llvm/llvm/include/llvm/ADT/DAGDeltaAlgorithm.h

//===- DAGDeltaAlgorithm.h - A DAG Minimization Algorithm ------*- 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
//===----------------------------------------------------------------------===//

#ifndef LLVM_ADT_DAGDELTAALGORITHM_H
#define LLVM_ADT_DAGDELTAALGORITHM_H

#include <set>
#include <utility>
#include <vector>

namespace llvm {

/// DAGDeltaAlgorithm - Implements a "delta debugging" algorithm for minimizing
/// directed acyclic graphs using a predicate function.
///
/// The result of the algorithm is a subset of the input change set which is
/// guaranteed to satisfy the predicate, assuming that the input set did. For
/// well formed predicates, the result set is guaranteed to be such that
/// removing any single element not required by the dependencies on the other
/// elements would falsify the predicate.
///
/// The DAG should be used to represent dependencies in the changes which are
/// likely to hold across the predicate function. That is, for a particular
/// changeset S and predicate P:
///
///   P(S) => P(S union pred(S))
///
/// The minimization algorithm uses this dependency information to attempt to
/// eagerly prune large subsets of changes. As with \see DeltaAlgorithm, the DAG
/// is not required to satisfy this property, but the algorithm will run
/// substantially fewer tests with appropriate dependencies. \see DeltaAlgorithm
/// for more information on the properties which the predicate function itself
/// should satisfy.
class DAGDeltaAlgorithm { … };

} // end namespace llvm

#endif // LLVM_ADT_DAGDELTAALGORITHM_H