1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2005 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/limits.h>
30#include <fenv.h>
31#include <math.h>
32
33#ifndef type
34#define type		double
35#define	roundit		round
36#define dtype		long
37#define	DTYPE_MIN	LONG_MIN
38#define	DTYPE_MAX	LONG_MAX
39#define	fn		lround
40#endif
41
42/*
43 * If type has more precision than dtype, the endpoints dtype_(min|max) are
44 * of the form xxx.5; they are "out of range" because lround() rounds away
45 * from 0.  On the other hand, if type has less precision than dtype, then
46 * all values that are out of range are integral, so we might as well assume
47 * that everything is in range.  At compile time, INRANGE(x) should reduce to
48 * two floating-point comparisons in the former case, or TRUE otherwise.
49 */
50static const type type_min = (type)DTYPE_MIN;
51static const type type_max = (type)DTYPE_MAX;
52static const type dtype_min = (type)DTYPE_MIN - 0.5;
53static const type dtype_max = (type)DTYPE_MAX + 0.5;
54#define	INRANGE(x)	(dtype_max - type_max != 0.5 || \
55			 ((x) > dtype_min && (x) < dtype_max))
56
57dtype
58fn(type x)
59{
60
61	if (INRANGE(x)) {
62		x = roundit(x);
63		return ((dtype)x);
64	} else {
65		feraiseexcept(FE_INVALID);
66		return (DTYPE_MAX);
67	}
68}
69