libm/nan.c

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