After more than a decade of optimizing the perl interpreter for modern usage (e.g. use strict;), it seems Perl is significantly faster when using "my". Here are my test results:

cavac@earthrise:~/src/temp$ ./speedtest.sh 
Speedtest bash script:
#!/bin/bash

echo "Speedtest bash script:"
cat speedtest.sh
echo 
echo Perl version:
perl -v | grep version
echo
echo "Warming up CPU to operating temp"
cat speedtest_warmup.pl
time perl speedtest_warmup.pl
echo 
time perl speedtest_warmup.pl
echo "########### Modern perl: strict and warnings enabled ###########
+#"
cat speedtest1.pl
echo 
time perl speedtest1.pl
echo "########### Outdated: my variables, but no strict and warnings #
+#######"
cat speedtest2.pl
echo 
time perl speedtest2.pl
echo "########### Noob perl: no strict, warnings or my variables #####
+##"
cat speedtest3.pl
echo 
time perl speedtest3.pl

Perl version:
This is perl 5, version 34, subversion 0 (v5.34.0) built for x86_64-li
+nux

Warming up CPU to operating temp
#!/usr/bin/env perl

# Just to get system load and CPU temp up to test conditions

use strict;
use warnings;

my $total = 0;

for(my $i = 0; $i < 200_000_000; $i++) {
    $total++;
}

real    0m14,558s
user    0m14,543s
sys    0m0,004s


real    0m14,845s
user    0m14,833s
sys    0m0,008s
########### Modern perl: strict and warnings enabled ############
#!/usr/bin/env perl

# STRICT & WARNINGS + MY #

use strict;
use warnings;

my $total = 0;

for(my $i = 0; $i < 300_000_000; $i++) {
    $total++;
}


real    0m22,095s
user    0m22,086s
sys    0m0,004s
########### Outdated: my variables, but no strict and warnings #######
+#
#!/usr/bin/env perl

# MY WITHOUT STRICT AND WARNINGS #

my $total = 0;

for(my $i = 0; $i < 300_000_000; $i++) {
    $total++;
}


real    0m21,943s
user    0m21,938s
sys    0m0,000s
########### Noob perl: no strict, warnings or my variables #######
#!/usr/bin/env perl

# NOOBIE VERSION WITHOUT STRICT; WARNINGS AND MY #

$total = 0;

for($i = 0; $i < 300_000_000; $i++) {
    $total++;
}


real    0m41,117s
user    0m41,100s
sys    0m0,008s

[download]

perl -e 'use Crypt::Digest::SHA256 qw[sha256_hex]; print substr(sha256_hex("the Answer To Life, The Universe And Everything"), 6, 2), "\n";'

In reply to Re: Faster with my keyword or no ? by cavac
in thread Faster with my keyword or no ? by abdan

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