xref: /relibc/openlibm/src/s_lrint.c (revision 388f0f1d324531e806ebd1206ec045d5268ad378)
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 "cdefs-compat.h"
28 
29 #include <openlibm_fenv.h>
30 #include <openlibm_math.h>
31 
32 #include "math_private.h"
33 
34 #ifndef type
35 //__FBSDID("$FreeBSD: src/lib/msun/src/s_lrint.c,v 1.1 2005/01/11 23:12:55 das Exp $");
36 #define type		double
37 #define	roundit		rint
38 #define dtype		long
39 #define	fn		lrint
40 #endif
41 
42 /*
43  * C99 says we should not raise a spurious inexact exception when an
44  * invalid exception is raised.  Unfortunately, the set of inputs
45  * that overflows depends on the rounding mode when 'dtype' has more
46  * significant bits than 'type'.  Hence, we bend over backwards for the
47  * sake of correctness; an MD implementation could be more efficient.
48  */
49 DLLEXPORT dtype
50 fn(type x)
51 {
52 	fenv_t env;
53 	dtype d;
54 
55 	feholdexcept(&env);
56 	d = (dtype)roundit(x);
57 	if (fetestexcept(FE_INVALID))
58 		feclearexcept(FE_INEXACT);
59 	feupdateenv(&env);
60 	return (d);
61 }
62