xref: /illumos-gate/usr/src/lib/libm/common/C/lgamma_r.c (revision b819cea2f73f98c5662230cc9affc8cc84f77fcf)
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  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
23  */
24 /*
25  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
26  * Use is subject to license terms.
27  */
28 
29 #pragma weak __lgamma_r = lgamma_r
30 
31 #include "libm.h"
32 
33 double
34 lgamma_r(double x, int *signgamp) {
35 	double	g;
36 
37 	if (isnan(x))
38 		return (x * x);
39 
40 	g = rint(x);
41 	if (x == g && x <= 0.0) {
42 		*signgamp = 1;
43 		return (_SVID_libm_err(x, x, 15));
44 	}
45 
46 	g = __k_lgamma(x, signgamp);
47 	if (!finite(g))
48 	    g = _SVID_libm_err(x, x, 14);
49 	return (g);
50 }
51