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 * All advertising materials mentioning features or use of this software 10 * must display the following acknowledgement: 11 * This product includes software developed by the University of 12 * California, Lawrence Berkeley Laboratory. 13 * 14 * Redistribution and use in source and binary forms, with or without 15 * modification, are permitted provided that the following conditions 16 * are met: 17 * 1. Redistributions of source code must retain the above copyright 18 * notice, this list of conditions and the following disclaimer. 19 * 2. Redistributions in binary form must reproduce the above copyright 20 * notice, this list of conditions and the following disclaimer in the 21 * documentation and/or other materials provided with the distribution. 22 * 3. All advertising materials mentioning features or use of this software 23 * must display the following acknowledgement: 24 * This product includes software developed by the University of 25 * California, Berkeley and its contributors. 26 * 4. Neither the name of the University nor the names of its contributors 27 * may be used to endorse or promote products derived from this software 28 * without specific prior written permission. 29 * 30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 40 * SUCH DAMAGE. 41 * 42 * @(#)ieee.h 8.1 (Berkeley) 6/11/93 43 * from: NetBSD: ieee.h,v 1.1.1.1 1998/06/20 04:58:51 eeh Exp 44 * $FreeBSD$ 45 */ 46 47 #ifndef _MACHINE_IEEE_H_ 48 #define _MACHINE_IEEE_H_ 49 50 /* 51 * ieee.h defines the machine-dependent layout of the machine's IEEE 52 * floating point. It does *not* define (yet?) any of the rounding 53 * mode bits, exceptions, and so forth. 54 */ 55 56 /* 57 * Define the number of bits in each fraction and exponent. 58 * 59 * k k+1 60 * Note that 1.0 x 2 == 0.1 x 2 and that denorms are represented 61 * 62 * (-exp_bias+1) 63 * as fractions that look like 0.fffff x 2 . This means that 64 * 65 * -126 66 * the number 0.10000 x 2 , for instance, is the same as the normalized 67 * 68 * -127 -128 69 * float 1.0 x 2 . Thus, to represent 2 , we need one leading zero 70 * 71 * -129 72 * in the fraction; to represent 2 , we need two, and so on. This 73 * 74 * (-exp_bias-fracbits+1) 75 * implies that the smallest denormalized number is 2 76 * 77 * for whichever format we are talking about: for single precision, for 78 * 79 * -126 -149 80 * instance, we get .00000000000000000000001 x 2 , or 1.0 x 2 , and 81 * 82 * -149 == -127 - 23 + 1. 83 */ 84 #define SNG_EXPBITS 8 85 #define SNG_FRACBITS 23 86 87 #define DBL_EXPBITS 11 88 #define DBL_FRACBITS 52 89 90 #ifdef notyet 91 #define E80_EXPBITS 15 92 #define E80_FRACBITS 64 93 #endif 94 95 #define EXT_EXPBITS 15 96 #define EXT_FRACBITS 112 97 98 struct ieee_single { 99 u_int sng_sign:1; 100 u_int sng_exp:8; 101 u_int sng_frac:23; 102 }; 103 104 struct ieee_double { 105 u_int dbl_sign:1; 106 u_int dbl_exp:11; 107 u_int dbl_frach:20; 108 u_int dbl_fracl; 109 }; 110 111 struct ieee_ext { 112 u_int ext_sign:1; 113 u_int ext_exp:15; 114 u_int ext_frach:16; 115 u_int ext_frachm; 116 u_int ext_fraclm; 117 u_int ext_fracl; 118 }; 119 120 /* 121 * Floats whose exponent is in [1..INFNAN) (of whatever type) are 122 * `normal'. Floats whose exponent is INFNAN are either Inf or NaN. 123 * Floats whose exponent is zero are either zero (iff all fraction 124 * bits are zero) or subnormal values. 125 * 126 * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its 127 * high fraction; if the bit is set, it is a `quiet NaN'. 128 */ 129 #define SNG_EXP_INFNAN 255 130 #define DBL_EXP_INFNAN 2047 131 #define EXT_EXP_INFNAN 32767 132 133 #if 0 134 #define SNG_QUIETNAN (1 << 22) 135 #define DBL_QUIETNAN (1 << 19) 136 #define EXT_QUIETNAN (1 << 15) 137 #endif 138 139 /* 140 * Exponent biases. 141 */ 142 #define SNG_EXP_BIAS 127 143 #define DBL_EXP_BIAS 1023 144 #define EXT_EXP_BIAS 16383 145 146 #endif 147