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/*-
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* Sean Eric Fagan.
*
* 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.
*
* $Id$
*/
#if defined(LIBC_RCS) && !defined(lint)
static const char rcsid[] = "$Id$";
#endif /* LIBC_RCS and not lint */
/*
* ldexp(value, exp): return value * (2 ** exp).
*
* Written by Sean Eric Fagan (sef@kithrup.COM)
* Sun Mar 11 20:27:09 PST 1990
*/
/*
* We do the conversion in C to let gcc optimize it away, if possible.
* The "fxch ; fstp" stuff is because value is still on the stack
* (stupid 8087!).
*/
double
ldexp (double value, int exp)
{
double temp, texp, temp2;
texp = exp;
#ifdef __GNUC__
#if __GNUC__ >= 2
asm ("fscale "
: "=u" (temp2), "=t" (temp)
: "0" (texp), "1" (value));
#else
asm ("fscale ; fxch %%st(1) ; fstp%L1 %1 "
: "=f" (temp), "=0" (temp2)
: "0" (texp), "f" (value));
#endif
#else
error unknown asm
#endif
return (temp);
}
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