temporal optimisation in loops

[wagner <wagnerf at gauvain dot u-strasbg dot fr>]

Hi, everyone

we're two students in computer science at the university of Strasbourg.
This year, as our master degree work we've implemented a really nice
loop optimization (temporal re-use of datas) in a fortran optimizer.

this algorithm is taken from a research work developped here at the 
university, and we think it hasn't been implemented anywhere yet :)

(http://icps.u-strasbg.fr/pub-01/CLM01.ps.gz
quite technical, so non-gurus, beware ;)

the small tests we've done work terrible, but for now it is
only available as a non usefull university tool, and we'd like to implement
it in our favorite compiler set. 

so, before starting we'd like to know what is the current state of loop
optimizations in gcc (we've seen not much) and if someone is working on 
something like that.

at first look we'll need to work on the tree representation, (that's what
we used in fortran) but we've seen on the list Diego Novillo speaking of a SSA
representation. We'd like to know what would be the best choice, and where
would be the best place in the passes to implement our algorithm.

we just need access to loop nodes (indices, bounds, body, step, ....)
(basically we modify the order of accessing the arrays elements inside the loop
by changing the loops indices and bounds, and the array indices)

if anyone has any questions, comments, tips, help, feature, flame or anything
to tell us, it will be welcome :)

regards


Wagner Frederic and Pop Sebastian