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
jit
4 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.
OPcache, the JIT, and where time actually goes
OPcache removes compilation, not execution. The JIT reaches arithmetic-heavy code and little else. Where the remaining time lives.
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.