benchmark function that iterates multiple times through the callables received and benchmark their speed

benchmark.php

<?php

function benchmark(callable ...$functions): void
{
    $times = array_combine(array_keys($functions), array_fill(0, count($functions), 0.));
    $baseTime = 0.;
    $baseCallable = fn() => null;

    $start = hrtime(true);
    $count = 0;

    while (hrtime(true) < $start + 1e9) {
        $startCall = hrtime(true);
        $baseCallable();
        $baseTime += hrtime(true) - $startCall;
        foreach ($functions as $key => $function) {
            $startCall = hrtime(true);
            $function();
            $times[$key] += hrtime(true) - $startCall;
        }
        $count++;
    }

    foreach ($times as $key => $time) {
        $times[$key] -= $baseTime;
    }

    if ($count < 100) {
        echo "Methods too low. Iterated only {$count} times\n";
    }

    asort($times);

    echo "Benchmark results after {$count} iterations in nanoseconds:\n";
    foreach ($times as $key => $time) {
        echo $key . ': ' . $time . "\n";
    }
}

Usage example:

$x1 = 'A';

benchmark(
    a: fn() => (strtolower($x1) == 'a'),
    b: fn() => ($x1 == 'a' || $x1 == 'A'),
    c: fn() => in_array($x1, ['a', 'A']),
);

and example output:

Benchmark results after 2102631 iterations in nanoseconds:
c: 16409563
b: 31326178
a: 61903067