foo(a)1 foo (a) 2 { 3 return (a & (1 << 31)) != 0; 4 } 5 main()6 main () 7 { 8 if (foo (0)) 9 puts ("foo"); 10 else 11 puts ("bar"); 12 if (foo (~0)) 13 puts ("foo"); 14 else 15 puts ("bar"); 16 } 17