using System;

namespace BizHawk.Emulation.CPUs.M68K
{
    public partial class M68000
    {
        private void MOVEtSR()
        {
            if (S == false)
                throw new Exception("Write to SR when not in supervisor mode. supposed to trap or something...");

            int mode = (op >> 3) & 7;
            int reg  = (op >> 0) & 7;
            SR = ReadValueW(mode, reg);
            PendingCycles -= (mode == 0) ? 12 : 12 + EACyclesBW[mode, reg];
        }

        private void MOVEtSR_Disasm(DisassemblyInfo info)
        {
            int pc = info.PC + 2;
            int mode = (op >> 3) & 7;
            int reg  = (op >> 0) & 7;
            info.Mnemonic = "move";
            info.Args = DisassembleValue(mode, reg, 2, ref pc) + ", SR";
            info.Length = pc - info.PC;
        }

        private void MOVEfSR()
        {
            int mode = (op >> 3) & 7;
            int reg = (op >> 0) & 7;
            WriteValueW(mode, reg, (short) SR);
            PendingCycles -= (mode == 0) ? 6 : 8 + EACyclesBW[mode, reg];
        }

        private void MOVEfSR_Disasm(DisassemblyInfo info)
        {
            int pc = info.PC + 2;
            int mode = (op >> 3) & 7;
            int reg  = (op >> 0) & 7;
            info.Mnemonic = "move";
            info.Args = "SR, " + DisassembleValue(mode, reg, 2, ref pc);
            info.Length = pc - info.PC;
        }

        private void MOVEUSP()
        {
            if (S == false)
                throw new Exception("MOVE to USP when not supervisor. needs to trap");

            int dir = (op >> 3) & 1;
            int reg = op & 7;

            if (dir == 0) usp = A[reg].s32;
            else A[reg].s32 = usp;

            PendingCycles -= 4;
        }

        private void MOVEUSP_Disasm(DisassemblyInfo info)
        {
            int pc = info.PC + 2;
            int dir = (op >> 3) & 1;
            int reg = op & 7;
            info.Mnemonic = "move";
            info.Args = (dir == 0) ? ("A" + reg + ", USP") : ("USP, A" + reg);
            info.Length = pc - info.PC;
        }

        private void ORI_SR()
        {
            if (S == false)
                throw new Exception("trap!");
            SR |= ReadWord(PC); PC += 2;
            PendingCycles -= 20;
        }

        private void ORI_SR_Disasm(DisassemblyInfo info)
        {
            int pc = info.PC + 2;
            info.Mnemonic = "ori";
            info.Args = DisassembleImmediate(2, ref pc) + ", SR";
            info.Length = pc - info.PC;
        }
    }
}