如何在MIPS中正确存储输入？

Question

尽管我尝试输入不同的值，但是Qtspim仍然打印出值“ 0”，并且输入也没有保存在寄存器中，我尝试在Internet上找到答案，但是似乎没人之前面对这个问题。我工作了4个小时，对此感到非常沮丧。 这是我的代码，我尝试定义输入是否为素数。

# Power program
# ----------------------------------
# Data Segment
.data
request:             .asciiz "Enter an integer:"
Yes:                  .asciiz " is  a prime number.\n"
No:                   .asciiz " is not a prime number\n."
End:                 .asciiz"End!\n"
Key:                 .word -1
One:                 .word 1

# ----------------------------------
# Text/Code Segment

.text
.globl  main
 main:
    lw $t1,One
    add $s2,$zero,$zero
    lw $s3,One
    lw   $s0,Key
    add  $s5,$zero,$zero


j   power       # call the function power   

li  $v0, 10     # call code for exit
syscall         # system call
.end main


.globl  power


power:  

       j power_loop



power_loop:    
                   la   $a0, request    # load string request in memory to $a0
                   li   $v0, 4              # print out the string
                    syscall          #prevent Memory address out of bounds
                    li  $v0, 5
                    syscall
                    move $s7,$v0
                    beq $s7, $s0, exit_L    #when input =-1 exit
                    j        Prime                 #otherwise go to define the input whether prime num

Prime:  
       beq $s7,$t1,result   
       div  $s7,$t1
       mthi $t4
       beq  $t4,$zero,count
       addi  $t1,$t1,1
       j       Prime


count:    #counting the number of factors 
      addi $s2,1                            
      addi $t1,$t1,1

result:  addi $t1,$zero,1
       bne  $s2,$s3,resultNo
       beq $s2,$s3,resultYes




resultYes:  li         $v0,1
            move $a0,$s7
             syscall
             add $s2,$zero,$zero
             la      $a0,Yes
             li         $v0,4
              syscall
              j            power_loop
resultNo:    li         $v0,1
             move $a0,$s7
             syscall
             add $s2,$zero,$zero
             la   $a0,No
             li     $v0,4
              syscall
              j       power_loop
exit_L:       
              la    $a0,End
              li    $v0,4
             syscall
              jr       $ra


.end    power