Dear list, I know we can use gcc -dumpspecs > specs copy specs to default specs location, and also can change the specs value for example, change *cc1: %(cc1_cpu) to *cc1: %(cc1_cpu) -march=native this can change gcc default option. But now I only want to change default gfortran specs option. I try to use *f951: -march=native or *f951_options: -march=native These are all invalid. And I see that : gcc -dumpspecs > specs1 g++ -dumpspecs > specs2 gfortran -dumpspecs > specs3 specs1, specs2 and specs3's content are all the same... Is it normal? But how to set default gfortran specs option? Thanks. -- Best Regards, xunxun