1 /* @(#)w_log.c 5.1 93/09/24 */
2 /*
3 * ====================================================
4 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
5 *
6 * Developed at SunPro, a Sun Microsystems, Inc. business.
7 * Permission to use, copy, modify, and distribute this
8 * software is freely granted, provided that this notice
9 * is preserved.
10 * ====================================================
11 */
12
13 #include <sys/cdefs.h>
14 #if defined(LIBM_SCCS) && !defined(lint)
15 __RCSID("$NetBSD: w_log.c,v 1.10 2007/08/20 16:01:40 drochner Exp $");
16 #endif
17
18 /*
19 * wrapper log(x)
20 */
21
22 #include "namespace.h"
23 #include "math.h"
24 #include "math_private.h"
25
26 #ifdef __weak_alias
__weak_alias(log,_log)27 __weak_alias(log, _log)
28 #endif
29
30 double
31 log(double x) /* wrapper log */
32 {
33 #ifdef _IEEE_LIBM
34 return __ieee754_log(x);
35 #else
36 double z;
37 z = __ieee754_log(x);
38 if(_LIB_VERSION == _IEEE_ || isnan(x) || x > 0.0) return z;
39 if(x==0.0)
40 return __kernel_standard(x,x,16); /* log(0) */
41 else
42 return __kernel_standard(x,x,17); /* log(x<0) */
43 #endif
44 }
45