C to MIPS conversions - c

Question

int MyArray[30];
int n = 2;
MyArray[0] = 1;
MyArray[1] = 1;
do{
MyArray[n] = MyArray[n-1] + MyArray[n-2];
n++;
}
while(n < 30);
While I was doing this I got stuck on how i can recursively call the function without the use of return address $ra or $sp since the code doesn't actually return anything.
This is my work so far :
#s1= Myarray[0]
addi $s0, $0, 2 #$s0=n=2
addi $t0, $s1,0
addi $t1,$0,1
sw $t1, 0 ($t0) #Myarray[0]=1
addi $t0,$t0,4
sw $t1, 0 ($t0) #Myarray[1]=1
add $t0,$s0,$s1 #MyArray[n]= Myarray[0] +n
Loop:
addi $t2,$t0,-4
addi $t3,$t0,-8
lw $t4,0 ($t2)
lw $t5,0 ($t3)
add $t5,$t4,$t5
sw $t5, 0 ($t0)
addi $t0, $t0 ,4
addi $s0,s0,4
slti $s6,$s0,30
beq #s6,$0,Exit
j loop
Exit

Answer 1

This code
sw $t1, 0 ($t0) #Myarray[0]=1
addi $t0,$t0,4
sw $t1, 0 ($t0) #Myarray[1]=1
add $t0,$s0,$s1 #MyArray[n]= Myarray[0] +n
should be
sw $t1, 0 ($t0) #Myarray[0]=1
addi $t0,$t0,4 #update 't0' to point to Myarray[1]
sw $t1, 0 ($t0) #Myarray[1]=1
addi $t0,$t0,4 #update 't0' to point to Myarray[2]
The error is in the last line. Note that $s1 points to the array, and $s0 has the value 2, so t0=s1+s0 points t0 to the wrong address. You really want t0=s1+(s0*4) since each int is four bytes.
However, since you've already updated t0 to point to Myarray[1] (in the second line), you can just update it again (in the fourth line).