Function vcombine_f16 

pub fn vcombine_f16(a: float16x4_t, b: float16x4_t) -> float16x8_t

Available on little-endian 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.

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