perl-5.30.0
===========
             Rate      regex      index      split filehandle
regex      9.98/s         --       -11%       -32%       -33%
index      11.2/s        12%         --       -23%       -25%
split      14.6/s        46%        30%         --        -2%
filehandle 14.9/s        49%        33%         2%         --