Verify:

grep_alone:    abdbcdc
grep_splice:   abdbcdc
grep_splice_2: abdbcdc
first_splice:  abdbcdc
findex_splice: abdbcdc


@short:

                 Rate first_splice findex_splice grep_splice_2 grep_alone grep_splice
first_splice  25097/s           --          -19%          -38%       -39%        -44%
findex_splice 31152/s          24%            --          -22%       -24%        -30%
grep_splice_2 40193/s          60%           29%            --        -2%        -10%
grep_alone    41059/s          64%           32%            2%         --         -8%
grep_splice   44790/s          78%           44%           11%         9%          --


@med:

                Rate first_splice grep_alone findex_splice grep_splice_2 grep_splice
first_splice  4218/s           --        -7%          -20%          -25%        -27%
grep_alone    4517/s           7%         --          -14%          -20%        -22%
findex_splice 5278/s          25%        17%            --           -6%         -9%
grep_splice_2 5624/s          33%        25%            7%            --         -3%
grep_splice   5816/s          38%        29%           10%            3%          --


@long:

                Rate grep_alone grep_splice_2 grep_splice first_splice findex_splice
grep_alone     457/s         --          -23%        -25%         -56%          -66%
grep_splice_2  593/s        30%            --         -3%         -42%          -55%
grep_splice    610/s        34%            3%          --         -41%          -54%
first_splice  1027/s       125%           73%         68%           --          -23%
findex_splice 1331/s       191%          124%        118%          30%            --


The XS versions of List::Util and List::MoreUtils were used.