Prime number in MIPS
I am supposed to write a function in MIPS that determines if a number is prime. The function should pass the number to be judged as an argument (through $a0) and return a value to indicate whether the number is a prime or not(through $v0). Use this function in a program that determines and prints all the prime numbers between 1 and 1000. This is supposed to be a recursive function. I wrote it but im not sure if i wrote it recursively.
#I/O console
.data
input_int: .asciiz "The prime numbers between 1 and 1000 are:\n"
newline: .asciiz "\n"
space: .asciiz " "
.text
.align 2
.globl main
main:
la $a0, input_int #print "The prime numbers between 1 and 1000 are:"
li $v0,4
syscall
li $a1,2 #the first prime is 2
li $s2,1000 #Stop searching for primes after 1000
li $t5,0 #zero initialized
li $t2,6 #initialized to 6
li $s0,1
jal primeloop #jumps back
primeloop:
#Find primes
beq $s2,0,exit
sub $s2,$s2,1 #Subtract to keep track as in counter
#Set $t1 to 2
li $t1,2
divide:
div $a1,$t1 #Divides by 2 to get next prime
mflo $t3
slt $v0,$t3,$t1 #if quotient less than divisor stop
beq $v0,$s0,fdprime #determine if prime ($v0=1), if prime prints
#If remainder is zero, it is a composite,not prime
mfhi $t4
beq $t4,0,nprime
#Try next divisor
add $t1,$t1,1
j divide
fdprime:
li $v0,1
move $a0,$a1
syscall
li $v0,4
la $a0,space
syscall
addi $t5,$t5,1
beq $t5,$t2,skip
nprime:
#Advances to the next number
add $a1,$a1,1
jr $ra #goes back to find the primes
skip:
li $v0,4
la $a0,newline
syscall
li $t5,0
j nprime
exit:
#I/O console
.data
input_int: .asciiz "The prime numbers between 1 and 1000 are:\n"
newline: .asciiz "\n"
space: .asciiz " "
.text
.align 2
.globl main
main:
la $a0, input_int #print "The prime numbers between 1 and 1000 are:"
li $v0,4
syscall
li $a1,2 #the first prime is 2
li $s2,1000 #Stop searching for primes after 1000
li $t5,0 #zero initialized
li $t2,6 #initialized to 6
li $s0,1
jal primeloop #jumps back
primeloop:
#Find primes
beq $s2,0,exit
sub $s2,$s2,1 #Subtract to keep track as in counter
#Set $t1 to 2
li $t1,2
divide:
div $a1,$t1 #Divides by 2 to get next prime
mflo $t3
slt $v0,$t3,$t1 #if quotient less than divisor stop
beq $v0,$s0,fdprime #determine if prime ($v0=1), if prime prints
#If remainder is zero, it is a composite,not prime
mfhi $t4
beq $t4,0,nprime
#Try next divisor
add $t1,$t1,1
j divide
fdprime:
li $v0,1
move $a0,$a1
syscall
li $v0,4
la $a0,space
syscall
addi $t5,$t5,1
beq $t5,$t2,skip
nprime:
#Advances to the next number
add $a1,$a1,1
jr $ra #goes back to find the primes
skip:
li $v0,4
la $a0,newline
syscall
li $t5,0
j nprime
exit:
0