Re: Revisiting RFC: Engine Warnings -- Undefined array index

On Tue, Dec 13, 2022 at 11:16 AM Andreas Leathley <a.leathley@gmx.net> wrote: > > On 13.12.22 11:01, Robert Landers wrote: > > intended: ($a['foo'] ?? null) || ($a['bar'] ?? null) > > Further, writing code like this increases the number of opcodes needed > > to perform relatively simple logic by ~150%, increasing end-user > > latency and spending CPU cycles somewhat needlessly. > I think it is quite the opposite: calling the error handler because of > E_NOTICE (or now E_WARNING) is quite the additional overhead, and if > projects just ignore E_NOTICE their applications will be slowed down > because of that, while fixing the code will avoid the error handler > altogether. Just because something is longer to write in a programming > language also does not make it necessarily slower. But if you have any > actual measurements why using the null coalescing operator would slow > down code in general that would be something useful to share. > > -- > PHP Internals - PHP Runtime Development Mailing List > To unsubscribe, visit: https://www.php.net/unsub.php > Ah, that's a good point. I ran some tests and was surprised that it was slower due to needing to call the error handler. I even disabled E_WARNING in my php.ini to see if that made a difference (it did, but still not the same quite as fast as using null coalesce). Results are here: https://gist.github.com/withinboredom/bd7276b7703663c26c12a18820747bcb Interestingly the null coalesces used more memory. That surprised me and was unexpected. Apparently using coalesce requires some temporary variables to work. Perhaps there would be a benefit for a FETCH_DIM_IS_COALESCE opcode?