read-rtl.c (join_c_conditions): Return the first string if the two strings are equal.

gcc/
	* read-rtl.c (join_c_conditions): Return the first string if the
	two strings are equal.

From-SVN: r135091

gcc/ChangeLog

 2008-05-08  Richard Sandiford  <rsandifo@nildram.co.uk>
 
+	* read-rtl.c (join_c_conditions): Return the first string if the
+	two strings are equal.
+
+2008-05-08  Richard Sandiford  <rsandifo@nildram.co.uk>
+
 	* gensupport.h (pred_data): Add a "num_codes" field.
 	(add_predicate_code): Declare.
 	* gensupport.c (add_predicate_code): New function.

gcc/read-rtl.c

@@ -787,6 +787,9 @@ join_c_conditions (const char *cond1, const char *cond2)
   if (cond2 == 0 || cond2[0] == 0)
     return cond1;
 
+  if (strcmp (cond1, cond2) == 0)
+    return cond1;
+
   result = concat ("(", cond1, ") && (", cond2, ")", NULL);
   obstack_ptr_grow (&joined_conditions_obstack, result);
   obstack_ptr_grow (&joined_conditions_obstack, cond1);