From 28f540f45bbacd939bfd07f213bcad2bf730b1bf Mon Sep 17 00:00:00 2001 From: Roland McGrath Date: Sat, 18 Feb 1995 01:27:10 +0000 Subject: initial import --- sysdeps/ieee754/isinfl.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 44 insertions(+) create mode 100644 sysdeps/ieee754/isinfl.c (limited to 'sysdeps/ieee754/isinfl.c') diff --git a/sysdeps/ieee754/isinfl.c b/sysdeps/ieee754/isinfl.c new file mode 100644 index 0000000000..ad03728ad8 --- /dev/null +++ b/sysdeps/ieee754/isinfl.c @@ -0,0 +1,44 @@ +/* Copyright (C) 1991, 1992, 1995 Free Software Foundation, Inc. +This file is part of the GNU C Library. + +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., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include +#include "ieee754.h" + +#undef __isinfl +#undef isinfl + + +/* Return 0 if VALUE is finite or NaN, +1 if it + is +Infinity, -1 if it is -Infinity. */ +int +__isinfl (long double value) +{ + union ieee854_long_double u; + + u.d = value; + + /* An IEEE 854 infinity has an exponent with the + maximum possible value and a zero mantissa. */ + if ((u.ieee.exponent & 0x7fff) == 0x7fff && + u.ieee.mantissa0 == 0 && u.ieee.mantissa1 == 0) + return u.ieee.negative ? -1 : 1; + + return 0; +} + +weak_alias (__isinfl, isinfl); -- cgit v1.2.1