1 //===- llvm/Analysis/AliasAnalysis.h - Alias Analysis Interface -*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file defines the generic AliasAnalysis interface, which is used as the
11 // common interface used by all clients of alias analysis information, and
12 // implemented by all alias analysis implementations. Mod/Ref information is
13 // also captured by this interface.
15 // Implementations of this interface must implement the various virtual methods,
16 // which automatically provides functionality for the entire suite of client
19 // This API identifies memory regions with the Location class. The pointer
20 // component specifies the base memory address of the region. The Size specifies
21 // the maximum size (in address units) of the memory region, or UnknownSize if
22 // the size is not known. The TBAA tag identifies the "type" of the memory
23 // reference; see the TypeBasedAliasAnalysis class for details.
25 // Some non-obvious details include:
26 // - Pointers that point to two completely different objects in memory never
27 // alias, regardless of the value of the Size component.
28 // - NoAlias doesn't imply inequal pointers. The most obvious example of this
29 // is two pointers to constant memory. Even if they are equal, constant
30 // memory is never stored to, so there will never be any dependencies.
31 // In this and other situations, the pointers may be both NoAlias and
32 // MustAlias at the same time. The current API can only return one result,
33 // though this is rarely a problem in practice.
35 //===----------------------------------------------------------------------===//
37 #ifndef LLVM_ANALYSIS_ALIASANALYSIS_H
38 #define LLVM_ANALYSIS_ALIASANALYSIS_H
40 #include "llvm/ADT/DenseMap.h"
41 #include "llvm/IR/CallSite.h"
42 #include "llvm/IR/Metadata.h"
50 class TargetLibraryInfo;
53 class MemTransferInst;
60 const TargetLibraryInfo *TLI;
63 AliasAnalysis *AA; // Previous Alias Analysis to chain to.
66 /// InitializeAliasAnalysis - Subclasses must call this method to initialize
67 /// the AliasAnalysis interface before any other methods are called. This is
68 /// typically called by the run* methods of these subclasses. This may be
69 /// called multiple times.
71 void InitializeAliasAnalysis(Pass *P, const DataLayout *DL);
73 /// getAnalysisUsage - All alias analysis implementations should invoke this
74 /// directly (using AliasAnalysis::getAnalysisUsage(AU)).
75 virtual void getAnalysisUsage(AnalysisUsage &AU) const;
78 static char ID; // Class identification, replacement for typeinfo
79 AliasAnalysis() : DL(nullptr), TLI(nullptr), AA(nullptr) {}
80 virtual ~AliasAnalysis(); // We want to be subclassed
82 /// UnknownSize - This is a special value which can be used with the
83 /// size arguments in alias queries to indicate that the caller does not
84 /// know the sizes of the potential memory references.
85 static uint64_t const UnknownSize = ~UINT64_C(0);
87 /// getTargetLibraryInfo - Return a pointer to the current TargetLibraryInfo
88 /// object, or null if no TargetLibraryInfo object is available.
90 const TargetLibraryInfo *getTargetLibraryInfo() const { return TLI; }
92 /// getTypeStoreSize - Return the DataLayout store size for the given type,
93 /// if known, or a conservative value otherwise.
95 uint64_t getTypeStoreSize(Type *Ty);
97 //===--------------------------------------------------------------------===//
101 /// Location - A description of a memory location.
103 /// Ptr - The address of the start of the location.
105 /// Size - The maximum size of the location, in address-units, or
106 /// UnknownSize if the size is not known. Note that an unknown size does
107 /// not mean the pointer aliases the entire virtual address space, because
108 /// there are restrictions on stepping out of one object and into another.
109 /// See http://llvm.org/docs/LangRef.html#pointeraliasing
111 /// AATags - The metadata nodes which describes the aliasing of the
112 /// location (each member is null if that kind of information is
116 explicit Location(const Value *P = nullptr, uint64_t S = UnknownSize,
117 const AAMDNodes &N = AAMDNodes())
118 : Ptr(P), Size(S), AATags(N) {}
120 Location getWithNewPtr(const Value *NewPtr) const {
121 Location Copy(*this);
126 Location getWithNewSize(uint64_t NewSize) const {
127 Location Copy(*this);
132 Location getWithoutAATags() const {
133 Location Copy(*this);
134 Copy.AATags = AAMDNodes();
139 /// getLocation - Fill in Loc with information about the memory reference by
140 /// the given instruction.
141 Location getLocation(const LoadInst *LI);
142 Location getLocation(const StoreInst *SI);
143 Location getLocation(const VAArgInst *VI);
144 Location getLocation(const AtomicCmpXchgInst *CXI);
145 Location getLocation(const AtomicRMWInst *RMWI);
146 static Location getLocationForSource(const MemTransferInst *MTI);
147 static Location getLocationForDest(const MemIntrinsic *MI);
148 Location getLocation(const Instruction *Inst) {
149 if (auto *I = dyn_cast<LoadInst>(Inst))
150 return getLocation(I);
151 else if (auto *I = dyn_cast<StoreInst>(Inst))
152 return getLocation(I);
153 else if (auto *I = dyn_cast<VAArgInst>(Inst))
154 return getLocation(I);
155 else if (auto *I = dyn_cast<AtomicCmpXchgInst>(Inst))
156 return getLocation(I);
157 else if (auto *I = dyn_cast<AtomicRMWInst>(Inst))
158 return getLocation(I);
159 llvm_unreachable("unsupported memory instruction");
162 /// Alias analysis result - Either we know for sure that it does not alias, we
163 /// know for sure it must alias, or we don't know anything: The two pointers
164 /// _might_ alias. This enum is designed so you can do things like:
165 /// if (AA.alias(P1, P2)) { ... }
166 /// to check to see if two pointers might alias.
168 /// See docs/AliasAnalysis.html for more information on the specific meanings
172 NoAlias = 0, ///< No dependencies.
173 MayAlias, ///< Anything goes.
174 PartialAlias, ///< Pointers differ, but pointees overlap.
175 MustAlias ///< Pointers are equal.
178 /// alias - The main low level interface to the alias analysis implementation.
179 /// Returns an AliasResult indicating whether the two pointers are aliased to
180 /// each other. This is the interface that must be implemented by specific
181 /// alias analysis implementations.
182 virtual AliasResult alias(const Location &LocA, const Location &LocB);
184 /// alias - A convenience wrapper.
185 AliasResult alias(const Value *V1, uint64_t V1Size,
186 const Value *V2, uint64_t V2Size) {
187 return alias(Location(V1, V1Size), Location(V2, V2Size));
190 /// alias - A convenience wrapper.
191 AliasResult alias(const Value *V1, const Value *V2) {
192 return alias(V1, UnknownSize, V2, UnknownSize);
195 /// isNoAlias - A trivial helper function to check to see if the specified
196 /// pointers are no-alias.
197 bool isNoAlias(const Location &LocA, const Location &LocB) {
198 return alias(LocA, LocB) == NoAlias;
201 /// isNoAlias - A convenience wrapper.
202 bool isNoAlias(const Value *V1, uint64_t V1Size,
203 const Value *V2, uint64_t V2Size) {
204 return isNoAlias(Location(V1, V1Size), Location(V2, V2Size));
207 /// isNoAlias - A convenience wrapper.
208 bool isNoAlias(const Value *V1, const Value *V2) {
209 return isNoAlias(Location(V1), Location(V2));
212 /// isMustAlias - A convenience wrapper.
213 bool isMustAlias(const Location &LocA, const Location &LocB) {
214 return alias(LocA, LocB) == MustAlias;
217 /// isMustAlias - A convenience wrapper.
218 bool isMustAlias(const Value *V1, const Value *V2) {
219 return alias(V1, 1, V2, 1) == MustAlias;
222 /// pointsToConstantMemory - If the specified memory location is
223 /// known to be constant, return true. If OrLocal is true and the
224 /// specified memory location is known to be "local" (derived from
225 /// an alloca), return true. Otherwise return false.
226 virtual bool pointsToConstantMemory(const Location &Loc,
227 bool OrLocal = false);
229 /// pointsToConstantMemory - A convenient wrapper.
230 bool pointsToConstantMemory(const Value *P, bool OrLocal = false) {
231 return pointsToConstantMemory(Location(P), OrLocal);
234 //===--------------------------------------------------------------------===//
235 /// Simple mod/ref information...
238 /// ModRefResult - Represent the result of a mod/ref query. Mod and Ref are
239 /// bits which may be or'd together.
241 enum ModRefResult { NoModRef = 0, Ref = 1, Mod = 2, ModRef = 3 };
243 /// These values define additional bits used to define the
244 /// ModRefBehavior values.
245 enum { Nowhere = 0, ArgumentPointees = 4, Anywhere = 8 | ArgumentPointees };
247 /// ModRefBehavior - Summary of how a function affects memory in the program.
248 /// Loads from constant globals are not considered memory accesses for this
249 /// interface. Also, functions may freely modify stack space local to their
250 /// invocation without having to report it through these interfaces.
251 enum ModRefBehavior {
252 /// DoesNotAccessMemory - This function does not perform any non-local loads
253 /// or stores to memory.
255 /// This property corresponds to the GCC 'const' attribute.
256 /// This property corresponds to the LLVM IR 'readnone' attribute.
257 /// This property corresponds to the IntrNoMem LLVM intrinsic flag.
258 DoesNotAccessMemory = Nowhere | NoModRef,
260 /// OnlyReadsArgumentPointees - The only memory references in this function
261 /// (if it has any) are non-volatile loads from objects pointed to by its
262 /// pointer-typed arguments, with arbitrary offsets.
264 /// This property corresponds to the IntrReadArgMem LLVM intrinsic flag.
265 OnlyReadsArgumentPointees = ArgumentPointees | Ref,
267 /// OnlyAccessesArgumentPointees - The only memory references in this
268 /// function (if it has any) are non-volatile loads and stores from objects
269 /// pointed to by its pointer-typed arguments, with arbitrary offsets.
271 /// This property corresponds to the IntrReadWriteArgMem LLVM intrinsic flag.
272 OnlyAccessesArgumentPointees = ArgumentPointees | ModRef,
274 /// OnlyReadsMemory - This function does not perform any non-local stores or
275 /// volatile loads, but may read from any memory location.
277 /// This property corresponds to the GCC 'pure' attribute.
278 /// This property corresponds to the LLVM IR 'readonly' attribute.
279 /// This property corresponds to the IntrReadMem LLVM intrinsic flag.
280 OnlyReadsMemory = Anywhere | Ref,
282 /// UnknownModRefBehavior - This indicates that the function could not be
283 /// classified into one of the behaviors above.
284 UnknownModRefBehavior = Anywhere | ModRef
287 /// Get the location associated with a pointer argument of a callsite.
288 /// The mask bits are set to indicate the allowed aliasing ModRef kinds.
289 /// Note that these mask bits do not necessarily account for the overall
290 /// behavior of the function, but rather only provide additional
291 /// per-argument information.
292 virtual Location getArgLocation(ImmutableCallSite CS, unsigned ArgIdx,
295 /// getModRefBehavior - Return the behavior when calling the given call site.
296 virtual ModRefBehavior getModRefBehavior(ImmutableCallSite CS);
298 /// getModRefBehavior - Return the behavior when calling the given function.
299 /// For use when the call site is not known.
300 virtual ModRefBehavior getModRefBehavior(const Function *F);
302 /// doesNotAccessMemory - If the specified call is known to never read or
303 /// write memory, return true. If the call only reads from known-constant
304 /// memory, it is also legal to return true. Calls that unwind the stack
305 /// are legal for this predicate.
307 /// Many optimizations (such as CSE and LICM) can be performed on such calls
308 /// without worrying about aliasing properties, and many calls have this
309 /// property (e.g. calls to 'sin' and 'cos').
311 /// This property corresponds to the GCC 'const' attribute.
313 bool doesNotAccessMemory(ImmutableCallSite CS) {
314 return getModRefBehavior(CS) == DoesNotAccessMemory;
317 /// doesNotAccessMemory - If the specified function is known to never read or
318 /// write memory, return true. For use when the call site is not known.
320 bool doesNotAccessMemory(const Function *F) {
321 return getModRefBehavior(F) == DoesNotAccessMemory;
324 /// onlyReadsMemory - If the specified call is known to only read from
325 /// non-volatile memory (or not access memory at all), return true. Calls
326 /// that unwind the stack are legal for this predicate.
328 /// This property allows many common optimizations to be performed in the
329 /// absence of interfering store instructions, such as CSE of strlen calls.
331 /// This property corresponds to the GCC 'pure' attribute.
333 bool onlyReadsMemory(ImmutableCallSite CS) {
334 return onlyReadsMemory(getModRefBehavior(CS));
337 /// onlyReadsMemory - If the specified function is known to only read from
338 /// non-volatile memory (or not access memory at all), return true. For use
339 /// when the call site is not known.
341 bool onlyReadsMemory(const Function *F) {
342 return onlyReadsMemory(getModRefBehavior(F));
345 /// onlyReadsMemory - Return true if functions with the specified behavior are
346 /// known to only read from non-volatile memory (or not access memory at all).
348 static bool onlyReadsMemory(ModRefBehavior MRB) {
352 /// onlyAccessesArgPointees - Return true if functions with the specified
353 /// behavior are known to read and write at most from objects pointed to by
354 /// their pointer-typed arguments (with arbitrary offsets).
356 static bool onlyAccessesArgPointees(ModRefBehavior MRB) {
357 return !(MRB & Anywhere & ~ArgumentPointees);
360 /// doesAccessArgPointees - Return true if functions with the specified
361 /// behavior are known to potentially read or write from objects pointed
362 /// to be their pointer-typed arguments (with arbitrary offsets).
364 static bool doesAccessArgPointees(ModRefBehavior MRB) {
365 return (MRB & ModRef) && (MRB & ArgumentPointees);
368 /// getModRefInfo - Return information about whether or not an
369 /// instruction may read or write memory (without regard to a
370 /// specific location)
371 ModRefResult getModRefInfo(const Instruction *I) {
372 if (auto CS = ImmutableCallSite(I)) {
373 auto MRB = getModRefBehavior(CS);
383 return getModRefInfo(I, Location());
386 /// getModRefInfo - Return information about whether or not an instruction may
387 /// read or write the specified memory location. An instruction
388 /// that doesn't read or write memory may be trivially LICM'd for example.
389 ModRefResult getModRefInfo(const Instruction *I,
390 const Location &Loc) {
391 switch (I->getOpcode()) {
392 case Instruction::VAArg: return getModRefInfo((const VAArgInst*)I, Loc);
393 case Instruction::Load: return getModRefInfo((const LoadInst*)I, Loc);
394 case Instruction::Store: return getModRefInfo((const StoreInst*)I, Loc);
395 case Instruction::Fence: return getModRefInfo((const FenceInst*)I, Loc);
396 case Instruction::AtomicCmpXchg:
397 return getModRefInfo((const AtomicCmpXchgInst*)I, Loc);
398 case Instruction::AtomicRMW:
399 return getModRefInfo((const AtomicRMWInst*)I, Loc);
400 case Instruction::Call: return getModRefInfo((const CallInst*)I, Loc);
401 case Instruction::Invoke: return getModRefInfo((const InvokeInst*)I,Loc);
402 default: return NoModRef;
406 /// getModRefInfo - A convenience wrapper.
407 ModRefResult getModRefInfo(const Instruction *I,
408 const Value *P, uint64_t Size) {
409 return getModRefInfo(I, Location(P, Size));
412 /// getModRefInfo (for call sites) - Return information about whether
413 /// a particular call site modifies or reads the specified memory location.
414 virtual ModRefResult getModRefInfo(ImmutableCallSite CS,
415 const Location &Loc);
417 /// getModRefInfo (for call sites) - A convenience wrapper.
418 ModRefResult getModRefInfo(ImmutableCallSite CS,
419 const Value *P, uint64_t Size) {
420 return getModRefInfo(CS, Location(P, Size));
423 /// getModRefInfo (for calls) - Return information about whether
424 /// a particular call modifies or reads the specified memory location.
425 ModRefResult getModRefInfo(const CallInst *C, const Location &Loc) {
426 return getModRefInfo(ImmutableCallSite(C), Loc);
429 /// getModRefInfo (for calls) - A convenience wrapper.
430 ModRefResult getModRefInfo(const CallInst *C, const Value *P, uint64_t Size) {
431 return getModRefInfo(C, Location(P, Size));
434 /// getModRefInfo (for invokes) - Return information about whether
435 /// a particular invoke modifies or reads the specified memory location.
436 ModRefResult getModRefInfo(const InvokeInst *I,
437 const Location &Loc) {
438 return getModRefInfo(ImmutableCallSite(I), Loc);
441 /// getModRefInfo (for invokes) - A convenience wrapper.
442 ModRefResult getModRefInfo(const InvokeInst *I,
443 const Value *P, uint64_t Size) {
444 return getModRefInfo(I, Location(P, Size));
447 /// getModRefInfo (for loads) - Return information about whether
448 /// a particular load modifies or reads the specified memory location.
449 ModRefResult getModRefInfo(const LoadInst *L, const Location &Loc);
451 /// getModRefInfo (for loads) - A convenience wrapper.
452 ModRefResult getModRefInfo(const LoadInst *L, const Value *P, uint64_t Size) {
453 return getModRefInfo(L, Location(P, Size));
456 /// getModRefInfo (for stores) - Return information about whether
457 /// a particular store modifies or reads the specified memory location.
458 ModRefResult getModRefInfo(const StoreInst *S, const Location &Loc);
460 /// getModRefInfo (for stores) - A convenience wrapper.
461 ModRefResult getModRefInfo(const StoreInst *S, const Value *P, uint64_t Size){
462 return getModRefInfo(S, Location(P, Size));
465 /// getModRefInfo (for fences) - Return information about whether
466 /// a particular store modifies or reads the specified memory location.
467 ModRefResult getModRefInfo(const FenceInst *S, const Location &Loc) {
468 // Conservatively correct. (We could possibly be a bit smarter if
469 // Loc is a alloca that doesn't escape.)
473 /// getModRefInfo (for fences) - A convenience wrapper.
474 ModRefResult getModRefInfo(const FenceInst *S, const Value *P, uint64_t Size){
475 return getModRefInfo(S, Location(P, Size));
478 /// getModRefInfo (for cmpxchges) - Return information about whether
479 /// a particular cmpxchg modifies or reads the specified memory location.
480 ModRefResult getModRefInfo(const AtomicCmpXchgInst *CX, const Location &Loc);
482 /// getModRefInfo (for cmpxchges) - A convenience wrapper.
483 ModRefResult getModRefInfo(const AtomicCmpXchgInst *CX,
484 const Value *P, unsigned Size) {
485 return getModRefInfo(CX, Location(P, Size));
488 /// getModRefInfo (for atomicrmws) - Return information about whether
489 /// a particular atomicrmw modifies or reads the specified memory location.
490 ModRefResult getModRefInfo(const AtomicRMWInst *RMW, const Location &Loc);
492 /// getModRefInfo (for atomicrmws) - A convenience wrapper.
493 ModRefResult getModRefInfo(const AtomicRMWInst *RMW,
494 const Value *P, unsigned Size) {
495 return getModRefInfo(RMW, Location(P, Size));
498 /// getModRefInfo (for va_args) - Return information about whether
499 /// a particular va_arg modifies or reads the specified memory location.
500 ModRefResult getModRefInfo(const VAArgInst* I, const Location &Loc);
502 /// getModRefInfo (for va_args) - A convenience wrapper.
503 ModRefResult getModRefInfo(const VAArgInst* I, const Value* P, uint64_t Size){
504 return getModRefInfo(I, Location(P, Size));
507 /// getModRefInfo - Return information about whether two call sites may refer
508 /// to the same set of memory locations. See
509 /// http://llvm.org/docs/AliasAnalysis.html#ModRefInfo
511 virtual ModRefResult getModRefInfo(ImmutableCallSite CS1,
512 ImmutableCallSite CS2);
514 /// callCapturesBefore - Return information about whether a particular call
515 /// site modifies or reads the specified memory location.
516 ModRefResult callCapturesBefore(const Instruction *I,
517 const AliasAnalysis::Location &MemLoc,
520 /// callCapturesBefore - A convenience wrapper.
521 ModRefResult callCapturesBefore(const Instruction *I, const Value *P,
522 uint64_t Size, DominatorTree *DT) {
523 return callCapturesBefore(I, Location(P, Size), DT);
526 //===--------------------------------------------------------------------===//
527 /// Higher level methods for querying mod/ref information.
530 /// canBasicBlockModify - Return true if it is possible for execution of the
531 /// specified basic block to modify the location Loc.
532 bool canBasicBlockModify(const BasicBlock &BB, const Location &Loc);
534 /// canBasicBlockModify - A convenience wrapper.
535 bool canBasicBlockModify(const BasicBlock &BB, const Value *P, uint64_t Size){
536 return canBasicBlockModify(BB, Location(P, Size));
539 /// canInstructionRangeModRef - Return true if it is possible for the
540 /// execution of the specified instructions to mod\ref (according to the
541 /// mode) the location Loc. The instructions to consider are all
542 /// of the instructions in the range of [I1,I2] INCLUSIVE.
543 /// I1 and I2 must be in the same basic block.
544 bool canInstructionRangeModRef(const Instruction &I1,
545 const Instruction &I2, const Location &Loc,
546 const ModRefResult Mode);
548 /// canInstructionRangeModRef - A convenience wrapper.
549 bool canInstructionRangeModRef(const Instruction &I1,
550 const Instruction &I2, const Value *Ptr,
551 uint64_t Size, const ModRefResult Mode) {
552 return canInstructionRangeModRef(I1, I2, Location(Ptr, Size), Mode);
555 //===--------------------------------------------------------------------===//
556 /// Methods that clients should call when they transform the program to allow
557 /// alias analyses to update their internal data structures. Note that these
558 /// methods may be called on any instruction, regardless of whether or not
559 /// they have pointer-analysis implications.
562 /// deleteValue - This method should be called whenever an LLVM Value is
563 /// deleted from the program, for example when an instruction is found to be
564 /// redundant and is eliminated.
566 virtual void deleteValue(Value *V);
568 /// copyValue - This method should be used whenever a preexisting value in the
569 /// program is copied or cloned, introducing a new value. Note that analysis
570 /// implementations should tolerate clients that use this method to introduce
571 /// the same value multiple times: if the analysis already knows about a
572 /// value, it should ignore the request.
574 virtual void copyValue(Value *From, Value *To);
576 /// addEscapingUse - This method should be used whenever an escaping use is
577 /// added to a pointer value. Analysis implementations may either return
578 /// conservative responses for that value in the future, or may recompute
579 /// some or all internal state to continue providing precise responses.
581 /// Escaping uses are considered by anything _except_ the following:
582 /// - GEPs or bitcasts of the pointer
583 /// - Loads through the pointer
584 /// - Stores through (but not of) the pointer
585 virtual void addEscapingUse(Use &U);
587 /// replaceWithNewValue - This method is the obvious combination of the two
588 /// above, and it provided as a helper to simplify client code.
590 void replaceWithNewValue(Value *Old, Value *New) {
596 // Specialize DenseMapInfo for Location.
598 struct DenseMapInfo<AliasAnalysis::Location> {
599 static inline AliasAnalysis::Location getEmptyKey() {
600 return AliasAnalysis::Location(DenseMapInfo<const Value *>::getEmptyKey(),
603 static inline AliasAnalysis::Location getTombstoneKey() {
604 return AliasAnalysis::Location(
605 DenseMapInfo<const Value *>::getTombstoneKey(), 0);
607 static unsigned getHashValue(const AliasAnalysis::Location &Val) {
608 return DenseMapInfo<const Value *>::getHashValue(Val.Ptr) ^
609 DenseMapInfo<uint64_t>::getHashValue(Val.Size) ^
610 DenseMapInfo<AAMDNodes>::getHashValue(Val.AATags);
612 static bool isEqual(const AliasAnalysis::Location &LHS,
613 const AliasAnalysis::Location &RHS) {
614 return LHS.Ptr == RHS.Ptr &&
615 LHS.Size == RHS.Size &&
616 LHS.AATags == RHS.AATags;
620 /// isNoAliasCall - Return true if this pointer is returned by a noalias
622 bool isNoAliasCall(const Value *V);
624 /// isNoAliasArgument - Return true if this is an argument with the noalias
626 bool isNoAliasArgument(const Value *V);
628 /// isIdentifiedObject - Return true if this pointer refers to a distinct and
629 /// identifiable object. This returns true for:
630 /// Global Variables and Functions (but not Global Aliases)
632 /// ByVal and NoAlias Arguments
633 /// NoAlias returns (e.g. calls to malloc)
635 bool isIdentifiedObject(const Value *V);
637 /// isIdentifiedFunctionLocal - Return true if V is umabigously identified
638 /// at the function-level. Different IdentifiedFunctionLocals can't alias.
639 /// Further, an IdentifiedFunctionLocal can not alias with any function
640 /// arguments other than itself, which is not necessarily true for
641 /// IdentifiedObjects.
642 bool isIdentifiedFunctionLocal(const Value *V);
644 } // End llvm namespace