From a671ba71b3e11ac72ed9b1fdf96bd38539e7a643 Mon Sep 17 00:00:00 2001 From: kleink Date: Sun, 26 Oct 2003 20:48:17 +0000 Subject: [PATCH] Have a common place for definitions related to IEEE 754 single-precision and double-precision formats. --- sys/sys/Makefile | 4 +- sys/sys/ieee754.h | 138 ++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 140 insertions(+), 2 deletions(-) create mode 100644 sys/sys/ieee754.h diff --git a/sys/sys/Makefile b/sys/sys/Makefile index 8304f605ac60..1a646001a79e 100644 --- a/sys/sys/Makefile +++ b/sys/sys/Makefile @@ -1,4 +1,4 @@ -# $NetBSD: Makefile,v 1.60 2003/10/08 04:25:46 lukem Exp $ +# $NetBSD: Makefile,v 1.61 2003/10/26 20:48:17 kleink Exp $ INCSDIR= /usr/include/sys @@ -12,7 +12,7 @@ INCS= acct.h agpio.h ansi.h ataio.h audioio.h \ exec_coff.h exec_ecoff.h exec_elf.h exec_script.h extent.h \ fcntl.h fdio.h featuretest.h file.h filedesc.h filio.h \ float_ieee754.h gmon.h hash.h \ - inttypes.h ioccom.h ioctl.h ioctl_compat.h ipc.h \ + ieee754.h inttypes.h ioccom.h ioctl.h ioctl_compat.h ipc.h \ kcore.h kgdb.h ksem.h ksyms.h ktrace.h \ lkm.h localedef.h lock.h lockf.h lwp.h \ malloc.h mallocvar.h mbuf.h md4.h \ diff --git a/sys/sys/ieee754.h b/sys/sys/ieee754.h new file mode 100644 index 000000000000..49a83e3b6559 --- /dev/null +++ b/sys/sys/ieee754.h @@ -0,0 +1,138 @@ +/* $NetBSD: ieee754.h,v 1.1 2003/10/26 20:48:17 kleink 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. 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 + */ + +/* + * NOTICE: This is not a standalone file. To use it, #include it in + * your port's ieee.h header. + */ + +#include + +/* + * defines the layout of IEEE 754 floating point types. + * Only single-precision and double-precision types are defined here; + * extended types, if available, are defined in the machine-dependent + * header. + */ + +/* + * 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 + +struct ieee_single { +#ifdef _BYTE_ORDER == _BIG_ENDIAN + u_int sng_sign:1; + u_int sng_exp:8; + u_int sng_frac:23; +#else + u_int sng_frac:23; + u_int sng_exp:8; + u_int sng_sign:1; +#endif +}; + +struct ieee_double { +#ifdef _BYTE_ORDER == _BIG_ENDIAN + u_int dbl_sign:1; + u_int dbl_exp:11; + u_int dbl_frach:20; + u_int dbl_fracl; +#else + u_int dbl_fracl; + u_int dbl_frach:20; + u_int dbl_exp:11; + u_int dbl_sign:1; +#endif +}; + +/* + * 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 + +#if 0 +#define SNG_QUIETNAN (1 << 22) +#define DBL_QUIETNAN (1 << 19) +#endif + +/* + * Exponent biases. + */ +#define SNG_EXP_BIAS 127 +#define DBL_EXP_BIAS 1023