Subroutine: x$\_$mod$\_$N

input: R$5$ unsigned $16-$bit integer x $--$ returned unchanged

R$6$ unsigned $16-$bit nonzero integer N $--$ returned unchanged

output: R$12$ unsigned $16-$bit integer y $--$ may be modified

y is the remainder when x is divided by N

Modifies R$12,$ all other core registers in R$4-$R$15$ unchanged

$----------$

x$\_$mod$\_$N:

mov.w R$5,$R$12$

repeat:

cmp$.$w R$6,$R$12$ ;set status bits for $($x$-$N$)$

jn end$\_$div ;if $($x$-$N$)<0$ we are done

;otherwise

sub.w R$6,$R$12$ ;x $<-$x$-$N

jmp repeat land repeat from top

end$\_$div:

ret

Sometimes it works correctly $($e$.$g$.,$ it can correctly compute $31273\%5=3),$ and at

other times it does not. Can you find the error and fix the subroutine?

$($a$)$ What line needs to be fixed? Enter the line number.