re PR tree-optimization/39132 (wrong code generated with -ftree-loop-disttribution)

2009-02-10  Richard Guenther  <rguenther@suse.de>

	PR tree-optimization/39132
	* tree-loop-distribution.c (todo): New global var.
	(generate_memset_zero): Trigger TODO_rebuild_alias.
	(tree_loop_distribution): Return todo.

	* gcc.dg/torture/pr39132.c: New testcase.

From-SVN: r144060

gcc/ChangeLog

+2009-02-10  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/39132
+	* tree-loop-distribution.c (todo): New global var.
+	(generate_memset_zero): Trigger TODO_rebuild_alias.
+	(tree_loop_distribution): Return todo.
+
 2009-02-10  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/39119

gcc/testsuite/ChangeLog

+2009-02-10  Richard Guenther  <rguenther@suse.de>
+
+	PR tree-optimization/39132
+	* gcc.dg/torture/pr39132.c: New testcase.
+
 2009-02-10  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/39119

gcc/testsuite/gcc.dg/torture/pr39132.c

+/* { dg-do run } */
+/* { dg-options "-ftree-loop-distribution" } */
+
+extern void abort(void);
+
+struct epic_private
+{
+  unsigned int *rx_ring;
+  unsigned int rx_skbuff[5];
+};
+
+int
+main (void)
+{
+  struct epic_private ep;
+  unsigned int rx_ring[5];
+  int i;
+
+  ep.rx_skbuff[0] = 5;
+
+  ep.rx_ring = rx_ring;
+
+  for (i = 0; i < 5; i++)
+    {
+      ep.rx_ring[i] = i;
+      ep.rx_skbuff[i] = 0;
+    }
+
+  if (ep.rx_skbuff[0] != 0)
+    abort ();
+
+  return 0;
+}
+

gcc/tree-loop-distribution.c

@@ -77,6 +77,9 @@ static bitmap remaining_stmts;
    predecessor a node that writes to memory.  */
 static bitmap upstream_mem_writes;
 
+/* TODOs we need to run after the pass.  */
+static unsigned int todo;
+
 /* Update the PHI nodes of NEW_LOOP.  NEW_LOOP is a duplicate of
    ORIG_LOOP.  */
 
@@ -331,6 +334,8 @@ generate_memset_zero (gimple stmt, tree op0, tree nb_iter,
   if (dump_file && (dump_flags & TDF_DETAILS))
     fprintf (dump_file, "generated memset zero\n");
 
+  todo |= TODO_rebuild_alias;
+
  end:
   free_data_ref (dr);
   return res;
@@ -1206,6 +1211,8 @@ tree_loop_distribution (void)
   loop_iterator li;
   int nb_generated_loops = 0;
 
+  todo = 0;
+
   FOR_EACH_LOOP (li, loop, 0)
     {
       VEC (gimple, heap) *work_list = VEC_alloc (gimple, heap, 3);
@@ -1237,7 +1244,7 @@ tree_loop_distribution (void)
       VEC_free (gimple, heap, work_list);
     }
 
-  return 0;
+  return todo;
 }
 
 static bool