pub const REG_COUNT: usize = 60;

macro_rules! constmod {
    ($vis:vis $mname:ident($repr:ty) { $($cname:ident = $val:expr),* $(,)? }) => {
        $vis mod $mname {
            $(pub const $cname: $repr = $val;)*
        }
    };
}

constmod!(pub opcode(u8) {
    NOP = 0, // _
    ADD = 1, // RRR
    SUB = 2, // RRR
    MUL = 3, // RRR
    DIV = 4, // RRR
    REM = 5, // RRR
    AND = 6, // RRR
    OR  = 7, // RRR
    XOR = 8, // RRR
    NOT = 9, // RR

    // TODO: Add instruction for integer and float
    // reg ← reg + imm instructions

    ADDF = 10, // RRR
    SUBF = 11, // RRR
    MULF = 12, // RRR
    DIVF = 13, // RRR

    LI = 14, // RI
    LD = 15, // RI
    ST = 16, // RI

    MAPPAGE   = 17, // ?
    UNMAPPAGE = 18, // ?

    JMP     = 100, // I
    JMPCOND = 101, // I
    RET     = 103, // _
    ECALL   = 255, // _
});

#[repr(packed)] pub struct ParamRRR(pub u8, pub u8, pub u8);
#[repr(packed)] pub struct ParamRR(pub u8, pub u8);

#[repr(packed)] pub struct ParamRI(pub u8, pub u64);

/// # Safety
/// TODO.
pub unsafe trait OpParam {}
unsafe impl OpParam for ParamRRR {}
unsafe impl OpParam for ParamRR {}
unsafe impl OpParam for ParamRI {}
unsafe impl OpParam for u64 {}
unsafe impl OpParam for () {}