Function vcombine_p64 

pub fn vcombine_p64(a: poly64x1_t, b: poly64x1_t) -> poly64x2_t

🔬This is a nightly-only experimental API. (stdarch_arm_neon_intrinsics #111800)

Available on (AArch64 or target_arch=arm64ec) and target feature neon and target feature v7 only.

Join two smaller vectors into a single larger vector Arm’s documentation