https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90691
--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> --- (In reply to Richard Biener from comment #4) > (In reply to Jakub Jelinek from comment #3) > > Started with r270136. I'd say we should stop considering > > -fcompare-debug=-W* as bugs, after all, it is extremely unlikely we are > > going to fix those anyway, warnings do affect code generation in pretty > > significant way, and just revert that change. > > Err, please no. -W* should not affect code generation otherwise we can > simply declare -g may as well for even more obvious reasons. The choices are live with -fcompare-debug=-W* goal resulting in worse warnings (like this PR), not considering -fcompare-debug=-W* a bug, slowing compile time by doing all the maybe_const_value etc. calls regardless if we need them for warnings or not, or perhaps some middle-ground like ask the constexpr evaluation to compute something only without trying to instantiate anything (nor copy_fn anything) when it is called from the warning guarded paths, just punting in that case.
