Kenneth Zadeck wrote:
I think that it is time that we in the GCC community took some time to address the problem of compiling very large functions in a somewhat systematic manner.
While I agree with you, I think that there are so many things we are already trying to address, that this one can wait. I think we've been doing a very good job on large functions too, and I believe that authors of very large functions are just getting not only what they deserve, but actually what the expect: large compile times (superlinear).
I think that the most obvious O(n^2) time spots have been cleared (dataflow is practically never O(n^2) with a good equation solver), and we can live with the remaining O(n^2) space spots since we have a bit, or half a bit in front of the n^2. Actually I just mentioned that PR28701 is worth a check on dataflow-branch, but I don't think it will be worse than what we have now on mainline (because df is also used in liveness, and the memory that fwprop eats might be reused), and it should be possible to fix outstanding problems easily (e.g. with bitmap obstacks).
Paolo
