xref: /illumos-gate/usr/src/lib/libm/common/Q/floorl.c (revision 97a9db610324e7db4393415018e0e737485a94cd)
1 /*
2  * CDDL HEADER START
3  *
4  * The contents of this file are subject to the terms of the
5  * Common Development and Distribution License (the "License").
6  * You may not use this file except in compliance with the License.
7  *
8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9  * or http://www.opensolaris.org/os/licensing.
10  * See the License for the specific language governing permissions
11  * and limitations under the License.
12  *
13  * When distributing Covered Code, include this CDDL HEADER in each
14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15  * If applicable, add the following below this CDDL HEADER, with the
16  * fields enclosed by brackets "[]" replaced with your own identifying
17  * information: Portions Copyright [yyyy] [name of copyright owner]
18  *
19  * CDDL HEADER END
20  */
21 
22 /*
23  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
24  */
25 /*
26  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
27  * Use is subject to license terms.
28  */
29 
30 /*
31  * ceill(x)	return the biggest integral value below x
32  * floorl(x)	return the least integral value above x
33  *
34  * NOTE: aintl(x), anintl(x), ceill(x), floorl(x), and rintl(x) return result
35  * with the same sign as x's,  including 0.0.
36  */
37 
38 #pragma weak __ceill = ceill
39 #pragma weak __floorl = floorl
40 
41 #include "libm.h"
42 #include "longdouble.h"
43 
44 static const long double qone = 1.0L;
45 
46 long double
47 ceill(long double x) {
48 	long double t;
49 
50 	if (!finitel(x))
51 		return (x + x);
52 	t = rintl(x);
53 	if (t >= x) 			/* already ceil(x) */
54 		return (t);
55 	else				/* t < x case: return t+1  */
56 		return (copysignl(t + qone, x));
57 }
58 
59 long double
60 floorl(long double x) {
61 	long double t;
62 
63 	if (!finitel(x))
64 		return (x + x);
65 	t = rintl(x);
66 	if (t <= x)
67 		return (t);		/* already floor(x) */
68 	else 				/* x < t case: return t-1  */
69 	    return (copysignl(t - qone, x));
70 }
71