11573Srgrimes/*- 21573Srgrimes * Copyright (c) 1992, 1993 31573Srgrimes * The Regents of the University of California. All rights reserved. 41573Srgrimes * 51573Srgrimes * This software was developed by the Computer Systems Engineering group 61573Srgrimes * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 71573Srgrimes * contributed to Berkeley. 81573Srgrimes * 91573Srgrimes * Redistribution and use in source and binary forms, with or without 101573Srgrimes * modification, are permitted provided that the following conditions 111573Srgrimes * are met: 121573Srgrimes * 1. Redistributions of source code must retain the above copyright 131573Srgrimes * notice, this list of conditions and the following disclaimer. 141573Srgrimes * 2. Redistributions in binary form must reproduce the above copyright 151573Srgrimes * notice, this list of conditions and the following disclaimer in the 161573Srgrimes * documentation and/or other materials provided with the distribution. 171573Srgrimes * 4. Neither the name of the University nor the names of its contributors 181573Srgrimes * may be used to endorse or promote products derived from this software 191573Srgrimes * without specific prior written permission. 201573Srgrimes * 211573Srgrimes * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 221573Srgrimes * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 231573Srgrimes * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 241573Srgrimes * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 251573Srgrimes * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 261573Srgrimes * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 271573Srgrimes * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 281573Srgrimes * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 291573Srgrimes * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 301573Srgrimes * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 311573Srgrimes * SUCH DAMAGE. 321573Srgrimes */ 331573Srgrimes 341573Srgrimes#if defined(LIBC_SCCS) && !defined(lint) 351573Srgrimesstatic char sccsid[] = "@(#)floatdidf.c 8.1 (Berkeley) 6/4/93"; 361573Srgrimes#endif /* LIBC_SCCS and not lint */ 3792986Sobrien#include <sys/cdefs.h> 3892986Sobrien__FBSDID("$FreeBSD$"); 391573Srgrimes 401573Srgrimes#include "quad.h" 411573Srgrimes 421573Srgrimes/* 431573Srgrimes * Convert (signed) quad to double. 441573Srgrimes */ 451573Srgrimesdouble 461573Srgrimes__floatdidf(x) 471573Srgrimes quad_t x; 481573Srgrimes{ 491573Srgrimes double d; 501573Srgrimes union uu u; 511573Srgrimes int neg; 521573Srgrimes 531573Srgrimes /* 541573Srgrimes * Get an unsigned number first, by negating if necessary. 551573Srgrimes */ 561573Srgrimes if (x < 0) 571573Srgrimes u.q = -x, neg = 1; 581573Srgrimes else 591573Srgrimes u.q = x, neg = 0; 601573Srgrimes 611573Srgrimes /* 621573Srgrimes * Now u.ul[H] has the factor of 2^32 (or whatever) and u.ul[L] 631573Srgrimes * has the units. Ideally we could just set d, add LONG_BITS to 641573Srgrimes * its exponent, and then add the units, but this is portable 651573Srgrimes * code and does not know how to get at an exponent. Machine- 661573Srgrimes * specific code may be able to do this more efficiently. 671573Srgrimes */ 681573Srgrimes d = (double)u.ul[H] * ((1 << (LONG_BITS - 2)) * 4.0); 691573Srgrimes d += u.ul[L]; 701573Srgrimes 711573Srgrimes return (neg ? -d : d); 721573Srgrimes} 73