我必須創建斐波那契序列號,然後檢查用戶輸入的數字是否是有效的Fib。數。如果是,我必須顯示n個號碼,直到他們輸入的號碼。 N由用戶給出。例如,如果他們選擇3作爲他們的Fib。號和2作爲計數它應該顯示 13,8Mips遞歸問題
我所擁有的一切,直到顯示「13 8」完成。任何有關如何退回堆棧並顯示已創建的變量並隨後被覆蓋的指導,將不勝感激。謝謝!
##### 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
正常情況下,彙編程序爲您處理延遲時隙。至少在GNU彙編程序中,除非你不要使用'.set noreorder'指令 – 2011-03-28 20:45:55
@Laurent來執行它,認真嗎?那麼,它的好呢。我已經在MIPS的最底層(動態地發佈二進制代碼本身),所以延遲插槽有很大的混亂。這就是爲什麼我不知道彙編程序如何解決這種情況。 – xappymah 2011-03-29 02:08:03
AFAIK,GNU彙編程序只嘗試將具有延遲槽的指令與其前任交換,同時確保它不會中斷依賴關係。大多數情況下,它會失敗,只需插入一條NOP。說實話,對於在一個給定的項目中值得在程序集中編寫的代碼行,我個人更喜歡自己處理延遲插槽(因此'.set noreorder' directive)。當你的項目大部分是組裝時,你肯定有自己處理它們所需的技能。再一次,它不值得讓組裝者完成這項工作。 – 2011-03-29 06:03:22