math/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 #if defined(LIBM_SCCS) && !defined(lint)
  14 static char rcsid[] = "$NetBSD: w_log10.c,v 1.6 1995/05/10 20:49:35 jtc Exp $";
  15 #endif
  16
  17 /*
  18  * wrapper log10(X)
  19  */
  20
  21 #include <math.h>
  22 #include "math_private.h"
  23
  24
  25 #ifdef __STDC__
  26         double __log10(double x)                /* wrapper log10 */
  27 #else
  28         double __log10(x)                       /* wrapper log10 */
  29         double x;
  30 #endif
  31 {
  32 #ifdef _IEEE_LIBM
  33         return __ieee754_log10(x);
  34 #else
  35         double z;
  36         z = __ieee754_log10(x);
  37         if(_LIB_VERSION == _IEEE_ || __isnan(x)) return z;
  38         if(x<=0.0) {
  39             if(x==0.0)
  40                 return __kernel_standard(x,x,18); /* log10(0) */
  41             else
  42                 return __kernel_standard(x,x,19); /* log10(x<0) */
  43         } else
  44             return z;
  45 #endif
  46 }
  47 weak_alias (__log10, log10)
  48 #ifdef NO_LONG_DOUBLE
  49 strong_alias (__log10, __log10l)
  50 weak_alias (__log10, log10l)
  51 #endif