xref: /netbsd-src/lib/libm/src/w_log.c (revision 4ff088e36b1d8173711ec3a2c9c55ed184ed9a62)
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 1.11 2024/07/16 14:52:50 riastradh Exp $");
16 #endif
17 
18 /*
19  * wrapper log(x)
20  */
21 
22 #include "namespace.h"
23 
24 #include "math.h"
25 #include "math_private.h"
26 
27 #ifndef __HAVE_LONG_DOUBLE
__weak_alias(logl,_logl)28 __weak_alias(logl, _logl)
29 __strong_alias(_logl, _log)
30 #endif
31 
32 __weak_alias(log, _log)
33 double
34 log(double x)		/* wrapper log */
35 {
36 #ifdef _IEEE_LIBM
37 	return __ieee754_log(x);
38 #else
39 	double z;
40 	z = __ieee754_log(x);
41 	if(_LIB_VERSION == _IEEE_ || isnan(x) || x > 0.0) return z;
42 	if(x==0.0)
43 	    return __kernel_standard(x,x,16); /* log(0) */
44 	else
45 	    return __kernel_standard(x,x,17); /* log(x<0) */
46 #endif
47 }
48