1 /*  $NetBSD: isnanl.c,v 1.5.16.1 2007/05/07 19:49:07 pavel 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/EfiCdefs.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 1.5.16.1 2007/05/07 19:49:07 pavel 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
__isnanl(long double x)55 __isnanl(long double x)
56 {
57   union ieee_ext_u u = { 0 };
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