/*- * 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. * * @(#)ldexp.c 8.1 (Berkeley) 6/4/93 * $FreeBSD: src/lib/libc/amd64/gen/ldexp.c,v 1.11 2003/06/10 21:17:55 obrien Exp $ * $DragonFly: src/lib/libc/amd64/gen/ldexp.c,v 1.1 2004/02/02 05:43:14 dillon 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. * 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__ __asm ("fscale " : "=u" (temp2), "=t" (temp) : "0" (texp), "1" (value)); #else error unknown asm #endif return (temp); }