newlib-cygwin/newlib/libm/common/sf_log2.c

49 lines
946 B
C

/* sf_log2.c -- float version of s_log2.c.
* Modification of sf_exp10.c by Yaakov Selkowitz 2009.
*/
/*
* ====================================================
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
*
* Developed at SunPro, a Sun Microsystems, Inc. business.
* Permission to use, copy, modify, and distribute this
* software is freely granted, provided that this notice
* is preserved.
* ====================================================
*/
/*
* wrapper log2f(x)
*/
#include "fdlibm.h"
#include <errno.h>
#include <math.h>
#undef log2
#undef log2f
#ifdef __STDC__
float log2f(float x) /* wrapper log2f */
#else
float log2f(x) /* wrapper log2f */
float x;
#endif
{
return (logf(x) / (float_t) M_LN2);
}
#ifdef _DOUBLE_IS_32BITS
#ifdef __STDC__
double log2(double x)
#else
double log2(x)
double x;
#endif
{
return (double) log2f((float) x);
}
#endif /* defined(_DOUBLE_IS_32BITS) */