implicit & explicit returns

[luben]

I have noticed that Rakudo (and NQP) generates different PIR code for 
implicit and explicit returns.

Example for implicit return:
sub foo($n){
   $n;
}

And example for explicit return:

sub foo($n){
   return $n;
}


Is this on purpose? The implicit return is 4-5 times faster than 
explicit return.


Best regards
luben