[ASM] [Almost Functional] Functions Calling Functions

.text
.globl main

main:
	li $t0, 0 #initialize t0
	li $t1, 0 #initialize t1

	jal input #call input

	li $v0, 10 #exit
	syscall

input:
	sub $sp, $sp, 4
	sw $ra, 0($sp) #store the value in $ra on the stack position 4

	li $v0, 4 #prompt stuff
	la $a0, prompt
	syscall

	li $v0, 5 #get number
	syscall

	move $a0, $v0 #store number
	#we can keep number in a0

	jal check

check:
	sub $sp, $sp, 4
	sw $ra, 0($sp) #store the value in $ra on the stack position 8

	#bltz $a0, negative
	#bgtz $a0, positive
	#beqz $a0, zero

	jal addnum
	jal output

addnum:
	sub $sp, $sp, 4
	sw $ra, 0($sp) #store the value in $ra on the stack position 12

	bltz $a0, negative
	bgtz $a0, positive
	beqz $a0, zero

negative:
	add $t0, $t0, $a0

	lw $ra, 0($sp)
	addu $sp, $sp, 8 #go back 8 spaces, to input

	jr $ra

positive:
	add $t1, $t1, $a0

	lw $ra, 0($sp)
	addu $sp, $sp, 8 #go back 8 spaces, to input

	jr $ra

zero:
	lw $ra, 0($sp)
	addu $sp, $sp, 8 #go back 4 spaces, to check

	jr $ra

output:
	li $v0, 4
	la $a0, posi_sum
	syscall

	move $a0, $t1
	li $v0, 1 #output positive sums

	li $v0, 4
	la $a0, nega_sum
	syscall

	move $a0, $t0
	li $v0, 1 #output negative sum

	lw $ra, 0($sp)
	addu $sp, $sp, 12 #go back to main

	jr $ra
.data

prompt:
	.asciiz "\nInput your number: "

posi_sum:
	.asciiz "\nYour positive sum is: "

nega_sum:
	.asciiz "\nYour negative sum is: "