I gave this patch a try on my system, time lilypond MSDM.ly, 'real' time, 3 repetitions
baseline (master, 0e7c26d40f): 0m42,533s; 0m42,547s; 0m42,430s Abstract Grob property storage into Mutable_properties. (https://codereview.appspot.com/561640043) 0m41,102s; 0m41,036s; 0m40,861s Rewrite Mutable_properties based on vector<SCM> (https://codereview.appspot.com/575990043/) 0m42,461s; 0m42,632s; 0m42,212s (I did not apply any of the other optimization patches posted in the last days.) If at all, Issue 561640043 seems to show some benefit. This _could_ be because Grob::Grob (Grob const &s) doesn't call ly_deep_copy anymore, but I've only looked into this very briefly because I think the introduction of Mutable_properties makes sense in any case. However I clearly don't see 7% improvement for this patch. Is there anything I missed? https://codereview.appspot.com/575990043/
