Thanks, everyone. FWIW (I usually distrust multi-millions-per-sec benchmarks):

cmpthese 5e7, {
    1 => sub { my $x = 1 + 1; return },
    2 => sub { my $x = 1 + 1; () },
    3 => sub { my $x = 1 + 1; _: },
};

1 27367269/s   -- -13% -22%
2 31367629/s  15%   -- -11%
3 35161744/s  28%  12%   --

[download]

"Perl subs are expensive"? The cheapest adjustment is just above. Otoh, now I have a justification (not that I need any or anyone cares) not to follow PBP's "Place the label on the line preceding the loop keyword" -- just in case, easier and safer while debugging and commenting-out this or that, to keep label and code on the same line.

In reply to Re^2: Label makes a sub to return empty list -- "secret"? documented? by Anonymous Monk
in thread Label makes a sub to return empty list -- "secret"? documented? by Anonymous Monk

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