No, but neither will compilation on a dev machine. You'll have to insert a manual switch witch depends on compilation target anyway. Phoronix did a test where

No, but neither will compilation on a dev machine. You'll have to insert a manual switch witch depends on compilation target anyway. Phoronix did a test where compiling with march=native sped up programs a substantial amount. 20% for one application. It astounds me that we throw away that sort of gains.