*** dpsub.s
* 	Double Precision Subtract
*	for Alcyon C
*
*	double dpsub(d1,d2)
*	double d1,d2;
*
*	Copyright Atari Corp. 1987,1988
*
*	MDJohnson       2/15/88
***

	.include fpmacro

; dpsub(x,y)
	fpinit	dpsub
	fpidle				; wait for idle state
	move.w	#$5400,FPCMD		; x -> fp0
	ckcir	#$9608			; ready for double
	move.l	4(sp),FPOP		; write first half
	move.l	8(sp),FPOP		; write second half

	fpidle				; wait for idle state
	move.w	#$5428,FPCMD		; x - y -> fp0
	ckcir	#$9608			; ready for double
	move.l	12(sp),FPOP		; write first half
	move.l	16(sp),FPOP		; write second half

	fpidle				; wait for idle state
	move.w	#$7400,FPCMD		; fp0 -> double
	ckcir	#$B208			; ready for double
	move.l	FPOP,d0			; get double
	move.l	FPOP,d1
	rts