objptr            568 gc/include/private/gc_priv.h # define HBLKPTR(objptr) ((struct hblk *)(((word) (objptr)) & ~(HBLKSIZE-1)))
objptr            570 gc/include/private/gc_priv.h # define HBLKDISPL(objptr) (((word) (objptr)) & (HBLKSIZE-1))