ira-build.c (sort_conflict_id_map): Don't call qsort if num is 0, as…

ira-build.c (sort_conflict_id_map): Don't call qsort if num is 0, as ira_object_id_map might be NULL, or 1.

	* ira-build.c (sort_conflict_id_map): Don't call
	qsort if num is 0, as ira_object_id_map might be NULL, or 1.

From-SVN: r212136

gcc/ChangeLog

+2014-06-30  Jakub Jelinek  <jakub@redhat.com>
+
+	* ira-build.c (sort_conflict_id_map): Don't call
+	qsort if num is 0, as ira_object_id_map might be NULL, or 1.
+
 2014-06-30  Zhenqiang Chen  <zhenqiang.chen@linaro.org>
 
 	* loop-invariant.c (get_inv_cost): Handle register class.

gcc/ira-build.c

@@ -2821,8 +2821,9 @@ sort_conflict_id_map (void)
       FOR_EACH_ALLOCNO_OBJECT (a, obj, oi)
 	ira_object_id_map[num++] = obj;
     }
-  qsort (ira_object_id_map, num, sizeof (ira_object_t),
-	 object_range_compare_func);
+  if (num > 1)
+    qsort (ira_object_id_map, num, sizeof (ira_object_t),
+	   object_range_compare_func);
   for (i = 0; i < num; i++)
     {
       ira_object_t obj = ira_object_id_map[i];