cmpthese( -2,{
 list => sub { list() },
 shiftit => sub { shiftit() },
} );
__END__
5.8.3       Rate shiftit    list
shiftit 217350/s      --    -12%
list    247334/s     14%      --
5.6.2       Rate shiftit    list
shiftit 212031/s      --    -14%
list    246447/s     16%      --