"Vladimir N. Makarov" <[EMAIL PROTECTED]> writes: > I know some work is being done on incremental df analysis. It could > decrease time for rescanning RTL between passes. Let us hope on this.
My understanding is that on dataflow-branch the DF information is now fully incremental. I don't really grasp where you are headed with this criticism. Criticism can be a good thing. But I think it would help me, at least, if you were more clear about what you see as the alternative. Moving all the RTL passes into tree-ssa might be a good idea. But it would be orders of magnitude more work than the dataflow work has required, so it is not comparable. We could contrain the dataflow work to be a 100% improvement on all platforms before it can be committed. But that would be extremely difficult, because they would continually be catching up to problems introduced in mainline. For example, I slowed them down by a few days as they fit my recent lower-subreg.c patch into the DF framework. So I think that imposing such a requirement would be unwise. I believe it would be tantamount to saying that we can never make a major infrastructure change. For tree-ssa (admittedly a much bigger change) we accepted slowdowns when it was committed because we believed that the end result would be better. I think that you should channel your concern into looking at the code on dataflow-branch and seeing how it can be improved, or determining that it is hopeless. I don't think this is a discussion which can be usefully carried on in the abstract. Ian
