+AC_CHECK_LIB([m],[yn],[AC_DEFINE([HAVE_YN],[1],[libm includes yn])])
+AC_CHECK_LIB([m],[ynl],[AC_DEFINE([HAVE_YNL],[1],[libm includes ynl])])
+
+# On AIX, clog is present in libm as __clog
+AC_CHECK_LIB([m],[__clog],[AC_DEFINE([HAVE_CLOG],[1],[libm includes clog])])
+
+# Check for a isfinite macro that works on long doubles.
+LIBGFOR_CHECK_FOR_BROKEN_ISFINITE
+
+# Check for a isnan macro that works on long doubles.
+LIBGFOR_CHECK_FOR_BROKEN_ISNAN
+
+# Check for a fpclassify macro that works on long doubles.
+LIBGFOR_CHECK_FOR_BROKEN_FPCLASSIFY
+
+# Check whether the system has a working stat()
+LIBGFOR_CHECK_WORKING_STAT