summaryrefslogtreecommitdiff
path: root/bits/inf.h
diff options
context:
space:
mode:
Diffstat (limited to 'bits/inf.h')
-rw-r--r--bits/inf.h33
1 files changed, 33 insertions, 0 deletions
diff --git a/bits/inf.h b/bits/inf.h
new file mode 100644
index 0000000000..2d526adb23
--- /dev/null
+++ b/bits/inf.h
@@ -0,0 +1,33 @@
+/* Default `INFINITY' constant.
+ Copyright (C) 2004 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 Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+#ifndef _MATH_H
+# error "Never use <bits/inf.h> directly; include <math.h> instead."
+#endif
+
+/* If we don't have real infinity, then we're supposed to produce a float
+ value that overflows at translation time, which is required to produce
+ a diagnostic. GCC's __builtin_inff produces a quite nice diagnostic
+ that tells the user that the target doesn't support infinities. */
+
+#if __GNUC_PREREQ(3,3)
+# define INFINITY (__builtin_inff())
+#else
+# define INFINITY (1e9999f)
+#endif