title	Module from library HIFLOAT_1 : FLTRUN
	name	('FLTRUN')
	maclib	baselib.lib

; Truncate function

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

;		Version 1.0 January 1989

; ENTRY	Number to be truncated in regs DE,HL

; EXIT	Reg HL holds the greatest integer less than
;	or equal to input number

	entry	?fltrnc

?fltrnc:
	bit	zero,h		; Test zero number
	ret	z		; .. end if so
	ld	a,SIGNB		; Test < 0
	and	h
	ld	c,a		; Save sign
	res	sign,h		; Make number > 0
	ld	a,exp.max	; Test range of exponent
	sub	d
	jr	z,trunc.equ
	jp	m,trunc.zero	; Out of range
	ld	b,a
trunc.shf:	
	srl	h		; Shift mantissa
	rr	l
	djnz	trunc.shf
trunc.equ:	
	inc	c		; Test sign
	ret	p
	ex	de,hl
	ld	hl,0
	or	a
	sbc	hl,de		; Negate result if < 0
	ret
trunc.zero:	
	ld	hl,0		; Return zero on underflow
	ret

	end