xref: /netbsd-src/lib/libm/src/w_log10.c (revision ae1bfcddc410612bc8c58b807e1830becb69a24c)
1 /* @(#)w_log10.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 #ifndef lint
14 static char rcsid[] = "$Id: w_log10.c,v 1.3 1994/02/18 02:27:58 jtc Exp $";
15 #endif
16 
17 /*
18  * wrapper log10(X)
19  */
20 
21 #include <math.h>
22 
23 
24 #ifdef __STDC__
25 	double log10(double x)		/* wrapper log10 */
26 #else
27 	double log10(x)			/* wrapper log10 */
28 	double x;
29 #endif
30 {
31 #ifdef _IEEE_LIBM
32 	return __ieee754_log10(x);
33 #else
34 	double z;
35 	z = __ieee754_log10(x);
36 	if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
37 	if(x<=0.0) {
38 	    if(x==0.0)
39 	        return __kernel_standard(x,x,18); /* log10(0) */
40 	    else
41 	        return __kernel_standard(x,x,19); /* log10(x<0) */
42 	} else
43 	    return z;
44 #endif
45 }
46