1/*-
2 * Copyright (c) 1992, 1993
3 *	The Regents of the University of California.  All rights reserved.
4 *
5 * This software was developed by the Computer Systems Engineering group
6 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
7 * contributed to Berkeley.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 *
33 *	@(#)ieee.h	8.1 (Berkeley) 6/11/93
34 *	from: NetBSD: ieee.h,v 1.1.1.1 1998/06/20 04:58:51 eeh Exp
35 * $FreeBSD: head/sys/sparc64/include/ieee.h 139825 2005-01-07 02:29:27Z imp $
36 */
37
38#ifndef _MACHINE_IEEE_H_
39#define	_MACHINE_IEEE_H_
40
41#include <stdint.h>
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/*
50 * Define the number of bits in each fraction and exponent.
51 *
52 *		     k	         k+1
53 * Note that  1.0 x 2  == 0.1 x 2      and that denorms are represented
54 *
55 *					  (-exp_bias+1)
56 * as fractions that look like 0.fffff x 2             .  This means that
57 *
58 *			 -126
59 * the number 0.10000 x 2    , for instance, is the same as the normalized
60 *
61 *		-127			   -128
62 * float 1.0 x 2    .  Thus, to represent 2    , we need one leading zero
63 *
64 *				  -129
65 * in the fraction; to represent 2    , we need two, and so on.  This
66 *
67 *						     (-exp_bias-fracbits+1)
68 * implies that the smallest denormalized number is 2
69 *
70 * for whichever format we are talking about: for single precision, for
71 *
72 *						-126		-149
73 * instance, we get .00000000000000000000001 x 2    , or 1.0 x 2    , and
74 *
75 * -149 == -127 - 23 + 1.
76 */
77#define	SNG_EXPBITS	8
78#define	SNG_FRACBITS	23
79
80#define	DBL_EXPBITS	11
81#define	DBL_FRACBITS	52
82
83#ifdef notyet
84#define	E80_EXPBITS	15
85#define	E80_FRACBITS	64
86#endif
87
88#define	EXT_EXPBITS	15
89#define	EXT_FRACBITS	112
90
91struct ieee_single {
92	uint32_t	sng_sign:1;
93	uint32_t	sng_exp:8;
94	uint32_t	sng_frac:23;
95};
96
97struct ieee_double {
98	uint32_t	dbl_sign:1;
99	uint32_t	dbl_exp:11;
100	uint32_t	dbl_frach:20;
101	uint32_t	dbl_fracl;
102};
103
104struct ieee_ext {
105	uint32_t	ext_sign:1;
106	uint32_t	ext_exp:15;
107	uint32_t	ext_frach:16;
108	uint32_t	ext_frachm;
109	uint32_t	ext_fraclm;
110	uint32_t	ext_fracl;
111};
112
113/*
114 * Floats whose exponent is in [1..INFNAN) (of whatever type) are
115 * `normal'.  Floats whose exponent is INFNAN are either Inf or NaN.
116 * Floats whose exponent is zero are either zero (iff all fraction
117 * bits are zero) or subnormal values.
118 *
119 * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its
120 * high fraction; if the bit is set, it is a `quiet NaN'.
121 */
122#define	SNG_EXP_INFNAN	255
123#define	DBL_EXP_INFNAN	2047
124#define	EXT_EXP_INFNAN	32767
125
126#if 0
127#define	SNG_QUIETNAN	(1 << 22)
128#define	DBL_QUIETNAN	(1 << 19)
129#define	EXT_QUIETNAN	(1 << 15)
130#endif
131
132/*
133 * Exponent biases.
134 */
135#define	SNG_EXP_BIAS	127
136#define	DBL_EXP_BIAS	1023
137#define	EXT_EXP_BIAS	16383
138
139#endif
140