diff options
Diffstat (limited to 'sysdeps/libm-ieee754/s_nanf.c')
-rw-r--r-- | sysdeps/libm-ieee754/s_nanf.c | 47 |
1 files changed, 47 insertions, 0 deletions
diff --git a/sysdeps/libm-ieee754/s_nanf.c b/sysdeps/libm-ieee754/s_nanf.c new file mode 100644 index 0000000000..e965b94b33 --- /dev/null +++ b/sysdeps/libm-ieee754/s_nanf.c @@ -0,0 +1,47 @@ +/* Return quiet nan. + Copyright (C) 1997 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +/* XXX The ISO C 9X standard mentions a `n-char-sequence' which is provided + as the argument to this function but I have no clue what this means. + Perhaps it is a description of the bits set in the mantissa. */ +#include <math.h> +#ifdef HANDLE_TAGP +# include <stdlib.h> +# include <string.h> +#else +# include <ieee754.h> +#endif + + +float +nanf (const char *tagp) +{ +#ifdef HANDLE_TAGP + /* If we ever should have use of the TAGP parameter we will use the + strtod function to analyze it. */ + char buf[6 + strlen (tagp)]; + sprintf (buf, "NAN(%s)", tagp); + return strtof (buf, NULL); +#else + static const union ieee754_float nan_value = + { ieee: { mantissa: 0x1, exponent: 0xff, negative: 0 } }; + return nan_value.f; +#endif +} |