prime/src/Runtime/w_log.c

39 lines
865 B
C

/* @(#)w_log.c 1.2 95/01/04 */
/*
* ====================================================
* 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 log(x)
*/
#include "fdlibm.h"
#ifdef __STDC__
double log(double x) /* wrapper pow */
#else
double log(x) /* wrapper log */
double x;
#endif
{
#ifdef _IEEE_LIBM
return __ieee754_log(x);
#else
double z;
z = __ieee754_log(x);
if (_LIB_VERSION == _IEEE_ || isnan(x) || x > 0.0)
return z;
if (x == 0.0)
return __kernel_standard(x, x, 16); /* log(0) */
else
return __kernel_standard(x, x, 17); /* log(x<0) */
#endif
}