#![no_std]

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, // N; Do nothing

    ADD = 1,  // RRR; #0 ← #1 + #2
    SUB = 2,  // RRR; #0 ← #1 - #2
    MUL = 3,  // RRR; #0 ← #1 × #2
    DIV = 4,  // RRR; #0 ← #1 ÷ #2
    REM = 5,  // RRR; #0 ← #1 % #2
    AND = 6,  // RRR; #0 ← #1 & #2
    OR  = 7,  // RRR; #0 ← #1 | #2
    XOR = 8,  // RRR; #0 ← #1 ^ #2
    SL  = 9,  // RRR; #0 ← #1 « #2
    SR  = 10, // RRR; #0 ← #1 » #2
    SRS = 11, // RRR; #0 ← #1 » #2 (signed)
    NOT = 12, // RR;  #0 ← !#1

    ADDF = 13, // RRR; #0 ← #1 +. #2
    SUBF = 14, // RRR; #0 ← #1 +. #2
    MULF = 15, // RRR; #0 ← #1 +. #2
    DIVF = 16, // RRR; #0 ← #1 +. #2

    ADDI = 17, // RRI; #0 ← #1 + imm #2
    MULI = 18, // RRI; #0 ← #1 × imm #2
    REMI = 19, // RRI; #0 ← #1 % imm #2
    ANDI = 20, // RRI; #0 ← #1 & imm #2
    ORI  = 21, // RRI; #0 ← #1 | imm #2
    XORI = 22, // RRI; #0 ← #1 ^ imm #2

    SLI  = 23, // RRI; #0 ← #1 « imm #2
    SRI  = 24, // RRI; #0 ← #1 » imm #2
    SRSI = 25, // RRI; #0 ← #1 » imm #2 (signed)

    ADDFI = 26, // RRI; #0 ← #1 +. imm #2
    MULFI = 27, // RRI; #0 ← #1 *. imm #2

    CP = 28, // RR;  Copy #0 ← #1
    LI = 29, // RI;  Load immediate, #0 ← imm #1
    LB = 30, // RRI; Load byte (8 bits), #0 ← [#1 + imm #2]
    LD = 31, // RRI; Load doublet (16 bits)
    LQ = 32, // RRI; Load quadlet (32 bits)
    LO = 33, // RRI; Load octlet (64 bits)
    SB = 34, // RRI; Store byte, [#1 + imm #2] ← #0
    SD = 35, // RRI; Store doublet
    SQ = 36, // RRI; Store quadlet
    SO = 37, // RRI; Store octlet

    JMP     = 38, // RI; Unconditional jump [#0 + imm #1]
    JMPCOND = 39, // ?; Conditional jump
    RET     = 40, // N; Return
    ECALL   = 42, // N; Issue system call
});

#[repr(packed)]
pub struct ParamRRR(pub u8, pub u8, pub u8);
#[repr(packed)]
pub struct ParamRRI(pub u8, pub u8, pub u64);
#[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 ParamRRI {}
unsafe impl OpParam for ParamRR {}
unsafe impl OpParam for ParamRI {}
unsafe impl OpParam for u64 {}
unsafe impl OpParam for () {}