building with -march=native

[coypu%SDF.ORG@localhost]

hi,
how do I use -march=native for building netbsd? I'm running into errors:

--- consttime_memequal.po ---
error: the 'sse' unit is not supported with this instruction set
--- clock_subr.po ---
error: the 'sse' unit is not supported with this instruction set
--- clock_subr.pico ---
error: the 'sse' unit is not supported with this instruction set

am using clang because gcc doesn't support -march=native (it's
linux-only now)

thanks