; 实验三-7：符号函数程序
; 功能：计算符号函数Y
; Y = 1 (X>0), Y = 0 (X=0), Y = -1 (X<0)

DATA SEGMENT
    X DW 5
    Y DW ?
DATA ENDS

CODE SEGMENT
    ASSUME CS:CODE, DS:DATA
START:
    MOV AX, DATA
    MOV DS, AX
    MOV AX, X
    CMP AX, 0
    JG POSITIVE
    JL NEGATIVE
    MOV Y, 0
    JMP EXIT
POSITIVE:
    MOV Y, 1
    JMP EXIT
NEGATIVE:
    MOV Y, -1
EXIT:
    MOV AH, 4CH
    INT 21H
CODE ENDS
END START