<?php

$s = microtime(true);
$var = "<  >< >Association football< ><  >";
for ($i = 1; $i <= 900000; $i++) {
  $var = preg_replace('/[ ](?=[^<>]*(?:<|$))/', '&nbsp', $var);
}
$e = microtime(true);
echo round($e - $s, 2) . " sec\tm.buettner\n";

$s = microtime(true);
$var = "<  >< >Association football< ><  >";
for ($i = 1; $i <= 900000; $i++) {
  $var = preg_replace('/[ ](?=[^>]*(?:<|$))/', '&nbsp', $var);
}
$e = microtime(true);
echo round($e - $s, 2) . " sec\tΩmega\n";

?>