On Thu, Jul 9, 2015 at 1:09 AM, David Chisnall <[email protected]> wrote: > On 9 Jul 2015, at 08:00, Xinliang David Li <[email protected]> wrote: >> >> You need to be more specific on why the regression is problematic (and more >> so than missed opportunities). Text size increase (shared and much smaller >> than heap) is usually not a big issue except for tiny devices which is >> likely to use Os/Oz in the build. For servers, there are are simple rules to >> compare cpu vs ram resource cost. > > Text size increase also means more TLB and i-cache misses. We’ve observed > that single-program benchmarks show this quite poorly, but the aggregate > increase in i-cache and TLB pressure across the entire system can degrade > performance overall on a typical desktop workload (not so relevant for > single-application servers, but very relevant for server VMs). > > I believe some folks at Apple did a more systematic analysis of this, but I > don’t know if their detailed results are public.
It may or may not increase itlb/TLB pressure . This should be considered by the inliner when computing the overall cost/benefit, but compiler today is generally very bad at modelling this effect -- especially when profile data is missing. David > > David > > _______________________________________________ cfe-commits mailing list [email protected] http://lists.cs.uiuc.edu/mailman/listinfo/cfe-commits
