LCOV - code coverage report
Current view: top level - include/llvm/Analysis - MemoryDependenceAnalysis.h (source / functions) Hit Total Coverage
Test: llvm-toolchain.info Lines: 15 19 78.9 %
Date: 2018-07-13 00:08:38 Functions: 5 5 100.0 %
Legend: Lines: hit not hit

          Line data    Source code
       1             : //===- llvm/Analysis/MemoryDependenceAnalysis.h - Memory Deps ---*- C++ -*-===//
       2             : //
       3             : //                     The LLVM Compiler Infrastructure
       4             : //
       5             : // This file is distributed under the University of Illinois Open Source
       6             : // License. See LICENSE.TXT for details.
       7             : //
       8             : //===----------------------------------------------------------------------===//
       9             : //
      10             : // This file defines the MemoryDependenceAnalysis analysis pass.
      11             : //
      12             : //===----------------------------------------------------------------------===//
      13             : 
      14             : #ifndef LLVM_ANALYSIS_MEMORYDEPENDENCEANALYSIS_H
      15             : #define LLVM_ANALYSIS_MEMORYDEPENDENCEANALYSIS_H
      16             : 
      17             : #include "llvm/ADT/DenseMap.h"
      18             : #include "llvm/ADT/Optional.h"
      19             : #include "llvm/ADT/PointerEmbeddedInt.h"
      20             : #include "llvm/ADT/PointerIntPair.h"
      21             : #include "llvm/ADT/PointerSumType.h"
      22             : #include "llvm/ADT/SmallPtrSet.h"
      23             : #include "llvm/Analysis/AliasAnalysis.h"
      24             : #include "llvm/Analysis/MemoryLocation.h"
      25             : #include "llvm/IR/BasicBlock.h"
      26             : #include "llvm/IR/Metadata.h"
      27             : #include "llvm/IR/PassManager.h"
      28             : #include "llvm/IR/PredIteratorCache.h"
      29             : #include "llvm/IR/ValueHandle.h"
      30             : #include "llvm/Pass.h"
      31             : #include "llvm/Support/ErrorHandling.h"
      32             : #include <cassert>
      33             : #include <cstdint>
      34             : #include <utility>
      35             : #include <vector>
      36             : 
      37             : namespace llvm {
      38             : 
      39             : class AssumptionCache;
      40             : class CallSite;
      41             : class DominatorTree;
      42             : class Function;
      43             : class Instruction;
      44             : class LoadInst;
      45             : class PHITransAddr;
      46             : class TargetLibraryInfo;
      47             : class Value;
      48             : 
      49             : /// A memory dependence query can return one of three different answers.
      50             : class MemDepResult {
      51             :   enum DepType {
      52             :     /// Clients of MemDep never see this.
      53             :     ///
      54             :     /// Entries with this marker occur in a LocalDeps map or NonLocalDeps map
      55             :     /// when the instruction they previously referenced was removed from
      56             :     /// MemDep.  In either case, the entry may include an instruction pointer.
      57             :     /// If so, the pointer is an instruction in the block where scanning can
      58             :     /// start from, saving some work.
      59             :     ///
      60             :     /// In a default-constructed MemDepResult object, the type will be Invalid
      61             :     /// and the instruction pointer will be null.
      62             :     Invalid = 0,
      63             : 
      64             :     /// This is a dependence on the specified instruction which clobbers the
      65             :     /// desired value.  The pointer member of the MemDepResult pair holds the
      66             :     /// instruction that clobbers the memory.  For example, this occurs when we
      67             :     /// see a may-aliased store to the memory location we care about.
      68             :     ///
      69             :     /// There are several cases that may be interesting here:
      70             :     ///   1. Loads are clobbered by may-alias stores.
      71             :     ///   2. Loads are considered clobbered by partially-aliased loads.  The
      72             :     ///      client may choose to analyze deeper into these cases.
      73             :     Clobber,
      74             : 
      75             :     /// This is a dependence on the specified instruction which defines or
      76             :     /// produces the desired memory location.  The pointer member of the
      77             :     /// MemDepResult pair holds the instruction that defines the memory.
      78             :     ///
      79             :     /// Cases of interest:
      80             :     ///   1. This could be a load or store for dependence queries on
      81             :     ///      load/store.  The value loaded or stored is the produced value.
      82             :     ///      Note that the pointer operand may be different than that of the
      83             :     ///      queried pointer due to must aliases and phi translation. Note
      84             :     ///      that the def may not be the same type as the query, the pointers
      85             :     ///      may just be must aliases.
      86             :     ///   2. For loads and stores, this could be an allocation instruction. In
      87             :     ///      this case, the load is loading an undef value or a store is the
      88             :     ///      first store to (that part of) the allocation.
      89             :     ///   3. Dependence queries on calls return Def only when they are readonly
      90             :     ///      calls or memory use intrinsics with identical callees and no
      91             :     ///      intervening clobbers.  No validation is done that the operands to
      92             :     ///      the calls are the same.
      93             :     Def,
      94             : 
      95             :     /// This marker indicates that the query has no known dependency in the
      96             :     /// specified block.
      97             :     ///
      98             :     /// More detailed state info is encoded in the upper part of the pair (i.e.
      99             :     /// the Instruction*)
     100             :     Other
     101             :   };
     102             : 
     103             :   /// If DepType is "Other", the upper part of the sum type is an encoding of
     104             :   /// the following more detailed type information.
     105             :   enum OtherType {
     106             :     /// This marker indicates that the query has no dependency in the specified
     107             :     /// block.
     108             :     ///
     109             :     /// To find out more, the client should query other predecessor blocks.
     110             :     NonLocal = 1,
     111             :     /// This marker indicates that the query has no dependency in the specified
     112             :     /// function.
     113             :     NonFuncLocal,
     114             :     /// This marker indicates that the query dependency is unknown.
     115             :     Unknown
     116             :   };
     117             : 
     118             :   using ValueTy = PointerSumType<
     119             :       DepType, PointerSumTypeMember<Invalid, Instruction *>,
     120             :       PointerSumTypeMember<Clobber, Instruction *>,
     121             :       PointerSumTypeMember<Def, Instruction *>,
     122             :       PointerSumTypeMember<Other, PointerEmbeddedInt<OtherType, 3>>>;
     123             :   ValueTy Value;
     124             : 
     125             :   explicit MemDepResult(ValueTy V) : Value(V) {}
     126             : 
     127             : public:
     128             :   MemDepResult() = default;
     129             : 
     130             :   /// get methods: These are static ctor methods for creating various
     131             :   /// MemDepResult kinds.
     132             :   static MemDepResult getDef(Instruction *Inst) {
     133             :     assert(Inst && "Def requires inst");
     134             :     return MemDepResult(ValueTy::create<Def>(Inst));
     135             :   }
     136             :   static MemDepResult getClobber(Instruction *Inst) {
     137             :     assert(Inst && "Clobber requires inst");
     138             :     return MemDepResult(ValueTy::create<Clobber>(Inst));
     139             :   }
     140             :   static MemDepResult getNonLocal() {
     141             :     return MemDepResult(ValueTy::create<Other>(NonLocal));
     142             :   }
     143             :   static MemDepResult getNonFuncLocal() {
     144             :     return MemDepResult(ValueTy::create<Other>(NonFuncLocal));
     145             :   }
     146             :   static MemDepResult getUnknown() {
     147             :     return MemDepResult(ValueTy::create<Other>(Unknown));
     148             :   }
     149             : 
     150             :   /// Tests if this MemDepResult represents a query that is an instruction
     151             :   /// clobber dependency.
     152             :   bool isClobber() const { return Value.is<Clobber>(); }
     153             : 
     154             :   /// Tests if this MemDepResult represents a query that is an instruction
     155             :   /// definition dependency.
     156             :   bool isDef() const { return Value.is<Def>(); }
     157             : 
     158             :   /// Tests if this MemDepResult represents a query that is transparent to the
     159             :   /// start of the block, but where a non-local hasn't been done.
     160             :   bool isNonLocal() const {
     161     6948906 :     return Value.is<Other>() && Value.cast<Other>() == NonLocal;
     162             :   }
     163             : 
     164             :   /// Tests if this MemDepResult represents a query that is transparent to the
     165             :   /// start of the function.
     166             :   bool isNonFuncLocal() const {
     167           0 :     return Value.is<Other>() && Value.cast<Other>() == NonFuncLocal;
     168             :   }
     169             : 
     170             :   /// Tests if this MemDepResult represents a query which cannot and/or will
     171             :   /// not be computed.
     172             :   bool isUnknown() const {
     173       52164 :     return Value.is<Other>() && Value.cast<Other>() == Unknown;
     174             :   }
     175             : 
     176             :   /// If this is a normal dependency, returns the instruction that is depended
     177             :   /// on.  Otherwise, returns null.
     178             :   Instruction *getInst() const {
     179     1762420 :     switch (Value.getTag()) {
     180      989375 :     case Invalid:
     181             :       return Value.cast<Invalid>();
     182     1280890 :     case Clobber:
     183             :       return Value.cast<Clobber>();
     184      862077 :     case Def:
     185             :       return Value.cast<Def>();
     186             :     case Other:
     187             :       return nullptr;
     188             :     }
     189           0 :     llvm_unreachable("Unknown discriminant!");
     190             :   }
     191             : 
     192             :   bool operator==(const MemDepResult &M) const { return Value == M.Value; }
     193             :   bool operator!=(const MemDepResult &M) const { return Value != M.Value; }
     194             :   bool operator<(const MemDepResult &M) const { return Value < M.Value; }
     195             :   bool operator>(const MemDepResult &M) const { return Value > M.Value; }
     196             : 
     197             : private:
     198             :   friend class MemoryDependenceResults;
     199             : 
     200             :   /// Tests if this is a MemDepResult in its dirty/invalid. state.
     201             :   bool isDirty() const { return Value.is<Invalid>(); }
     202             : 
     203             :   static MemDepResult getDirty(Instruction *Inst) {
     204             :     return MemDepResult(ValueTy::create<Invalid>(Inst));
     205             :   }
     206             : };
     207             : 
     208             : /// This is an entry in the NonLocalDepInfo cache.
     209             : ///
     210             : /// For each BasicBlock (the BB entry) it keeps a MemDepResult.
     211             : class NonLocalDepEntry {
     212             :   BasicBlock *BB;
     213             :   MemDepResult Result;
     214             : 
     215             : public:
     216             :   NonLocalDepEntry(BasicBlock *bb, MemDepResult result)
     217     1609055 :       : BB(bb), Result(result) {}
     218             : 
     219             :   // This is used for searches.
     220             :   NonLocalDepEntry(BasicBlock *bb) : BB(bb) {}
     221             : 
     222             :   // BB is the sort key, it can't be changed.
     223             :   BasicBlock *getBB() const { return BB; }
     224             : 
     225        8490 :   void setResult(const MemDepResult &R) { Result = R; }
     226             : 
     227           0 :   const MemDepResult &getResult() const { return Result; }
     228             : 
     229             :   bool operator<(const NonLocalDepEntry &RHS) const { return BB < RHS.BB; }
     230             : };
     231             : 
     232             : /// This is a result from a NonLocal dependence query.
     233             : ///
     234             : /// For each BasicBlock (the BB entry) it keeps a MemDepResult and the
     235             : /// (potentially phi translated) address that was live in the block.
     236             : class NonLocalDepResult {
     237             :   NonLocalDepEntry Entry;
     238             :   Value *Address;
     239             : 
     240             : public:
     241             :   NonLocalDepResult(BasicBlock *bb, MemDepResult result, Value *address)
     242     1217284 :       : Entry(bb, result), Address(address) {}
     243             : 
     244             :   // BB is the sort key, it can't be changed.
     245      509786 :   BasicBlock *getBB() const { return Entry.getBB(); }
     246             : 
     247             :   void setResult(const MemDepResult &R, Value *Addr) {
     248             :     Entry.setResult(R);
     249             :     Address = Addr;
     250             :   }
     251             : 
     252             :   const MemDepResult &getResult() const { return Entry.getResult(); }
     253             : 
     254             :   /// Returns the address of this pointer in this block.
     255             :   ///
     256             :   /// This can be different than the address queried for the non-local result
     257             :   /// because of phi translation.  This returns null if the address was not
     258             :   /// available in a block (i.e. because phi translation failed) or if this is
     259             :   /// a cached result and that address was deleted.
     260             :   ///
     261             :   /// The address is always null for a non-local 'call' dependence.
     262             :   Value *getAddress() const { return Address; }
     263             : };
     264             : 
     265             : /// Provides a lazy, caching interface for making common memory aliasing
     266             : /// information queries, backed by LLVM's alias analysis passes.
     267             : ///
     268             : /// The dependency information returned is somewhat unusual, but is pragmatic.
     269             : /// If queried about a store or call that might modify memory, the analysis
     270             : /// will return the instruction[s] that may either load from that memory or
     271             : /// store to it.  If queried with a load or call that can never modify memory,
     272             : /// the analysis will return calls and stores that might modify the pointer,
     273             : /// but generally does not return loads unless a) they are volatile, or
     274             : /// b) they load from *must-aliased* pointers.  Returning a dependence on
     275             : /// must-alias'd pointers instead of all pointers interacts well with the
     276             : /// internal caching mechanism.
     277      882288 : class MemoryDependenceResults {
     278             :   // A map from instructions to their dependency.
     279             :   using LocalDepMapType = DenseMap<Instruction *, MemDepResult>;
     280             :   LocalDepMapType LocalDeps;
     281             : 
     282             : public:
     283             :   using NonLocalDepInfo = std::vector<NonLocalDepEntry>;
     284             : 
     285             : private:
     286             :   /// A pair<Value*, bool> where the bool is true if the dependence is a read
     287             :   /// only dependence, false if read/write.
     288             :   using ValueIsLoadPair = PointerIntPair<const Value *, 1, bool>;
     289             : 
     290             :   /// This pair is used when caching information for a block.
     291             :   ///
     292             :   /// If the pointer is null, the cache value is not a full query that starts
     293             :   /// at the specified block.  If non-null, the bool indicates whether or not
     294             :   /// the contents of the block was skipped.
     295             :   using BBSkipFirstBlockPair = PointerIntPair<BasicBlock *, 1, bool>;
     296             : 
     297             :   /// This record is the information kept for each (value, is load) pair.
     298      747639 :   struct NonLocalPointerInfo {
     299             :     /// The pair of the block and the skip-first-block flag.
     300             :     BBSkipFirstBlockPair Pair;
     301             :     /// The results of the query for each relevant block.
     302             :     NonLocalDepInfo NonLocalDeps;
     303             :     /// The maximum size of the dereferences of the pointer.
     304             :     ///
     305             :     /// May be UnknownSize if the sizes are unknown.
     306             :     LocationSize Size = MemoryLocation::UnknownSize;
     307             :     /// The AA tags associated with dereferences of the pointer.
     308             :     ///
     309             :     /// The members may be null if there are no tags or conflicting tags.
     310             :     AAMDNodes AATags;
     311             : 
     312           0 :     NonLocalPointerInfo() = default;
     313             :   };
     314             : 
     315             :   /// Cache storing single nonlocal def for the instruction.
     316             :   /// It is set when nonlocal def would be found in function returning only
     317             :   /// local dependencies.
     318             :   DenseMap<AssertingVH<const Value>, NonLocalDepResult> NonLocalDefsCache;
     319             :   using ReverseNonLocalDefsCacheTy =
     320             :     DenseMap<Instruction *, SmallPtrSet<const Value*, 4>>;
     321             :   ReverseNonLocalDefsCacheTy ReverseNonLocalDefsCache;
     322             : 
     323             :   /// This map stores the cached results of doing a pointer lookup at the
     324             :   /// bottom of a block.
     325             :   ///
     326             :   /// The key of this map is the pointer+isload bit, the value is a list of
     327             :   /// <bb->result> mappings.
     328             :   using CachedNonLocalPointerInfo =
     329             :       DenseMap<ValueIsLoadPair, NonLocalPointerInfo>;
     330             :   CachedNonLocalPointerInfo NonLocalPointerDeps;
     331             : 
     332             :   // A map from instructions to their non-local pointer dependencies.
     333             :   using ReverseNonLocalPtrDepTy =
     334             :       DenseMap<Instruction *, SmallPtrSet<ValueIsLoadPair, 4>>;
     335             :   ReverseNonLocalPtrDepTy ReverseNonLocalPtrDeps;
     336             : 
     337             :   /// This is the instruction we keep for each cached access that we have for
     338             :   /// an instruction.
     339             :   ///
     340             :   /// The pointer is an owning pointer and the bool indicates whether we have
     341             :   /// any dirty bits in the set.
     342             :   using PerInstNLInfo = std::pair<NonLocalDepInfo, bool>;
     343             : 
     344             :   // A map from instructions to their non-local dependencies.
     345             :   using NonLocalDepMapType = DenseMap<Instruction *, PerInstNLInfo>;
     346             : 
     347             :   NonLocalDepMapType NonLocalDeps;
     348             : 
     349             :   // A reverse mapping from dependencies to the dependees.  This is
     350             :   // used when removing instructions to keep the cache coherent.
     351             :   using ReverseDepMapType =
     352             :       DenseMap<Instruction *, SmallPtrSet<Instruction *, 4>>;
     353             :   ReverseDepMapType ReverseLocalDeps;
     354             : 
     355             :   // A reverse mapping from dependencies to the non-local dependees.
     356             :   ReverseDepMapType ReverseNonLocalDeps;
     357             : 
     358             :   /// Current AA implementation, just a cache.
     359             :   AliasAnalysis &AA;
     360             :   AssumptionCache &AC;
     361             :   const TargetLibraryInfo &TLI;
     362             :   DominatorTree &DT;
     363             :   PredIteratorCache PredCache;
     364             : 
     365             : public:
     366      125262 :   MemoryDependenceResults(AliasAnalysis &AA, AssumptionCache &AC,
     367             :                           const TargetLibraryInfo &TLI,
     368             :                           DominatorTree &DT)
     369     1127358 :       : AA(AA), AC(AC), TLI(TLI), DT(DT) {}
     370             : 
     371             :   /// Handle invalidation in the new PM.
     372             :   bool invalidate(Function &F, const PreservedAnalyses &PA,
     373             :                   FunctionAnalysisManager::Invalidator &Inv);
     374             : 
     375             :   /// Some methods limit the number of instructions they will examine.
     376             :   /// The return value of this method is the default limit that will be
     377             :   /// used if no limit is explicitly passed in.
     378             :   unsigned getDefaultBlockScanLimit() const;
     379             : 
     380             :   /// Returns the instruction on which a memory operation depends.
     381             :   ///
     382             :   /// See the class comment for more details. It is illegal to call this on
     383             :   /// non-memory instructions.
     384             :   MemDepResult getDependency(Instruction *QueryInst);
     385             : 
     386             :   /// Perform a full dependency query for the specified call, returning the set
     387             :   /// of blocks that the value is potentially live across.
     388             :   ///
     389             :   /// The returned set of results will include a "NonLocal" result for all
     390             :   /// blocks where the value is live across.
     391             :   ///
     392             :   /// This method assumes the instruction returns a "NonLocal" dependency
     393             :   /// within its own block.
     394             :   ///
     395             :   /// This returns a reference to an internal data structure that may be
     396             :   /// invalidated on the next non-local query or when an instruction is
     397             :   /// removed.  Clients must copy this data if they want it around longer than
     398             :   /// that.
     399             :   const NonLocalDepInfo &getNonLocalCallDependency(CallSite QueryCS);
     400             : 
     401             :   /// Perform a full dependency query for an access to the QueryInst's
     402             :   /// specified memory location, returning the set of instructions that either
     403             :   /// define or clobber the value.
     404             :   ///
     405             :   /// Warning: For a volatile query instruction, the dependencies will be
     406             :   /// accurate, and thus usable for reordering, but it is never legal to
     407             :   /// remove the query instruction.
     408             :   ///
     409             :   /// This method assumes the pointer has a "NonLocal" dependency within
     410             :   /// QueryInst's parent basic block.
     411             :   void getNonLocalPointerDependency(Instruction *QueryInst,
     412             :                                     SmallVectorImpl<NonLocalDepResult> &Result);
     413             : 
     414             :   /// Removes an instruction from the dependence analysis, updating the
     415             :   /// dependence of instructions that previously depended on it.
     416             :   void removeInstruction(Instruction *InstToRemove);
     417             : 
     418             :   /// Invalidates cached information about the specified pointer, because it
     419             :   /// may be too conservative in memdep.
     420             :   ///
     421             :   /// This is an optional call that can be used when the client detects an
     422             :   /// equivalence between the pointer and some other value and replaces the
     423             :   /// other value with ptr. This can make Ptr available in more places that
     424             :   /// cached info does not necessarily keep.
     425             :   void invalidateCachedPointerInfo(Value *Ptr);
     426             : 
     427             :   /// Clears the PredIteratorCache info.
     428             :   ///
     429             :   /// This needs to be done when the CFG changes, e.g., due to splitting
     430             :   /// critical edges.
     431             :   void invalidateCachedPredecessors();
     432             : 
     433             :   /// Returns the instruction on which a memory location depends.
     434             :   ///
     435             :   /// If isLoad is true, this routine ignores may-aliases with read-only
     436             :   /// operations.  If isLoad is false, this routine ignores may-aliases
     437             :   /// with reads from read-only locations. If possible, pass the query
     438             :   /// instruction as well; this function may take advantage of the metadata
     439             :   /// annotated to the query instruction to refine the result. \p Limit
     440             :   /// can be used to set the maximum number of instructions that will be
     441             :   /// examined to find the pointer dependency. On return, it will be set to
     442             :   /// the number of instructions left to examine. If a null pointer is passed
     443             :   /// in, the limit will default to the value of -memdep-block-scan-limit.
     444             :   ///
     445             :   /// Note that this is an uncached query, and thus may be inefficient.
     446             :   MemDepResult getPointerDependencyFrom(const MemoryLocation &Loc, bool isLoad,
     447             :                                         BasicBlock::iterator ScanIt,
     448             :                                         BasicBlock *BB,
     449             :                                         Instruction *QueryInst = nullptr,
     450             :                                         unsigned *Limit = nullptr);
     451             : 
     452             :   MemDepResult getSimplePointerDependencyFrom(const MemoryLocation &MemLoc,
     453             :                                               bool isLoad,
     454             :                                               BasicBlock::iterator ScanIt,
     455             :                                               BasicBlock *BB,
     456             :                                               Instruction *QueryInst,
     457             :                                               unsigned *Limit = nullptr);
     458             : 
     459             :   /// This analysis looks for other loads and stores with invariant.group
     460             :   /// metadata and the same pointer operand. Returns Unknown if it does not
     461             :   /// find anything, and Def if it can be assumed that 2 instructions load or
     462             :   /// store the same value and NonLocal which indicate that non-local Def was
     463             :   /// found, which can be retrieved by calling getNonLocalPointerDependency
     464             :   /// with the same queried instruction.
     465             :   MemDepResult getInvariantGroupPointerDependency(LoadInst *LI, BasicBlock *BB);
     466             : 
     467             :   /// Looks at a memory location for a load (specified by MemLocBase, Offs, and
     468             :   /// Size) and compares it against a load.
     469             :   ///
     470             :   /// If the specified load could be safely widened to a larger integer load
     471             :   /// that is 1) still efficient, 2) safe for the target, and 3) would provide
     472             :   /// the specified memory location value, then this function returns the size
     473             :   /// in bytes of the load width to use.  If not, this returns zero.
     474             :   static unsigned getLoadLoadClobberFullWidthSize(const Value *MemLocBase,
     475             :                                                   int64_t MemLocOffs,
     476             :                                                   unsigned MemLocSize,
     477             :                                                   const LoadInst *LI);
     478             : 
     479             :   /// Release memory in caches.
     480             :   void releaseMemory();
     481             : 
     482             : private:
     483             :   MemDepResult getCallSiteDependencyFrom(CallSite C, bool isReadOnlyCall,
     484             :                                          BasicBlock::iterator ScanIt,
     485             :                                          BasicBlock *BB);
     486             :   bool getNonLocalPointerDepFromBB(Instruction *QueryInst,
     487             :                                    const PHITransAddr &Pointer,
     488             :                                    const MemoryLocation &Loc, bool isLoad,
     489             :                                    BasicBlock *BB,
     490             :                                    SmallVectorImpl<NonLocalDepResult> &Result,
     491             :                                    DenseMap<BasicBlock *, Value *> &Visited,
     492             :                                    bool SkipFirstBlock = false);
     493             :   MemDepResult GetNonLocalInfoForBlock(Instruction *QueryInst,
     494             :                                        const MemoryLocation &Loc, bool isLoad,
     495             :                                        BasicBlock *BB, NonLocalDepInfo *Cache,
     496             :                                        unsigned NumSortedEntries);
     497             : 
     498             :   void RemoveCachedNonLocalPointerDependencies(ValueIsLoadPair P);
     499             : 
     500             :   void verifyRemoved(Instruction *Inst) const;
     501             : };
     502             : 
     503             : /// An analysis that produces \c MemoryDependenceResults for a function.
     504             : ///
     505             : /// This is essentially a no-op because the results are computed entirely
     506             : /// lazily.
     507             : class MemoryDependenceAnalysis
     508             :     : public AnalysisInfoMixin<MemoryDependenceAnalysis> {
     509             :   friend AnalysisInfoMixin<MemoryDependenceAnalysis>;
     510             : 
     511             :   static AnalysisKey Key;
     512             : 
     513             : public:
     514             :   using Result = MemoryDependenceResults;
     515             : 
     516             :   MemoryDependenceResults run(Function &F, FunctionAnalysisManager &AM);
     517             : };
     518             : 
     519             : /// A wrapper analysis pass for the legacy pass manager that exposes a \c
     520             : /// MemoryDepnedenceResults instance.
     521       17643 : class MemoryDependenceWrapperPass : public FunctionPass {
     522             :   Optional<MemoryDependenceResults> MemDep;
     523             : 
     524             : public:
     525             :   static char ID;
     526             : 
     527             :   MemoryDependenceWrapperPass();
     528             :   ~MemoryDependenceWrapperPass() override;
     529             : 
     530             :   /// Pass Implementation stuff.  This doesn't do any analysis eagerly.
     531             :   bool runOnFunction(Function &) override;
     532             : 
     533             :   /// Clean up memory in between runs
     534             :   void releaseMemory() override;
     535             : 
     536             :   /// Does not modify anything.  It uses Value Numbering and Alias Analysis.
     537             :   void getAnalysisUsage(AnalysisUsage &AU) const override;
     538             : 
     539             :   MemoryDependenceResults &getMemDep() { return *MemDep; }
     540             : };
     541             : 
     542             : } // end namespace llvm
     543             : 
     544             : #endif // LLVM_ANALYSIS_MEMORYDEPENDENCEANALYSIS_H

Generated by: LCOV version 1.13