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 * $FreeBSD$ 36 */ 37 38#ifndef _MACHINE_IEEE_H_ 39#define _MACHINE_IEEE_H_ 40 41/* 42 * ieee.h defines the machine-dependent layout of the machine's IEEE 43 * floating point. It does *not* define (yet?) any of the rounding 44 * mode bits, exceptions, and so forth. 45 */ 46 47/* 48 * Define the number of bits in each fraction and exponent. 49 * 50 * k k+1 51 * Note that 1.0 x 2 == 0.1 x 2 and that denorms are represented 52 * 53 * (-exp_bias+1) 54 * as fractions that look like 0.fffff x 2 . This means that 55 * 56 * -126 57 * the number 0.10000 x 2 , for instance, is the same as the normalized 58 * 59 * -127 -128 60 * float 1.0 x 2 . Thus, to represent 2 , we need one leading zero 61 * 62 * -129 63 * in the fraction; to represent 2 , we need two, and so on. This 64 * 65 * (-exp_bias-fracbits+1) 66 * implies that the smallest denormalized number is 2 67 * 68 * for whichever format we are talking about: for single precision, for 69 * 70 * -126 -149 71 * instance, we get .00000000000000000000001 x 2 , or 1.0 x 2 , and 72 * 73 * -149 == -127 - 23 + 1. 74 */ 75#define SNG_EXPBITS 8 76#define SNG_FRACBITS 23 77 78#define DBL_EXPBITS 11 79#define DBL_FRACBITS 52 80 81#ifdef notyet 82#define E80_EXPBITS 15 83#define E80_FRACBITS 64 84#endif 85 86#define EXT_EXPBITS 15 87#define EXT_FRACBITS 112 88 89struct ieee_single { 90 u_int sng_sign:1; 91 u_int sng_exp:8; 92 u_int sng_frac:23; 93}; 94 95struct ieee_double { 96 u_int dbl_sign:1; 97 u_int dbl_exp:11; 98 u_int dbl_frach:20; 99 u_int dbl_fracl; 100}; 101 102struct ieee_ext { 103 u_int ext_sign:1; 104 u_int ext_exp:15; 105 u_int ext_frach:16; 106 u_int ext_frachm; 107 u_int ext_fraclm; 108 u_int ext_fracl; 109}; 110 111/* 112 * Floats whose exponent is in [1..INFNAN) (of whatever type) are 113 * `normal'. Floats whose exponent is INFNAN are either Inf or NaN. 114 * Floats whose exponent is zero are either zero (iff all fraction 115 * bits are zero) or subnormal values. 116 * 117 * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its 118 * high fraction; if the bit is set, it is a `quiet NaN'. 119 */ 120#define SNG_EXP_INFNAN 255 121#define DBL_EXP_INFNAN 2047 122#define EXT_EXP_INFNAN 32767 123 124#if 0 125#define SNG_QUIETNAN (1 << 22) 126#define DBL_QUIETNAN (1 << 19) 127#define EXT_QUIETNAN (1 << 15) 128#endif 129 130/* 131 * Exponent biases. 132 */ 133#define SNG_EXP_BIAS 127 134#define DBL_EXP_BIAS 1023 135#define EXT_EXP_BIAS 16383 136 137#endif 138