libm/nan.c

   1 /*
   2  * Copyright (C) 2002 by Erik Andersen <andersen@uclibc.org>
   3  *
   4  * Licensed under the LGPL v2.1, see the file COPYING.LIB in this tarball.
   5  */
   6
   7 /***********************************************************************
   8     nan, nanf, nanl - return quiet NaN
   9
  10         These functions shall return a quiet NaN, if available, with content
  11         indicated through tagp.
  12
  13         If the implementation does not support quiet NaNs, these functions
  14         shall return zero.
  15
  16    Calls:  strlen(), sprintf(), strtod()
  17
  18 ***********************************************************************/
  19 #include <math.h>
  20 #include <string.h>
  21 #include <stdlib.h>
  22 #include <stdio.h>
  23
  24 double nan (const char *tagp)
  25 {
  26         if (tagp[0] != '\0') {
  27                 char buf[6 + strlen (tagp)];
  28                 sprintf (buf, "NAN(%s)", tagp);
  29                 return strtod (buf, NULL);
  30         }
  31         return NAN;
  32 }
  33 libm_hidden_def(nan)
  34
  35 libm_hidden_proto(nanf)
  36 float nanf (const char *tagp)
  37 {
  38         if (tagp[0] != '\0') {
  39                 char buf[6 + strlen (tagp)];
  40                 sprintf (buf, "NAN(%s)", tagp);
  41                 return strtof (buf, NULL);
  42         }
  43         return NAN;
  44 }
  45 libm_hidden_def(nanf)
  46
  47 #if defined __UCLIBC_HAS_LONG_DOUBLE_MATH__ && !defined __NO_LONG_DOUBLE_MATH
  48 libm_hidden_proto(nanl)
  49 long double nanl (const char *tagp)
  50 {
  51         if (tagp[0] != '\0') {
  52                 char buf[6 + strlen (tagp)];
  53                 sprintf (buf, "NAN(%s)", tagp);
  54                 return strtold (buf, NULL);
  55         }
  56         return NAN;
  57 }
  58 libm_hidden_def(nanl)
  59 #endif