bcopy

[Guy Harris]

 >It seems to me the idea is that memcpy should be the most efficient
 >possible way to copy SMALL things - maybe even things like structs
 >containing four bytes, in which case a 32 bit integer move instruction
 >could be generated (if the alignemnt was right).

The C compilers I know of generate inline code, not calls to "memcpy" or
any other subroutine, for structure assignments; they may even generate
such a move instruction if appropriate.