2 * SPDX-License-Identifier: BSD-3-Clause
4 * Copyright (c) 1992, 1993
5 * The Regents of the University of California. All rights reserved.
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.
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.
16 * Redistribution and use in source and binary forms, with or without
17 * modification, are permitted provided that the following conditions
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.
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
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
45 #ifndef _MACHINE_IEEE_H_
46 #define _MACHINE_IEEE_H_
49 * ieee.h defines the machine-dependent layout of the machine's IEEE
50 * floating point. It does *not* define (yet?) any of the rounding
51 * mode bits, exceptions, and so forth.
55 * Define the number of bits in each fraction and exponent.
58 * Note that 1.0 x 2 == 0.1 x 2 and that denorms are represented
61 * as fractions that look like 0.fffff x 2 . This means that
64 * the number 0.10000 x 2 , for instance, is the same as the normalized
67 * float 1.0 x 2 . Thus, to represent 2 , we need one leading zero
70 * in the fraction; to represent 2 , we need two, and so on. This
72 * (-exp_bias-fracbits+1)
73 * implies that the smallest denormalized number is 2
75 * for whichever format we are talking about: for single precision, for
78 * instance, we get .00000000000000000000001 x 2 , or 1.0 x 2 , and
80 * -149 == -127 - 23 + 1.
83 #define SNG_FRACBITS 23
85 #define DBL_EXPBITS 11
86 #define DBL_FRACBITS 52
89 #define E80_EXPBITS 15
90 #define E80_FRACBITS 64
93 #define EXT_EXPBITS 15
94 #define EXT_FRACBITS 112
119 * Floats whose exponent is in [1..INFNAN) (of whatever type) are
120 * `normal'. Floats whose exponent is INFNAN are either Inf or NaN.
121 * Floats whose exponent is zero are either zero (iff all fraction
122 * bits are zero) or subnormal values.
124 * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its
125 * high fraction; if the bit is set, it is a `quiet NaN'.
127 #define SNG_EXP_INFNAN 255
128 #define DBL_EXP_INFNAN 2047
129 #define EXT_EXP_INFNAN 32767
132 #define SNG_QUIETNAN (1 << 22)
133 #define DBL_QUIETNAN (1 << 19)
134 #define EXT_QUIETNAN (1 << 15)
140 #define SNG_EXP_BIAS 127
141 #define DBL_EXP_BIAS 1023
142 #define EXT_EXP_BIAS 16383