CONS_INDEX 2668 src/alloc.c GETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr))) CONS_INDEX 2671 src/alloc.c SETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr))) CONS_INDEX 2674 src/alloc.c UNSETMARKBIT (CONS_BLOCK (fptr), CONS_INDEX ((fptr)))