__tbi
#define tbi(x,y) __tbi(x,__r17=(y),"1" (__r17))
#define tbisi(x) __tbi(1,__r17=(x),"1" (__r17))
#define tbisd(x) __tbi(2,__r17=(x),"1" (__r17))
#define tbis(x) __tbi(3,__r17=(x),"1" (__r17))
#define tbiap() __tbi(-1, /* no second argument */)
#define tbia() __tbi(-2, /* no second argument */)