Function vaddl_s16 

pub fn vaddl_s16(a: int16x4_t, b: int16x4_t) -> int32x4_t

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

Add Long (vector). Arm’s documentation