Function vext_f16 

pub fn vext_f16(a: float16x4_t, b: float16x4_t, const N: i32) -> float16x4_t

Available on little-endian and target feature fp16 and target feature neon and (AArch64 or ARM or ARM64EC) and (AArch64 or ARM64EC) and (AArch64 or ARM64EC or target feature v7) and non-ARM64EC only.

Extract vector from pair of vectors Arm’s documentation