study() is intended to be used to help optimize regular expressions on the scalar.

I have done benchmarks repeating the same regex on the scalar, and multiple regex's on the same scalar. I have never found a speedup.

BTW, my benchmarks were like:

use Benchmark qw(&cmpthese);

$STUDIED_TEXT = $TEXT;
study $STUDIED_TEXT;

cmpthese($COUNT, { 'with study' => \&fn1,
                   'w/o study'  => \&fn2 } );
[download]

Basically, study() is an anachronism. Feel free to ignore it, everybody else does.