$.$ text

main: li $a$0,5$ hardcode factorial$(5)$

jal factorial

move $a$0,$ $v$0$ # copy return from factorialk into argument $0$

li $$v0,1,$ # integer print $$a0$ with syscall $1$

syscall

exit: li $$v0,10,$ # exit with syscall $10$

syscall

# subroutine FACTORIAL$(n)$

# calculates $n**(n-1)**(n-2)**dots**1$

#IN: $,$$$a0=n,$ as unsigned integer

# OUT: $,$$$V0=$ FACTORIAL $(n)$

# CHANGES: $t$0,$ $t$1,$ $v$0$

factorial:

bne $$a0,$ zero, nonzero $,$ # special case $N=0$

li $$a0,1$ # same as FACTORIAL $(1)$

nonzero:

move $t$0,$ $a$0$ #t$0=$ a$0$

addi $t$0,$ $t$0,1,$# t$0=a0+1$ for $N+1$ comparison

li $t$1,1$ # counter $t1=1$

li $v$0,1$ # result $v0=1$

loop: mul $$v0,$$$v0,$$$t1,$#$v0**=t1$

addi $$t1,$$$t1,1,$#$t1+=1$

bne $$t0,$$$t,$ loop

$jr$ $ $ra$