https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86866
--- Comment #2 from Aleksey Konovalov <konovalov.alv at ya dot ru> --- (In reply to Andrew Pinski from comment #1) > I think you forgot to the flush as required. The mmx programming model > requires the user to do it. You are right. Calling _m_empty() solves problem Thank you