ok 1 - f0-f1-undef
ok 2 - f0-f2-undef
ok 3 - f0-f1-
ok 4 - f0-f2-
ok 5 - f0-f1-fred
ok 6 - f0-f2-fred
ok 7 - f0-f1-1
ok 8 - f0-f2-1
ok 9 - f0-f1-1.5
ok 10 - f0-f2-1.5
1..10
         Rate  first   grep simple
first   570/s     --   -14%   -45%
grep    661/s    16%     --   -36%
simple 1036/s    82%    57%     --