https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99835
--- Comment #3 from Richard Biener <rguenth at gcc dot gnu.org> --- (In reply to Jan Hubicka from comment #2) > > At -O3 the unused 'c' remains. Likely different (recursive?) inlining > > makes us > > process a cgraph cycle in different order and thus fail to elide the output > > of 'c' (it's output first at -O3). > > > > Fixing that would need processing cgraph SCCs with an extra IPA phase in > > main > > optimization so we get a chance to do extra node removal (maybe order > > the cycles so that functions we can elide - aka static ones - are processed > > last). > That would tamper with optimizations that propagate from callee to > caller during late optimization, like IPA register allocation, stack > alignment propagation or late pure/const discovery. But inside a SCC the order is arbitrary anyway. Note I'd only re-order SCCs and keep the postordering the same otherwise. > Honza
