GET_BIT2
GET_BIT2(probLit, symbol, offs &= ~bit, offs &= bit)
#define GET_BIT(p, i) GET_BIT2(p, i, ; , ;)
GET_BIT2(prob + i, i, ; , distance |= mask);
GET_BIT2(prob + i, i, ; , distance |= 1);
GET_BIT2(prob + i, i, ; , distance |= 2);
GET_BIT2(prob + i, i, ; , distance |= 4);
GET_BIT2(prob + i, i, ; , distance |= 8);