# perl 5.8.8:
           Rate   grep  first  regex   hash
grep     8219/s     --   -17%   -72%  -100%
first    9863/s    20%     --   -67%  -100%
regex   29805/s   263%   202%     --   -99%
hash  3682290/s 44701% 37233% 12255%     --

# perl 5.10.0:
           Rate   grep  first  regex   hash
grep     8532/s     --   -21%   -80%  -100%
first   10778/s    26%     --   -75%  -100%
regex   43115/s   405%   300%     --   -99%
hash  3429921/s 40099% 31723%  7855%     --