https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89652
--- Comment #2 from Jakub Jelinek <jakub at gcc dot gnu.org> --- Created attachment 45937 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45937&action=edit gcc9-pr89652.patch IMHO either we need to do what this patch does, i.e. only remove SAVE_EXPRs that are in new_ctx.values, or we should save_exprs.empty (); after: /* Forget saved values of SAVE_EXPRs. */ for (hash_set<tree>::iterator iter = save_exprs.begin(); iter != save_exprs.end(); ++iter) new_ctx.values->remove (*iter); loop in cxx_eval_loop_expr. Arguably my patch made things worse, in that there is this loop and one at the end of function, on the other side before that it was a latent thing, e.g. if some SAVE_EXPRs are encountered only during certain iterations of a loop and not others, if we never remove anything from save_exprs, we'll keep adding all SAVE_EXPRs ever encountered, but then try to remove even those that were already removed. Or, yet another option might be change save_exprs into a vec and always truncate the vec after traversing it for removal from values.
