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: head/sys/sparc64/include/ieee.h 139825 2005-01-07 02:29:27Z imp $ 36 */ 37 38 #ifndef _MACHINE_IEEE_H_ 39 #define _MACHINE_IEEE_H_ 40 41 #include <stdint.h> 42 43 /* 44 * ieee.h defines the machine-dependent layout of the machine's IEEE 45 * floating point. It does *not* define (yet?) any of the rounding 46 * mode bits, exceptions, and so forth. 47 */ 48 49 /* 50 * Define the number of bits in each fraction and exponent. 51 * 52 * k k+1 53 * Note that 1.0 x 2 == 0.1 x 2 and that denorms are represented 54 * 55 * (-exp_bias+1) 56 * as fractions that look like 0.fffff x 2 . This means that 57 * 58 * -126 59 * the number 0.10000 x 2 , for instance, is the same as the normalized 60 * 61 * -127 -128 62 * float 1.0 x 2 . Thus, to represent 2 , we need one leading zero 63 * 64 * -129 65 * in the fraction; to represent 2 , we need two, and so on. This 66 * 67 * (-exp_bias-fracbits+1) 68 * implies that the smallest denormalized number is 2 69 * 70 * for whichever format we are talking about: for single precision, for 71 * 72 * -126 -149 73 * instance, we get .00000000000000000000001 x 2 , or 1.0 x 2 , and 74 * 75 * -149 == -127 - 23 + 1. 76 */ 77 #define SNG_EXPBITS 8 78 #define SNG_FRACBITS 23 79 80 #define DBL_EXPBITS 11 81 #define DBL_FRACBITS 52 82 83 #ifdef notyet 84 #define E80_EXPBITS 15 85 #define E80_FRACBITS 64 86 #endif 87 88 #define EXT_EXPBITS 15 89 #define EXT_FRACBITS 112 90 91 struct ieee_single { 92 uint32_t sng_sign:1; 93 uint32_t sng_exp:8; 94 uint32_t sng_frac:23; 95 }; 96 97 struct ieee_double { 98 uint32_t dbl_sign:1; 99 uint32_t dbl_exp:11; 100 uint32_t dbl_frach:20; 101 uint32_t dbl_fracl; 102 }; 103 104 struct ieee_ext { 105 uint32_t ext_sign:1; 106 uint32_t ext_exp:15; 107 uint32_t ext_frach:16; 108 uint32_t ext_frachm; 109 uint32_t ext_fraclm; 110 uint32_t ext_fracl; 111 }; 112 113 /* 114 * Floats whose exponent is in [1..INFNAN) (of whatever type) are 115 * `normal'. Floats whose exponent is INFNAN are either Inf or NaN. 116 * Floats whose exponent is zero are either zero (iff all fraction 117 * bits are zero) or subnormal values. 118 * 119 * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its 120 * high fraction; if the bit is set, it is a `quiet NaN'. 121 */ 122 #define SNG_EXP_INFNAN 255 123 #define DBL_EXP_INFNAN 2047 124 #define EXT_EXP_INFNAN 32767 125 126 #if 0 127 #define SNG_QUIETNAN (1 << 22) 128 #define DBL_QUIETNAN (1 << 19) 129 #define EXT_QUIETNAN (1 << 15) 130 #endif 131 132 /* 133 * Exponent biases. 134 */ 135 #define SNG_EXP_BIAS 127 136 #define DBL_EXP_BIAS 1023 137 #define EXT_EXP_BIAS 16383 138 139 #endif 140