On Wed, 2006-10-25 at 13:01 -0700, Devang Patel wrote: > > > However, various optimizer needs to know about this special tree node. > > > > not really (not any more than they know about other tree codes that are > > not interesting for them). > > If we take an example of Jump Threading pass then it needs to know > about this tree node and update it properly. That could get awful ugly.
> > So, the passes that maniuplate loop structure need to know about > LOOP_HEADER and others do not need to worry about LOOP_HEADER. Passes which do code motions may need to know about it -- they don't need to update its contents, but they may need to be careful about how statements are moved around in the presence of a LOOP_HEADER note. Personally I think this is a bad idea. jeff
