toolchain/gcc/newlib/libm/math/wf_log10.c

   1 /* wf_log10.c -- float version of w_log10.c.
   2  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
   3  */
   4
   5 /*
   6  * ====================================================
   7  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   8  *
   9  * Developed at SunPro, a Sun Microsystems, Inc. business.
  10  * Permission to use, copy, modify, and distribute this
  11  * software is freely granted, provided that this notice
  12  * is preserved.
  13  * ====================================================
  14  */
  15
  16 /*
  17  * wrapper log10f(X)
  18  */
  19
  20 #include "fdlibm.h"
  21 #include <errno.h>
  22
  23 #ifdef __STDC__
  24         float log10f(float x)           /* wrapper log10f */
  25 #else
  26         float log10f(x)                 /* wrapper log10f */
  27         float x;
  28 #endif
  29 {
  30 #ifdef _IEEE_LIBM
  31         return __ieee754_log10f(x);
  32 #else
  33         float z;
  34         struct exception exc;
  35         z = __ieee754_log10f(x);
  36         if(_LIB_VERSION == _IEEE_ || isnanf(x)) return z;
  37         if(x<=(float)0.0) {
  38 #ifndef HUGE_VAL
  39 #define HUGE_VAL inf
  40             double inf = 0.0;
  41
  42             SET_HIGH_WORD(inf,0x7ff00000);      /* set inf to infinite */
  43 #endif
  44             exc.name = "log10f";
  45             exc.err = 0;
  46             exc.arg1 = exc.arg2 = (double)x;
  47             if (_LIB_VERSION == _SVID_)
  48                exc.retval = -HUGE;
  49             else
  50                exc.retval = -HUGE_VAL;
  51             if(x==(float)0.0) {
  52                 /* log10f(0) */
  53                 exc.type = SING;
  54                 if (_LIB_VERSION == _POSIX_)
  55                    errno = ERANGE;
  56                 else if (!matherr(&exc)) {
  57                    errno = EDOM;
  58                 }
  59             } else {
  60                 /* log10f(x<0) */
  61                 exc.type = DOMAIN;
  62                 if (_LIB_VERSION == _POSIX_)
  63                    errno = EDOM;
  64                 else if (!matherr(&exc)) {
  65                    errno = EDOM;
  66                 }
  67             }
  68             if (exc.err != 0)
  69                errno = exc.err;
  70             return (float)exc.retval;
  71         } else
  72             return z;
  73 #endif
  74 }
  75
  76 #ifdef _DOUBLE_IS_32BITS
  77
  78 #ifdef __STDC__
  79         double log10(double x)
  80 #else
  81         double log10(x)
  82         double x;
  83 #endif
  84 {
  85         return (double) log10f((float) x);
  86 }
  87
  88 #endif /* defined(_DOUBLE_IS_32BITS) */