The function is of limited use and is an almost a direct clone of memmove/memcpy (with arguments swapped). Introduction of ERMS variants of string routines would mean avoidable growth of libc. bcopy will get redefined to a __builtin_memmove later on with this symbol only left for compatibility. Reviewed by: kib Approved by: re (gjb) Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D17539