+
−/* { dg-do link } */
+
−/* { dg-options "-O2" } */
+
−
+
−struct S
+
−{
+
−  int w, x, y, z;
+
−};
+
−
+
−struct T
+
−{
+
−  int r;
+
−  struct S s;
+
−};
+
−
+
−void link_error (void);
+
−int bar (struct S, int);
+
−
+
−void
+
−foo (int a, struct T b)
+
−{
+
−  struct S *c = 0;
+
−
+
−  if (a)
+
−    c = &b.s;
+
−
+
−  b.s.w = 3;
+
−
+
−  /* Since 'c' may be pointing to NULL here, we used to flag it as
+
−     pointing anywhere, which was forcing the aliaser to mark as
+
−     call-clobbered every other variable pointed-to by 'c' ('b' in
+
−     this case).  This, in turn, caused the insertion of V_MAY_DEFs
+
−     for 'b' at this call-site, which prevented constant propagation
+
−     from 'b.s.w = 3' to 'if (b.s.w != 3)'.  */
+
−  bar (*c, a);
+
−
+
−  if (b.s.w != 3)
+
−    link_error ();
+
−}
+
−
+
−int main ()
+
−{
+
−  struct T b;
+
−  foo (3, b);
+
−  return 0;
+
−}
+
−
+
−int X;
+
−
+
−int bar (struct S x, int i)
+
−{
+
−  X = 3;
+
−}