1/*-
2 * Copyright (c) 2005 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#include <sys/limits.h>
29#include <fenv.h>
30#include <math.h>
31
32#ifndef type
33__FBSDID("$FreeBSD$");
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 dtype_min = DTYPE_MIN - 0.5;
51static const type dtype_max = DTYPE_MAX + 0.5;
52#define	INRANGE(x)	(dtype_max - DTYPE_MAX != 0.5 || \
53			 ((x) > dtype_min && (x) < dtype_max))
54
55dtype
56fn(type x)
57{
58
59	if (INRANGE(x)) {
60		x = roundit(x);
61		return ((dtype)x);
62	} else {
63		feraiseexcept(FE_INVALID);
64		return (DTYPE_MAX);
65	}
66}
67