OpenCL 64bit code generation

I’ve learned that the NV OpenCL runtime compiler accepts parameters like
-cl-nv-arch compute_13 and
-cl-nv-cstd=CL1.1

Is it possible to force the OpenCL runtime compiler to create 64bit ptx ?
I’ve tried stuff like -cl-nv-machine 64, but without success.
Anyone tried that?
i’m using the 310.90 driver.

thx tomschi