Code
The first test, "if ($x) if ($y)", was:
for ($i = 0; $i < 100; $i++) { if ($GLOBALS['dummy_false'] === false) if ($GLOBALS['dummy_true'] === true) $GLOBALS['dummy'] = 42; }
The second test, "if ($x && $y)", was:
for ($i = 0; $i < 100; $i++) { if ($GLOBALS['dummy_false'] === false && $GLOBALS['dummy_true'] === true) $GLOBALS['dummy'] = 42; }