GCNHazardRecognizer.h

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//===-- GCNHazardRecognizers.h - GCN Hazard Recognizers ---------*- 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 defines hazard recognizers for scheduling on GCN processors.
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_LIB_TARGET_AMDGPUHAZARDRECOGNIZERS_H
#define LLVM_LIB_TARGET_AMDGPUHAZARDRECOGNIZERS_H

#include "llvm/ADT/BitVector.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/CodeGen/ScheduleHazardRecognizer.h"
#include "llvm/CodeGen/TargetSchedule.h"
#include <list>

namespace llvm {

class MachineFunction;
class MachineInstr;
class MachineOperand;
class MachineRegisterInfo;
class ScheduleDAG;
class SIInstrInfo;
class SIRegisterInfo;
class GCNSubtarget;

class GCNHazardRecognizer final : public ScheduleHazardRecognizer {
public:
  typedef function_ref<bool(MachineInstr *)> IsHazardFn;

private:
  // Distinguish if we are called from scheduler or hazard recognizer
  bool IsHazardRecognizerMode;

  // This variable stores the instruction that has been emitted this cycle. It
  // will be added to EmittedInstrs, when AdvanceCycle() or RecedeCycle() is
  // called.
  MachineInstr *CurrCycleInstr;
  std::list<MachineInstr*> EmittedInstrs;
  const MachineFunction &MF;
  const GCNSubtarget &ST;
  const SIInstrInfo &TII;
  const SIRegisterInfo &TRI;
  TargetSchedModel TSchedModel;

  /// RegUnits of uses in the current soft memory clause.
  BitVector ClauseUses;

  /// RegUnits of defs in the current soft memory clause.
  BitVector ClauseDefs;

  void resetClause() {
    ClauseUses.reset();
    ClauseDefs.reset();
  }

  void addClauseInst(const MachineInstr &MI);

  // Advance over a MachineInstr bundle. Look for hazards in the bundled
  // instructions.
  void processBundle();

  int getWaitStatesSince(IsHazardFn IsHazard, int Limit);
  int getWaitStatesSinceDef(unsigned Reg, IsHazardFn IsHazardDef, int Limit);
  int getWaitStatesSinceSetReg(IsHazardFn IsHazard, int Limit);

  int checkSoftClauseHazards(MachineInstr *SMEM);
  int checkSMRDHazards(MachineInstr *SMRD);
  int checkVMEMHazards(MachineInstr* VMEM);
  int checkDPPHazards(MachineInstr *DPP);
  int checkDivFMasHazards(MachineInstr *DivFMas);
  int checkGetRegHazards(MachineInstr *GetRegInstr);
  int checkSetRegHazards(MachineInstr *SetRegInstr);
  int createsVALUHazard(const MachineInstr &MI);
  int checkVALUHazards(MachineInstr *VALU);
  int checkVALUHazardsHelper(const MachineOperand &Def, const MachineRegisterInfo &MRI);
  int checkRWLaneHazards(MachineInstr *RWLane);
  int checkRFEHazards(MachineInstr *RFE);
  int checkInlineAsmHazards(MachineInstr *IA);
  int checkAnyInstHazards(MachineInstr *MI);
  int checkReadM0Hazards(MachineInstr *SMovRel);
  int checkNSAtoVMEMHazard(MachineInstr *MI);
  int checkFPAtomicToDenormModeHazard(MachineInstr *MI);
  void fixHazards(MachineInstr *MI);
  bool fixVcmpxPermlaneHazards(MachineInstr *MI);
  bool fixVMEMtoScalarWriteHazards(MachineInstr *MI);
  bool fixSMEMtoVectorWriteHazards(MachineInstr *MI);
  bool fixVcmpxExecWARHazard(MachineInstr *MI);
  bool fixLdsBranchVmemWARHazard(MachineInstr *MI);

  int checkMAIHazards(MachineInstr *MI);
  int checkMAILdStHazards(MachineInstr *MI);

public:
  GCNHazardRecognizer(const MachineFunction &MF);
  // We can only issue one instruction per cycle.
  bool atIssueLimit() const override { return true; }
  void EmitInstruction(SUnit *SU) override;
  void EmitInstruction(MachineInstr *MI) override;
  HazardType getHazardType(SUnit *SU, int Stalls) override;
  void EmitNoop() override;
  unsigned PreEmitNoops(SUnit *SU) override;
  unsigned PreEmitNoops(MachineInstr *) override;
  unsigned PreEmitNoopsCommon(MachineInstr *);
  void AdvanceCycle() override;
  void RecedeCycle() override;
};

} // end namespace llvm

#endif //LLVM_LIB_TARGET_AMDGPUHAZARDRECOGNIZERS_H