llvm/mlir/include/mlir/Analysis/Liveness.h

//===- Liveness.h - Liveness analysis for MLIR ------------------*- 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
//
//===----------------------------------------------------------------------===//
//
// This file contains an analysis for computing liveness information from a
// given top-level operation. The current version of the analysis uses a
// traditional algorithm to resolve detailed live-range information about all
// values within the specified regions. It is also possible to query liveness
// information on block level.
//
//===----------------------------------------------------------------------===//

#ifndef MLIR_ANALYSIS_LIVENESS_H
#define MLIR_ANALYSIS_LIVENESS_H

#include <vector>

#include "mlir/Support/LLVM.h"
#include "llvm/ADT/ArrayRef.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"

namespace mlir {

class Block;
class LivenessBlockInfo;
class Operation;
class Region;
class Value;

/// Represents an analysis for computing liveness information from a
/// given top-level operation. The analysis iterates over all associated
/// regions that are attached to the given top-level operation. It
/// computes liveness information for every value and block that are
/// included in the mentioned regions. It relies on a fixpoint iteration
/// to compute all live-in and live-out values of all included blocks.
/// Sample usage:
///   Liveness liveness(topLevelOp);
///   auto &allInValues = liveness.getLiveIn(block);
///   auto &allOutValues = liveness.getLiveOut(block);
///   auto allOperationsInWhichValueIsLive = liveness.resolveLiveness(value);
///   bool isDeafAfter = liveness.isDeadAfter(value, operation);
class Liveness { … };

/// This class represents liveness information on block level.
class LivenessBlockInfo { … };

} // namespace mlir

#endif // MLIR_ANALYSIS_LIVENESS_H