1 /* $OpenBSD: e_tgammal.c,v 1.1 2011/07/06 00:02:42 martynas Exp $ */
2
3 /*
4 * Copyright (c) 2011 Martynas Venckus <martynas@openbsd.org>
5 *
6 * Permission to use, copy, modify, and distribute this software for any
7 * purpose with or without fee is hereby granted, provided that the above
8 * copyright notice and this permission notice appear in all copies.
9 *
10 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17 */
18
19 #include <math.h>
20
21 #include "math_private.h"
22
23 long double
tgammal(long double x)24 tgammal(long double x)
25 {
26 int64_t i0,i1;
27
28 GET_LDOUBLE_WORDS64(i0,i1,x);
29 if (((i0&0x7fffffffffffffffLL)|i1) == 0) {
30 signgam = 0;
31 return (1.0/x);
32 }
33
34 if (i0<0 && (u_int64_t)i0<0xffff000000000000ULL && rintl(x)==x) {
35 signgam = 0;
36 return (x-x)/(x-x);
37 }
38
39 if (i0==0xffff000000000000ULL && i1==0) {
40 signgam = 0;
41 return (x-x);
42 }
43
44 return expl(lgammal(x));
45 }
46