1 /* $OpenBSD: s_lroundl.c,v 1.5 2021/05/31 17:39:24 tb Exp $ */
2
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 long double
35 #define roundit roundl
36 #define dtype long
37 #define DTYPE_MIN LONG_MIN
38 #define DTYPE_MAX LONG_MAX
39 #define fn lroundl
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 */
50 static const type dtype_min = DTYPE_MIN - 0.5;
51 static 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
55 dtype
fn(type x)56 fn(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