Benchmark: timing 2222234 iterations of code_1, code_2...
    code_1:  4 wallclock secs ( 4.03 usr +  0.00 sys =  4.03 CPU) @ 551422.83/s (n=2222234)
    code_2:  2 wallclock secs ( 2.27 usr + -0.01 sys =  2.26 CPU) @ 983289.38/s (n=2222234)
           Rate code_1 code_2
code_1 551423/s     --   -44%
code_2 983289/s    78%     --

##</code><code>##

$mytarget = "I am a perl program";
$mystring = "Perl";
if ($mytarget =~ m/\Q$mystring\E/i)
     {       
         print "It matches: ${^MATCH}\n";   
     }   
  else {       
         print "It doesn't match\n";    
    }