return 1<<tn->bits; 
return 1 << tn->bits; 
static inline int tnode_child_length(struct tnode *tn){        return 1<<tn->bits;}
4520	/local/tlutelli/issta_data/temp/c/2005_temp/2005/4520/91b9a277fc4d207249e459a455abf804ebb5499d/fib_trie.c/buggy/net/ipv4/fib_trie.c