Function svmla_s64_x 

pub fn svmla_s64_x(
    pg: svbool_t,
    op1: svint64_t,
    op2: svint64_t,
    op3: svint64_t,
) -> svint64_t

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

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

Multiply-add, addend first Arm’s documentation