In your place, I wouldn't make it three subs. I'd make it just one sub, with a mode parameter indicating how you want it searched. Like this:

search(simple => $stuff);

search(normal => $stuff);

search(extended => $stuff);
[download]

The definition of the search routine then could look like this:

use Carp;

sub search($$) {
     my(%parameter);  # Those parameters that you set
     my $mode = shift;
     if($mode eq 'simple') {
         # set parameters to simple
           ...
     } elsif($mode eq 'normal') {
         # set parameters to normal
           ...
     } elsif($mode eq 'extended') {
         # set parameters to extended
           ...
     } else {
         croak("mode '$mode' not supported");
     }

     # Now just do your process_search
        ...
}
[download]

And your problem simply evaporates.

Any former syntax related problems, i.e. use of an invalid mode, would now only be detected at runtime, thus when the call is made. But actually that's not different from the original code, where a call to an undefined sub would only be detected when an attempt to call it, is made.