如何循环汇编语言

时间:2011-11-28 19:24:25

标签: loops assembly x86 masm irvine32

如何计算Fibonacci数列中的前12个值并将其置于EAX reg中。并显示调用DumpRegs?使用间接寻址我知道我需要一个for循环,但我不知道如何解决这个问题。任何帮助或提示表示赞赏。

      INCLUDE Irvine32.inc

; (insert symbol definitions here)

.data

; (insert variables here)
   Fibonacci BYTE 1, 1, 10 DUP (?)

.code
main PROC

; (insert executable instructions here)


    ; (This below will show hexa contents of string.)
      mov   esi, OFFSET Fibonacci       ; offset the variables
      mov   ebx,1                   ; byte format
      mov   ecx, SIZEOF Fibonacci       ; counter
      call  dumpMem 


    exit        ; exit to operating system
main ENDP

; (insert additional procedures here)

END main

3 个答案:

答案 0 :(得分:4)

你可以这样做一个循环:

mov ecx,12
your_label:
; your code
loop your_label

循环指令递减ecx并跳转到指定的标签,除非ecx等于零。您也可以像这样构建相同的循环:

mov ecx,12
your_label:
; your code
dec ecx
jnz your_label

答案 1 :(得分:1)

你确定你需要一个for循环来实现你的目标,所以也许for循环的C实现可以帮助你:

Code Generation for For Loop

for (i=0; i < 100; i++)
{
  . . .
}

      * Data Register D2 is used to implement i.
      * Set D2 to zero (i=0)
      CLR.L D2

  L1  
      . . .
      * Increment i for (i++)
      ADDQ.L #1, D2
      * Check for the for loop exit condition ( i < 100)
      CMPI.L #100, D2
      * Branch to the beginning of for loop if less than flag is set
      BLT.S L1

消息来源:eventhelix.com

答案 2 :(得分:0)

.model small
.stack 100h
.data
   msg db 'Enter height of the square form 1-9: $'
   hash db '#$'
   height db 1
   length db 0
   ctr dw 0
   msgagain db 13,10,'Do you want to repeat the program? $'
   msgend db 13,10,'Program Terminated! Press any key to exit..$'
.code
   mov ax, @data
   mov ds, ax
REPEAT:   
   mov ax, 03
   int 10h

   mov ah, 09
   lea dx, msg
   int 21h

   mov ah, 01
   int 21h

   cmp al, '1'
   jl REPEAT
   cmp al, '9'
   jg REPEAT

   sub al, 48
   mov length, al
   mov bl, 1
   mul bl

   mov height, 1  
   mov di, 1 
   mov ctr, ax

   mov cx, ax
   nextline:
      dec length

      mov ah, 02
      mov bh, 00
      mov dl, length
      mov dh, height
      int 10h

      mov cx, di
      hashtags:
         mov ah, 09
         lea dx, hash
         int 21h
      loop hashtags      

      inc di
      inc height
      mov cx, ctr
      dec ctr
   loop nextline

   mov ah, 09
   lea dx, msgagain
   int 21h

   mov ah, 01
   int 21h

   cmp al, 'Y'
   je REPEAT
   cmp al, 'y'
   je REPEAT   

   mov ah, 09
   lea dx, msgend
   int 21h

   mov ah, 01
   int 21h

   mov ah, 4ch
   int 21h

END