gistfile1.php

function supamicrotime() {
   list($usec, $sec) = explode(' ', microtime());
   return (float)$usec;
}


for ($y=0; $y<100; $y++) {
    $beforex = supamicrotime();
    for ($z=0; $z<10; $z++) {
        test_function();
    }
    $afterx = supamicrotime();
    echo bcdiv(bcsub($afterx, $beforex, 9), $z, 9);
}