perl> cmpthese -1, {
    '<=>' => q[@s1=sort{$b<=>$a} 1..10000], 
    '-'   => q[@s2=sort{$b - $a} 1..10000] 
};;
       Rate  <=>    -
 <=> 33.8/s   -- -82%
-     183/s 441%   --