Question

我必须创建Fibonacci序列号，然后检查用户输入的数字是否是有效的Fib。数。如果是，我必须显示n个数字，直到输入的数字。 N由用户给出。例如，如果他们选择3作为他们的Fib。数字和2作为它应显示的计数 13,8

我完成所有工作，直到显示“13,8”完成。任何关于如何退回堆栈并显示已创建并随后被覆盖的变量的指导将不胜感激。谢谢！

    ##### The Data Segment #########
.data
strNumber:     .asciiz  "Enter a valid Fibonacci Number: "
strCount:       .asciiz "Enter the numbers of Fibonacci numbers to be displayed: "
strError:       .asciiz " is not a valid Fibonacci Number.\n"
strMore:         .asciiz "There are no more Fibonacci Numbers to be displayed."
newLine:         .asciiz "\n"
strBadEntry:     .asciiz "is not a valid entry."
strValid:       .asciiz "Valid Fib Number\n\n"

#### The Text Segment ##########

.text
.globl main

main:
li $t3, 39
li $t2, 0
li $t4, 1
li $t5, 1
#Get the User's Number          #Gets the number from the user
li $v0, 4
la $a0, strNumber   
syscall
li $v0, 5           #prepares to take in the user entered value
syscall             #retrives what the user entered in the console
move $s1, $v0
bltz $v0, in_error      #calls the error function if less than 0.
j DoneIf            #if those conditions aren't meant it jumps to the DoneIf

in_error: 
li $t4, 1
li $t5, 1
li $v0, 1               # print int
move $a0, $s1           # prints the user's number
syscall
li $v0, 4
la $a0, strError
syscall
li $v0, 4
la $a0, strNumber
syscall
li $v0, 5
syscall
move $s1, $v0
bltz $v0, in_error      #recall the inerror function if still less than 0 


DoneIf:                 
move $t0, $v0           #moves the value to a new location, for future use
li $v0, 4
la $a0, newLine 
syscall

#Second Number              #Gets the second number from the user
li $v0, 4
la $a0, strCount
syscall
li $v0, 5
syscall             #retrieves what the user entered in the console
bltz $v0, in_error2     #calls the second error function if less than 0
bgeu $v0, $t3, in_error2    #calls the second error function if greater than 63
j DoneIf2           #jumps to the DoneIf2 if those conditions aren't met            

in_error2:
li $v0, 4
la $a0, strBadEntry
syscall
li $v0, 4
la $a0, newLine 
syscall
li $v0, 4
la $a0, strCount
syscall
li $v0, 5
syscall
blez $v0, in_error2     #recalls the error2 function if number conditions stil aren't met
bgeu $v0, $t3, in_error2    #recalls the error2 function if number conditions still aren't meet

DoneIf2:
move $t1, $v0


jal RecursiveFunction       #Jump to Recursive Function

Exit:




RecursiveFunction:
sw $ra, 0($sp)
sw $t4, 4($sp)
sw $t5, 8($sp)


bge $t5, $t4, t5_Greater
bgt $t4, $t5, t4_Greater

Check:
bgt $t4, $t0, check_t5
check_t5:   
bgt $t5, $t0, in_error  
beq $t4, $t0, Valid
beq $t5, $t0, Valid
jal RecursiveFunction



t5_Greater:
add $t4, $t5, $t4
j Check

t4_Greater:
add $t5, $t5, $t4
j Check







Valid:  
li $v0, 4
la $a0, strValid    
syscall 
lw  $ra, 20($sp)  # Restore return address
    lw  $fp, 16($sp)  # Restore frame pointer
li $v0, 1
move $a0, $t5
syscall

Answer 1

事实上，这不是你问题的答案，而是一些指导在哪里寻找错误。

对“延迟槽”以及它与MIPS处理器中的分支指令的关系进行一些研究。

Answer 2

除了代码看起来不完整之外，还有很多奇怪的东西，例如：

没有增加或减少堆栈指针的指令

RecursiveFunction

保存的注册表永不恢复

我的建议是用C编写大部分代码，并开始仅使用MIPS来处理递归函数。当你得到它，然后完成你的工作，写下其余的。

Mips递归问题

2 个答案: