LLVM  9.0.0svn
CFLAndersAliasAnalysis.h
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1 //==- CFLAndersAliasAnalysis.h - Unification-based Alias Analysis -*- C++-*-==//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 /// \file
9 /// This is the interface for LLVM's inclusion-based alias analysis
10 /// implemented with CFL graph reachability.
11 ///
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_ANALYSIS_CFLANDERSALIASANALYSIS_H
15 #define LLVM_ANALYSIS_CFLANDERSALIASANALYSIS_H
16 
17 #include "llvm/ADT/DenseMap.h"
18 #include "llvm/ADT/Optional.h"
21 #include "llvm/IR/PassManager.h"
22 #include "llvm/Pass.h"
23 #include <forward_list>
24 #include <memory>
25 
26 namespace llvm {
27 
28 class Function;
29 class MemoryLocation;
30 class TargetLibraryInfo;
31 
32 namespace cflaa {
33 
34 struct AliasSummary;
35 
36 } // end namespace cflaa
37 
38 class CFLAndersAAResult : public AAResultBase<CFLAndersAAResult> {
40 
41  class FunctionInfo;
42 
43 public:
44  explicit CFLAndersAAResult(const TargetLibraryInfo &TLI);
47 
48  /// Handle invalidation events from the new pass manager.
49  /// By definition, this result is stateless and so remains valid.
52  return false;
53  }
54 
55  /// Evict the given function from cache
56  void evict(const Function *Fn);
57 
58  /// Get the alias summary for the given function
59  /// Return nullptr if the summary is not found or not available
60  const cflaa::AliasSummary *getAliasSummary(const Function &);
61 
63  AliasResult alias(const MemoryLocation &, const MemoryLocation &,
64  AAQueryInfo &);
65 
66 private:
67  /// Ensures that the given function is available in the cache.
68  /// Returns the appropriate entry from the cache.
69  const Optional<FunctionInfo> &ensureCached(const Function &);
70 
71  /// Inserts the given Function into the cache.
72  void scan(const Function &);
73 
74  /// Build summary for a given function
75  FunctionInfo buildInfoFrom(const Function &);
76 
77  const TargetLibraryInfo &TLI;
78 
79  /// Cached mapping of Functions to their StratifiedSets.
80  /// If a function's sets are currently being built, it is marked
81  /// in the cache as an Optional without a value. This way, if we
82  /// have any kind of recursion, it is discernable from a function
83  /// that simply has empty sets.
85 
86  std::forward_list<cflaa::FunctionHandle<CFLAndersAAResult>> Handles;
87 };
88 
89 /// Analysis pass providing a never-invalidated alias analysis result.
90 ///
91 /// FIXME: We really should refactor CFL to use the analysis more heavily, and
92 /// in particular to leverage invalidation to trigger re-computation.
93 class CFLAndersAA : public AnalysisInfoMixin<CFLAndersAA> {
95 
96  static AnalysisKey Key;
97 
98 public:
100 
102 };
103 
104 /// Legacy wrapper pass to provide the CFLAndersAAResult object.
106  std::unique_ptr<CFLAndersAAResult> Result;
107 
108 public:
109  static char ID;
110 
112 
113  CFLAndersAAResult &getResult() { return *Result; }
114  const CFLAndersAAResult &getResult() const { return *Result; }
115 
116  void initializePass() override;
117  void getAnalysisUsage(AnalysisUsage &AU) const override;
118 };
119 
120 // createCFLAndersAAWrapperPass - This pass implements a set-based approach to
121 // alias analysis.
123 
124 } // end namespace llvm
125 
126 #endif // LLVM_ANALYSIS_CFLANDERSALIASANALYSIS_H
This class represents lattice values for constants.
Definition: AllocatorList.h:23
This class stores info we want to provide to or retain within an alias query.
F(f)
static void query(const MachineInstr &MI, AliasAnalysis &AA, bool &Read, bool &Write, bool &Effects, bool &StackPointer)
A CRTP-driven "mixin" base class to help implement the function alias analysis results concept...
Key
PAL metadata keys.
AliasSummary is just a collection of ExternalRelation and ExternalAttribute.
const CFLAndersAAResult & getResult() const
AliasResult
The possible results of an alias query.
Definition: AliasAnalysis.h:78
A set of analyses that are preserved following a run of a transformation pass.
Definition: PassManager.h:153
A CRTP mix-in that provides informational APIs needed for analysis passes.
Definition: PassManager.h:382
Legacy wrapper pass to provide the CFLAndersAAResult object.
Represent the analysis usage information of a pass.
Analysis pass providing a never-invalidated alias analysis result.
Representation for a specific memory location.
ImmutablePass class - This class is used to provide information that does not need to be run...
Definition: Pass.h:255
Provides information about what library functions are available for the current target.
bool invalidate(Function &, const PreservedAnalyses &, FunctionAnalysisManager::Invalidator &)
Handle invalidation events from the new pass manager.
API to communicate dependencies between analyses during invalidation.
Definition: PassManager.h:641
A container for analyses that lazily runs them and caches their results.
ImmutablePass * createCFLAndersAAWrapperPass()
This header defines various interfaces for pass management in LLVM.
A special type used by analysis passes to provide an address that identifies that particular analysis...
Definition: PassManager.h:70
static Expected< BitVector > scan(StringRef &S, StringRef Original)
Definition: GlobPattern.cpp:66