[dragonfly.git] / lib / libc / x86_64 / gen / ldexp.c

/*-
 * 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.
 * 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.
 *
 * @(#)ldexp.c	8.1 (Berkeley) 6/4/93
 * $FreeBSD: src/lib/libc/amd64/gen/ldexp.c,v 1.14 2007/01/09 00:38:24 imp Exp $
 */

/*
 * 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.
 */
double
ldexp(double value, int exp)
{
	double temp, texp, temp2;
	texp = exp;
#ifdef __GNUC__
	__asm ("fscale "
		: "=u" (temp2), "=t" (temp)
		: "0" (texp), "1" (value));
#else
#error unknown asm
#endif
	return (temp);
}
Commit	Line	Data
17030342 MD	1	/*-
	2	* Copyright (c) 1990, 1993
	3	* The Regents of the University of California. All rights reserved.
	4	*
	5	* This code is derived from software contributed to Berkeley by
	6	* Sean Eric Fagan.
	7	*
	8	* Redistribution and use in source and binary forms, with or without
	9	* modification, are permitted provided that the following conditions
	10	* are met:
	11	* 1. Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* 2. Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in the
	15	* documentation and/or other materials provided with the distribution.
17030342 MD	16	* 4. Neither the name of the University nor the names of its contributors
	17	* may be used to endorse or promote products derived from this software
	18	* without specific prior written permission.
	19	*
	20	* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
	21	* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	22	* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	23	* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
	24	* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	25	* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	26	* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	27	* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	28	* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	29	* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	30	* SUCH DAMAGE.
	31	*
	32	* @(#)ldexp.c 8.1 (Berkeley) 6/4/93
eb9f4715	33	* $FreeBSD: src/lib/libc/amd64/gen/ldexp.c,v 1.14 2007/01/09 00:38:24 imp Exp $
17030342 MD	34	*/
	35
	36	/*
	37	* ldexp(value, exp): return value * (2 ** exp).
	38	*
	39	* Written by Sean Eric Fagan (sef@kithrup.COM)
	40	* Sun Mar 11 20:27:09 PST 1990
	41	*/
	42
	43	/*
	44	* We do the conversion in C to let gcc optimize it away, if possible.
17030342 MD	45	*/
17030342 MD	46	double
eb9f4715	47	ldexp(double value, int exp)
17030342 MD	48	{
	49	double temp, texp, temp2;
	50	texp = exp;
	51	#ifdef __GNUC__
	52	__asm ("fscale "
	53	: "=u" (temp2), "=t" (temp)
	54	: "0" (texp), "1" (value));
	55	#else
eb9f4715	56	#error unknown asm
17030342 MD	57	#endif
	58	return (temp);
	59	}