How to write optional code for G++

[Galloth]

Hi
I have some programs, which runs slow even with optimalization on. I
want ask, if there are some good texts about how write fast code? For
example I need to know, if is faster to use recursive functions or if
I should rewrite this recursive code to loops? (I THINK, that loops
will faster, but It will take big deal of time to rewrite code to see
if I was right and I would like to find some good tricks) My code is
more about working with data than some computations. I look to google
and find bout 250 000 references, but It is too much and I am also not
sure if I can trust all of them.

-- 
Jan Kastil
galloth@jabbim.cz