; Instead of using jump instructions,
; this program uses 'CALL' and 'RET' to use labels as if they were functions.

; This program creates a function for calculating modulus.
; Then it uses that function for modulus to do modulus math on 2 numbers.
; Then it stops the CPU.

LOAD r0, 7 ; First number.
LOAD r1, 2 ; Second number.
LOAD r2, 0 ; The result register.

CALL @FnMod ; First Number % Second Number

COPY r15, r2 ; Copy the return value into the register we wanna put the result in.

JUMP @Exit

@FnMod:
    DIV r0, r1, r2 ; Divide r0 by r1, and store in r2.
    MUL r2, r1, r2 ; Scale division result by the divide-by number.
    SUB r0, r2, r0 ; Subtract r2 from r0, and store in r0.
    COPY r0, r15 ; Copy the value of r0 into r15. (This program's return convention I guess.)
    RET ; Return to where the 'CALL' instruction was invoked.

; Exit point. This is just to avoid running code under labels by accident.
@Exit:
    HLT ; Stop the CPU.