> > How expensive is the check? If the result is worth caching, perhaps > > we should have two bitmaps: the existing one, and one that records > > whether we've checked a particular SSA name. > > > > If the check is relatively cheap then that won't be worth it though. > > If you're asking about the range_of_expr check, that's all cached, so > it should be pretty cheap. Besides, we're no longer calculating > ranges for each statement in the IL, as we were doing in lv_dom_walker > with evrp's record_ranges_from_stmt. Only statements of interest are > queried.
You know, we already have infrastructure to test performance of small changes with callgrind. If you want I can compare numbers for: 1. mainline right now 2. my proposed patch 3. my proposed patch without a dom walk Aldy
