Function vraddhn_high_s64 

pub fn vraddhn_high_s64(a: int32x2_t, b: int64x2_t, c: int64x2_t) -> int32x4_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.

Rounding Add returning High Narrow (high half). Arm’s documentation