tree-predcom.c (determine_roots_comp): Avoid memory leak by freeing reference of trivial component.

	* tree-predcom.c (determine_roots_comp): Avoid memory leak by freeing
	reference of trivial component.

From-SVN: r254625

gcc/ChangeLog

+2017-11-10  Bin Cheng  <bin.cheng@arm.com>
+
+	* tree-predcom.c (determine_roots_comp): Avoid memory leak by freeing
+	reference of trivial component.
+
 2017-11-10  Jakub Jelinek  <jakub@redhat.com>
 
 	PR bootstrap/82916

gcc/tree-predcom.c

@@ -1331,7 +1331,14 @@ determine_roots_comp (struct loop *loop,
 
   /* Trivial component.  */
   if (comp->refs.length () <= 1)
-    return;
+    {
+      if (comp->refs.length () == 1)
+	{
+	  free (comp->refs[0]);
+	  comp->refs.truncate (0);
+	}
+      return;
+    }
 
   comp->refs.qsort (order_drefs);
   FOR_EACH_VEC_ELT (comp->refs, i, a)