tree-vect-loop.c (vect_create_epilog_for_reduction): Only insert gimple seq if it's not empty.

	* tree-vect-loop.c (vect_create_epilog_for_reduction): Only
	insert gimple seq if it's not empty.

From-SVN: r237550

gcc/ChangeLog

 2016-06-17 Bin Cheng  <bin.cheng@arm.com>
 
+	* tree-vect-loop.c (vect_create_epilog_for_reduction): Only
+	insert gimple seq if it's not empty.
+
+2016-06-17  Bin Cheng  <bin.cheng@arm.com>
+
 	* tree-vectorizer.h (struct dr_with_seg_len): Remove class
 	member OFFSET.
 	* tree-vect-data-refs.c (operator ==): Handle DR_OFFSET directly,

gcc/tree-vect-loop.c

@@ -4353,7 +4353,9 @@ vect_create_epilog_for_reduction (vec<tree> vect_defs, gimple *stmt,
       gimple_seq stmts;
       vec_init_def = force_gimple_operand (vec_initial_defs[i], &stmts,
 					   true, NULL_TREE);
+      if (stmts)
 	gsi_insert_seq_on_edge_immediate (loop_preheader_edge (loop), stmts);
+
       def = vect_defs[i];
       for (j = 0; j < ncopies; j++)
         {