A2_BC_D pascal with asm

Tính A^2-B(C-D). Nhập xuất bằng pascal, tính toàn bằng ASM.

File A2_BC_D.pas.

program bai1;
var a, b, c, d: integer;
{$F+}
     function CAL:integer; external;
     {$L C:\TASM\CALPROC.OBJ}
{$F-}


BEGIN
     write('a = '); readln(a);
     write('b = '); readln(b);
     write('c = '); readln(c);
     write('d = '); readln(d);
     writeln('a^2 - b(c - d) = ', CAL);
     readln;
END.

File CALPROC.asm nằm trong C:\TASM\

.model large
.data
    EXTRN a: word, b: word, c: word, d: word


.code
    public CAL
    CAL proc

        mov ax, a
        mul ax          ; ax = ax*ax
        push ax

        mov cx, c
        mov dx, d
        sub cx, dx      ; cx = cx - dx

        mov ax, b       ; ax = b
        mul cx          ; ax = ax * cx = bx*(cx-dx)
        mov bx, ax      ; bx = ax
        pop ax          ; ax = ax^2
        sub ax, bx      ; ax = ax^2-bx(cx-dx)

        ret
    CAL endp
END