re PR rtl-optimization/71634 (Invalid write with in mark_loops_for_removal…

re PR rtl-optimization/71634 (Invalid write with in mark_loops_for_removal (ira-build.c:2256) with --param ira-max-loops-num=0)

Fix PR rtl-optimization/71634

	* ira-build.c (mark_loops_for_removal): Properly iterate
	loops.

From-SVN: r238247

gcc/ChangeLog

+2016-07-12  Martin Liska  <mliska@suse.cz>
+
+	* ira-build.c (mark_loops_for_removal): Properly iterate
+	loops.
+
 2016-07-12  Steven Bosscher  <steven@gcc.gnu.org>
 	Richard Biener  <rguenther@suse.de>
 

gcc/ira-build.c

@@ -2251,7 +2251,7 @@ mark_loops_for_removal (void)
 	     );
       }
   qsort (sorted_loops, n, sizeof (ira_loop_tree_node_t), loop_compare_func);
-  for (i = 0; n - i + 1 > IRA_MAX_LOOPS_NUM; i++)
+  for (i = 0; i < n - IRA_MAX_LOOPS_NUM; i++)
     {
       sorted_loops[i]->to_remove_p = true;
       if (internal_flag_ira_verbose > 1 && ira_dump_file != NULL)