On 4/26/2012 9:35 AM, Mathias Gaunard wrote: > On 26/04/12 18:02, Eric Niebler wrote: > >> Interesting. I avoided this design because I was uncertain whether the >> compiler would be able to optimize out all the copies of the >> intermediate nodes. You're saying NT2 does it this way and doesn't >> suffer performance problems? And you've hand-checked the generated code >> and found it to be optimal? That would certainly change things. >> > > NT2 treats large amounts of data per expression, so construction time is > not very important. It's the time to evaluate the tree in a given > position that matters (which only really depends on proto::value and > proto::child_c<N>, which are always inlined now). > > We also have another domain that does register-level computation, where > construction overhead could be a problem. The last tests we did with > this was a while ago and was with the default Proto behaviour. That > particular domain didn't get sufficient testing to give real conclusions > about the Proto overhead.
In that case, I will hold off making any core changes to Proto until I have some evidence that it won't cause performance regressions. Thanks, -- Eric Niebler BoostPro Computing http://www.boostpro.com _______________________________________________ proto mailing list proto@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/proto
