c-warn.c (warn_logical_operator): Return early if -Wlogical-op is not in effect.

	* c-warn.c (warn_logical_operator): Return early if -Wlogical-op is
	not in effect.

From-SVN: r255782

gcc/c-family/ChangeLog

+2017-12-18  Marek Polacek  <polacek@redhat.com>
+
+	* c-warn.c (warn_logical_operator): Return early if -Wlogical-op is
+	not in effect.
+
 2017-12-17  Martin Sebor  <msebor@redhat.com>
 
 	* c-attribs.c (common_handle_aligned_attribute): Avoid issuing

gcc/c-family/c-warn.c

@@ -180,6 +180,9 @@ warn_logical_operator (location_t location, enum tree_code code, tree type,
   tree low0, low1, low, high0, high1, high, lhs, rhs, tem;
   bool strict_overflow_p = false;
 
+  if (!warn_logical_op)
+    return;
+
   if (code != TRUTH_ANDIF_EXPR
       && code != TRUTH_AND_EXPR
       && code != TRUTH_ORIF_EXPR