pl.txt

汇编判断正负的代码

DATA SEGMENT
SOURCE DB 1EH,91H,74H,91H,42H,30H,81H,0F3H,18H,25H
COUNT EQU $-SOURCE
CNT EQU COUNT+1 ;CNT是一个常量，后面要用
RESULT DB COUNT+2 DUP (?)
DATA ENDS

;----------------------------------------------------
CODE SEGMENT
          ASSUME CS:CODE,DS:DATA
         MAIN PROC FAR
        PUSH DS
        XOR AX,AX
        PUSH AX
        MOV AX,DATA
        MOV DS,AX
START: MOV SI,OFFSET SOURCE
        MOV DI,OFFSET RESULT
         MOV CX,COUNT
         MOV DL,0 ；正数计数器
        MOV DH,0 ；负数计数器
        MOV BX,OFFSET RESULT+CNT ；(此处用到了CNT)将指针知道RESULT最后
REPEAT: MOV AL,[SI] ；取数比较
       CMP AL,0
      JG LOP
      INC DH ；小于零，DH加1 
      MOV [BX],AL ；负数从后往前存放 
      DEC BX
     JMP DONE
LOP : INC DL ；正数DL加1
    MOV [DI+1],AL ；正数从前往后存放
     INC DI
DONE: INC SI
    LOOP REPEAT
    MOV [BX],DH
    MOV DI,OFFSET RESULT
     MOV [DI],DL
    RET
    MAIN ENDP
    CODE ENDS
               END MAIN