frontend-passes: (optimize_lexical_comparison): New function.

2010-04-04  Thomas Koenig  <tkoenig@gcc.gnu.org>

	* frontend-passes: (optimize_lexical_comparison): New function.
	(optimize_expr): Call it.
	(optimize_comparison): Also handle lexical comparison functions.
	Return false instad of -2 for unequal comparison.

From-SVN: r171954

gcc/fortran/ChangeLog

+2010-04-04  Thomas Koenig  <tkoenig@gcc.gnu.org>
+
+	* frontend-passes: (optimize_lexical_comparison): New function.
+	(optimize_expr): Call it.
+	(optimize_comparison): Also handle lexical comparison functions.
+	Return false instad of -2 for unequal comparison.
+
 2011-04-04  Thomas Koenig  <tkoenig@gcc.gnu.org>
 
 	PR fortran/48412