re PR libfortran/26253 (fallback scalbn doesn't handle denormals correctly)

	PR libfortran/26253
	* intrinsics/c99_functions.c (scalbn): Use ldexp if appopriate.

From-SVN: r128648

libgfortran/ChangeLog

 2007-09-21  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
 
+	PR libfortran/26253
+	* intrinsics/c99_functions.c (scalbn): Use ldexp if appopriate.
+
+2007-09-21  Francois-Xavier Coudert  <fxcoudert@gcc.gnu.org>
+
 	PR libfortran/23272
 	* io/unix.c (id_from_handle, id_from_path, id_from_fd): New
 	functions.

libgfortran/intrinsics/c99_functions.c

@@ -341,7 +341,11 @@ log10f(float x)
 double
 scalbn(double x, int y)
 {
+#if (FLT_RADIX == 2) && defined(HAVE_LDEXP)
+  return ldexp (x, y);
+#else
   return x * pow(FLT_RADIX, y);
+#endif
 }
 #endif