+/* e.g. libsunmath doesn't have modfl and frexpl as of mid-March 2000 */
+# ifdef HAS_MODFL
+# define Perl_modf(x,y) modfl(x,y)
+# else
+# define Perl_modf(x,y) ((long double)modf((double)(x),(double*)(y)))
+# endif
+# ifdef HAS_FREXPL
+# define Perl_frexp(x,y) frexpl(x,y)
+# else
+# define Perl_frexp(x,y) ((long double)frexp((double)(x),y))
+# endif
+# ifdef HAS_ISNANL
+# define Perl_isnan(x) isnanl(x)
+# else
+# ifdef HAS_ISNAN
+# define Perl_isnan(x) isnan((double)(x))
+# else
+# define Perl_isnan(x) ((x)!=(x))
+# endif
+# endif