AliasAnalysis.hpp

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/*
 * Copyright 2025 Håvard Krogstie <krogstie.havard@gmail.com>
 * See COPYING for terms of redistribution.
 */
 
#ifndef JLM_LLVM_OPT_ALIAS_ANALYSES_ALIASANALYSIS_HPP
#define JLM_LLVM_OPT_ALIAS_ANALYSES_ALIASANALYSIS_HPP
 
#include <jlm/rvsdg/node.hpp>
 
namespace jlm::llvm::aa
{
 
class AliasAnalysis
{
public:
  enum AliasQueryResponse
  {
    // The analysis guarantees that [p1, p1+s1) and [p2, p2+s2) never overlap
    NoAlias,
 
    // The analysis is unable to determine any facts about p1 and p2
    MayAlias,
 
    // p1 and p2 always have identical values (s1 and s2 are ignored)
    MustAlias
  };
 
  AliasAnalysis();
 
  virtual ~AliasAnalysis() noexcept;
 
  [[nodiscard]] virtual std::string
  ToString() const = 0;
 
  virtual AliasQueryResponse
  Query(const rvsdg::Output & p1, size_t s1, const rvsdg::Output & p2, size_t s2) = 0;
};
 
class ChainedAliasAnalysis final : public AliasAnalysis
{
public:
  ChainedAliasAnalysis(AliasAnalysis & first, AliasAnalysis & second);
 
  ~ChainedAliasAnalysis() noexcept override;
 
  std::string
  ToString() const override;
 
  AliasQueryResponse
  Query(const rvsdg::Output & p1, size_t s1, const rvsdg::Output & p2, size_t s2) override;
 
private:
  AliasAnalysis & First_;
  AliasAnalysis & Second_;
};
 
[[nodiscard]] bool
IsPointerCompatible(const rvsdg::Output & value);
 
}
 
#endif // JLM_LLVM_OPT_ALIAS_ANALYSES_ALIASANALYSIS_HPP