The short answer is, no: 
#!/usr/bin/perl -w
use strict;
use Benchmark;
my $testlarge = "a " x 100000;
my $testsmall = "a b c d e f";
timethese(-10,{
        One   => sub { my ($y) = (split(/\s+/,$testlarge))[0]; },
        Two   => sub { my ($y) = (split(/\s+/,$testsmall))[0]; },
        Three => sub { $testsmall =~ /([^\s]*)\s+/; my $y = $1; },
        Four  => sub { $testlarge =~ /([^\s]*)\s+/; my $y = $1; },
              });

[download]
And the results: 
Benchmark: running Four, One, Three, Two, each for at least 10 CPU sec
+onds...
      Four: 10 wallclock secs ( 4.55 usr +  5.48 sys = 10.03 CPU) @ 43
+9.88/s (n=4412)
       One: 13 wallclock secs (12.83 usr +  0.07 sys = 12.90 CPU) @  4
+.88/s (n=63)
     Three: 11 wallclock secs (10.62 usr +  0.00 sys = 10.62 CPU) @ 94
+938.32/s (n=1008245)
       Two: 10 wallclock secs (10.01 usr +  0.00 sys = 10.01 CPU) @ 67
+121.98/s (n=671891)

[download]

Enjoy!
Gryn

In reply to Re: is split optimized? by gryng
in thread is split optimized? by Anonymous Monk

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