1 /* { dg-do link } */
2 /* { dg-options "-O2" } */
3 
4 struct S
5 {
6   int w, x, y, z;
7 };
8 
9 struct T
10 {
11   int r;
12   struct S s;
13 };
14 
15 void link_error (void);
16 int bar (struct S, int);
17 
18 void
foo(int a,struct T b)19 foo (int a, struct T b)
20 {
21   struct S *c = 0;
22 
23   if (a)
24     c = &b.s;
25 
26   b.s.w = 3;
27 
28   /* Since 'c' may be pointing to NULL here, we used to flag it as
29      pointing anywhere, which was forcing the aliaser to mark as
30      call-clobbered every other variable pointed-to by 'c' ('b' in
31      this case).  This, in turn, caused the insertion of V_MAY_DEFs
32      for 'b' at this call-site, which prevented constant propagation
33      from 'b.s.w = 3' to 'if (b.s.w != 3)'.  */
34   bar (*c, a);
35 
36   if (b.s.w != 3)
37     link_error ();
38 }
39 
main()40 int main ()
41 {
42   struct T b;
43   foo (3, b);
44   return 0;
45 }
46 
47 int X;
48 
bar(struct S x,int i)49 int bar (struct S x, int i)
50 {
51   X = 3;
52 }
53