Question

Why this code is giving exception at storing the float number. I am unable to figure out the problem. Here is the code:

li $t1,0

Loop:

add $t0,$t1,$s0

li $v0,6
syscall
mov.s $f1,$f0

swc1 $f1,0($t0)

addi $t1,$t1,4

beq $t1,20,Mult

j Loop

Answer 1

You are probably getting an unalignment exception executing swc1 $f1,0($t0).
The instruction swc1 needs the second argument to be an effective memory address aligned at word boundary. This means that the two least significant bits of this effective memory address (in your case the address stored at $t0) need to be zero.

The code you posted does not show the initialization of $s0 which is likely to have at least one of the two least significant bits with 1.

To fix your code, ensure that $s0 starts with those bits in zero so the effective memory address used in swc1 is word-aligned.

If the initialization of $s0 is done with la $s0, label you might want to use .align 2 directive when you declare the buffer to store the data, e.g.:

label: .align 2
       .space ...