Pointers 在MIPS/MARS中如何在反转前添加/打印用户输入

这是我在火星上的密码。它请求一个名称并将其反转。示例输出：

输入您的姓名（格式为“FIRST-LAST”）：arya stark 相反的是：斯塔克，雅利娅 --程序已完成运行（从底部掉落）--

我想说： 输入您的姓名（格式为“FIRST-LAST”）：arya stark 雅利娅·斯塔克反过来说是：斯塔克，雅利娅 --程序已完成运行（从底部掉落）--

我该怎么做

############################ data segment ################################
.data
promptuser: .asciiz "Enter your name (format 'FIRST LAST'): "
putComma:   .asciiz ", " #prompt for string
userinput:  .space 400 #string that user enters
reverse:    .asciiz " reversed is : " #prompt for string
############################ code segment ################################ 
.text 
.globl main

main: 
    li $v0, 4
    la $a0, promptuser  #prints a srting prompt to the user 
    syscall
    
    li $v0, 8
    la $a0, userinput   #asks the user to enter name
    li $a1, 100
    syscall
    
    move $s0, $a0        #move data to s0
    move $s1, $a1
    li $v0, 4
    la $a0, reverse     #prompt to reverse
    syscall

    move $s1,$s0
loop: 
    #loop while end of string
    lb $a0, 0($s0)      #load first character to a0
    addi $s0, $s0, 1    #add index by one
    beq $a0, $zero, exit    #else print character
    beq $a0, 32, exitLoop   #if current character is space go to loop
    j loop

exitLoop:

loopPrint: 
    lb $a0, 0($s0)          #load first character to a0
    addi $s0, $s0, 1        #add index by one
    beq $a0, $zero, printOtherStr   #else print character
    beq $a0, 10, printOtherStr  #else print character
    beq $a0, 32, exit       #if current character is space go to loop
    li $v0, 11
    syscall
    j loopPrint

printOtherStr:
    li $v0, 4
    la $a0, putComma    #padding comma to name
    syscall

printOther:
    lb $a0, 0($s1)      #load first character to a0
    addi $s1, $s1, 1    #add index by one
    beq $a0, $zero, exit    #else print character
    beq $a0, 32, exit   #if current character is space go to loop
    li $v0, 11
    syscall
    j printOther 
    
    exit: