tree-loop-distribution.c (pass_loop_distribution::execute): Skip if no loops.

	* tree-loop-distribution.c (pass_loop_distribution::execute): Skip
	if no loops.

From-SVN: r249984

gcc/ChangeLog

 2017-07-05  Bin Cheng  <bin.cheng@arm.com>
 
+	* tree-loop-distribution.c (pass_loop_distribution::execute): Skip
+	if no loops.
+
+2017-07-05  Bin Cheng  <bin.cheng@arm.com>
+
 	* cfgloop.h (struct loop): Add comment.  New field orig_loop_num.
 	* cfgloopmanip.c (lv_adjust_loop_entry_edge): Comment change.
 	* internal-fn.c (expand_LOOP_DIST_ALIAS): New function.

gcc/tree-loop-distribution.c

@@ -1758,6 +1758,9 @@ pass_loop_distribution::execute (function *fun)
   control_dependences *cd = NULL;
   auto_vec<loop_p> loops_to_be_destroyed;
 
+  if (number_of_loops (fun) <= 1)
+    return 0;
+
   FOR_ALL_BB_FN (bb, fun)
     {
       gimple_stmt_iterator gsi;