llvm/llvm/include/llvm/CodeGen/ScheduleDAG.h

//===- llvm/CodeGen/ScheduleDAG.h - Common Base Class -----------*- 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 Implements the ScheduleDAG class, which is used as the common base
/// class for instruction schedulers. This encapsulates the scheduling DAG,
/// which is shared between SelectionDAG and MachineInstr scheduling.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_SCHEDULEDAG_H
#define LLVM_CODEGEN_SCHEDULEDAG_H

#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/iterator.h"
#include "llvm/CodeGen/MachineInstr.h"
#include "llvm/CodeGen/TargetLowering.h"
#include "llvm/Support/ErrorHandling.h"
#include <cassert>
#include <cstddef>
#include <iterator>
#include <string>
#include <vector>

namespace llvm {

template <class GraphType> struct GraphTraits;
template<class Graph> class GraphWriter;
class LLVMTargetMachine;
class MachineFunction;
class MachineRegisterInfo;
class MCInstrDesc;
struct MCSchedClassDesc;
class SDNode;
class SUnit;
class ScheduleDAG;
class TargetInstrInfo;
class TargetRegisterClass;
class TargetRegisterInfo;

  /// Scheduling dependency. This represents one direction of an edge in the
  /// scheduling DAG.
  class SDep { … };

  /// Scheduling unit. This is a node in the scheduling DAG.
  class SUnit { … };

  /// Returns true if the specified SDep is equivalent except for latency.
  inline bool SDep::overlaps(const SDep &Other) const { … }

  //// Returns the SUnit to which this edge points.
  inline SUnit *SDep::getSUnit() const { … }

  //// Assigns the SUnit to which this edge points.
  inline void SDep::setSUnit(SUnit *SU) { … }

  /// Returns an enum value representing the kind of the dependence.
  inline SDep::Kind SDep::getKind() const { … }

  //===--------------------------------------------------------------------===//

  /// This interface is used to plug different priorities computation
  /// algorithms into the list scheduler. It implements the interface of a
  /// standard priority queue, where nodes are inserted in arbitrary order and
  /// returned in priority order.  The computation of the priority and the
  /// representation of the queue are totally up to the implementation to
  /// decide.
  class SchedulingPriorityQueue { … };

  class ScheduleDAG { … };

  class SUnitIterator { … };

  template <> struct GraphTraits<SUnit*> { … };

  template <> struct GraphTraits<ScheduleDAG*> : public GraphTraits<SUnit*> { … };

  /// This class can compute a topological ordering for SUnits and provides
  /// methods for dynamically updating the ordering as new edges are added.
  ///
  /// This allows a very fast implementation of IsReachable, for example.
  class ScheduleDAGTopologicalSort { … };

} // end namespace llvm

#endif // LLVM_CODEGEN_SCHEDULEDAG_H