sub foo {
    my $t0 = Benchmark->new();
    .. code ..
    my $t1 = Benchmark->new();
    say "foo() took" . timestr(timediff($t1, $t0));
}

sub bar {
    my $t0 = Benchmark->new();
    .. code ..
    my $t1 = Benchmark->new();
    say "bar() took" . timestr(timediff($t1, $t0));
}

##</code><code>##

sub foo {
    say "Starting foo() with yadda";
    .. code ..
    say "Now doing stuff";
    .. code ..
    say "Now munging";
    say "Done with foo()";
}

##</code><code>##

my $DEBUG = 1;

sub foo {
    logit "Starting foo() with yadda";
    .. code ..
    logit "Now doing stuff";
    .. code ..
    logit "Now munging";
    logit "Done with foo()";
}

sub logit {
     my ($msg) = @_;

     if ($DEBUG) {
          say $msg;
     }
}