Function svcnt_u64_m 

pub fn svcnt_u64_m(
    inactive: svuint64_t,
    pg: svbool_t,
    op: svuint64_t,
) -> svuint64_t

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

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

Count nonzero bits Arm’s documentation