Select Code to Download

#!/usr/bin/perl

...
        $m += ( 'a' eq substr $target, $_, 1 ) for 0 .. -2 + length $t
+arget;
        },
});

perl-5.38.2
==========
...
rindex       704/s       289%   192%   142%   131%   129%   80%    5% 
+   1%     --     -96%   -98%
split_by   16747/s      9166%  6845%  5665%  5403%  5360% 4177% 2387% 
+2302%  2280%       --   -51%
tr / y     34296/s     18876% 14124% 11707% 11170% 11081% 8658% 4994% 
+4819%  4773%     105%     --

cmpthese(-1,{
    '=()=' =>     sub { my $m = 0; $m = () = $target =~ m/ab/g; },
...
        $m ++ while -1 < ( $pos = rindex $target, 'ab', $pos - $pat_le
+n );
        },
});

perl-5.38.2
...
index     814/s     119%      76%      70%       1%       --      -3% 
+    -92%
while     836/s     125%      81%      75%       4%       3%       -- 
+    -91%
split_by 9752/s    2524%    2013%    1941%    1108%    1099%    1066% 
+      --