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/* $OpenBSD: ieee.h,v 1.2 2008/07/24 17:36:52 deraadt Exp $ */
/* $NetBSD: ieee.h,v 1.2 2001/02/21 17:43:50 bjh21 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.
*/
/*
* 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.
*/
/*
* The ARM has two sets of FP data formats. The FPA supports 32-bit, 64-bit
* and 96-bit IEEE formats, with the words in big-endian order. VFP supports
* 32-bin and 64-bit IEEE formats with the words in the CPU's native byte
* order.
*
* The FPA also has two packed decimal formats, but we ignore them here.
*/
#define SNG_EXPBITS 8
#define SNG_FRACBITS 23
#define DBL_EXPBITS 11
#define DBL_FRACBITS 52
#ifndef __VFP_FP__
#define E80_EXPBITS 15
#define E80_FRACBITS 64
#define EXT_EXPBITS 15
#define EXT_FRACBITS 112
#endif
struct ieee_single {
u_int sng_frac:23;
u_int sng_exp:8;
u_int sng_sign:1;
};
#ifdef __VFP_FP__
struct ieee_double {
#ifdef __ARMEB__
u_int dbl_sign:1;
u_int dbl_exp:11;
u_int dbl_frach:20;
u_int dbl_fracl;
#else /* !__ARMEB__ */
u_int dbl_fracl;
u_int dbl_frach:20;
u_int dbl_exp:11;
u_int dbl_sign:1;
#endif /* !__ARMEB__ */
};
#else /* !__VFP_FP__ */
struct ieee_double {
u_int dbl_frach:20;
u_int dbl_exp:11;
u_int dbl_sign:1;
u_int dbl_fracl;
};
union ieee_double_u {
double dblu_d;
struct ieee_double dblu_dbl;
};
struct ieee_e80 {
u_int e80_exp:15;
u_int e80_zero:16;
u_int e80_sign:1;
u_int e80_frach:31;
u_int e80_j:1;
u_int e80_fracl;
};
struct ieee_ext {
u_int ext_frach:16;
u_int ext_exp:15;
u_int ext_sign:1;
u_int ext_frachm;
u_int ext_fraclm;
u_int ext_fracl;
};
#endif /* !__VFP_FP__ */
/*
* 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
#ifndef __VFP_FP__
#define E80_EXP_INFNAN 32767
#define EXT_EXP_INFNAN 32767
#endif /* !__VFP_FP__ */
#if 0
#define SNG_QUIETNAN (1 << 22)
#define DBL_QUIETNAN (1 << 19)
#ifndef __VFP_FP__
#define E80_QUIETNAN (1 << 15)
#define EXT_QUIETNAN (1 << 15)
#endif /* !__VFP_FP__ */
#endif
/*
* Exponent biases.
*/
#define SNG_EXP_BIAS 127
#define DBL_EXP_BIAS 1023
#ifndef __VFP_FP__
#define E80_EXP_BIAS 16383
#define EXT_EXP_BIAS 16383
#endif /* !__VFP_FP__ */
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