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/*-
* 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.
*
* 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.
*/
#if defined(LIBC_SCCS) && !defined(lint)
static char rcsid[] = "$OpenBSD: floatdidf.c,v 1.3 2003/06/02 20:18:36 millert Exp $";
#endif /* LIBC_SCCS and not lint */
#include "quad.h"
/*
* Convert (signed) quad to double.
*/
double
__floatdidf(x)
quad_t x;
{
double d;
union uu u;
int neg;
/*
* Get an unsigned number first, by negating if necessary.
*/
if (x < 0)
u.q = -x, neg = 1;
else
u.q = x, neg = 0;
/*
* Now u.ul[H] has the factor of 2^32 (or whatever) and u.ul[L]
* has the units. Ideally we could just set d, add LONG_BITS to
* its exponent, and then add the units, but this is portable
* code and does not know how to get at an exponent. Machine-
* specific code may be able to do this more efficiently.
*/
d = (double)u.ul[H] * (((long)1 << (LONG_BITS - 2)) * 4.0);
d += u.ul[L];
return (neg ? -d : d);
}
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