So I have a task to write the algorithm for eratosthenes' sieve. The code works fine apart from the fact that it just won't print the newline when i need it. It just ignores the syscall for printing. I tried googling but couldn't find anything similar to my problem.
The problematic syscall is in lines 119-121
Here is my code:
.data #Data Segment
isprime:
.space 400 #Array size 100*sizeof(int)
nl:
.asciiz "\n" #New line
.text #Text Segment
.globl main
main:
subu $sp, $sp, 32 #Stack frame is 32 bytes long
sw $ra, 20($sp) #Save return address to the stack
sw $fp, 16($sp) #Save the old frame pointer to the stack
addiu $fp, $sp, 28 #Set up frame pointer
la $a0, isprime #Load pointer to isprime and prepare argument of initialize function
sw $a0, 12($sp) #Save pointer to isprime to the stack
jal initialize #Call initialize function
lw $a0, 12($sp) #Prepare argument of find_primes function
jal find_primes #Call find_primes function
lw $a0, 12($sp) #Prepare argument of print function
jal print #Call print function
#Return code
lw $ra, 20($sp) #Restore return address
lw $fp, 16($sp) #Restore old frame pointer
addiu $sp, $sp, 32 #Pop stack
jr $ra #Return to caller
initialize: #Function initialize
subu $sp, $sp, 32 #Stack frame is 32 bytes long
sw $ra, 20($sp) #Save return address
sw $fp, 16($sp) #Save old frame pointer
addiu $fp, $sp, 28 #Set up new frame pointer
li $t0, 2 #Initialize i=2
li $t1, 100 #Initialize N
li $s1, 1 #Store value 1 to a register
sw $zero, 0($a0) #isprime[0] = 0
addi $a0, 4
sw $zero, 0($a0) #isprime[1] = 0
addi $a0, 4
init_loop: #loop for(i=2; i<=N; i++)
sw $s1, 0($a0) #isprime[i] = 1
addi $a0, 4
addi $t0, 1
bne $t0, $t1, init_loop
#Return code
lw $ra, 20($sp) #Restore return address
lw $fp, 16($sp) #Restore old frame pointer
addiu $sp, $sp, 32 #Pop stack
jr $ra #Return to caller
la $a0, nl
li $v0, 4 #Prepare for system call print_string
la $a0, nl
syscall
find_primes: #Function find_primes
subu $sp, $sp, 32 #Stack frame is 32 bytes long
sw $ra, 20($sp) #Save return address
sw $fp, 16($sp) #Save old frame pointer
addiu $fp, $fp, 28 #Set up new frame pointer
la $a1, isprime #Save pointer to isprime to a register other than $a0
li $t0, 2 #Initialize i=2
li $s1, 1 #Store value 1 to a register
li $t1, 100 #Initialize N
addi $a1, 8 #Start from isprime[2]
outer_loop: #loop for(i=2; i<N; i++)
lw $t5, 0($a1)
bne $t5, $s1, cont #if(isprime[i])
add $t2, $t0, $t0 #Initialize j
inner_loop: #loop for(j=i+i; j<=N; j+=i)
mul $t3, $t0, 4 #align address of the next element of isprime
add $a1, $a1, $t3
sw $zero, 0($a1) #isprime[j] = 0
add $t2, $t2 ,$t0
ble $t2, $t1, inner_loop
cont:
addi $t0, 1
mul $t4, $t0, 4
add $a1, $a0, $t4
bne $t0, $t1, outer_loop
#Return code
lw $ra, 20($sp) #Restore return address
lw $fp, 16($sp) #Restore old frame pointer
addiu $sp, $sp, 32 #Pop stack
jr $ra #Return to caller
print: #Function print
subu $sp, $sp, 32 #Stack frame is 32 bytes long
sw $ra, 20($sp) #Save return address
sw $fp, 16($sp) #Save old frame pointer
addiu $fp, $fp, 28 #Set up new frame pointer
la $a1, isprime #Save pointer to isprime to a register other than $a0
li $t0, 0 #Initialize i=0
li $t1, 100 #Initialize N
li $s1, 1 #Store value 1 to a register
print_primes_loop: #loop for(i=0; i<=N; i++)
lw $t5, 0($a1)
bne $t5, $s1, cont_print #if(isprime[i])
move $a0, $t0
li $v0, 1 #Prepare for system call print_int
syscall
li $v0, 4 #Prepare for system call print_string
la $a0, nl
syscall
cont_print:
addi $a1, 4
addi $t0, 1
ble $t0, $t1, print_primes_loop
#Return code
lw $ra, 20($sp) #Restore return address
lw $fp, 16($sp) #Restore old frame pointer
addiu $sp, $sp, 32 #Pop stack
jr $ra #Return to callerThere is also something that weirds me out. I tried randomly pasting the same syscall in other parts of the program and it only worked when i placed it in line 40. I have no idea what it could be.
If you want me to clarify someting just ask, thanks in advance!