how to make llvm-ld pass -m64 to as?

A quick question, is there any way to make llvm-ld pass -m64 to the assembler (when running llvm-ld with -native). By default AS generate 32 bit code on OS X (x86)?

Regards,
Mattias

I don't know the answer, because I don't use llvm-ld. If you're on a mac, why not use transparent lto, which should handle this?

-Chris