Question

Hi have to code this loop:

for($6=10;$6!=0;$6--){ 
    $7=$6; 
}

but with some conditions. I can only use BEQ and must assume that the initial value of each register is the number of the register.

How can evaluate that difference only using BEQ?

I’ve made this

main:
    add   $6,$5,$5
    for:
        add     $7,$6,$0
        sub     $6,$6,$1
        beq     $6,for

but I’m stuck on the verification.

Answer 1

1. Set $6 equal to 10. Why give $6 an initial value of 6 when you’re
   just going to overwrite it?
2. Enter your loop and set $7 to $6.
3. Decrement $6 and jump to the next label if $6 equals zero, otherwise
   jump back to the start of the loop.

The code:

li $6, 10
for:
    move $7, $6
    subi $6, $6, 1
    beq $6, $0, end
    j for
end: