I frequently use redo as a more readable version of do/while. But in my off-the-cuff test using your functions, f1 is always about 50% faster than f2. I tested using perls 5.10 .. 5.14. 
use Benchmark qw(cmpthese);
my ($a, $b) = (0,0);
my $limit = 10_000;
sub f1 { ++$a < $limit ? goto &f1 : return $a}
sub f2 {{ ++$b < $limit ? redo : return $b }}
cmpthese -1, { f1 => \&f1, f2 => \&f2 };

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In reply to Re: Syntactic sugar for tail call optimizations by Anonymous Monk
in thread Syntactic sugar for tail call optimizations by LanX

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