atomicCAS undefined? Compiler troubles

I’m trying to acquire a lock in my kernel using atomicCAS, but no matter what I try, nvcc does not recognize that call. I include “sm_11_atomic_functions.h” and nothing. I define CUDACC beforehand. Nothing. I also define in desperation __cplusplus and still nothing.
Has anyone else experienced this problem?

nvcc -arch sm_11

Thanks.