https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113646
--- Comment #3 from Martin Jambor <jamborm at gcc dot gnu.org> --- (In reply to Richard Biener from comment #1) > Did you try with -fprofile-partial-training (is that default on? it > probably should ...). Can you please try training with the rate data > instead of train > to rule out a mismatch? With -fprofile-partial-training the znver4 LTO vs LTOPGO regression (on a newer master) goes down from 66% to 54%. So far I did not find a way to easily train with the reference run (when I add "train_with = refrate" to the config, I always get "ERROR: The workload specified by train_with MUST be a training workload!")