Description:
------------
I was using this script to benchmark a question on StackOverflow and I noticed that in PHP 7.1.0 the creation of a stdClass() object increased in time taken by an appreciable amount between PHP7.0.13 and PHP7.1.0

This seemed rather odd based on all the speed improvment work done in 7.0 and 7.1 so I thought I would report it, in case it pointed someone at something that may have changed in 7.1 to the damage a speed improvement.

Results for different versions of PHP


    PHP7.1.0
    Using (object) [] method     10,000,000 times 22.970033168793
    Using new stdClass() method 10,000,000 times 38.114390850067
    Difference (-ve) means (object) [] is quicker -15.144357681274
    
    PHP7.0.13
    Using (object) [] method     10,000,000 times 22.230031967163
    Using new stdClass() method 10,000,000 times 29.300040960312
    Difference (-ve) means (object) [] is quicker -7.0700089931488


    PHP5.6.25
    Using (object) [] method     10,000,000 times 47.920066833496
    Using new stdClass() method 10,000,000 times 54.20007610321
    Difference (-ve) means (object) [] is quicker -6.2800092697144


    PHP5.5.36
    Using (object) [] method     10,000,000 times 46.450064897537
    Using new stdClass() method 10,000,000 times 53.110074043274
    Difference (-ve) means (object) [] is quicker -6.6600091457367

Test script:
---------------
    function one() {
        $obj = (object) ['prop1' => 1, 'prop2' => 2]; 
        return $obj;
    }
    
    function two() {
        $obj = new stdClass(); 
        $obj->prop1 = 1; 
        $obj->prop2 = 2;
        return $obj;
    }
    $looper = 10000000;
    
    $a = microtime(1);
    for ( $i=0; $i < $looper; $i++) { $x = one(); }
    $b = microtime(1);
    $c = $b-$a;
    echo "Using (object) [] method     $looper times " . $c . PHP_EOL;
    
    $a = microtime(1);
    for ( $i=0; $i < $looper; $i++) { $x = two(); }
    $b = microtime(1);
    $d = $b-$a;
    echo "Using new stdClass() method $looper times " . $d . PHP_EOL;
    
    echo 'Difference (-ve) means (object) [] is quicker ' . ($c - $d) . PHP_EOL;