; Input: HL
; Output: HL
	di \ ld a, l \ push hl \ inc sp \ pop de \ dec sp \ or a,a \ sbc hl, hl \ ld h, d \ ld l, e
; Input: H,L,A
	ld	de, 0040h	; 40h appends "01" to D
	ld	c, d
	ld	b, 8
	or	a, a
_loop1:
	sbc	hl, de
	jr	nc, $+3
	add	hl, de
	ccf
	rl	d
	rla
	adc	hl, hl
	rla
	adc	hl, hl

	djnz	_loop1
	ld	b, 8
_loop2:
	sbc	hl, de
	jr	nc, $+3
	add	hl, de
	ccf
	rl	c
	add hl, hl
	add hl, hl
	djnz	_loop2

	sbc	hl, de		; optimised last iteration
	ccf
	rl	c

	or	a, a
	sbc	hl, hl
	ld	l, d
	ld	h, c
	ret