// SPDX-License-Identifier: GPL-3.0-or-later

#ifndef RCC_CODEGEN_GLOBALISEL_UTILS_H
#define RCC_CODEGEN_GLOBALISEL_UTILS_H

#include "rcc/CodeGen/LowLevelType.h"
#include "rcc/CodeGen/Register.h"
#include "rcc/Support/Error.h"

#include <cstddef>
#include <span>
#include <vector>

namespace rcc {

class MachineIRBuilder;
class MachineInstr;
class MachineRegisterInfo;
class TargetDescription;

/// Check whether an instruction only defines dead virtual registers and has no
/// observable side effects.
[[nodiscard]] bool isTriviallyDead(const MachineInstr &Instruction,
                                   const MachineRegisterInfo &MRI,
                                   const TargetDescription &Target) noexcept;

[[nodiscard]] Expected<void> eraseInstrs(std::span<MachineInstr *const> Instructions,
                                         MachineRegisterInfo &MRI,
                                         const TargetDescription &Target);

[[nodiscard]] Expected<void> eraseInstr(MachineInstr &Instruction,
                                        MachineRegisterInfo &MRI,
                                        const TargetDescription &Target);

[[nodiscard]] Expected<void> extractParts(Register Reg, LowLevelType Type,
                                          int PartCount,
                                          std::vector<Register> &Parts,
                                          MachineIRBuilder &MIRBuilder,
                                          MachineRegisterInfo &MRI);

[[nodiscard]] Expected<bool>
extractParts(Register Reg, LowLevelType RegisterType, LowLevelType MainType,
             LowLevelType &LeftoverType, std::vector<Register> &Parts,
             std::vector<Register> &LeftoverParts,
             MachineIRBuilder &MIRBuilder, MachineRegisterInfo &MRI);

[[nodiscard]] Expected<LowLevelType> getLCMType(LowLevelType OriginalType,
                                                LowLevelType TargetType);
[[nodiscard]] Expected<LowLevelType> getGCDType(LowLevelType OriginalType,
                                                LowLevelType TargetType);

} // namespace rcc

#endif // RCC_CODEGEN_GLOBALISEL_UTILS_H