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
27#include <sys/cdefs.h>
28__FBSDID("$FreeBSD$");
29
30#include <fenv.h>
31#include <math.h>
32
33/*
34 * We save and restore the floating-point environment to avoid raising
35 * an inexact exception.  We can get away with using fesetenv()
36 * instead of feclearexcept()/feupdateenv() to restore the environment
37 * because the only exception defined for rint() is overflow, and
38 * rounding can't overflow as long as emax >= p.
39 *
40 * The volatile keyword is needed below because clang incorrectly assumes
41 * that rint won't raise any floating-point exceptions. Declaring ret volatile
42 * is sufficient to trick the compiler into doing the right thing.
43 */
44#define	DECL(type, fn, rint)	\
45type				\
46fn(type x)			\
47{				\
48	volatile type ret;	\
49	fenv_t env;		\
50				\
51	fegetenv(&env);		\
52	ret = rint(x);		\
53	fesetenv(&env);		\
54	return (ret);		\
55}
56
57DECL(double, nearbyint, rint)
58DECL(float, nearbyintf, rintf)
59DECL(long double, nearbyintl, rintl)
60