Hello, with preloading and Composer, we don't need anymore to consider autoloading for functions and/or constants. The reason is that basically Composer is already doing a great job at loading functions: just give it a list of files and it will ensure they are included all the time. Actually, Composer is just an example, all similar "require all the time" strategies work.
The drawback of this approach used to be that requiring a bunch of (potentially unused) files could be costly. But now that we have preloading, this cost is zero. As such, autoloading functions/constants would serve no purpose. Then, we periodically have discussions about the rules for namespace resolution of functions/constants. The fallback-to-root-namespace has no measurable performance overhead - the cache is very effective. Yet, Nikita has stated a few times that knowing the type of the arguments of the function being called helps the engine a bit. With JIT, this might be (/become) more important (is that correct, Dmitry and/or Nikita?) I'm thus wondering: could we resolve the fallback-to-root-namespace rule at preload time, for all preloaded implementations? For runtime-loaded code, we would keep the current behavior. In practice, this means that during development (when preloading is not used), we would preserve all the hackability that the rule provides (PHP being a hackable engine is a big PRO, here, this can help e.g. testing a lot). The fallback-to-root-namespace is a wise pragmatic rule that serves the language well IMHO. But in prod, in full-perf mode (aka when preloading is enabled), this proposal would pave the way for better performance with JIT, if confirmed. WDYT? Nicolas PS: I fear I would be unable to implement anything related to this proposal so I'm just sharing the idea to see if it could be interesting.
