llvm/llvm/include/llvm/Analysis/LoopAnalysisManager.h

//===- LoopAnalysisManager.h - Loop analysis management ---------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
/// \file
///
/// This header provides classes for managing per-loop analyses. These are
/// typically used as part of a loop pass pipeline over the loop nests of
/// a function.
///
/// Loop analyses are allowed to make some simplifying assumptions:
/// 1) Loops are, where possible, in simplified form.
/// 2) Loops are *always* in LCSSA form.
/// 3) A collection of analysis results are available:
///    - LoopInfo
///    - DominatorTree
///    - ScalarEvolution
///    - AAManager
///
/// The primary mechanism to provide these invariants is the loop pass manager,
/// but they can also be manually provided in order to reason about a loop from
/// outside of a dedicated pass manager.
///
//===----------------------------------------------------------------------===//

#ifndef LLVM_ANALYSIS_LOOPANALYSISMANAGER_H
#define LLVM_ANALYSIS_LOOPANALYSISMANAGER_H

#include "llvm/IR/PassManager.h"

namespace llvm {

class AAResults;
class AssumptionCache;
class BlockFrequencyInfo;
class BranchProbabilityInfo;
class DominatorTree;
class Function;
class Loop;
class LoopInfo;
class MemorySSA;
class ScalarEvolution;
class TargetLibraryInfo;
class TargetTransformInfo;

/// The adaptor from a function pass to a loop pass computes these analyses and
/// makes them available to the loop passes "for free". Each loop pass is
/// expected to update these analyses if necessary to ensure they're
/// valid after it runs.
struct LoopStandardAnalysisResults { … };

/// Extern template declaration for the analysis set for this IR unit.
extern template class AllAnalysesOn<Loop>;

extern template class AnalysisManager<Loop, LoopStandardAnalysisResults &>;
/// The loop analysis manager.
///
/// See the documentation for the AnalysisManager template for detail
/// documentation. This typedef serves as a convenient way to refer to this
/// construct in the adaptors and proxies used to integrate this into the larger
/// pass manager infrastructure.
LoopAnalysisManager;

/// A proxy from a \c LoopAnalysisManager to a \c Function.
LoopAnalysisManagerFunctionProxy;

/// A specialized result for the \c LoopAnalysisManagerFunctionProxy which
/// retains a \c LoopInfo reference.
///
/// This allows it to collect loop objects for which analysis results may be
/// cached in the \c LoopAnalysisManager.
template <> class LoopAnalysisManagerFunctionProxy::Result { … };

/// Provide a specialized run method for the \c LoopAnalysisManagerFunctionProxy
/// so it can pass the \c LoopInfo to the result.
template <>
LoopAnalysisManagerFunctionProxy::Result
LoopAnalysisManagerFunctionProxy::run(Function &F, FunctionAnalysisManager &AM);

// Ensure the \c LoopAnalysisManagerFunctionProxy is provided as an extern
// template.
extern template class InnerAnalysisManagerProxy<LoopAnalysisManager, Function>;

extern template class OuterAnalysisManagerProxy<FunctionAnalysisManager, Loop,
                                                LoopStandardAnalysisResults &>;
/// A proxy from a \c FunctionAnalysisManager to a \c Loop.
FunctionAnalysisManagerLoopProxy;

/// Returns the minimum set of Analyses that all loop passes must preserve.
PreservedAnalyses getLoopPassPreservedAnalyses();
}

#endif // LLVM_ANALYSIS_LOOPANALYSISMANAGER_H