Subversion Repositories openrisc_2011-10-31

/* @(#)z_log10.c 1.0 98/08/13 */

/******************************************************************

 * Logarithm

 *

 * Input:

 *   x - floating point value

 *

 * Output:

 *   logarithm of x

 *

 * Description:

 *   This routine returns the logarithm of x (base 10).

 *

 *****************************************************************/

/*

FUNCTION

        <<log10>>, <<log10f>>---base 10 logarithms

INDEX

log10

INDEX

log10f

ANSI_SYNOPSIS

        #include <math.h>

        double log10(double <[x]>);

        float log10f(float <[x]>);

TRAD_SYNOPSIS

        #include <math.h>

        double log10(<[x]>)

        double <[x]>;

        float log10f(<[x]>)

        float <[x]>;

DESCRIPTION

<<log10>> returns the base 10 logarithm of <[x]>.

It is implemented as <<log(<[x]>) / log(10)>>.

<<log10f>> is identical, save that it takes and returns <<float>> values.

RETURNS

<<log10>> and <<log10f>> return the calculated value.

See the description of <<log>> for information on errors.

PORTABILITY

<<log10>> is ANSI C.  <<log10f>> is an extension.

*/

#include "fdlibm.h"

#include "zmath.h"

#ifndef _DOUBLE_IS_32BITS

double

_DEFUN (log10, (double),

        double x)

{

  return (logarithm (x, 1));

}

#endif /* _DOUBLE_IS_32BITS */