我写一些代码MIPS采取的ASCII数字串和字符串转换为整数。 该字符串是通过用户输入，并且可以是在长度为至多10个数字。 我的代码工作正常，并通过由所述数组的索引来确定10的幂字符串中的最低有效数乘以后使用进行环加成的显而易见的方法，从最后一位数字开始输入（10 ^ 0）到第一个数字输入（10 ^ N，N- =阵列中的位数）。
我想知道是否有是，会更快或更短的写的替代方法。 我特别想知道，如果使用的是逻辑移位可能会使这个过程更短。 优化或改善该代码任何想法，将不胜感激！
此外，作为一个方面说明，我想打电话给gets和子程序的readInt使用日航，但由于得到和的readInt两个呼叫子程序，使用日航的主要方法调用获取或造成的readInt问题。 任何想法如何解决这个问题？ 再次感谢干杯
PS：抱歉对该代码的注释的格式，复制和粘贴从MARS模拟器入堆栈溢出文本框引起的对齐为关闭：/
#IO
#Prompts user to input 10 ascii digits into an array
#Converts the string of digits into a single int
#Also handles any number of digits between 1 and 10
#Returns 0 if non-digit chars are entered into the string
.data #declaration of vars follows
array: .space 11 #reserves space for a 10 elem array
char: .space 2
prompt: .asciiz "Please enter 10 numbers, then press ENTER: \n"
null: .asciiz ""
space: .ascii " "
newline: .asciiz "\n"
.text #instructions follow
main:
la $a0, prompt #load prompt message into $a0 for syscall
li $v0, 4 #load syscall to print string
syscall #print prompt message
j readInt #call readInt function to get user input string
gets: #read multiple chars from keyboard buffer until ENTER key,
#add NULL char and store into buffer pointed to by *array
#passed to the subroutine
la $s1, array #set base address of array to s1
loop: #start of read loop
jal getc #jump to getc subroutine
lb $t0, char #load the char from char buffer into t0, stripping null
sb $t0, 0($s1) #store the char into the nth elem of array
lb $t1, newline #load newline char into t1
beq $t0, $t1, done #end of string? jump to done
addi $s1, $s1, 1 #increments base address of array
j loop #jump to start of read loop
getc: #read char from keyboard buffer and return ascii value
li $v0, 8 #call code for read string
la $a0, char #load address of char for read
li $a1, 2 #length of string is 1byte char and 1byte for null
syscall #store the char byte from input buffer into char
jr $ra #jump-register to calling function
readInt: #read string of ascii digits, store into a local variable and
#convert into integer, return that int unless string contains
#non-integers
j gets #let s1 be top address of array, let s0 be the digitcounter
done: #let s2 be the sum total
addi $s1, $s1, -1 #reposition array pointer to last char before newline char
la $s0, array #set base address of array to s0 for use as counter
addi $s0, $s0, -1 #reposition base array to read leftmost char in string
add $s2, $zero, $zero #initialize sum to 0
li $t0, 10 #set t0 to be 10, used for decimal conversion
li $t3, 1
lb $t1, 0($s1) #load char from array into t1
blt $t1, 48, error #check if char is not a digit (ascii<'0')
bgt $t1, 57, error #check if char is not a digit (ascii>'9')
addi $t1, $t1, -48 #converts t1's ascii value to dec value
add $s2, $s2, $t1 #add dec value of t1 to sumtotal
addi $s1, $s1, -1 #decrement array address
lp: #loop for all digits preceeding the LSB
mul $t3, $t3, $t0 #multiply power by 10
beq $s1, $s0, FIN #exit if beginning of string is reached
lb $t1, ($s1) #load char from array into t1
blt $t1, 48, error #check if char is not a digit (ascii<'0')
bgt $t1, 57, error #check if char is not a digit (ascii>'9')
addi $t1, $t1, -48 #converts t1's ascii value to dec value
mul $t1, $t1, $t3 #t1*10^(counter)
add $s2, $s2, $t1 #sumtotal=sumtotal+t1
addi $s1, $s1, -1 #decrement array address
j lp #jump to start of loop
error: #if non digit chars are entered, readInt returns 0
add $s2, $zero, $zero
j FIN
FIN:
li $v0, 1
add $a0, $s2, $zero
syscall
li $v0, 10 #ends program
syscall
