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//===-- llvm/CodeGen/GlobalISel/CombinerHelper.h --------------*- 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 contains common combine transformations that may be used in a combine
/// pass,or by the target elsewhere.
/// Targets can pick individual opcode transformations from the helper or use
/// tryCombine which invokes all transformations. All of the transformations
/// return true if the MachineInstruction changed and false otherwise.
//
//===--------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_GLOBALISEL_COMBINER_HELPER_H
#define LLVM_CODEGEN_GLOBALISEL_COMBINER_HELPER_H
#include "llvm/CodeGen/LowLevelType.h"
#include "llvm/CodeGen/Register.h"
namespace llvm {
class GISelChangeObserver;
class MachineIRBuilder;
class MachineRegisterInfo;
class MachineInstr;
class MachineOperand;
struct PreferredTuple {
LLT Ty; // The result type of the extend.
unsigned ExtendOpcode; // G_ANYEXT/G_SEXT/G_ZEXT
MachineInstr *MI;
};
class CombinerHelper {
MachineIRBuilder &Builder;
MachineRegisterInfo &MRI;
GISelChangeObserver &Observer;
public:
CombinerHelper(GISelChangeObserver &Observer, MachineIRBuilder &B);
/// MachineRegisterInfo::replaceRegWith() and inform the observer of the changes
void replaceRegWith(MachineRegisterInfo &MRI, Register FromReg, Register ToReg) const;
/// Replace a single register operand with a new register and inform the
/// observer of the changes.
void replaceRegOpWith(MachineRegisterInfo &MRI, MachineOperand &FromRegOp,
Register ToReg) const;
/// If \p MI is COPY, try to combine it.
/// Returns true if MI changed.
bool tryCombineCopy(MachineInstr &MI);
bool matchCombineCopy(MachineInstr &MI);
void applyCombineCopy(MachineInstr &MI);
/// If \p MI is extend that consumes the result of a load, try to combine it.
/// Returns true if MI changed.
bool tryCombineExtendingLoads(MachineInstr &MI);
bool matchCombineExtendingLoads(MachineInstr &MI, PreferredTuple &MatchInfo);
void applyCombineExtendingLoads(MachineInstr &MI, PreferredTuple &MatchInfo);
bool matchCombineBr(MachineInstr &MI);
bool tryCombineBr(MachineInstr &MI);
/// Try to transform \p MI by using all of the above
/// combine functions. Returns true if changed.
bool tryCombine(MachineInstr &MI);
};
} // namespace llvm
#endif