wenlei added a comment. > I wonder if this is just a single example, where there could be various other > (header-related) peepholes that cause similar problems for stable output. > IIRC, the usual Clang approach is to make as-close-to-optimal IR up front, > but maybe in some situations it's desirable to delay optimizations to improve > stability. Another application where that could be useful is caching.
I think this nounwind propagation a classic IPA problem, where you need proper per-function summary first and then propagate that through call graph to get final per-function attribute (like Attributor). Frontend is not the right place to do this kind of IPA/IPO. > Do we want IRGen to prefer stable IR, or optimized IR? Should there be a -cc1 > flag to decide (which AutoFDO could set)? Unstable IR is a side of trying to do IPA in frontend which is naturally going to be half-complete. I'm not sure if I follow why invoke -> call optimization can not be done in mid-end. If possible, I think this should be deferred to mid-end. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D83906/new/ https://reviews.llvm.org/D83906 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
