https://gcc.gnu.org/bugzilla/show_bug.cgi?id=66122
--- Comment #12 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Markus Trippelsdorf from comment #11) > The compiler isn't psychic, e.g. it doesn't parse asm statements at all (so > it cannot know how many insn it contains). Actually it does some parsing just to see how many statements. That is it uses ';', and newline as an estimate of how many statements there are. And then uses that for an estimate in the cost (I know it does this because I added this support). But there are some many different heuristics for the inliner and it could decide if it is one instruction not to inline it anyways for other reasons.