Enum mosis::Instruction

pub enum Instruction {
    Mov {
        dst: Register,
        src: Register,
    },
    Movi {
        dst: Register,
        imm: u8,
    },
    Add {
        dst: Register,
        x: Register,
        y: Register,
    },
    Sub {
        dst: Register,
        x: Register,
        y: Register,
    },
    Cmp {
        x: Register,
        y: Register,
    },
    Jcc {
        cond: Condition,
        offset: i8,
    },
    Jmp {
        address: Address,
    },
    Call {
        address: Address,
    },
    Ret,
    Nop,
    In {
        dst: Register,
    },
    Out {
        src: Register,
    },
    Mul {
        dst: Register,
        x: Register,
        y: Register,
    },
}

MOSIS instruction type.

All instructions are 16-bits. The first 4 bits represent the opcode, and the remaining 12 bits are used in an instruction-dependent way. Instructions have between 0 and 3 parameters. Most of the instruction names are fixed, except the conditional jump instruction (Jcc).

Variants

Mov

Fields

dst: Register

src: Register

Copy the contents of the src register to the dst register.

Movi

Fields

dst: Register

imm: u8

Move a number encoded in the instruction (imm)into the dst register.

Add

Fields

dst: Register

x: Register

y: Register

Add two registers x and y, and store the result in the dst register.

Sub

Fields

dst: Register

x: Register

y: Register

Subtract register y from register x, (x - y), and store the result in the dst register.

Cmp

Fields

x: Register

y: Register

Compare two registers (using Sub) and set the flags register. Used by Jcc.

Jcc

Fields

cond: Condition

offset: i8

Jump if a certain condition is true (based on the result of a Cmp).

The conditional jump instruction’s name can be rendered differently depending on the condition (e.g. it becomes JLT when checking for “less than” or JNE when checking for “not equal”).

If condition is true, jump to the offset; otherwise, execute the next instruction. The offset is an instruction count, positive or negative based on the sign bit. Offset is from the beginning of the Jcc instruction.

Jmp

Fields

address: Address

Jump to a fixed address.

Call

Fields

address: Address

Call a function at a fixed address.

More specifically, push the address of the following instruction onto the call stack, then Jmp to the address specified.

Ret

Return from a function.

More specifically, pop the address off the call stack, and Jmp there.

Nop

No operation. Do nothing.

In

Fields

dst: Register

Read from external memory or device and store in dst register.

Out

Fields

src: Register

Write contents of src register to external memory or device.

Mul

Fields

dst: Register

x: Register

y: Register

Multiply two registers x and y and store the result in the dst register.

Implementations

impl Instruction

pub fn assemble(&self) -> u16

Assemble an instruction to u16.

pub fn disassemble(inst: u16) -> Result<Self, MOSISError>

All MOSIS instructions are 16 bits, but endianness is not specified in the documentation, so disassembly simply takes a u16 to skirt around this ambiguity.

Trait Implementations

impl Debug for Instruction

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Instruction

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl PartialEq<Instruction> for Instruction

fn eq(&self, other: &Instruction) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Instruction) -> bool

This method tests for !=.

impl TryFrom<u16> for Instruction

type Error = MOSISError

The type returned in the event of a conversion error.

fn try_from(value: u16) -> Result<Self, Self::Error>

Performs the conversion.

impl Eq for Instruction

impl StructuralEq for Instruction

impl StructuralPartialEq for Instruction