1 /* { dg-do compile } */
2 /* { dg-options "-O2 -ftree-tail-merge -fdump-tree-pre" } */
3 
4 struct node
5 {
6   struct node *next;
7   struct node *prev;
8 };
9 
10 struct node node;
11 
12 struct head
13 {
14   struct node *first;
15 };
16 
17 struct head heads[5];
18 
19 int k = 2;
20 
21 struct head *head = &heads[2];
22 
23 int
main()24 main ()
25 {
26   struct node *p;
27 
28   node.next = (void*)0;
29 
30   node.prev = (void *)head;
31 
32   asm("":"=m"(node.prev));
33 
34   head->first = &node;
35 
36   struct node *n = head->first;
37 
38   struct head *h = &heads[k];
39 
40   heads[2].first = n->next;
41 
42   if ((void*)n->prev == (void *)h)
43     p = h->first;
44   else
45     /* Dead tbaa-unsafe load from ((struct node *)&heads[2])->next.  */
46     p = n->prev->next;
47 
48   return !(p == (void*)0);
49 }
50 
51 /* { dg-final { scan-tree-dump-not "Removing basic block" "pre"} } */
52