/* $OpenBSD: ieee.h,v 1.2 1997/08/08 08:26:24 downsj Exp $ */ /* $NetBSD: ieee.h,v 1.2 1994/11/20 20:53:10 deraadt Exp $ */ /* * Copyright (c) 1992, 1993 * The Regents of the University of California. All rights reserved. * * This software was developed by the Computer Systems Engineering group * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and * contributed to Berkeley. * * All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Lawrence Berkeley Laboratory. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * This product includes software developed by the University of * California, Berkeley and its contributors. * 4. Neither the name of the University nor the names of its contributors * may be used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * @(#)ieee.h 8.1 (Berkeley) 6/11/93 */ /* * ieee.h defines the machine-dependent layout of the machine's IEEE * floating point. It does *not* define (yet?) any of the rounding * mode bits, exceptions, and so forth. */ /* * Define the number of bits in each fraction and exponent. * * k k+1 * Note that 1.0 x 2 == 0.1 x 2 and that denorms are represented * * (-exp_bias+1) * as fractions that look like 0.fffff x 2 . This means that * * -126 * the number 0.10000 x 2 , for instance, is the same as the normalized * * -127 -128 * float 1.0 x 2 . Thus, to represent 2 , we need one leading zero * * -129 * in the fraction; to represent 2 , we need two, and so on. This * * (-exp_bias-fracbits+1) * implies that the smallest denormalized number is 2 * * for whichever format we are talking about: for single precision, for * * -126 -149 * instance, we get .00000000000000000000001 x 2 , or 1.0 x 2 , and * * -149 == -127 - 23 + 1. */ #define SNG_EXPBITS 8 #define SNG_FRACBITS 23 #define DBL_EXPBITS 11 #define DBL_FRACBITS 52 #ifdef notyet #define E80_EXPBITS 15 #define E80_FRACBITS 64 #endif #define EXT_EXPBITS 15 #define EXT_FRACBITS 112 struct ieee_single { u_int sng_sign:1; u_int sng_exp:8; u_int sng_frac:23; }; struct ieee_double { u_int dbl_sign:1; u_int dbl_exp:11; u_int dbl_frach:20; u_int dbl_fracl; }; struct ieee_ext { u_int ext_sign:1; u_int ext_exp:15; u_int ext_frach:16; u_int ext_frachm; u_int ext_fraclm; u_int ext_fracl; }; /* * Floats whose exponent is in [1..INFNAN) (of whatever type) are * `normal'. Floats whose exponent is INFNAN are either Inf or NaN. * Floats whose exponent is zero are either zero (iff all fraction * bits are zero) or subnormal values. * * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its * high fraction; if the bit is set, it is a `quiet NaN'. */ #define SNG_EXP_INFNAN 255 #define DBL_EXP_INFNAN 2047 #define EXT_EXP_INFNAN 32767 #if 0 #define SNG_QUIETNAN (1 << 22) #define DBL_QUIETNAN (1 << 19) #define EXT_QUIETNAN (1 << 15) #endif /* * Exponent biases. */ #define SNG_EXP_BIAS 127 #define DBL_EXP_BIAS 1023 #define EXT_EXP_BIAS 16383