1*e44725a8Skettenis /* $OpenBSD: s_lrint.c,v 1.12 2021/10/14 21:30:00 kettenis Exp $ */
2d7c6e841Skettenis
3d7c6e841Skettenis /*-
4*e44725a8Skettenis * Copyright (c) 2005 David Schultz <das@FreeBSD.ORG>
5*e44725a8Skettenis * All rights reserved.
6d7c6e841Skettenis *
7d7c6e841Skettenis * Redistribution and use in source and binary forms, with or without
8d7c6e841Skettenis * modification, are permitted provided that the following conditions
9d7c6e841Skettenis * are met:
10d7c6e841Skettenis * 1. Redistributions of source code must retain the above copyright
11d7c6e841Skettenis * notice, this list of conditions and the following disclaimer.
12d7c6e841Skettenis * 2. Redistributions in binary form must reproduce the above copyright
13d7c6e841Skettenis * notice, this list of conditions and the following disclaimer in the
14d7c6e841Skettenis * documentation and/or other materials provided with the distribution.
15d7c6e841Skettenis *
16d7c6e841Skettenis * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17d7c6e841Skettenis * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18d7c6e841Skettenis * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19d7c6e841Skettenis * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20d7c6e841Skettenis * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21d7c6e841Skettenis * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22d7c6e841Skettenis * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23d7c6e841Skettenis * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24d7c6e841Skettenis * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25d7c6e841Skettenis * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
26d7c6e841Skettenis * SUCH DAMAGE.
27d7c6e841Skettenis */
28d7c6e841Skettenis
29*e44725a8Skettenis #include <fenv.h>
30d7c6e841Skettenis #include <math.h>
3149393c00Smartynas
32*e44725a8Skettenis #ifndef type
33*e44725a8Skettenis #define type double
34*e44725a8Skettenis #define roundit rint
35*e44725a8Skettenis #define dtype long
36*e44725a8Skettenis #define fn lrint
37d7c6e841Skettenis #endif
38d7c6e841Skettenis
39*e44725a8Skettenis /*
40*e44725a8Skettenis * C99 says we should not raise a spurious inexact exception when an
41*e44725a8Skettenis * invalid exception is raised. Unfortunately, the set of inputs
42*e44725a8Skettenis * that overflows depends on the rounding mode when 'dtype' has more
43*e44725a8Skettenis * significant bits than 'type'. Hence, we bend over backwards for the
44*e44725a8Skettenis * sake of correctness; an MD implementation could be more efficient.
45*e44725a8Skettenis */
46*e44725a8Skettenis dtype
fn(type x)47*e44725a8Skettenis fn(type x)
48d7c6e841Skettenis {
49*e44725a8Skettenis fenv_t env;
50*e44725a8Skettenis dtype d;
51d7c6e841Skettenis
52*e44725a8Skettenis feholdexcept(&env);
53*e44725a8Skettenis d = (dtype)roundit(x);
54*e44725a8Skettenis if (fetestexcept(FE_INVALID))
55*e44725a8Skettenis feclearexcept(FE_INEXACT);
56*e44725a8Skettenis feupdateenv(&env);
57*e44725a8Skettenis return (d);
58d7c6e841Skettenis }
59*e44725a8Skettenis DEF_STD(fn);
60*e44725a8Skettenis LDBL_MAYBE_CLONE(fn);
61