https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69453
Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |NEW Last reconfirmed| |2016-01-25 Ever confirmed|0 |1 --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Confirmed. Even the following: -fmo-unroll-loops Should recommend -fno-unroll-loops instead of -funroll-loops . The n and m switch up happens when you are typing the command manually and very quickly without looking at the keyboard.