That explains my benchmark code results. But I still have
conflicting results from -Devel::SmallProf for execution
times between tr and eq.

count wall tm  cpu time line
16183 0.197199 0.700000   368: next unless ($_ = ($_ =~ tr/1/1/));

count wall tm  cpu time line
16183 0.282621 0.750000   369: next if ($_ eq '0000000000000');
15923 0.157497 0.890000   370: $_ = ($_ =~ tr/1/1/);
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