X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fisnanf.h;h=774942c728e2499f9c63afd7ec67c55e1c9c0531;hb=6c38d72875ec56c4b2c250717d458e70b2cb97ef;hp=67bbfc6793fdbce19de06c20b9e625e4193bd376;hpb=57fdfd3f8ec62b105c53bcdf6f127c35c7fe7391;p=gnulib.git

diff --git a/lib/isnanf.h b/lib/isnanf.h
index 67bbfc679..774942c72 100644
--- a/lib/isnanf.h
+++ b/lib/isnanf.h
@@ -1,5 +1,5 @@
 /* Test for NaN that does not need libm.
-   Copyright (C) 2007 Free Software Foundation, Inc.
+   Copyright (C) 2007-2008 Free Software Foundation, Inc.
 
    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
@@ -17,7 +17,11 @@
 #if HAVE_ISNANF_IN_LIBC
 /* Get declaration of isnan macro or (older) isnanf function.  */
 # include <math.h>
-# ifdef isnan
+# if __GNUC__ >= 4
+   /* GCC 4.0 and newer provides three built-ins for isnan.  */
+#  undef isnanf
+#  define isnanf(x) __builtin_isnanf ((float)(x))
+# elif defined isnan
 #  undef isnanf
 #  define isnanf(x) isnan ((float)(x))
 # endif