Question $4-$ Fix the subroutine $(2+6$ pts$)$

You are given following subroutine and contract

$```$

$100$;

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

$108$;

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

$109$ x$\_$mod$\_$N:

$110$ mov.w R$5,$ R$12$

$111$ repeat:

$112$ cmp$.$w R$6,$ R$12$ ; set status bits for $($x$-$N$)$

$113$ jn end$\_$div ; if $($x$-$N$)<mn>0</mn>$ we are done

$```$

$```$

$115$ sub.w R$6,$ R$12$ ; x x$-$N

$```$

$```$

$117$end$\_$div:

$118$ ret

$```$

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

$($b$)$ What should the correct line be$?$ Enter the instruction and operands. Watch out for autocorrect when entering your line.