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 * from: NetBSD: ieee.h,v 1.1.1.1 1998/06/20 04:58:51 eeh Exp 40 */ 41 42 #ifndef _MACHINE_IEEE_H_ 43 #define _MACHINE_IEEE_H_ 44 45 /* 46 * ieee.h defines the machine-dependent layout of the machine's IEEE 47 * floating point. It does *not* define (yet?) any of the rounding 48 * mode bits, exceptions, and so forth. 49 */ 50 51 /* 52 * Define the number of bits in each fraction and exponent. 53 * 54 * k k+1 55 * Note that 1.0 x 2 == 0.1 x 2 and that denorms are represented 56 * 57 * (-exp_bias+1) 58 * as fractions that look like 0.fffff x 2 . This means that 59 * 60 * -126 61 * the number 0.10000 x 2 , for instance, is the same as the normalized 62 * 63 * -127 -128 64 * float 1.0 x 2 . Thus, to represent 2 , we need one leading zero 65 * 66 * -129 67 * in the fraction; to represent 2 , we need two, and so on. This 68 * 69 * (-exp_bias-fracbits+1) 70 * implies that the smallest denormalized number is 2 71 * 72 * for whichever format we are talking about: for single precision, for 73 * 74 * -126 -149 75 * instance, we get .00000000000000000000001 x 2 , or 1.0 x 2 , and 76 * 77 * -149 == -127 - 23 + 1. 78 */ 79 #define SNG_EXPBITS 8 80 #define SNG_FRACBITS 23 81 82 #define DBL_EXPBITS 11 83 #define DBL_FRACBITS 52 84 85 #ifdef notyet 86 #define E80_EXPBITS 15 87 #define E80_FRACBITS 64 88 #endif 89 90 #define EXT_EXPBITS 15 91 #define EXT_FRACBITS 112 92 93 struct ieee_single { 94 u_int sng_sign:1; 95 u_int sng_exp:8; 96 u_int sng_frac:23; 97 }; 98 99 struct ieee_double { 100 u_int dbl_sign:1; 101 u_int dbl_exp:11; 102 u_int dbl_frach:20; 103 u_int dbl_fracl; 104 }; 105 106 struct ieee_ext { 107 u_int ext_sign:1; 108 u_int ext_exp:15; 109 u_int ext_frach:16; 110 u_int ext_frachm; 111 u_int ext_fraclm; 112 u_int ext_fracl; 113 }; 114 115 /* 116 * Floats whose exponent is in [1..INFNAN) (of whatever type) are 117 * `normal'. Floats whose exponent is INFNAN are either Inf or NaN. 118 * Floats whose exponent is zero are either zero (iff all fraction 119 * bits are zero) or subnormal values. 120 * 121 * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its 122 * high fraction; if the bit is set, it is a `quiet NaN'. 123 */ 124 #define SNG_EXP_INFNAN 255 125 #define DBL_EXP_INFNAN 2047 126 #define EXT_EXP_INFNAN 32767 127 128 #if 0 129 #define SNG_QUIETNAN (1 << 22) 130 #define DBL_QUIETNAN (1 << 19) 131 #define EXT_QUIETNAN (1 << 15) 132 #endif 133 134 /* 135 * Exponent biases. 136 */ 137 #define SNG_EXP_BIAS 127 138 #define DBL_EXP_BIAS 1023 139 #define EXT_EXP_BIAS 16383 140 141 #endif 142