ieee.h revision 1.1.2.2
1 1.1.2.2 bouyer /* $NetBSD: ieee.h,v 1.1.2.2 2001/03/12 13:27:22 bouyer Exp $ */ 2 1.1.2.2 bouyer 3 1.1.2.2 bouyer /* 4 1.1.2.2 bouyer * Copyright (c) 1992, 1993 5 1.1.2.2 bouyer * The Regents of the University of California. All rights reserved. 6 1.1.2.2 bouyer * 7 1.1.2.2 bouyer * This software was developed by the Computer Systems Engineering group 8 1.1.2.2 bouyer * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 1.1.2.2 bouyer * contributed to Berkeley. 10 1.1.2.2 bouyer * 11 1.1.2.2 bouyer * All advertising materials mentioning features or use of this software 12 1.1.2.2 bouyer * must display the following acknowledgement: 13 1.1.2.2 bouyer * This product includes software developed by the University of 14 1.1.2.2 bouyer * California, Lawrence Berkeley Laboratory. 15 1.1.2.2 bouyer * 16 1.1.2.2 bouyer * Redistribution and use in source and binary forms, with or without 17 1.1.2.2 bouyer * modification, are permitted provided that the following conditions 18 1.1.2.2 bouyer * are met: 19 1.1.2.2 bouyer * 1. Redistributions of source code must retain the above copyright 20 1.1.2.2 bouyer * notice, this list of conditions and the following disclaimer. 21 1.1.2.2 bouyer * 2. Redistributions in binary form must reproduce the above copyright 22 1.1.2.2 bouyer * notice, this list of conditions and the following disclaimer in the 23 1.1.2.2 bouyer * documentation and/or other materials provided with the distribution. 24 1.1.2.2 bouyer * 3. All advertising materials mentioning features or use of this software 25 1.1.2.2 bouyer * must display the following acknowledgement: 26 1.1.2.2 bouyer * This product includes software developed by the University of 27 1.1.2.2 bouyer * California, Berkeley and its contributors. 28 1.1.2.2 bouyer * 4. Neither the name of the University nor the names of its contributors 29 1.1.2.2 bouyer * may be used to endorse or promote products derived from this software 30 1.1.2.2 bouyer * without specific prior written permission. 31 1.1.2.2 bouyer * 32 1.1.2.2 bouyer * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 33 1.1.2.2 bouyer * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 34 1.1.2.2 bouyer * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 35 1.1.2.2 bouyer * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 36 1.1.2.2 bouyer * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 37 1.1.2.2 bouyer * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 38 1.1.2.2 bouyer * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 39 1.1.2.2 bouyer * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 40 1.1.2.2 bouyer * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 41 1.1.2.2 bouyer * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 42 1.1.2.2 bouyer * SUCH DAMAGE. 43 1.1.2.2 bouyer * 44 1.1.2.2 bouyer * @(#)ieee.h 8.1 (Berkeley) 6/11/93 45 1.1.2.2 bouyer */ 46 1.1.2.2 bouyer 47 1.1.2.2 bouyer /* 48 1.1.2.2 bouyer * ieee.h defines the machine-dependent layout of the machine's IEEE 49 1.1.2.2 bouyer * floating point. 50 1.1.2.2 bouyer */ 51 1.1.2.2 bouyer 52 1.1.2.2 bouyer /* 53 1.1.2.2 bouyer * Define the number of bits in each fraction and exponent. 54 1.1.2.2 bouyer * 55 1.1.2.2 bouyer * k k+1 56 1.1.2.2 bouyer * Note that 1.0 x 2 == 0.1 x 2 and that denorms are represented 57 1.1.2.2 bouyer * 58 1.1.2.2 bouyer * (-exp_bias+1) 59 1.1.2.2 bouyer * as fractions that look like 0.fffff x 2 . This means that 60 1.1.2.2 bouyer * 61 1.1.2.2 bouyer * -126 62 1.1.2.2 bouyer * the number 0.10000 x 2 , for instance, is the same as the normalized 63 1.1.2.2 bouyer * 64 1.1.2.2 bouyer * -127 -128 65 1.1.2.2 bouyer * float 1.0 x 2 . Thus, to represent 2 , we need one leading zero 66 1.1.2.2 bouyer * 67 1.1.2.2 bouyer * -129 68 1.1.2.2 bouyer * in the fraction; to represent 2 , we need two, and so on. This 69 1.1.2.2 bouyer * 70 1.1.2.2 bouyer * (-exp_bias-fracbits+1) 71 1.1.2.2 bouyer * implies that the smallest denormalized number is 2 72 1.1.2.2 bouyer * 73 1.1.2.2 bouyer * for whichever format we are talking about: for single precision, for 74 1.1.2.2 bouyer * 75 1.1.2.2 bouyer * -126 -149 76 1.1.2.2 bouyer * instance, we get .00000000000000000000001 x 2 , or 1.0 x 2 , and 77 1.1.2.2 bouyer * 78 1.1.2.2 bouyer * -149 == -127 - 23 + 1. 79 1.1.2.2 bouyer */ 80 1.1.2.2 bouyer 81 1.1.2.2 bouyer /* 82 1.1.2.2 bouyer * The ARM has two sets of FP data formats. The FPA supports 32-bit, 64-bit 83 1.1.2.2 bouyer * and 96-bit IEEE formats, with the words in big-endian order. VFP supports 84 1.1.2.2 bouyer * 32-bin and 64-bit IEEE formats with the words in the CPU's native byte 85 1.1.2.2 bouyer * order. 86 1.1.2.2 bouyer * 87 1.1.2.2 bouyer * The FPA also has two packed decimal formats, but we ignore them here. 88 1.1.2.2 bouyer */ 89 1.1.2.2 bouyer 90 1.1.2.2 bouyer #define SNG_EXPBITS 8 91 1.1.2.2 bouyer #define SNG_FRACBITS 23 92 1.1.2.2 bouyer 93 1.1.2.2 bouyer #define DBL_EXPBITS 11 94 1.1.2.2 bouyer #define DBL_FRACBITS 52 95 1.1.2.2 bouyer 96 1.1.2.2 bouyer #ifndef __VFP_FP__ 97 1.1.2.2 bouyer #define E80_EXPBITS 15 98 1.1.2.2 bouyer #define E80_FRACBITS 64 99 1.1.2.2 bouyer 100 1.1.2.2 bouyer #define EXT_EXPBITS 15 101 1.1.2.2 bouyer #define EXT_FRACBITS 112 102 1.1.2.2 bouyer #endif 103 1.1.2.2 bouyer 104 1.1.2.2 bouyer struct ieee_single { 105 1.1.2.2 bouyer u_int sng_frac:23; 106 1.1.2.2 bouyer u_int sng_exponent:8; 107 1.1.2.2 bouyer u_int sng_sign:1; 108 1.1.2.2 bouyer }; 109 1.1.2.2 bouyer 110 1.1.2.2 bouyer #ifdef __VFP_FP__ 111 1.1.2.2 bouyer struct ieee_double { 112 1.1.2.2 bouyer #ifdef __ARMEB__ 113 1.1.2.2 bouyer u_int dbl_sign:1; 114 1.1.2.2 bouyer u_int dbl_exp:11; 115 1.1.2.2 bouyer u_int dbl_frach:20; 116 1.1.2.2 bouyer u_int dbl_fracl; 117 1.1.2.2 bouyer #else /* !__ARMEB__ */ 118 1.1.2.2 bouyer u_int dbl_fracl; 119 1.1.2.2 bouyer u_int dbl_frach:20; 120 1.1.2.2 bouyer u_int dbl_exp:11; 121 1.1.2.2 bouyer u_int dbl_sign:1; 122 1.1.2.2 bouyer #endif /* !__ARMEB__ */ 123 1.1.2.2 bouyer }; 124 1.1.2.2 bouyer #else /* !__VFP_FP__ */ 125 1.1.2.2 bouyer struct ieee_double { 126 1.1.2.2 bouyer u_int dbl_frach:20; 127 1.1.2.2 bouyer u_int dbl_exp:11; 128 1.1.2.2 bouyer u_int dbl_sign:1; 129 1.1.2.2 bouyer u_int dbl_fracl; 130 1.1.2.2 bouyer }; 131 1.1.2.2 bouyer 132 1.1.2.2 bouyer struct ieee_e80 { 133 1.1.2.2 bouyer u_int e80_exp:15; 134 1.1.2.2 bouyer u_int e80_zero:16; 135 1.1.2.2 bouyer u_int e80_sign:1; 136 1.1.2.2 bouyer u_int e80_frach:31; 137 1.1.2.2 bouyer u_int e80_j:1; 138 1.1.2.2 bouyer u_int e80_fracl; 139 1.1.2.2 bouyer }; 140 1.1.2.2 bouyer 141 1.1.2.2 bouyer struct ieee_ext { 142 1.1.2.2 bouyer u_int ext_frach:16; 143 1.1.2.2 bouyer u_int ext_exp:15; 144 1.1.2.2 bouyer u_int ext_sign:1; 145 1.1.2.2 bouyer u_int ext_frachm; 146 1.1.2.2 bouyer u_int ext_fraclm; 147 1.1.2.2 bouyer u_int ext_fracl; 148 1.1.2.2 bouyer }; 149 1.1.2.2 bouyer #endif /* !__VFP_FP__ */ 150 1.1.2.2 bouyer 151 1.1.2.2 bouyer /* 152 1.1.2.2 bouyer * Floats whose exponent is in [1..INFNAN) (of whatever type) are 153 1.1.2.2 bouyer * `normal'. Floats whose exponent is INFNAN are either Inf or NaN. 154 1.1.2.2 bouyer * Floats whose exponent is zero are either zero (iff all fraction 155 1.1.2.2 bouyer * bits are zero) or subnormal values. 156 1.1.2.2 bouyer * 157 1.1.2.2 bouyer * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its 158 1.1.2.2 bouyer * high fraction; if the bit is set, it is a `quiet NaN'. 159 1.1.2.2 bouyer */ 160 1.1.2.2 bouyer #define SNG_EXP_INFNAN 255 161 1.1.2.2 bouyer #define DBL_EXP_INFNAN 2047 162 1.1.2.2 bouyer #ifndef __VFP_FP__ 163 1.1.2.2 bouyer #define E80_EXP_INFNAN 32767 164 1.1.2.2 bouyer #define EXT_EXP_INFNAN 32767 165 1.1.2.2 bouyer #endif /* !__VFP_FP__ */ 166 1.1.2.2 bouyer 167 1.1.2.2 bouyer #if 0 168 1.1.2.2 bouyer #define SNG_QUIETNAN (1 << 22) 169 1.1.2.2 bouyer #define DBL_QUIETNAN (1 << 19) 170 1.1.2.2 bouyer #ifndef __VFP_FP__ 171 1.1.2.2 bouyer #define E80_QUIETNAN (1 << 15) 172 1.1.2.2 bouyer #define EXT_QUIETNAN (1 << 15) 173 1.1.2.2 bouyer #endif /* !__VFP_FP__ */ 174 1.1.2.2 bouyer #endif 175 1.1.2.2 bouyer 176 1.1.2.2 bouyer /* 177 1.1.2.2 bouyer * Exponent biases. 178 1.1.2.2 bouyer */ 179 1.1.2.2 bouyer #define SNG_EXP_BIAS 127 180 1.1.2.2 bouyer #define DBL_EXP_BIAS 1023 181 1.1.2.2 bouyer #ifndef __VFP_FP__ 182 1.1.2.2 bouyer #define E80_EXP_BIAS 16383 183 1.1.2.2 bouyer #define EXT_EXP_BIAS 16383 184 1.1.2.2 bouyer #endif /* !__VFP_FP__ */ 185
Indexes created Sun Oct 12 20:09:57 GMT 2025