How to set default gfortran specs option?

[xunxun]

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