re PR ipa/68721 (wrong code at -Os and above on x86_64-linux-gnu)

2015-12-10  Richard Biener  <rguenther@suse.de>

	PR ipa/68721
	* ipa-split.c (split_function): Record return value properly
	when the split part doesn't set it.

	* gcc.dg/torture/pr68721.c: New testcase.

From-SVN: r231494

gcc/ChangeLog

 2015-12-10  Richard Biener  <rguenther@suse.de>
 
+	PR ipa/68721
+	* ipa-split.c (split_function): Record return value properly
+	when the split part doesn't set it.
+
+2015-12-10  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/68806
 	* tree-vect-loop.c (vect_analyze_loop_2): Properly detect
 	reduction chains and ignore SLP reductions.

gcc/ipa-split.c

@@ -1281,7 +1281,7 @@ split_function (basic_block return_bb, struct split_point *split_point,
      to return void instead of just outputting function with undefined return
      value.  For structures this affects quality of codegen.  */
   else if (!split_point->split_part_set_retval
-           && find_retval (return_bb))
+           && (retval = find_retval (return_bb)))
     {
       bool redirected = true;
       basic_block new_return_bb = create_basic_block (NULL, 0, return_bb);
@@ -1305,6 +1305,7 @@ split_function (basic_block return_bb, struct split_point *split_point,
       e->count = new_return_bb->count;
       add_bb_to_loop (new_return_bb, current_loops->tree_root);
       bitmap_set_bit (split_point->split_bbs, new_return_bb->index);
+      retbnd = find_retbnd (return_bb);
     }
   /* When we pass around the value, use existing return block.  */
   else

gcc/testsuite/ChangeLog

 2015-12-10  Richard Biener  <rguenther@suse.de>
 
+	PR ipa/68721
+	* gcc.dg/torture/pr68721.c: New testcase.
+
+2015-12-10  Richard Biener  <rguenther@suse.de>
+
 	PR tree-optimization/68806
 	* gcc.dg/torture/pr68806.c: New testcase.
 

gcc/testsuite/gcc.dg/torture/pr68721.c

+/* { dg-do run } */
+
+extern void abort (void);
+
+int a, b, c, *d, **e = &d;
+
+int *
+fn1 ()
+{
+  for (;;)
+    {
+      for (; a;)
+	if (b)
+	  abort ();
+      break;
+    }
+  for (; c;)
+    ;
+  return &a;
+}
+
+int
+main ()
+{
+  *e = fn1 ();
+
+  if (!d)
+    abort ();
+
+  return 0;
+}