benchmark demonstrating static method-calls being slower than instance method-calls in PHP

bench_calls.php

<?php

/*

This benchmarks demonstrates that static method-calls are slower than instance method-calls.

Typical results:

Static method-calls: 157.247 msec
Instance method-calls: 120.566 msec
Static method-call overhead: 30%

*/

header('Content-type: text/plain');

// benchmark static vs instance method-calls

define('NUM_RUNS', 100000);

class A
{
  public static function getValue()
  {
    return 'VALUE';
  }
}

class B
{
  public function getValue()
  {
    return 'VALUE';
  }
}

// benchmark static method-calls:

$a_value = '';

$start = microtime(true);

for ($i=0; $i<NUM_RUNS; $i++)
{
  $a_value .= A::getValue();
}

$end = microtime(true);

$a_time = 1000 * ($end-$start);

echo 'Static method-calls: ' . number_format($a_time, 3) . ' msec' . "\n";

// benchmark instance method-calls:

$b = new B;
$b_value = '';

$start = microtime(true);

for ($i=0; $i<NUM_RUNS; $i++)
{
  $b_value .= $b->getValue();
}

$end = microtime(true);

$b_time = 1000 * ($end-$start);

echo 'Instance method-calls: ' . number_format(1000 * ($end-$start), 3) . ' msec' . "\n";

// assert correctness:

if ($a_value !== $b_value)
  die('Inconsistent test-result!');

// compare results:

echo 'Static method-call overhead: ' . number_format(100 * ($a_time / $b_time) - 100) . '%' . "\n";