Howto prelink to boost performance

[vittorio]

In an openbsd ML I have read that it is possible for a desktop instalation to 
improve the performance by using the prelinking ability of openbsd similar to 
that of linux.
here the key sentence:"........
prelinking... can be enabled using 
`ldconfig -P /usr/bin /usr/sbin /usr/local/bin /usr/local/sbin /usr/X11R6/bin'. 
This should result in a noticeable speed increase, especially on programs 
with lots of loaded libraries ...................." (mozilla, firefox, etc.)

In freebsd 6.2 the option -P doesn't seem to exist for ldconfig.
How could I - under freebsd - get the same result   (prelink I mean!)?

Ciao
Vittorio