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      1 /*	$NetBSD: ieee.h,v 1.18 2025/07/02 14:41:35 christos Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This software was developed by the Computer Systems Engineering group
      8  * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and
      9  * contributed to Berkeley.
     10  *
     11  * All advertising materials mentioning features or use of this software
     12  * must display the following acknowledgement:
     13  *	This product includes software developed by the University of
     14  *	California, Lawrence Berkeley Laboratory.
     15  *
     16  * Redistribution and use in source and binary forms, with or without
     17  * modification, are permitted provided that the following conditions
     18  * are met:
     19  * 1. Redistributions of source code must retain the above copyright
     20  *    notice, this list of conditions and the following disclaimer.
     21  * 2. Redistributions in binary form must reproduce the above copyright
     22  *    notice, this list of conditions and the following disclaimer in the
     23  *    documentation and/or other materials provided with the distribution.
     24  * 3. Neither the name of the University nor the names of its contributors
     25  *    may be used to endorse or promote products derived from this software
     26  *    without specific prior written permission.
     27  *
     28  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     29  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     30  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     31  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     32  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     33  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     34  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     35  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     36  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     37  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     38  * SUCH DAMAGE.
     39  *
     40  *	@(#)ieee.h	8.1 (Berkeley) 6/11/93
     41  */
     42 
     43 #ifndef	__68K_IEEE_H_INCLUDED
     44 #define	__68K_IEEE_H_INCLUDED
     45 
     46 /*
     47  * ieee.h defines the machine-dependent layout of the machine's IEEE
     48  * floating point.  It does *not* define (yet?) any of the rounding
     49  * mode bits, exceptions, and so forth.
     50  */
     51 
     52 #include <sys/ieee754.h>
     53 
     54 #if !defined(__mc68010__) || defined(_KERNEL)
     55 #define	EXT_EXPBITS	15
     56 #define	EXT_FRACHBITS	32
     57 #define	EXT_FRACLBITS	32
     58 #define	EXT_FRACBITS	(EXT_FRACLBITS + EXT_FRACHBITS)
     59 
     60 #define	EXT_TO_ARRAY32(u, a) do {			\
     61 	(a)[0] = (uint32_t)(u).extu_ext.ext_fracl;	\
     62 	(a)[1] = (uint32_t)(u).extu_ext.ext_frach;	\
     63 } while(/*CONSTCOND*/0)
     64 
     65 struct ieee_ext {
     66 	uint32_t	ext_sign:1;
     67 	uint32_t	ext_exp:EXT_EXPBITS;
     68 	uint32_t	ext_zero:16;
     69 #if 0
     70 	uint32_t	ext_int:1;
     71 #endif
     72 	uint32_t	ext_frach;
     73 	uint32_t	ext_fracl;
     74 };
     75 
     76 /*
     77  * Extended floats whose exponent is in [0..INFNAN) and have their
     78  * explicit integer bit (the most significant bit of the fraction)
     79  * set are `normal'.  Floats whose exponent is INFNAN are either Inf or NaN.
     80  * Floats whose exponent is zero are either zero (iff all fraction
     81  * bits are zero) or subnormal values.
     82  *
     83  * A NaN is a `signalling NaN' if its QUIETNAN bit is clear in its
     84  * high fraction; if the bit is set, it is a `quiet NaN'.
     85  */
     86 #define	EXT_EXP_INFNAN	0x7fff
     87 #define	EXT_EXP_INF	0x7fff
     88 #define	EXT_EXP_NAN	0x7fff
     89 
     90 #if 0
     91 #define	SNG_QUIETNAN	(1 << 22)
     92 #define	DBL_QUIETNAN	(1 << 19)
     93 #define	EXT_QUIETNAN	(1 << 30)
     94 #endif
     95 
     96 /*
     97  * Exponent biases.
     98  */
     99 #define	EXT_EXP_BIAS	16383
    100 
    101 /*
    102  * Convenience data structures.
    103  */
    104 union ieee_ext_u {
    105 	long double		extu_ld;
    106 	struct ieee_ext		extu_ext;
    107 };
    108 
    109 #define extu_exp	extu_ext.ext_exp
    110 #define extu_sign	extu_ext.ext_sign
    111 #define extu_fracl	extu_ext.ext_fracl
    112 #define extu_frach	extu_ext.ext_frach
    113 
    114 #define LDBL_NBIT	0x80000000
    115 #define mask_nbit_l(u)	((u).extu_frach &= ~LDBL_NBIT)
    116 #endif /* !__mc68010__ || _KERNEL */
    117 
    118 #endif /* __68K_IEEE_H_INCLUDED */
    119