1/*	$NetBSD: ieee.h,v 1.16 2010/09/20 16:13:35 christos Exp $	*/
  2
  3/*
  4 * Copyright (c) 1992, 1993
  5 *	The Regents of the University of California.  All rights reserved.
  6 *
  7 * This software was developed by the Computer Systems Engineering group
  8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
  9 * contributed to Berkeley.
 10 *
 11 * All advertising materials mentioning features or use of this software
 12 * must display the following acknowledgement:
 13 *	This product includes software developed by the University of
 14 *	California, Lawrence Berkeley Laboratory.
 15 *
 16 * Redistribution and use in source and binary forms, with or without
 17 * modification, are permitted provided that the following conditions
 18 * are met:
 19 * 1. Redistributions of source code must retain the above copyright
 20 *    notice, this list of conditions and the following disclaimer.
 21 * 2. Redistributions in binary form must reproduce the above copyright
 22 *    notice, this list of conditions and the following disclaimer in the
 23 *    documentation and/or other materials provided with the distribution.
 24 * 3. Neither the name of the University nor the names of its contributors
 25 *    may be used to endorse or promote products derived from this software
 26 *    without specific prior written permission.
 27 *
 28 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 29 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 30 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 31 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 32 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 33 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 34 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 35 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 36 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 37 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 38 * SUCH DAMAGE.
 39 *
 40 *	@(#)ieee.h	8.1 (Berkeley) 6/11/93
 41 */
 42
 43/*
 44 * ieee.h defines the machine-dependent layout of the machine's IEEE
 45 * floating point.  It does *not* define (yet?) any of the rounding
 46 * mode bits, exceptions, and so forth.
 47 */
 48
 49#include <sys/ieee754.h>
 50
 51#if !defined(__mc68010__) || defined(_KERNEL)
 52#define	EXT_EXPBITS	15
 53#define	EXT_FRACHBITS	32
 54#define	EXT_FRACLBITS	32
 55#define	EXT_FRACBITS	(EXT_FRACLBITS + EXT_FRACHBITS)
 56
 57#define	EXT_TO_ARRAY32(u, a) do {			\
 58	(a)[0] = (uint32_t)(u).extu_ext.ext_fracl;	\
 59	(a)[1] = (uint32_t)(u).extu_ext.ext_frach;	\
 60} while(/*CONSTCOND*/0)
 61
 62struct ieee_ext {
 63	u_int	ext_sign:1;
 64	u_int	ext_exp:EXT_EXPBITS;
 65	u_int	ext_zero:16;
 66#if 0
 67	u_int	ext_int:1;
 68#endif
 69	u_int	ext_frach;
 70	u_int	ext_fracl;
 71};
 72
 73/*
 74 * Extended floats whose exponent is in [0..INFNAN) and have their
 75 * explicit integer bit (the most significant bit of the fraction)
 76 * set are `normal'.  Floats whose exponent is INFNAN are either Inf or NaN.
 77 * Floats whose exponent is zero are either zero (iff all fraction
 78 * bits are zero) or subnormal values.
 79 *
 80 * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its
 81 * high fraction; if the bit is set, it is a `quiet NaN'.
 82 */
 83#define	EXT_EXP_INFNAN	0x7fff
 84#define	EXT_EXP_INF	0x7fff
 85#define	EXT_EXP_NAN	0x7fff
 86
 87#if 0
 88#define	SNG_QUIETNAN	(1 << 22)
 89#define	DBL_QUIETNAN	(1 << 19)
 90#define	EXT_QUIETNAN	(1 << 30)
 91#endif
 92
 93/*
 94 * Exponent biases.
 95 */
 96#define	EXT_EXP_BIAS	16383
 97
 98/*
 99 * Convenience data structures.
100 */
101union ieee_ext_u {
102	long double		extu_ld;
103	struct ieee_ext		extu_ext;
104};
105
106#define extu_exp	extu_ext.ext_exp
107#define extu_sign	extu_ext.ext_sign
108#define extu_fracl	extu_ext.ext_fracl
109#define extu_frach	extu_ext.ext_frach
110
111#define LDBL_NBIT	0x80000000
112#define mask_nbit_l(u)	((u).extu_frach &= ~LDBL_NBIT)
113#endif /* !__mc68010__ || _KERNEL */