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