.define .sbi
.text

	! #bytes in cx , top of stack in ax
.sbi:
	pop     bx              ! return subress
	cmp     cx,#2
	jne     1f
	pop     cx
	sub     ax,cx
	neg     ax
	jmp     (bx)
1:
	cmp     cx,#4
	jne     9f
	pop     dx
	pop     cx
	sub     cx,ax
	mov     ax,cx
	pop     cx
	sbb     cx,dx
	push    cx
	jmp     (bx)
9:
.extern .trpilin
	push    bx
	jmp     .trpilin