1 //===- ScopedNoAliasAA.h - Scoped No-Alias 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 //
9 /// \file
10 /// This is the interface for a metadata-based scoped no-alias analysis.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_ANALYSIS_SCOPEDNOALIASAA_H
15 #define LLVM_ANALYSIS_SCOPEDNOALIASAA_H
16 
17 #include "llvm/Analysis/AliasAnalysis.h"
18 #include "llvm/IR/InstrTypes.h"
19 #include "llvm/IR/PassManager.h"
20 #include "llvm/Pass.h"
21 #include <memory>
22 
23 namespace llvm {
24 
25 class Function;
26 class MDNode;
27 class MemoryLocation;
28 
29 /// A simple AA result which uses scoped-noalias metadata to answer queries.
30 class ScopedNoAliasAAResult : public AAResultBase<ScopedNoAliasAAResult> {
31   friend AAResultBase<ScopedNoAliasAAResult>;
32 
33 public:
34   /// Handle invalidation events from the new pass manager.
35   ///
36   /// By definition, this result is stateless and so remains valid.
37   bool invalidate(Function &, const PreservedAnalyses &,
38                   FunctionAnalysisManager::Invalidator &) {
39     return false;
40   }
41 
42   AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB,
43                     AAQueryInfo &AAQI);
44   ModRefInfo getModRefInfo(const CallBase *Call, const MemoryLocation &Loc,
45                            AAQueryInfo &AAQI);
46   ModRefInfo getModRefInfo(const CallBase *Call1, const CallBase *Call2,
47                            AAQueryInfo &AAQI);
48 
49 private:
50   bool mayAliasInScopes(const MDNode *Scopes, const MDNode *NoAlias) const;
51 };
52 
53 /// Analysis pass providing a never-invalidated alias analysis result.
54 class ScopedNoAliasAA : public AnalysisInfoMixin<ScopedNoAliasAA> {
55   friend AnalysisInfoMixin<ScopedNoAliasAA>;
56 
57   static AnalysisKey Key;
58 
59 public:
60   using Result = ScopedNoAliasAAResult;
61 
62   ScopedNoAliasAAResult run(Function &F, FunctionAnalysisManager &AM);
63 };
64 
65 /// Legacy wrapper pass to provide the ScopedNoAliasAAResult object.
66 class ScopedNoAliasAAWrapperPass : public ImmutablePass {
67   std::unique_ptr<ScopedNoAliasAAResult> Result;
68 
69 public:
70   static char ID;
71 
72   ScopedNoAliasAAWrapperPass();
73 
74   ScopedNoAliasAAResult &getResult() { return *Result; }
75   const ScopedNoAliasAAResult &getResult() const { return *Result; }
76 
77   bool doInitialization(Module &M) override;
78   bool doFinalization(Module &M) override;
79   void getAnalysisUsage(AnalysisUsage &AU) const override;
80 };
81 
82 //===--------------------------------------------------------------------===//
83 //
84 // createScopedNoAliasAAWrapperPass - This pass implements metadata-based
85 // scoped noalias analysis.
86 //
87 ImmutablePass *createScopedNoAliasAAWrapperPass();
88 
89 } // end namespace llvm
90 
91 #endif // LLVM_ANALYSIS_SCOPEDNOALIASAA_H
92