xref: /openbsd-src/lib/libc/gen/signbit.c (revision 4c1e55dc91edd6e69ccc60ce855900fbc12cf34f)
1 /*	$OpenBSD: signbit.c,v 1.4 2011/05/30 17:28:15 martynas Exp $	*/
2 /*
3  * Copyright (c) 2008 Martynas Venckus <martynas@openbsd.org>
4  *
5  * Permission to use, copy, modify, and distribute this software for any
6  * purpose with or without fee is hereby granted, provided that the above
7  * copyright notice and this permission notice appear in all copies.
8  *
9  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
10  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
11  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
12  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
13  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
14  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
15  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
16  */
17 
18 /* LINTLIBRARY */
19 
20 #include <sys/types.h>
21 #include <sys/cdefs.h>
22 #include <machine/ieee.h>
23 #include <float.h>
24 #include <math.h>
25 
26 int
27 __signbit(double d)
28 {
29 	struct ieee_double *p = (struct ieee_double *)&d;
30 
31 	return p->dbl_sign;
32 }
33 
34 int
35 __signbitf(float f)
36 {
37 	struct ieee_single *p = (struct ieee_single *)&f;
38 
39 	return p->sng_sign;
40 }
41 
42 #if	LDBL_MANT_DIG == 53
43 #ifdef	lint
44 /* PROTOLIB1 */
45 int __signbitl(long double);
46 #else	/* lint */
47 __weak_alias(__signbitl, __signbit);
48 #endif	/* lint */
49 #endif	/* LDBL_MANT_DIG == 53 */
50