PORTMAP_L1_MASK
b = UINT64_C(1) << (chunk_bit & PORTMAP_L1_MASK);
bm1->bits1[off] |= UINT64_C(1) << (v & PORTMAP_L1_MASK);
b = UINT64_C(1) << (chunk_bit & PORTMAP_L1_MASK);
b = UINT64_C(1) << (chunk_bit & PORTMAP_L1_MASK);