1 /*-
2 * Copyright (c) 2003, Steven G. Kargl
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 unmodified, this list of conditions, and the following
10 * disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27 #include <sys/cdefs.h>
28 #if defined(LIBM_SCCS) && !defined(lint)
29 __RCSID("$NetBSD: s_round.c,v 1.3 2013/11/11 23:57:34 joerg Exp $");
30 #if 0
31 __FBSDID("$FreeBSD: src/lib/msun/src/s_round.c,v 1.1 2004/06/07 08:05:36 das Exp $");
32 #endif
33 #endif
34
35 #include <math.h>
36
37 #ifndef __HAVE_LONG_DOUBLE
__strong_alias(_roundl,round)38 __strong_alias(_roundl, round)
39 __weak_alias(roundl, round)
40 #endif
41
42 double
43 round(double x)
44 {
45 double t;
46 int i;
47
48 i = fpclassify(x);
49 if (i == FP_INFINITE || i == FP_NAN)
50 return (x);
51
52 if (x >= 0.0) {
53 t = floor(x);
54 if (x - t >= 0.5)
55 t += 1.0;
56 return (t);
57 } else {
58 x = -x;
59 t = floor(x);
60 if (x - t >= 0.5)
61 t += 1.0;
62 return (-t);
63 }
64 }
65