compiler/mlib/w_log10.c

   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 #ifndef lint
  14 static char rcsid[] = "$FreeBSD: src/lib/msun/src/w_log10.c,v 1.5 1999/08/28 00:07:06 peter Exp $";
  15 #endif
  16
  17 /*
  18  * wrapper log10(X)
  19  */
  20
  21 #include "math.h"
  22 #include "math_private.h"
  23
  24
  25 double
  26 log10(double x)         /* wrapper log10 */
  27 {
  28 #ifdef _IEEE_LIBM
  29         return __ieee754_log10(x);
  30 #else
  31         double z;
  32         z = __ieee754_log10(x);
  33         if(_LIB_VERSION == _IEEE_ || isnan(x)) return z;
  34         if(x<=0.0) {
  35             if(x==0.0)
  36                 return __kernel_standard(x,x,18); /* log10(0) */
  37             else
  38                 return __kernel_standard(x,x,19); /* log10(x<0) */
  39         } else
  40             return z;
  41 #endif
  42 }