macro_rules! reg_conflicts {
    (
                $(
                    $q:ident : $d0:ident $d1:ident : $s0:ident $s1:ident $s2:ident $s3:ident
                ),*;
                $(
                    $q_high:ident : $d0_high:ident $d1_high:ident
                ),*;
            ) => { ... };
}