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();
138 bool operator==(const AliasAnalysis::Location &Other) const {
139 return Ptr == Other.Ptr && Size == Other.Size && AATags == Other.AATags;
143 /// getLocation - Fill in Loc with information about the memory reference by
144 /// the given instruction.
145 Location getLocation(const LoadInst *LI);
146 Location getLocation(const StoreInst *SI);
147 Location getLocation(const VAArgInst *VI);
148 Location getLocation(const AtomicCmpXchgInst *CXI);
149 Location getLocation(const AtomicRMWInst *RMWI);
150 static Location getLocationForSource(const MemTransferInst *MTI);
151 static Location getLocationForDest(const MemIntrinsic *MI);
152 Location getLocation(const Instruction *Inst) {
153 if (auto *I = dyn_cast<LoadInst>(Inst))
154 return getLocation(I);
155 else if (auto *I = dyn_cast<StoreInst>(Inst))
156 return getLocation(I);
157 else if (auto *I = dyn_cast<VAArgInst>(Inst))
158 return getLocation(I);
159 else if (auto *I = dyn_cast<AtomicCmpXchgInst>(Inst))
160 return getLocation(I);
161 else if (auto *I = dyn_cast<AtomicRMWInst>(Inst))
162 return getLocation(I);
163 llvm_unreachable("unsupported memory instruction");
166 /// Alias analysis result - Either we know for sure that it does not alias, we
167 /// know for sure it must alias, or we don't know anything: The two pointers
168 /// _might_ alias. This enum is designed so you can do things like:
169 /// if (AA.alias(P1, P2)) { ... }
170 /// to check to see if two pointers might alias.
172 /// See docs/AliasAnalysis.html for more information on the specific meanings
176 NoAlias = 0, ///< No dependencies.
177 MayAlias, ///< Anything goes.
178 PartialAlias, ///< Pointers differ, but pointees overlap.
179 MustAlias ///< Pointers are equal.
182 /// alias - The main low level interface to the alias analysis implementation.
183 /// Returns an AliasResult indicating whether the two pointers are aliased to
184 /// each other. This is the interface that must be implemented by specific
185 /// alias analysis implementations.
186 virtual AliasResult alias(const Location &LocA, const Location &LocB);
188 /// alias - A convenience wrapper.
189 AliasResult alias(const Value *V1, uint64_t V1Size,
190 const Value *V2, uint64_t V2Size) {
191 return alias(Location(V1, V1Size), Location(V2, V2Size));
194 /// alias - A convenience wrapper.
195 AliasResult alias(const Value *V1, const Value *V2) {
196 return alias(V1, UnknownSize, V2, UnknownSize);
199 /// isNoAlias - A trivial helper function to check to see if the specified
200 /// pointers are no-alias.
201 bool isNoAlias(const Location &LocA, const Location &LocB) {
202 return alias(LocA, LocB) == NoAlias;
205 /// isNoAlias - A convenience wrapper.
206 bool isNoAlias(const Value *V1, uint64_t V1Size,
207 const Value *V2, uint64_t V2Size) {
208 return isNoAlias(Location(V1, V1Size), Location(V2, V2Size));
211 /// isNoAlias - A convenience wrapper.
212 bool isNoAlias(const Value *V1, const Value *V2) {
213 return isNoAlias(Location(V1), Location(V2));
216 /// isMustAlias - A convenience wrapper.
217 bool isMustAlias(const Location &LocA, const Location &LocB) {
218 return alias(LocA, LocB) == MustAlias;
221 /// isMustAlias - A convenience wrapper.
222 bool isMustAlias(const Value *V1, const Value *V2) {
223 return alias(V1, 1, V2, 1) == MustAlias;
226 /// pointsToConstantMemory - If the specified memory location is
227 /// known to be constant, return true. If OrLocal is true and the
228 /// specified memory location is known to be "local" (derived from
229 /// an alloca), return true. Otherwise return false.
230 virtual bool pointsToConstantMemory(const Location &Loc,
231 bool OrLocal = false);
233 /// pointsToConstantMemory - A convenient wrapper.
234 bool pointsToConstantMemory(const Value *P, bool OrLocal = false) {
235 return pointsToConstantMemory(Location(P), OrLocal);
238 //===--------------------------------------------------------------------===//
239 /// Simple mod/ref information...
242 /// ModRefResult - Represent the result of a mod/ref query. Mod and Ref are
243 /// bits which may be or'd together.
245 enum ModRefResult { NoModRef = 0, Ref = 1, Mod = 2, ModRef = 3 };
247 /// These values define additional bits used to define the
248 /// ModRefBehavior values.
249 enum { Nowhere = 0, ArgumentPointees = 4, Anywhere = 8 | ArgumentPointees };
251 /// ModRefBehavior - Summary of how a function affects memory in the program.
252 /// Loads from constant globals are not considered memory accesses for this
253 /// interface. Also, functions may freely modify stack space local to their
254 /// invocation without having to report it through these interfaces.
255 enum ModRefBehavior {
256 /// DoesNotAccessMemory - This function does not perform any non-local loads
257 /// or stores to memory.
259 /// This property corresponds to the GCC 'const' attribute.
260 /// This property corresponds to the LLVM IR 'readnone' attribute.
261 /// This property corresponds to the IntrNoMem LLVM intrinsic flag.
262 DoesNotAccessMemory = Nowhere | NoModRef,
264 /// OnlyReadsArgumentPointees - The only memory references in this function
265 /// (if it has any) are non-volatile loads from objects pointed to by its
266 /// pointer-typed arguments, with arbitrary offsets.
268 /// This property corresponds to the IntrReadArgMem LLVM intrinsic flag.
269 OnlyReadsArgumentPointees = ArgumentPointees | Ref,
271 /// OnlyAccessesArgumentPointees - The only memory references in this
272 /// function (if it has any) are non-volatile loads and stores from objects
273 /// pointed to by its pointer-typed arguments, with arbitrary offsets.
275 /// This property corresponds to the IntrReadWriteArgMem LLVM intrinsic flag.
276 OnlyAccessesArgumentPointees = ArgumentPointees | ModRef,
278 /// OnlyReadsMemory - This function does not perform any non-local stores or
279 /// volatile loads, but may read from any memory location.
281 /// This property corresponds to the GCC 'pure' attribute.
282 /// This property corresponds to the LLVM IR 'readonly' attribute.
283 /// This property corresponds to the IntrReadMem LLVM intrinsic flag.
284 OnlyReadsMemory = Anywhere | Ref,
286 /// UnknownModRefBehavior - This indicates that the function could not be
287 /// classified into one of the behaviors above.
288 UnknownModRefBehavior = Anywhere | ModRef
291 /// Get the location associated with a pointer argument of a callsite.
292 /// The mask bits are set to indicate the allowed aliasing ModRef kinds.
293 /// Note that these mask bits do not necessarily account for the overall
294 /// behavior of the function, but rather only provide additional
295 /// per-argument information.
296 virtual Location getArgLocation(ImmutableCallSite CS, unsigned ArgIdx,
299 /// getModRefBehavior - Return the behavior when calling the given call site.
300 virtual ModRefBehavior getModRefBehavior(ImmutableCallSite CS);
302 /// getModRefBehavior - Return the behavior when calling the given function.
303 /// For use when the call site is not known.
304 virtual ModRefBehavior getModRefBehavior(const Function *F);
306 /// doesNotAccessMemory - If the specified call is known to never read or
307 /// write memory, return true. If the call only reads from known-constant
308 /// memory, it is also legal to return true. Calls that unwind the stack
309 /// are legal for this predicate.
311 /// Many optimizations (such as CSE and LICM) can be performed on such calls
312 /// without worrying about aliasing properties, and many calls have this
313 /// property (e.g. calls to 'sin' and 'cos').
315 /// This property corresponds to the GCC 'const' attribute.
317 bool doesNotAccessMemory(ImmutableCallSite CS) {
318 return getModRefBehavior(CS) == DoesNotAccessMemory;
321 /// doesNotAccessMemory - If the specified function is known to never read or
322 /// write memory, return true. For use when the call site is not known.
324 bool doesNotAccessMemory(const Function *F) {
325 return getModRefBehavior(F) == DoesNotAccessMemory;
328 /// onlyReadsMemory - If the specified call is known to only read from
329 /// non-volatile memory (or not access memory at all), return true. Calls
330 /// that unwind the stack are legal for this predicate.
332 /// This property allows many common optimizations to be performed in the
333 /// absence of interfering store instructions, such as CSE of strlen calls.
335 /// This property corresponds to the GCC 'pure' attribute.
337 bool onlyReadsMemory(ImmutableCallSite CS) {
338 return onlyReadsMemory(getModRefBehavior(CS));
341 /// onlyReadsMemory - If the specified function is known to only read from
342 /// non-volatile memory (or not access memory at all), return true. For use
343 /// when the call site is not known.
345 bool onlyReadsMemory(const Function *F) {
346 return onlyReadsMemory(getModRefBehavior(F));
349 /// onlyReadsMemory - Return true if functions with the specified behavior are
350 /// known to only read from non-volatile memory (or not access memory at all).
352 static bool onlyReadsMemory(ModRefBehavior MRB) {
356 /// onlyAccessesArgPointees - Return true if functions with the specified
357 /// behavior are known to read and write at most from objects pointed to by
358 /// their pointer-typed arguments (with arbitrary offsets).
360 static bool onlyAccessesArgPointees(ModRefBehavior MRB) {
361 return !(MRB & Anywhere & ~ArgumentPointees);
364 /// doesAccessArgPointees - Return true if functions with the specified
365 /// behavior are known to potentially read or write from objects pointed
366 /// to be their pointer-typed arguments (with arbitrary offsets).
368 static bool doesAccessArgPointees(ModRefBehavior MRB) {
369 return (MRB & ModRef) && (MRB & ArgumentPointees);
372 /// getModRefInfo - Return information about whether or not an
373 /// instruction may read or write memory (without regard to a
374 /// specific location)
375 ModRefResult getModRefInfo(const Instruction *I) {
376 if (auto CS = ImmutableCallSite(I)) {
377 auto MRB = getModRefBehavior(CS);
387 return getModRefInfo(I, Location());
390 /// getModRefInfo - Return information about whether or not an instruction may
391 /// read or write the specified memory location. An instruction
392 /// that doesn't read or write memory may be trivially LICM'd for example.
393 ModRefResult getModRefInfo(const Instruction *I,
394 const Location &Loc) {
395 switch (I->getOpcode()) {
396 case Instruction::VAArg: return getModRefInfo((const VAArgInst*)I, Loc);
397 case Instruction::Load: return getModRefInfo((const LoadInst*)I, Loc);
398 case Instruction::Store: return getModRefInfo((const StoreInst*)I, Loc);
399 case Instruction::Fence: return getModRefInfo((const FenceInst*)I, Loc);
400 case Instruction::AtomicCmpXchg:
401 return getModRefInfo((const AtomicCmpXchgInst*)I, Loc);
402 case Instruction::AtomicRMW:
403 return getModRefInfo((const AtomicRMWInst*)I, Loc);
404 case Instruction::Call: return getModRefInfo((const CallInst*)I, Loc);
405 case Instruction::Invoke: return getModRefInfo((const InvokeInst*)I,Loc);
406 default: return NoModRef;
410 /// getModRefInfo - A convenience wrapper.
411 ModRefResult getModRefInfo(const Instruction *I,
412 const Value *P, uint64_t Size) {
413 return getModRefInfo(I, Location(P, Size));
416 /// getModRefInfo (for call sites) - Return information about whether
417 /// a particular call site modifies or reads the specified memory location.
418 virtual ModRefResult getModRefInfo(ImmutableCallSite CS,
419 const Location &Loc);
421 /// getModRefInfo (for call sites) - A convenience wrapper.
422 ModRefResult getModRefInfo(ImmutableCallSite CS,
423 const Value *P, uint64_t Size) {
424 return getModRefInfo(CS, Location(P, Size));
427 /// getModRefInfo (for calls) - Return information about whether
428 /// a particular call modifies or reads the specified memory location.
429 ModRefResult getModRefInfo(const CallInst *C, const Location &Loc) {
430 return getModRefInfo(ImmutableCallSite(C), Loc);
433 /// getModRefInfo (for calls) - A convenience wrapper.
434 ModRefResult getModRefInfo(const CallInst *C, const Value *P, uint64_t Size) {
435 return getModRefInfo(C, Location(P, Size));
438 /// getModRefInfo (for invokes) - Return information about whether
439 /// a particular invoke modifies or reads the specified memory location.
440 ModRefResult getModRefInfo(const InvokeInst *I,
441 const Location &Loc) {
442 return getModRefInfo(ImmutableCallSite(I), Loc);
445 /// getModRefInfo (for invokes) - A convenience wrapper.
446 ModRefResult getModRefInfo(const InvokeInst *I,
447 const Value *P, uint64_t Size) {
448 return getModRefInfo(I, Location(P, Size));
451 /// getModRefInfo (for loads) - Return information about whether
452 /// a particular load modifies or reads the specified memory location.
453 ModRefResult getModRefInfo(const LoadInst *L, const Location &Loc);
455 /// getModRefInfo (for loads) - A convenience wrapper.
456 ModRefResult getModRefInfo(const LoadInst *L, const Value *P, uint64_t Size) {
457 return getModRefInfo(L, Location(P, Size));
460 /// getModRefInfo (for stores) - Return information about whether
461 /// a particular store modifies or reads the specified memory location.
462 ModRefResult getModRefInfo(const StoreInst *S, const Location &Loc);
464 /// getModRefInfo (for stores) - A convenience wrapper.
465 ModRefResult getModRefInfo(const StoreInst *S, const Value *P, uint64_t Size){
466 return getModRefInfo(S, Location(P, Size));
469 /// getModRefInfo (for fences) - Return information about whether
470 /// a particular store modifies or reads the specified memory location.
471 ModRefResult getModRefInfo(const FenceInst *S, const Location &Loc) {
472 // Conservatively correct. (We could possibly be a bit smarter if
473 // Loc is a alloca that doesn't escape.)
477 /// getModRefInfo (for fences) - A convenience wrapper.
478 ModRefResult getModRefInfo(const FenceInst *S, const Value *P, uint64_t Size){
479 return getModRefInfo(S, Location(P, Size));
482 /// getModRefInfo (for cmpxchges) - Return information about whether
483 /// a particular cmpxchg modifies or reads the specified memory location.
484 ModRefResult getModRefInfo(const AtomicCmpXchgInst *CX, const Location &Loc);
486 /// getModRefInfo (for cmpxchges) - A convenience wrapper.
487 ModRefResult getModRefInfo(const AtomicCmpXchgInst *CX,
488 const Value *P, unsigned Size) {
489 return getModRefInfo(CX, Location(P, Size));
492 /// getModRefInfo (for atomicrmws) - Return information about whether
493 /// a particular atomicrmw modifies or reads the specified memory location.
494 ModRefResult getModRefInfo(const AtomicRMWInst *RMW, const Location &Loc);
496 /// getModRefInfo (for atomicrmws) - A convenience wrapper.
497 ModRefResult getModRefInfo(const AtomicRMWInst *RMW,
498 const Value *P, unsigned Size) {
499 return getModRefInfo(RMW, Location(P, Size));
502 /// getModRefInfo (for va_args) - Return information about whether
503 /// a particular va_arg modifies or reads the specified memory location.
504 ModRefResult getModRefInfo(const VAArgInst* I, const Location &Loc);
506 /// getModRefInfo (for va_args) - A convenience wrapper.
507 ModRefResult getModRefInfo(const VAArgInst* I, const Value* P, uint64_t Size){
508 return getModRefInfo(I, Location(P, Size));
510 /// getModRefInfo - Return information about whether a call and an instruction
511 /// may refer to the same memory locations.
512 ModRefResult getModRefInfo(Instruction *I,
513 ImmutableCallSite Call);
515 /// getModRefInfo - Return information about whether two call sites may refer
516 /// to the same set of memory locations. See
517 /// http://llvm.org/docs/AliasAnalysis.html#ModRefInfo
519 virtual ModRefResult getModRefInfo(ImmutableCallSite CS1,
520 ImmutableCallSite CS2);
522 /// callCapturesBefore - Return information about whether a particular call
523 /// site modifies or reads the specified memory location.
524 ModRefResult callCapturesBefore(const Instruction *I,
525 const AliasAnalysis::Location &MemLoc,
528 /// callCapturesBefore - A convenience wrapper.
529 ModRefResult callCapturesBefore(const Instruction *I, const Value *P,
530 uint64_t Size, DominatorTree *DT) {
531 return callCapturesBefore(I, Location(P, Size), DT);
534 //===--------------------------------------------------------------------===//
535 /// Higher level methods for querying mod/ref information.
538 /// canBasicBlockModify - Return true if it is possible for execution of the
539 /// specified basic block to modify the location Loc.
540 bool canBasicBlockModify(const BasicBlock &BB, const Location &Loc);
542 /// canBasicBlockModify - A convenience wrapper.
543 bool canBasicBlockModify(const BasicBlock &BB, const Value *P, uint64_t Size){
544 return canBasicBlockModify(BB, Location(P, Size));
547 /// canInstructionRangeModRef - Return true if it is possible for the
548 /// execution of the specified instructions to mod\ref (according to the
549 /// mode) the location Loc. The instructions to consider are all
550 /// of the instructions in the range of [I1,I2] INCLUSIVE.
551 /// I1 and I2 must be in the same basic block.
552 bool canInstructionRangeModRef(const Instruction &I1,
553 const Instruction &I2, const Location &Loc,
554 const ModRefResult Mode);
556 /// canInstructionRangeModRef - A convenience wrapper.
557 bool canInstructionRangeModRef(const Instruction &I1,
558 const Instruction &I2, const Value *Ptr,
559 uint64_t Size, const ModRefResult Mode) {
560 return canInstructionRangeModRef(I1, I2, Location(Ptr, Size), Mode);
563 //===--------------------------------------------------------------------===//
564 /// Methods that clients should call when they transform the program to allow
565 /// alias analyses to update their internal data structures. Note that these
566 /// methods may be called on any instruction, regardless of whether or not
567 /// they have pointer-analysis implications.
570 /// deleteValue - This method should be called whenever an LLVM Value is
571 /// deleted from the program, for example when an instruction is found to be
572 /// redundant and is eliminated.
574 virtual void deleteValue(Value *V);
576 /// copyValue - This method should be used whenever a preexisting value in the
577 /// program is copied or cloned, introducing a new value. Note that analysis
578 /// implementations should tolerate clients that use this method to introduce
579 /// the same value multiple times: if the analysis already knows about a
580 /// value, it should ignore the request.
582 virtual void copyValue(Value *From, Value *To);
584 /// addEscapingUse - This method should be used whenever an escaping use is
585 /// added to a pointer value. Analysis implementations may either return
586 /// conservative responses for that value in the future, or may recompute
587 /// some or all internal state to continue providing precise responses.
589 /// Escaping uses are considered by anything _except_ the following:
590 /// - GEPs or bitcasts of the pointer
591 /// - Loads through the pointer
592 /// - Stores through (but not of) the pointer
593 virtual void addEscapingUse(Use &U);
595 /// replaceWithNewValue - This method is the obvious combination of the two
596 /// above, and it provided as a helper to simplify client code.
598 void replaceWithNewValue(Value *Old, Value *New) {
604 // Specialize DenseMapInfo for Location.
606 struct DenseMapInfo<AliasAnalysis::Location> {
607 static inline AliasAnalysis::Location getEmptyKey() {
608 return AliasAnalysis::Location(DenseMapInfo<const Value *>::getEmptyKey(),
611 static inline AliasAnalysis::Location getTombstoneKey() {
612 return AliasAnalysis::Location(
613 DenseMapInfo<const Value *>::getTombstoneKey(), 0);
615 static unsigned getHashValue(const AliasAnalysis::Location &Val) {
616 return DenseMapInfo<const Value *>::getHashValue(Val.Ptr) ^
617 DenseMapInfo<uint64_t>::getHashValue(Val.Size) ^
618 DenseMapInfo<AAMDNodes>::getHashValue(Val.AATags);
620 static bool isEqual(const AliasAnalysis::Location &LHS,
621 const AliasAnalysis::Location &RHS) {
626 /// isNoAliasCall - Return true if this pointer is returned by a noalias
628 bool isNoAliasCall(const Value *V);
630 /// isNoAliasArgument - Return true if this is an argument with the noalias
632 bool isNoAliasArgument(const Value *V);
634 /// isIdentifiedObject - Return true if this pointer refers to a distinct and
635 /// identifiable object. This returns true for:
636 /// Global Variables and Functions (but not Global Aliases)
638 /// ByVal and NoAlias Arguments
639 /// NoAlias returns (e.g. calls to malloc)
641 bool isIdentifiedObject(const Value *V);
643 /// isIdentifiedFunctionLocal - Return true if V is umabigously identified
644 /// at the function-level. Different IdentifiedFunctionLocals can't alias.
645 /// Further, an IdentifiedFunctionLocal can not alias with any function
646 /// arguments other than itself, which is not necessarily true for
647 /// IdentifiedObjects.
648 bool isIdentifiedFunctionLocal(const Value *V);
650 } // End llvm namespace