITIALIZE_PASS_DEPENDENCY(BasicAAWrapperPass)
604 INITIALIZE_PASS_DEPENDENCY(CFLAndersAAWrapperPass)
605 INITIALIZE_PASS_DEPENDENCY(CFLSteensAAWrapperPass)
606 INITIALIZE_PASS_DEPENDENCY(ExternalAAWrapperPass)
607 INITIALIZE_PASS_DEPENDENCY(GlobalsAAWrapperPass)
608 INITIALIZE_PASS_DEPENDENCY(ObjCARCAAWrapperPass)
609 INITIALIZE_PASS_DEPENDENCY(SCEVAAWrapperPass)
610 INITIALIZE_PASS_DEPENDENCY(ScopedNoAliasAAWrapperPass)
611 INITIALIZE_PASS_DEPENDENCY(TypeBasedAAWrapperPass)
612 INITIALIZE_PASS_END(AAResultsWrapperPass, "aa",
613 "Function Alias Analysis Results", false, true)
615 FunctionPass *llvm::createAAResultsWrapperPass() {
616 return new AAResultsWrapperPass();
619 /// Run the wrapper pass to rebuild an aggregation over known AA passes.
621 /// This is the legacy pass manager's interface to the new-style AA results
622 /// aggregation object. Because this is somewhat shoe-horned into the legacy
623 /// pass manager, we hard code all the specific alias analyses available into
624 /// it. While the particular set enabled is configured via commandline flags,
625 /// adding a new alias analysis to LLVM will require adding support for it to
627 bool AAResultsWrapperPass::runOnFunction(Function &F) {
628 // NB! This *must* be reset before adding new AA results to the new
629 // AAResults object because in the legacy pass manager, each instance
630 // of these will refer to the *same* immutable analyses, registering and
631 // unregistering themselves with them. We need to carefully tear down the
632 // previous object first, in this case replacing it with an empty one, before
633 // registering new results.
635 new AAResults(getAnalysis<TargetLibraryInfoWrapperPass>().getTLI()));
637 // BasicAA is always available for function analyses. Also, we add it first
638 // so that it can trump TBAA results when it proves MustAlias.
639 // FIXME: TBAA should have an explicit mode to support this and then we
640 // should reconsider the ordering here.
642 AAR->addAAResult(getAnalysis<BasicAAWrapperPass>().getResult());
644 // Populate the results with the currently available AAs.
645 if (auto *WrapperPass = getAnalysisIfAvailable<ScopedNoAliasAAWrapperPass>())
646 AAR->addAAResult(WrapperPass->getResult());
647 if (auto *WrapperPass = getAnalysisIfAvailable<TypeBasedAAWrapperPass>())
648 AAR->addAAResult(WrapperPass->getResult());
649 if (auto *WrapperPass =
650 getAnalysisIfAvailable<objcarc::ObjCARCAAWrapperPass>())
651 AAR->addAAResult(WrapperPass->getResult());
652 if (auto *WrapperPass = getAnalysisIfAvailable<GlobalsAAWrapperPass>())
653 AAR->addAAResult(WrapperPass->getResult());
654 if (auto *WrapperPass = getAnalysisIfAvailable<SCEVAAWrapperPass>())
655 AAR->addAAResult(WrapperPass->getResult());
656 if (auto *WrapperPass = getAnalysisIfAvailable<CFLAndersAAWrapperPass>())
657 AAR->addAAResult(WrapperPass->getResult());
658 if (auto *WrapperPass = getAnalysisIfAvailable<CFLSteensAAWrapperPass>())
659 AAR->addAAResult(WrapperPass->getResult());
661 // If available, run an external AA providing callback over the results as
663 if (auto *WrapperPass = getAnalysisIfAvailable<ExternalAAWrapperPass>())
665 WrapperPass->CB(*this, F, *AAR);
667 // Analyses don't mutate the IR, so return false.
671 void AAResultsWrapperPass::getAnalysisUsage(AnalysisUsage &AU) const {
672 AU.setPreservesAll();
673 AU.addRequired<BasicAAWrapperPass>();
674 AU.addRequired<TargetLibraryInfoWrapperPass>();
676 // We also need to mark all the alias analysis passes we will potentially
677 // probe in runOnFunction as used here to ensure the legacy pass manager
678 // preserves them. This hard coding of lists of alias analyses is specific to
679 // the legacy pass manager.
680 AU.addUsedIfAvailable<ScopedNoAliasAAWrapperPass>();
681 AU.addUsedIfAvailable<TypeBasedAAWrapperPass>();
682 AU.addUsedIfAvailable<objcarc::ObjCARCAAWrapperPass>();
683 AU.addUsedIfAvailable<GlobalsAAWrapperPass>();
684 AU.addUsedIfAvailable<SCEVAAWrapperPass>();
685 AU.addUsedIfAvailable<CFLAndersAAWrapperPass>();
686 AU.addUsedIfAvailable<CFLSteensAAWrapperPass>();
689 AAResults llvm::createLegacyPMAAResults(Pass &P, Function &F,
690 BasicAAResult &BAR) {
691 AAResults AAR(P.getAnalysis<TargetLibraryInfoWrapperPass>().getTLI());
693 // Add in our explicitly constructed BasicAA results.
695 AAR.addAAResult(BAR);
697 // Populate the results with the other currently available AAs.
698 if (auto *WrapperPass =
699 P.getAnalysisIfAvailable<ScopedNoAliasAAWrapperPass>())
700 AAR.addAAResult(WrapperPass->getResult());
701 if (auto *WrapperPass = P.getAnalysisIfAvailable<TypeBasedAAWrapperPass>())
702 AAR.addAAResult(WrapperPass->getResult());
703 if (auto *WrapperPass =
704 P.getAnalysisIfAvailable<objcarc::ObjCARCAAWrapperPass>())
705 AAR.addAAResult(WrapperPass->getResult());
706 if (auto *WrapperPass = P.getAnalysisIfAvailable<GlobalsAAWrapperPass>())
707 AAR.addAAResult(WrapperPass->getResult());
708 if (auto *WrapperPass = P.getAnalysisIfAvailable<CFLAndersAAWrapperPass>())
709 AAR.addAAResult(WrapperPass->getResult());
710 if (auto *WrapperPass = P.getAnalysisIfAvailable<CFLSteensAAWrapperPass>())
711 AAR.addAAResult(WrapperPass->getResult());
716 bool llvm::isNoAliasCall(const Value *V) {
717 if (auto CS = ImmutableCallSite(V))
718 return CS.hasRetAttr(Attribute::NoAlias);
722 bool llvm::isNoAliasArgument(const Value *V) {
723 if (const Argument *A = dyn_cast<Argument>(V))
724 return A->hasNoAliasAttr();
728 bool llvm::isIdentifiedObject(const Value *V) {
729 if (isa<AllocaInst>(V))
731 if (isa<GlobalValue>(V) && !isa<GlobalAlias>(V))
733 if (isNoAliasCall(V))
735 if (const Argument *A = dyn_cast<Argument>(V))
736 return A->hasNoAliasAttr() || A->hasByValAttr();
740 bool llvm::isIdentifiedFunctionLocal(const Value *V) {
741 return isa<AllocaInst>(V) || isNoAliasCall(V) || isNoAliasArgument(V);
744 void llvm::getAAResultsAnalysisUsage(AnalysisUsage &AU) {
745 // This function needs to be in sync with llvm::createLegacyPMAAResults -- if
746 // more alias analyses are added to llvm::createLegacyPMAAResults, they need
747 // to be added here also.
748 AU.addRequired<TargetLibraryInfoWrapperPass>();
749 AU.addUsedIfAvailable<ScopedNoAliasAAWrapperPass>();
750 AU.addUsedIfAvailable<TypeBasedAAWrapperPass>();
751 AU.addUsedIfAvailable<objcarc::ObjCARCAAWrapperPass>();
752 AU.addUsedIfAvailable<GlobalsAAWrapperPass>();
753 AU.addUsedIfAvailable<CFLAndersAAWrapperPass>();
754 AU.addUsedIfAvailable<CFLSteensAAWrapperPass>();