Function vpaddl_u8 

pub fn vpaddl_u8(a: uint8x8_t) -> uint16x4_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.

Unsigned Add and Accumulate Long Pairwise. Arm’s documentation