xref: /netbsd-src/lib/libm/src/w_log10.c (revision ce0bb6e8d2e560ecacbe865a848624f94498063b)
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 #if defined(LIBM_SCCS) && !defined(lint)
14 static char rcsid[] = "$Id: w_log10.c,v 1.5 1994/09/22 16:45:56 jtc Exp $";
15 #endif
16 
17 /*
18  * wrapper log10(X)
19  */
20 
21 #include "math.h"
22 #include "math_private.h"
23 
24 
25 #ifdef __STDC__
26 	double log10(double x)		/* wrapper log10 */
27 #else
28 	double log10(x)			/* wrapper log10 */
29 	double x;
30 #endif
31 {
32 #ifdef _IEEE_LIBM
33 	return __ieee754_log10(x);
34 #else
35 	double z;
36 	z = __ieee754_log10(x);
37 	if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
38 	if(x<=0.0) {
39 	    if(x==0.0)
40 	        return __kernel_standard(x,x,18); /* log10(0) */
41 	    else
42 	        return __kernel_standard(x,x,19); /* log10(x<0) */
43 	} else
44 	    return z;
45 #endif
46 }
47