Function vtrn_p8 

pub fn vtrn_p8(a: poly8x8_t, b: poly8x8_t) -> poly8x8x2_t

Available on (AArch64 or ARM64EC) and (AArch64 or ARM64EC or target feature v7) and (ARM or AArch64 or ARM64EC) and target feature neon only.

Transpose elements Arm’s documentation