[PATCH] Use memcpy in memmove when possible

[Roland McGrath]

Definitely do not insert an extra RETURN (dest).  There's no reason for that.

You should use tail calls for the memcpy invocations.  i.e.
	return memcpy (dest, src, len);

To avoid more #if nonsense for the bcopy case, write:
	dest = memcpy (dest, src, len);

Then the compiler ought to turn it into the tail call (but verify that).

Is there really ever going to be a case for MEMCPY_OK_FOR_BWD_MEMMOVE?
That is, will there ever be an implementation of memcpy that works for the
overlapping case but not the nonoverlapping case?  I can't really imagine
one.  If there isn't, then any case that would define your
MEMCPY_OK_FOR_BWD_MEMMOVE macro should really just be making memmove an
alias for memcpy instead.


Thanks,
Roland