Function vrsubhn_high_u16 

pub fn vrsubhn_high_u16(
    a: uint8x8_t,
    b: uint16x8_t,
    c: uint16x8_t,
) -> uint8x16_t

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

Rounding subtract returning high narrow Arm’s documentation