master
1/*-
2 * SPDX-License-Identifier: BSD-3-Clause
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 * from: NetBSD: ieee.h,v 1.1.1.1 1998/06/20 04:58:51 eeh Exp
42 */
43
44#ifndef _MACHINE_IEEE_H_
45#define _MACHINE_IEEE_H_
46
47/*
48 * ieee.h defines the machine-dependent layout of the machine's IEEE
49 * floating point. It does *not* define (yet?) any of the rounding
50 * mode bits, exceptions, and so forth.
51 */
52
53/*
54 * Define the number of bits in each fraction and exponent.
55 *
56 * k k+1
57 * Note that 1.0 x 2 == 0.1 x 2 and that denorms are represented
58 *
59 * (-exp_bias+1)
60 * as fractions that look like 0.fffff x 2 . This means that
61 *
62 * -126
63 * the number 0.10000 x 2 , for instance, is the same as the normalized
64 *
65 * -127 -128
66 * float 1.0 x 2 . Thus, to represent 2 , we need one leading zero
67 *
68 * -129
69 * in the fraction; to represent 2 , we need two, and so on. This
70 *
71 * (-exp_bias-fracbits+1)
72 * implies that the smallest denormalized number is 2
73 *
74 * for whichever format we are talking about: for single precision, for
75 *
76 * -126 -149
77 * instance, we get .00000000000000000000001 x 2 , or 1.0 x 2 , and
78 *
79 * -149 == -127 - 23 + 1.
80 */
81#define SNG_EXPBITS 8
82#define SNG_FRACBITS 23
83
84#define DBL_EXPBITS 11
85#define DBL_FRACBITS 52
86
87#ifdef notyet
88#define E80_EXPBITS 15
89#define E80_FRACBITS 64
90#endif
91
92#define EXT_EXPBITS 15
93#define EXT_FRACBITS 112
94
95struct ieee_single {
96 u_int sng_sign:1;
97 u_int sng_exp:8;
98 u_int sng_frac:23;
99};
100
101struct ieee_double {
102 u_int dbl_sign:1;
103 u_int dbl_exp:11;
104 u_int dbl_frach:20;
105 u_int dbl_fracl;
106};
107
108struct ieee_ext {
109 u_int ext_sign:1;
110 u_int ext_exp:15;
111 u_int ext_frach:16;
112 u_int ext_frachm;
113 u_int ext_fraclm;
114 u_int ext_fracl;
115};
116
117/*
118 * Floats whose exponent is in [1..INFNAN) (of whatever type) are
119 * `normal'. Floats whose exponent is INFNAN are either Inf or NaN.
120 * Floats whose exponent is zero are either zero (iff all fraction
121 * bits are zero) or subnormal values.
122 *
123 * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its
124 * high fraction; if the bit is set, it is a `quiet NaN'.
125 */
126#define SNG_EXP_INFNAN 255
127#define DBL_EXP_INFNAN 2047
128#define EXT_EXP_INFNAN 32767
129
130#if 0
131#define SNG_QUIETNAN (1 << 22)
132#define DBL_QUIETNAN (1 << 19)
133#define EXT_QUIETNAN (1 << 15)
134#endif
135
136/*
137 * Exponent biases.
138 */
139#define SNG_EXP_BIAS 127
140#define DBL_EXP_BIAS 1023
141#define EXT_EXP_BIAS 16383
142
143#endif