1 /* $NetBSD: isnanl.c,v 1.8 2011/06/05 14:43:13 christos 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 * from: Header: isinf.c,v 1.1 91/07/08 19:03:34 torek Exp 36 */ 37 38 #include <sys/cdefs.h> 39 #if defined(LIBC_SCCS) && !defined(lint) 40 #if 0 41 static char sccsid[] = "@(#)isinf.c 8.1 (Berkeley) 6/4/93"; 42 #else 43 __RCSID("$NetBSD: isnanl.c,v 1.8 2011/06/05 14:43:13 christos Exp $"); 44 #endif 45 #endif /* LIBC_SCCS and not lint */ 46 47 #include <machine/ieee.h> 48 #include <math.h> 49 50 /* 51 * 7.12.3.4 isnan - test for a NaN 52 * IEEE 754 compatible 80-bit extended-precision Intel 386 version 53 */ 54 int 55 __isnanl(long double x) 56 { 57 union ieee_ext_u u; 58 59 u.extu_ld = x; 60 61 return (u.extu_ext.ext_exp == EXT_EXP_INFNAN && 62 (u.extu_ext.ext_frach & 0x80000000) != 0 && 63 (u.extu_ext.ext_frach != 0x80000000 || u.extu_ext.ext_fracl != 0)); 64 } 65