The opcode is not the handler
The same loop ran 23% faster with int parameters, and only with OPcache on. Operand classes pick a handler when the file compiles; proven types pick a different one.
Tags
zend-vm
7 posts
Two tools printed different opcodes for one function
phpdbg showed thirteen instructions and the optimizer showed nine. Both were right. How to read the notation, and which listing is the one that runs.
A property hook emits the same opcode as a plain property
Plain, backed and virtual property reads compile to one identical FETCH_OBJ_R. What separates them is a function call the opcode does not show, measured at nine times.
Two hundred thousand objects, and the collector never ran
Two hundred thousand objects created and dropped, and zero collections. What puts an object in the root buffer, and why the collector's cost is set by what you keep alive.
What a PHP variable actually is
A zval is sixteen bytes, a value union and a type tag. What that tag says decides whether an assignment copies anything, what a reference costs, and which variable pays.
PHP arrays are not arrays
One structure serves as list, dictionary and set. Packed and hashed layouts, what each costs in memory, and when a conversion happens.
What happens when PHP runs your code
A request walks from the SAPI to the Zend VM — lexing, compilation to opcodes, the OPcache lookup that skips both, and execution.