1/*	$NetBSD: s_nearbyint.c,v 1.5 2024/02/24 15:16:53 christos Exp $	*/
2
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 <sys/cdefs.h>
30#if 0
31__FBSDID("$FreeBSD: src/lib/msun/src/s_nearbyint.c,v 1.2 2008/01/14 02:12:06 das Exp $");
32#else
33__RCSID("$NetBSD: s_nearbyint.c,v 1.5 2024/02/24 15:16:53 christos Exp $");
34#endif
35
36#include "namespace.h"
37
38#include <machine/ieee.h>
39#include <fenv.h>
40#include <math.h>
41
42/*
43 * We save and restore the floating-point environment to avoid raising
44 * an inexact exception.  We can get away with using fesetenv()
45 * instead of feclearexcept()/feupdateenv() to restore the environment
46 * because the only exception defined for rint() is overflow, and
47 * rounding can't overflow as long as emax >= p.
48 */
49#define	DECL(type, fn, rint)	\
50type				\
51fn(type x)			\
52{				\
53	type ret;		\
54	fenv_t env;		\
55				\
56	fegetenv(&env);		\
57	ret = rintl(x);		\
58	fesetenv(&env);		\
59	return (ret);		\
60}
61
62DECL(double, nearbyint, rint)
63DECL(float, nearbyintf, rintf)
64DECL(long double, nearbyintl, rintl)
65