1 /* $NetBSD: floatundisf.c,v 1.3 2012/08/05 04:28:58 matt Exp $ */ 2 3 /*- 4 * Copyright (c) 1992, 1993 5 * The Regents of the University of California. All rights reserved. 6 * 7 * This software was developed by the Computer Systems Engineering group 8 * at Lawrence Berkeley Laboratory under DARPA contract BG 91-66 and 9 * contributed to Berkeley. 10 * 11 * Redistribution and use in source and binary forms, with or without 12 * modification, are permitted provided that the following conditions 13 * are met: 14 * 1. Redistributions of source code must retain the above copyright 15 * notice, this list of conditions and the following disclaimer. 16 * 2. Redistributions in binary form must reproduce the above copyright 17 * notice, this list of conditions and the following disclaimer in the 18 * documentation and/or other materials provided with the distribution. 19 * 3. Neither the name of the University nor the names of its contributors 20 * may be used to endorse or promote products derived from this software 21 * without specific prior written permission. 22 * 23 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 24 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 25 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 26 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 27 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 28 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 29 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 30 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 31 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 32 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 33 * SUCH DAMAGE. 34 */ 35 36 #include <sys/cdefs.h> 37 #if defined(LIBC_SCCS) && !defined(lint) 38 #if 0 39 static char sccsid[] = "@(#)floatdisf.c 8.1 (Berkeley) 6/4/93"; 40 #else 41 __RCSID("$NetBSD: floatundisf.c,v 1.3 2012/08/05 04:28:58 matt Exp $"); 42 #endif 43 #endif /* LIBC_SCCS and not lint */ 44 45 #ifdef SOFTFLOAT 46 #include "softfloat/softfloat-for-gcc.h" 47 #endif 48 49 #include "quad.h" 50 51 /* 52 * Convert (unsigned) quad to float. 53 */ 54 float 55 __floatundisf(u_quad_t x) 56 { 57 float f; 58 union uu u; 59 60 u.q = x; 61 62 /* 63 * Now u.ul[H] has the factor of 2^32 (or whatever) and u.ul[L] 64 * has the units. Ideally we could just set f, add INT_BITS to 65 * its exponent, and then add the units, but this is portable 66 * code and does not know how to get at an exponent. Machine- 67 * specific code may be able to do this more efficiently. 68 * 69 * Using double here may be excessive paranoia. 70 */ 71 f = (double)u.ul[H] * (((int)1 << (unsigned int)(INT_BITS - 2)) * 4.0); 72 f += u.ul[L]; 73 74 return f; 75 } 76