1139825Simp/*- 2109480Sgrehan * Copyright (c) 1992, 1993 3109480Sgrehan * The Regents of the University of California. All rights reserved. 4109480Sgrehan * 5109480Sgrehan * This software was developed by the Computer Systems Engineering group 6109480Sgrehan * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 7109480Sgrehan * contributed to Berkeley. 8109480Sgrehan * 9109480Sgrehan * All advertising materials mentioning features or use of this software 10109480Sgrehan * must display the following acknowledgement: 11109480Sgrehan * This product includes software developed by the University of 12109480Sgrehan * California, Lawrence Berkeley Laboratory. 13109480Sgrehan * 14109480Sgrehan * Redistribution and use in source and binary forms, with or without 15109480Sgrehan * modification, are permitted provided that the following conditions 16109480Sgrehan * are met: 17109480Sgrehan * 1. Redistributions of source code must retain the above copyright 18109480Sgrehan * notice, this list of conditions and the following disclaimer. 19109480Sgrehan * 2. Redistributions in binary form must reproduce the above copyright 20109480Sgrehan * notice, this list of conditions and the following disclaimer in the 21109480Sgrehan * documentation and/or other materials provided with the distribution. 22109480Sgrehan * 4. Neither the name of the University nor the names of its contributors 23109480Sgrehan * may be used to endorse or promote products derived from this software 24109480Sgrehan * without specific prior written permission. 25109480Sgrehan * 26109480Sgrehan * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 27109480Sgrehan * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 28109480Sgrehan * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 29109480Sgrehan * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 30109480Sgrehan * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 31109480Sgrehan * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 32109480Sgrehan * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 33109480Sgrehan * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 34109480Sgrehan * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 35109480Sgrehan * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 36109480Sgrehan * SUCH DAMAGE. 37109480Sgrehan * 38109480Sgrehan * @(#)ieee.h 8.1 (Berkeley) 6/11/93 39109480Sgrehan * from: NetBSD: ieee.h,v 1.1.1.1 1998/06/20 04:58:51 eeh Exp 40109480Sgrehan * $FreeBSD: releng/10.3/sys/powerpc/include/ieee.h 139825 2005-01-07 02:29:27Z imp $ 41109480Sgrehan */ 42109480Sgrehan 43109480Sgrehan#ifndef _MACHINE_IEEE_H_ 44109480Sgrehan#define _MACHINE_IEEE_H_ 45109480Sgrehan 46109480Sgrehan/* 47109480Sgrehan * ieee.h defines the machine-dependent layout of the machine's IEEE 48109480Sgrehan * floating point. It does *not* define (yet?) any of the rounding 49109480Sgrehan * mode bits, exceptions, and so forth. 50109480Sgrehan */ 51109480Sgrehan 52109480Sgrehan/* 53109480Sgrehan * Define the number of bits in each fraction and exponent. 54109480Sgrehan * 55109480Sgrehan * k k+1 56109480Sgrehan * Note that 1.0 x 2 == 0.1 x 2 and that denorms are represented 57109480Sgrehan * 58109480Sgrehan * (-exp_bias+1) 59109480Sgrehan * as fractions that look like 0.fffff x 2 . This means that 60109480Sgrehan * 61109480Sgrehan * -126 62109480Sgrehan * the number 0.10000 x 2 , for instance, is the same as the normalized 63109480Sgrehan * 64109480Sgrehan * -127 -128 65109480Sgrehan * float 1.0 x 2 . Thus, to represent 2 , we need one leading zero 66109480Sgrehan * 67109480Sgrehan * -129 68109480Sgrehan * in the fraction; to represent 2 , we need two, and so on. This 69109480Sgrehan * 70109480Sgrehan * (-exp_bias-fracbits+1) 71109480Sgrehan * implies that the smallest denormalized number is 2 72109480Sgrehan * 73109480Sgrehan * for whichever format we are talking about: for single precision, for 74109480Sgrehan * 75109480Sgrehan * -126 -149 76109480Sgrehan * instance, we get .00000000000000000000001 x 2 , or 1.0 x 2 , and 77109480Sgrehan * 78109480Sgrehan * -149 == -127 - 23 + 1. 79109480Sgrehan */ 80109480Sgrehan#define SNG_EXPBITS 8 81109480Sgrehan#define SNG_FRACBITS 23 82109480Sgrehan 83109480Sgrehan#define DBL_EXPBITS 11 84109480Sgrehan#define DBL_FRACBITS 52 85109480Sgrehan 86109480Sgrehan#ifdef notyet 87109480Sgrehan#define E80_EXPBITS 15 88109480Sgrehan#define E80_FRACBITS 64 89109480Sgrehan#endif 90109480Sgrehan 91109480Sgrehan#define EXT_EXPBITS 15 92109480Sgrehan#define EXT_FRACBITS 112 93109480Sgrehan 94109480Sgrehanstruct ieee_single { 95109480Sgrehan u_int sng_sign:1; 96109480Sgrehan u_int sng_exp:8; 97109480Sgrehan u_int sng_frac:23; 98109480Sgrehan}; 99109480Sgrehan 100109480Sgrehanstruct ieee_double { 101109480Sgrehan u_int dbl_sign:1; 102109480Sgrehan u_int dbl_exp:11; 103109480Sgrehan u_int dbl_frach:20; 104109480Sgrehan u_int dbl_fracl; 105109480Sgrehan}; 106109480Sgrehan 107109480Sgrehanstruct ieee_ext { 108109480Sgrehan u_int ext_sign:1; 109109480Sgrehan u_int ext_exp:15; 110109480Sgrehan u_int ext_frach:16; 111109480Sgrehan u_int ext_frachm; 112109480Sgrehan u_int ext_fraclm; 113109480Sgrehan u_int ext_fracl; 114109480Sgrehan}; 115109480Sgrehan 116109480Sgrehan/* 117109480Sgrehan * Floats whose exponent is in [1..INFNAN) (of whatever type) are 118109480Sgrehan * `normal'. Floats whose exponent is INFNAN are either Inf or NaN. 119109480Sgrehan * Floats whose exponent is zero are either zero (iff all fraction 120109480Sgrehan * bits are zero) or subnormal values. 121109480Sgrehan * 122109480Sgrehan * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its 123109480Sgrehan * high fraction; if the bit is set, it is a `quiet NaN'. 124109480Sgrehan */ 125109480Sgrehan#define SNG_EXP_INFNAN 255 126109480Sgrehan#define DBL_EXP_INFNAN 2047 127109480Sgrehan#define EXT_EXP_INFNAN 32767 128109480Sgrehan 129109480Sgrehan#if 0 130109480Sgrehan#define SNG_QUIETNAN (1 << 22) 131109480Sgrehan#define DBL_QUIETNAN (1 << 19) 132109480Sgrehan#define EXT_QUIETNAN (1 << 15) 133109480Sgrehan#endif 134109480Sgrehan 135109480Sgrehan/* 136109480Sgrehan * Exponent biases. 137109480Sgrehan */ 138109480Sgrehan#define SNG_EXP_BIAS 127 139109480Sgrehan#define DBL_EXP_BIAS 1023 140109480Sgrehan#define EXT_EXP_BIAS 16383 141109480Sgrehan 142109480Sgrehan#endif 143