xref: /minix3/lib/libm/src/w_logf.c (revision 2fe8fb192fe7e8720e3e7a77f928da545e872a6a)
1 /* w_logf.c -- float version of w_log.c.
2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
3  */
4 
5 /*
6  * ====================================================
7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
8  *
9  * Developed at SunPro, a Sun Microsystems, Inc. business.
10  * Permission to use, copy, modify, and distribute this
11  * software is freely granted, provided that this notice
12  * is preserved.
13  * ====================================================
14  */
15 
16 #include <sys/cdefs.h>
17 #if defined(LIBM_SCCS) && !defined(lint)
18 __RCSID("$NetBSD: w_logf.c,v 1.7 2007/08/20 16:01:40 drochner Exp $");
19 #endif
20 
21 /*
22  * wrapper logf(x)
23  */
24 
25 #include "namespace.h"
26 #include "math.h"
27 #include "math_private.h"
28 
29 #ifdef __weak_alias
__weak_alias(logf,_logf)30 __weak_alias(logf, _logf)
31 #endif
32 
33 float
34 logf(float x)		/* wrapper logf */
35 {
36 #ifdef _IEEE_LIBM
37 	return __ieee754_logf(x);
38 #else
39 	float z;
40 	z = __ieee754_logf(x);
41 	if(_LIB_VERSION == _IEEE_ || isnanf(x) || x > (float)0.0) return z;
42 	if(x==(float)0.0)
43 	    /* logf(0) */
44 	    return (float)__kernel_standard((double)x,(double)x,116);
45 	else
46 	    /* logf(x<0) */
47 	    return (float)__kernel_standard((double)x,(double)x,117);
48 #endif
49 }
50