xref: /freebsd/lib/msun/src/s_isnan.c (revision 7899f917b1c0ea178f1d2be0cfb452086d079d23)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
5  * All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26  * SUCH DAMAGE.
27  */
28 
29 #include <math.h>
30 
31 #include "fpmath.h"
32 
33 /* Provided by libc.so */
34 #ifndef PIC
35 #undef isnan
36 int
37 isnan(double d)
38 {
39 	union IEEEd2bits u;
40 
41 	u.d = d;
42 	return (u.bits.exp == 2047 && (u.bits.manl != 0 || u.bits.manh != 0));
43 }
44 #endif /* !PIC */
45 
46 /*
47  * Because math.h defines __isnanf as an alias for compatibility with glibc and
48  * CUDA, we have to undefine it here to avoid redefinition errors.
49  */
50 #undef __isnanf
51 
52 int
53 __isnanf(float f)
54 {
55 	union IEEEf2bits u;
56 
57 	u.f = f;
58 	return (u.bits.exp == 255 && u.bits.man != 0);
59 }
60 
61 int
62 __isnanl(long double e)
63 {
64 	union IEEEl2bits u;
65 
66 	u.e = e;
67 	mask_nbit_l(u);
68 	return (u.bits.exp == 32767 && (u.bits.manl != 0 || u.bits.manh != 0));
69 }
70 
71 __weak_reference(__isnanf, isnanf);
72