Assembly Language for Beginners

(nextflipdebug2) #1

3.29. WINDOWS 16-BIT


push bp
mov bp, sp
mov ax, [bp+arg_8]
mov dx, [bp+arg_A]
mov bx, [bp+arg_4]
mov cx, [bp+arg_6]
call sub_B2 ; long 32-bit multiplication
add ax, [bp+arg_0]
adc dx, [bp+arg_2]
pop bp
retn 12
func2 endp


func3 proc near


arg_0 = word ptr 4
arg_2 = word ptr 6
arg_4 = word ptr 8
arg_6 = word ptr 0Ah
arg_8 = word ptr 0Ch
arg_A = word ptr 0Eh
arg_C = word ptr 10h


push bp
mov bp, sp
mov ax, [bp+arg_A]
mov dx, [bp+arg_C]
mov bx, [bp+arg_6]
mov cx, [bp+arg_8]
call sub_B2 ; long 32-bit multiplication
mov cx, [bp+arg_2]
add cx, ax
mov bx, [bp+arg_4]
adc bx, dx ; BX=high part, CX=low part
mov ax, [bp+arg_0]
cwd ; AX=low part d, DX=high part d
sub cx, ax
mov ax, cx
sbb bx, dx
mov dx, bx
pop bp
retn 14
func3 endp


WinMain proc near
push bp
mov bp, sp
mov ax, 123
push ax
mov ax, 456
push ax
mov ax, 789
push ax
call func1
mov ax, 9 ; high part of 600000
push ax
mov ax, 27C0h ; low part of 600000
push ax
mov ax, 0Ah ; high part of 700000
push ax
mov ax, 0AE60h ; low part of 700000
push ax
mov ax, 0Ch ; high part of 800000
push ax
mov ax, 3500h ; low part of 800000
push ax
call func2
mov ax, 9 ; high part of 600000
push ax

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