1 //===- ScalarEvolutionAliasAnalysis.h - SCEV-based AA -----------*- 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 a SCEV-based alias analysis.
10 ///
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_ANALYSIS_SCALAREVOLUTIONALIASANALYSIS_H
14 #define LLVM_ANALYSIS_SCALAREVOLUTIONALIASANALYSIS_H
15 
16 #include "llvm/Analysis/AliasAnalysis.h"
17 #include "llvm/Analysis/ScalarEvolutionExpressions.h"
18 #include "llvm/IR/Function.h"
19 #include "llvm/IR/Module.h"
20 #include "llvm/Pass.h"
21 
22 namespace llvm {
23 
24 /// A simple alias analysis implementation that uses ScalarEvolution to answer
25 /// queries.
26 class SCEVAAResult : public AAResultBase<SCEVAAResult> {
27   ScalarEvolution &SE;
28 
29 public:
30   explicit SCEVAAResult(ScalarEvolution &SE) : AAResultBase(), SE(SE) {}
31   SCEVAAResult(SCEVAAResult &&Arg) : AAResultBase(std::move(Arg)), SE(Arg.SE) {}
32 
33   AliasResult alias(const MemoryLocation &LocA, const MemoryLocation &LocB,
34                     AAQueryInfo &AAQI);
35 
36 private:
37   Value *GetBaseValue(const SCEV *S);
38 };
39 
40 /// Analysis pass providing a never-invalidated alias analysis result.
41 class SCEVAA : public AnalysisInfoMixin<SCEVAA> {
42   friend AnalysisInfoMixin<SCEVAA>;
43   static AnalysisKey Key;
44 
45 public:
46   typedef SCEVAAResult Result;
47 
48   SCEVAAResult run(Function &F, FunctionAnalysisManager &AM);
49 };
50 
51 /// Legacy wrapper pass to provide the SCEVAAResult object.
52 class SCEVAAWrapperPass : public FunctionPass {
53   std::unique_ptr<SCEVAAResult> Result;
54 
55 public:
56   static char ID;
57 
58   SCEVAAWrapperPass();
59 
60   SCEVAAResult &getResult() { return *Result; }
61   const SCEVAAResult &getResult() const { return *Result; }
62 
63   bool runOnFunction(Function &F) override;
64   void getAnalysisUsage(AnalysisUsage &AU) const override;
65 };
66 
67 /// Creates an instance of \c SCEVAAWrapperPass.
68 FunctionPass *createSCEVAAWrapperPass();
69 
70 }
71 
72 #endif
73