MIPS-syscall打印错误的asciiz

问题描述

我正在编写一个程序，该程序以升序从用户读取4个整数到数组。如果值不升序，则程序将显示错误消息（.data中的“更大”标签），并从用户读取另一个整数。 读取整数后，我对每个整数进行迭代并用逗号打印。

当我调用逗号打印时，我得到一个空格+“更大”标签（错误消息）的值而不是逗号。 代码：

.data
array:  .byte   4
comma:  .asciiz ",\n"
bigger: .asciiz "The array inputs should be in an ascending order!\n"

.text
main:   # main program entry    
la $a0,array       # load array address
jal get_array       # call get_array procedure with the array address
addi $t0,$zero,0  # set loop counter to 0
la   $t1,array     # load array address
loop: beq $t0,4,endLoop # for $t0 < 4
      li $v0,1     # v0 integer syscall
      lb $a0,0($t1)    # load current byte of the array    
      syscall       # print it
      la $a0,comma # load address of comma string
      li $v0,4     # v0 string syscall    
      syscall       # print comma
      addi $t1,$t1,1  # array address pointer++
      addi $t0,$t0,1  # loop counter++
      j loop        # loop
endLoop:
      li $v0,10    # exit program
      syscall

get_array:          # read asceding integer array from the user
    addi $t0,1  # inserts count
    la   $t1,($a0)     # array address pointer
    addi $v0,5  # read integer syscall
    syscall         # read integer from the user
    sb   $v0,0($t1)    # save integer in current array address pointer
    addi $t1,1    # array address pointer++
loop1:  beq  $t0,endLoop1   # for $t0 < 4
    addi $v0,5  # read integer syscall
    syscall         # read integer from the user
    lb   $t2,-1($t1)   # read the previous array value
    slt  $t3,$t2,$v0  # check if current value is bigger than previous value
    beq  $t3,invalid    # if not go to invalid
valid:  sb   $v0,0($t1)    # valid - save new value in current array address pointer
    addi $t1,1    # array address pointer++
    addi $t0,1    # inserts count++
    j    loop1      # loop
invalid:            # invalid - new value doesnt keep array ascending
    addi $v0,4  # print string syscall 
    la $a0,bigger      # print error message
    syscall         # print error message       
    j    loop1      # loop
endLoop1:
    jr $ra          # return to caller

示例： 输入：

1
2
3
4

打印为：

1  The array inputs should be in an ascending order!
2  The array inputs should be in an ascending order!
3  The array inputs should be in an ascending order!
4  The array inputs should be in an ascending order!

预期结果：

1,2,3,4

解决方法

array: .byte 4不会为4个字节保留空间；它为初始值为4的单个字节保留空间。

您想要的是.space，即array: .space 4

---

现在最终发生的是，您输入的最后3个覆盖了comma字符串，包括其NUL终止符。