Gnuradio uses volk which has vectorised pow() for 32 bits: https://github.com/gnuradio/volk/blob/master/kernels/volk/volk_32f_s32f_power_32f.h
Might be slower due to precision, unknown.
It would make sense to contribute a 64 bit vectorised pow() to volk but doing so is not required. If adding my previous contribution, mention it having taken so long with a link to the issue thread. If you can, mention political targeting and abuse regarding pursuing public shielding or somesuch.