Mips递归问题

Question

我必须创建斐波那契序列号，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个号码，直到他们输入的号码。 N由用户给出。例如，如果他们选择3作为他们的Fib。号和2作为计数它应该显示 13，8

我所拥有的一切，直到显示“13 8”完成。任何有关如何退回堆栈并显示已创建的变量并随后被覆盖的指导，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

这不是你的问题的答案，而是一些指导在哪里寻找错误。

做关于“延迟槽”以及它是如何与在MIPS处理器的分支指令的一些研究。

Answer 2

除了一个事实，即代码看起来不完整的，也有它很多的奇怪的事情，例如：

• 没有指示递增或递减堆栈指针进入RecursiveFunction时
• 寄存器保存是从来没有恢复的

我的建议是写你的大部分代码在C中，并开始只使用MIPS玩递归函数。当你得到它，然后完成你的工作，写下其余的。