llvm/llvm/lib/Target/SystemZ/SystemZHazardRecognizer.h

//=-- SystemZHazardRecognizer.h - SystemZ Hazard Recognizer -----*- 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 declares a hazard recognizer for the SystemZ scheduler.
//
// This class is used by the SystemZ scheduling strategy to maintain
// the state during scheduling, and provide cost functions for
// scheduling candidates. This includes:
//
// * Decoder grouping. A decoder group can maximally hold 3 uops, and
// instructions that always begin a new group should be scheduled when
// the current decoder group is empty.
// * Processor resources usage. It is beneficial to balance the use of
// resources.
//
// A goal is to consider all instructions, also those outside of any
// scheduling region. Such instructions are "advanced" past and include
// single instructions before a scheduling region, branches etc.
//
// A block that has only one predecessor continues scheduling with the state
// of it (which may be updated by emitting branches).
//
// ===---------------------------------------------------------------------===//

#ifndef LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZHAZARDRECOGNIZER_H
#define LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZHAZARDRECOGNIZER_H

#include "SystemZSubtarget.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/CodeGen/MachineFunction.h"
#include "llvm/CodeGen/MachineScheduler.h"
#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
#include "llvm/MC/MCInstrDesc.h"
#include "llvm/Support/raw_ostream.h"
#include <string>

namespace llvm {

/// SystemZHazardRecognizer maintains the state for one MBB during scheduling.
class SystemZHazardRecognizer : public ScheduleHazardRecognizer { … };

} // namespace llvm

#endif /* LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZHAZARDRECOGNIZER_H */