C:\test>1064178-b.pl
                 Rate     OPdiff hash_grep OPdiffModified OPdiff_undef using_vec
OPdiff         90.9/s         --      -47%           -52%         -55%      -64%
hash_grep       170/s        87%        --           -10%         -17%      -33%
OPdiffModified  189/s       108%       11%             --          -7%      -26%
OPdiff_undef    204/s       124%       20%             8%           --      -20%
using_vec       254/s       180%       49%            35%          25%        --