NEEDED_MASK
#define NEEDED(x) (((bitmap_counter_t) x) & NEEDED_MASK)
*bmc |= NEEDED_MASK;
*bmc &= ~NEEDED_MASK;
*bmc |= NEEDED_MASK;
*bmc |= NEEDED_MASK;
*bmc_new |= NEEDED_MASK;
*bmc = NEEDED_MASK | 2;