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 <fenv.h>
30#include <math.h>
31
32/*
33 * We save and restore the floating-point environment to avoid raising
34 * an inexact exception.  We can get away with using fesetenv()
35 * instead of feclearexcept()/feupdateenv() to restore the environment
36 * because the only exception defined for rint() is overflow, and
37 * rounding can't overflow as long as emax >= p.
38 *
39 * The volatile keyword is needed below because clang incorrectly assumes
40 * that rint won't raise any floating-point exceptions. Declaring ret volatile
41 * is sufficient to trick the compiler into doing the right thing.
42 */
43#define	DECL(type, fn, rint)	\
44type				\
45fn(type x)			\
46{				\
47	volatile type ret;	\
48	fenv_t env;		\
49				\
50	fegetenv(&env);		\
51	ret = rint(x);		\
52	fesetenv(&env);		\
53	return (ret);		\
54}
55
56DECL(double, nearbyint, rint)
57DECL(float, nearbyintf, rintf)
58DECL(long double, nearbyintl, rintl)
59