title	Module from library HIFLOAT_4 : FLSQRT
	name	('FLSQRT')
	maclib	baselib.lib

; Calculate the SQUARE ROOT

; Copyright (C)	Werner Cirsovius
;		Hohe Weide 44
;		D-20253 Hamburg
;		Tel.: +49-40-4223247

;		Version 1.0 January 1989

; ENTRY	Operand in regs DE,HL

; EXIT	Square root in regs DE,HL

	entry	?flsqrt

	ext	?fladd,?fldiv,flperr,?num1

SYS.ERR:
	ld	l,true
	ld	h,10
	ld	(flperr),hl	; Set error
	ret
?flsqrt:
	ld	a,false
	ld	(flperr),a	; Reset error
	ld	a,h		; Test negative sign
	or	a
	jp	m,SYS.ERR	; .. error
	ret	z		; End on zero
	ld	(?num1+2),de	; Save number
	ld	(?num1),hl
	sra	d		; Init exponent
	ld	b,4		; .. and loop
sqr.loop:	
	push	bc
	push	hl
	push	de
	ld	bc,(?num1)
	push	bc
	ld	bc,(?num1+2)
	push	bc
	call	?fldiv		; Build the square root
	call	?fladd
	dec	d		; .. count down exponent
	pop	bc
	djnz	sqr.loop
	ret

	end