Benchmarking tells you if something is faster or not. B::Deparse tells you how Perl compiled your code. Both are useful in a case like this, so here's the Deparse way...

<mir 112 [8:56] ~ >perl -MO=Deparse -le 'use constant X=>17; print X'
-e syntax OK

sub X () {
    package constant;
    $scalar;
}
print 17;
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