sub processA {
    # common stuff
    # special stuff
    }
sub processB {
    loop (1..1000) {
         # common stuff
         # special stuff
         }
    }

##</code><code>##

sub processA {
    common_stuff($);
    # special stuff
    }
sub processB {
    loop (1..1000) {
         common_stuff($);
         # special stuff
         }
    }
sub common_stuff {
    # common stuff
    }