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/* { dg-do run } */
/* { dg-options "-O2" } */
void abort ();
typedef struct _Node
{
struct _Node *next, *prev;
} Node;
void __attribute__ ((noinline)) append (Node * q, Node * p)
{
p->next = q;
p->prev = q;
q->next = p;
q->prev = p;
}
inline void
swap (Node ** a, Node ** b)
{
Node *tmp = *a;
*a = *b;
*b = tmp;
}
/* Miscompilation seems to happen here. If one removes the if condition
(which should be true) the program works fine. */
void
ListSwap (Node * x, Node * y)
{
Node *tmp;
if (x->next)
{
swap (&x->next, &y->next);
swap (&x->prev, &y->prev);
x->next->prev = x->prev->next = x;
y->next->prev = y->prev->next = y;
}
}
int
main ()
{
Node A, A1, B, B1;
append (&A, &A1);
append (&B, &B1);
ListSwap (&A, &B);
if (&A != A.next->prev)
abort ();
return 0;
}
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