CLK/InstructionSets/PowerPC/Decoder.hpp

//
//  Decoder.hpp
//  Clock Signal
//
//  Created by Thomas Harte on 12/30/20.
//  Copyright © 2020 Thomas Harte. All rights reserved.
//

#ifndef InstructionSets_PowerPC_Decoder_hpp
#define InstructionSets_PowerPC_Decoder_hpp

#include "Instruction.hpp"

namespace CPU {
namespace Decoder {
namespace PowerPC {

enum class Model {
	/// i.e. 32-bit, with POWER carry-over instructions.
	MPC601,
	/// i.e. 32-bit, no POWER instructions.
	MPC603,
	/// i.e. 64-bit.
	MPC620,
};

/*!
	Implements PowerPC instruction decoding.

	This is an experimental implementation; it has not yet undergone significant testing.
*/
struct Decoder {
	public:
		Decoder(Model model);

		Instruction decode(uint32_t opcode);

	private:
		Model model_;

		bool is64bit() const {
			return model_ == Model::MPC620;
		}

		bool is32bit() const {
			return !is64bit();
		}

		bool is601() const {
			return model_ == Model::MPC601;
		}
};

}
}
}

#endif /* InstructionSets_PowerPC_Decoder_hpp */