74 lines
2.5 KiB
C
74 lines
2.5 KiB
C
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/*-
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* Copyright (c) 1991, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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static char rcsid[] = "$OpenBSD: frexp.c,v 1.3 1997/07/23 20:55:24 kstailey Exp $";
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#endif /* LIBC_SCCS and not lint */
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#include <sys/types.h>
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#include <machine/endian.h>
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#include <math.h>
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double
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frexp(value, eptr)
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double value;
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int *eptr;
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{
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union {
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double v;
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struct {
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#if BYTE_ORDER == LITTLE_ENDIAN
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u_int u_mant2 : 32;
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u_int u_mant1 : 20;
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u_int u_exp : 11;
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u_int u_sign : 1;
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#else
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u_int u_sign : 1;
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u_int u_exp : 11;
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u_int u_mant1 : 20;
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u_int u_mant2 : 32;
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#endif
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} s;
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} u;
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if (value) {
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u.v = value;
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*eptr = u.s.u_exp - 1022;
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u.s.u_exp = 1022;
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return(u.v);
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} else {
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*eptr = 0;
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return((double)0);
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}
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}
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