mirror.s

            .data 0x10000000
num:        .word 11288511
is_mirror:  .byte 0
num_digits: .word 0
mirror_val: .byte 0,1,5,'x','x',2,'x','x',8,'x'

            .globl __start
            .text 0x00400000


__start:    la   $t0,num
            lw   $t0,0($t0) # N

            ## Extract digits in $t2 ##
            li   $s0,0      # Counter
            move $t3,$t0    # Take aux from num
            li   $t2,10     # Save 10 constant
$L1:        div  $t3,$t2    # Num / 10
            mflo $t3        # Mov quocient to aux
            addi $s0,$s0,1  # Increment digit counter
            bnez $t3,$L1
            la $t3,num_digits
            sw $s0,0($t3)   # Save digit counter
            ## Mirror process ##
            move $t1,$s0     # $t1 = c  (length)
            li   $t3,1       # $t3 = control signal (0->Not mirror,1->Mirror)
$L2:        div  $t0,$t2     # num%10 ( While num > 9 -has more than one digit- )
            mfhi $s0         # take remainder from hi
            addiu $t1,$t1,-1         # to calculate this pow, it's necessary to rest 1 to $t1 (length)
            jal $PowTen
            addiu $t1,$t1,1         # restore length
            move $s1,$v0     # s1 = (10**(c-1))
            div  $t0,$s1     # n/(10**(c-1))
            mflo $s1         # s1 = n/10**(c-1)
            la $s2,mirror_val
            add $s2,$s2,$s1  # mirror_val offset to read byte
            lb $s1,0($s2)    # s1 = mirrored value
            bne $s1,$s0,$EndFalse      # if n%10 != mirror[n/(10**(c-1))]
            div $t0,$t2      # n /= 10
            mflo $t0         # t0 = t0 / 10
            addi $t1,$t1,-2  # $t1 -= 2 (c-2)
            jal $PowTen      # (10**(c-2))
            move $s1,$v0     # s1 = (10**(c-2))
            li $s3,9         # 9 constant
            bgt $t0,$s3,$L2 # if num < 10
            ## if comes here, is equal in mirror ##
            li $t0,1
            la $t1,is_mirror
            sb $t0,0($t1)
            jal exit
$EndFalse:  li $t0,0
            la $t1,is_mirror
            sb $t0,0($t1)    # control signal = 0 -> X
            jal exit

            ## Pow 10         ##
$PowTen:    move $a0,$t1     # Save length for counter
            li $s1,10
$LPT:       mult $s1,$t2     # $s1 = 10*10
            mflo $s1         # $s1 = 10*10
            addi $a0,$a0,-1  # Dec counter
            bnez $a0,$LPT
            move $v0,$s1
            jr $ra

            ## Exit ##
exit:       li $v0,10
            syscall
.end