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 <fenv.h>
29 #include <math.h>
30
31 #ifndef type
32 __FBSDID("$FreeBSD$");
33 #define type double
34 #define roundit rint
35 #define dtype long
36 #define fn lrint
37 #endif
38
39 /*
40 * C99 says we should not raise a spurious inexact exception when an
41 * invalid exception is raised. Unfortunately, the set of inputs
42 * that overflows depends on the rounding mode when 'dtype' has more
43 * significant bits than 'type'. Hence, we bend over backwards for the
44 * sake of correctness; an MD implementation could be more efficient.
45 */
46 dtype
fn(type x)47 fn(type x)
48 {
49 fenv_t env;
50 dtype d;
51
52 feholdexcept(&env);
53 d = (dtype)roundit(x);
54 if (fetestexcept(FE_INVALID))
55 feclearexcept(FE_INEXACT);
56 feupdateenv(&env);
57 return (d);
58 }
59