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[glibc/history.git] / bits / inf.h
blob2d526adb23bd27bf5d52e5c871e1f886e78672d3
1 /* Default `INFINITY' constant.
2 Copyright (C) 2004 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, write to the Free
17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
18 02111-1307 USA. */
20 #ifndef _MATH_H
21 # error "Never use <bits/inf.h> directly; include <math.h> instead."
22 #endif
24 /* If we don't have real infinity, then we're supposed to produce a float
25 value that overflows at translation time, which is required to produce
26 a diagnostic. GCC's __builtin_inff produces a quite nice diagnostic
27 that tells the user that the target doesn't support infinities. */
29 #if __GNUC_PREREQ(3,3)
30 # define INFINITY (__builtin_inff())
31 #else
32 # define INFINITY (1e9999f)
33 #endif