我正在尝试在汇编中重新创建一个 C 片段。C程序本质上是：
-
创建一个字符数组[256]以及一个初始化为空的指针*A。
-
然后将某个字符串的用户输入存储到 char 数组中
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而数组的每个第 i 个元素 ！= 0
-
检查第 i 个元素是 == 一些定义的字符值 V。
-
如果数组[i] == V ->集合 A = &array[i]
-
破
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最后检查 A 是否仍初始化为 NULL 如果不是品脱地址和 A 的值
- 否则未找到
不幸的是，当我用Qtspim运行MIPS代码时，我得到上述错误PC=0x004000a8发生异常 ->(之后中止( -> 后跟 inst/data fetch 中的未对齐地址：0x1001012b
我觉得这与我在数组中存储字节值的方式或我访问这些内存位置的方式有关，但我无法弄清楚问题是什么。任何人可以提供的任何见解将不胜感激。祝大家节日快乐！
波纹管是我的汇编代码：
# global functions aforementioned error
.globl main
# .text assembler directive
.text
# main
main:
# register map
# use $t0 for i
# use $t1 for NULL
# use $s0 for &inputArray[i]
# use $s1 for indexed array value
# use $s2 for the base address inputArray
# use $s3 for result
# use $t2 for constCharlwr
# Prompt user for input
la $a0, str1
li $v0, 4
syscall
# Get user input and store in input array
la $a0, inputArray
li $a1, 256
li $v0, 8
syscall
# set up registers
lb $t0, i
lb $t1, NULL
la $s2, inputArray
lb $s3, result
lb $t2, constCharlwr
li $s0, 0
add $s0, $s0, $s2 # s0 = &arrayA[i]
while: # while loop
add $s0, $s0, $t0 # base address + 1 byte
lb $s1, 0($s0) # load array index value into s1
beq $s1, $t1, outsideWhile # inputArray[i] != ' '
if1:
bne $s1, $t2, outsideIf # check if inputArray[i] == e
move $s3, $s1 # if true copy s1(inputArray[i] into s3(result)
sb $s3, result
j outsideWhile
outsideIf:
addi $t0, $t0, 1
j while
outsideWhile:
if2:
beq $s3, $t1, else
# Print results
# Print string 2
lw $a0, str2
li $v0, 4
syscall
# Print address of result
la $a0, result
li $v0, 4
syscall
# Print next line
lb $a0, nextline
li $v0, 4
syscall
# Print string 3
lw $a0, str3
li $v0, 4
syscall
# Print result char value
lb $a0, result
li $v0, 4
syscall
# Print next line
lb $a0, nextline
li $v0, 4
syscall
j exitPrgm
else:
# Print No match
lw $a0, str4
li $v0, 4
syscall
# Exit the program by means of syscall.
exitPrgm:
li $v0, 10 # Sets $v0 to "10" to select exit syscall
syscall # Exit
# .data assembler directive
.data
inputArray: .space 256
constCharlwr: .byte 'e'
result: .byte 0
NULL: .byte 0
i: .byte 0
str1: .asciiz "Enter a word to search for letter e: n"
str2: .asciiz "First match at address "
str3: .asciiz "The matching character is "
str4: .asciiz "No match foundn"
nextline: .asciiz "n"
好的，所以我解决了我最初的问题，我没有将 la 用于我的系统调用，一旦我修复了我开始获得我想要的输出。现在唯一的问题是我可以弄清楚如何打印结果的实际地址。有人可以帮我解决这个问题吗？ 新代码，尝试一些不同的方式来获取内存地址，但似乎没有任何效果。
# Prompt user for input
la $a0, str1
li $v0, 4
syscall
# Get user input and store in input array
la $a0, inputArray
li $a1, 255
li $v0, 8
syscall
# set up registers
lb $t0, i
lb $t1, NULL
la $s2, inputArray
lb $s3, result
lb $t2, constCharlwr
li $s0, 0
add $s0, $s0, $s2 # s0 = &arrayA[i]
while: # while loop
add $s0, $s0, $t0 # base address + 1 byte
lb $s1, 0($s0) # load array index value into s1
beq $s1, $t1, outsideWhile # inputArray[i] != ' '
if1:
bne $s1, $t2, outsideIf # check if inputArray[i] == e
sb $s1, result
j outsideWhile
outsideIf:
addi $t0, $t0, 1
j while
outsideWhile:
if2:
beq $s1, $t1, else
# Print results
# Print string 2
la $a0, str2
li $v0, 4
syscall
# Print address of result
la $t9, result
li $t8, 4
li $t0, 0
#for:
# bge $t0, $t8 outsideFor
# add $t9, $t9, $t0
# lb $t7, 0($t9)
# sb $t7, resultAddr
# la $a0, resultAddr
# li $v0, 4
# syscall
# addi $t0, $t0, 1
# j for
#outsideFor:
sb 0($t9) resultAddr
la $a0, resultAddr
li $v0, 4
syscall
sb 1($t9) resultAddr
la $a0, resultAddr
li $v0, 4
syscall
sb 2($t9) resultAddr
la $a0, resultAddr
li $v0, 4
syscall
sb 3($t9) resultAddr
la $a0, resultAddr
li $v0, 4
syscall
# Print next line
la $a0, nextline
li $v0, 4
syscall
# Print string 3
la $a0, str3
li $v0, 4
syscall
# Print result char value
la $a0, result
li $v0, 4
syscall
# Print next line
la $a0, nextline
li $v0, 4
syscall
j exitPrgm
else:
# Print No match
la $a0, str4
li $v0, 4
syscall