https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93689
--- Comment #4 from Marek Polacek <mpolacek at gcc dot gnu.org> --- That's hard to say without really understanding what the issue is, but I'm afraid this might not be the best first issue -- it involves some pretty convoluted features, plus it seems there are two issues (that maybe_constant_value gets a template code and the gimplifier ICE). "Luckily" we have over 3000 C++ issues and some of them should be more straightforward: https://gcc.gnu.org/bugzilla/buglist.cgi?component=c%2B%2B&limit=0&list_id=240106&product=gcc&query_format=advanced&resolution=---&order=bug_id%20DESC&query_based_on= Note that we're in stage 4 now, meaning that we only fix regressions. Good luck.