gcc/testsuite/gcc.dg/tree-ssa/vrp56.c

/* { dg-do compile } */ 
/* { dg-options "-O2 -fdump-tree-ethread-stats" } */
typedef struct basic_block_def *basic_block;
struct basic_block_def;
struct edge_def;
typedef struct edge_def *edge;
typedef struct VEC_edge_base
{
  unsigned num;
} VEC_edge_base;
typedef struct VEC_edge_none
{
  VEC_edge_base base;
} VEC_edge_none;
static __inline__ unsigned
VEC_edge_base_length (VEC_edge_base * vec_)
{
  return vec_ ? vec_->num : 0;
}

typedef struct VEC_edge_gc
{
  VEC_edge_base base;
} VEC_edge_gc;
struct basic_block_def
{
  VEC_edge_gc *succs;
};
void foo (void);

unsigned char
cleanup_empty_eh (basic_block bb)
{
  edge e_out;
  switch (VEC_edge_base_length (&bb->succs->base))
    {
    case 1:
	foo ();
    }
}
/* { dg-final { scan-tree-dump "Jumps threaded: 1" "ethread"} } */