https://gcc.gnu.org/bugzilla/show_bug.cgi?id=106499
--- Comment #8 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Tomasz Kłoczko from comment #7) > Hmm .. Martin even if that can be fixed in libfabric code does it still mean > that it something wrong with LO optimisation? > Sorry for asking maybe dumb question but this situation is not clear for me > :) Basically with the flatten attribute and lto, every function needs to there and cloned and inlined causing a lot of memory and time really. Functions become huge and all. Gcc memory usage for some things can be improved but it won't be enough.