bnrisprincipal to slow

[Markus Endres <me@mendres.org>]

hi,

I want to compute the exponents on the class group generators of a given
bnr (in bnrinit) with bnrisprincipal. 

I know, if I use the flag 0, than I only get the exponents. But for my
examples this is too slow. One computation with bnrisprincipal is about
4 minutes, and I have a lot of these computations (on a fast computer!).

Is there a faster method to compute the exponents on the class group
generators?

thanks in advance

cheers

markus