Function svsubhnt_u64 

pub fn svsubhnt_u64(
    even: svuint32_t,
    op1: svuint64_t,
    op2: svuint64_t,
) -> svuint32_t

🔬This is a nightly-only experimental API. (stdarch_aarch64_sve #145052)

Available on (AArch64 or ARM64EC) and target feature sve and target feature sve2 only.

Subtract narrow high part (top) Arm’s documentation