X-Git-Url: http://erislabs.net/gitweb/?a=blobdiff_plain;f=lib%2Fisnanl-nolibm.h;h=3dbba8bc67d559b234daff49bad879cf0f632cfa;hb=870daa58035b4bb39549f15d20ad1422dd649d63;hp=77284331d715f30babe59c655c4d385ee67b6414;hpb=57fdfd3f8ec62b105c53bcdf6f127c35c7fe7391;p=gnulib.git

diff --git a/lib/isnanl-nolibm.h b/lib/isnanl-nolibm.h
index 77284331d..3dbba8bc6 100644
--- a/lib/isnanl-nolibm.h
+++ b/lib/isnanl-nolibm.h
@@ -1,5 +1,5 @@
 /* Test for NaN that does not need libm.
-   Copyright (C) 2007 Free Software Foundation, Inc.
+   Copyright (C) 2007-2010 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_ISNANL_IN_LIBC
 /* Get declaration of isnan macro or (older) isnanl function.  */
 # include <math.h>
-# ifdef isnan
+# if __GNUC__ >= 4
+   /* GCC 4.0 and newer provides three built-ins for isnan.  */
+#  undef isnanl
+#  define isnanl(x) __builtin_isnanl ((long double)(x))
+# elif defined isnan
 #  undef isnanl
 #  define isnanl(x) isnan ((long double)(x))
 # endif