xref: /freebsd/lib/libc/gen/isnan.c (revision 0b3105a37d7adcadcb720112fed4dc4e8040be99)
1 /*-
2  * Copyright (c) 2004 David Schultz <das@FreeBSD.ORG>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <math.h>
30 
31 #include "fpmath.h"
32 
33 /*
34  * XXX These routines belong in libm, but they must remain in libc for
35  *     binary compat until we can bump libm's major version number.
36  *
37  * Note this only applies to the dynamic versions of libm and libc, so
38  * for the static and profiled versions we stub out the definitions.
39  * Otherwise you cannot link statically to libm and libc at the same
40  * time, when calling both functions.
41  */
42 
43 #ifdef PIC
44 __weak_reference(__isnan, isnan);
45 __weak_reference(__isnanf, isnanf);
46 
47 int
48 __isnan(double d)
49 {
50 	union IEEEd2bits u;
51 
52 	u.d = d;
53 	return (u.bits.exp == 2047 && (u.bits.manl != 0 || u.bits.manh != 0));
54 }
55 
56 int
57 __isnanf(float f)
58 {
59 	union IEEEf2bits u;
60 
61 	u.f = f;
62 	return (u.bits.exp == 255 && u.bits.man != 0);
63 }
64 #endif /* PIC */
65