POK
log.c
1 /*
2  * POK header
3  *
4  * The following file is a part of the POK project. Any modification should
5  * made according to the POK licence. You CANNOT use this file or a part of
6  * this file is this part of a file for your own project
7  *
8  * For more information on the POK licence, please see our LICENCE FILE
9  *
10  * Please follow the coding guidelines described in doc/CODING_GUIDELINES
11  *
12  * Copyright (c) 2007-2009 POK team
13  *
14  * Created by julien on Fri Jan 30 14:41:34 2009
15  */
16 
17 /* @(#)w_log.c 5.1 93/09/24 */
18 /*
19  * ====================================================
20  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
21  *
22  * Developed at SunPro, a Sun Microsystems, Inc. business.
23  * Permission to use, copy, modify, and distribute this
24  * software is freely granted, provided that this notice
25  * is preserved.
26  * ====================================================
27  */
28 
29 #ifdef POK_NEEDS_LIBMATH
30 
31 /*
32  * wrapper log(x)
33  */
34 
35 #include <libm.h>
36 #include "namespace.h"
37 #include "math_private.h"
38 
39 #ifdef __weak_alias
40 __weak_alias(log, _log)
41 #endif
42 
43 double
44 log(double x) /* wrapper log */
45 {
46 #ifdef _IEEE_LIBM
47  return __ieee754_log(x);
48 #else
49  double z;
50  z = __ieee754_log(x);
51  if(_LIB_VERSION == _IEEE_ || isnan(x) || x > 0.0) return z;
52  if(x==0.0)
53  return __kernel_standard(x,x,16); /* log(0) */
54  else
55  return __kernel_standard(x,x,17); /* log(x<0) */
56 #endif
57 }
58 
59 #endif