Re: Object getter method optimization

HI Yo-An Lin, I added comments to PR. After fixing obvious errors (explained in comments), few tests are still failed tests/classes/unset_properties.phpt Zend/tests/bug52614.phpt The introduced run-time check in ZEND_INIT_METHOD_CALL speed-ups getters in cost of small overhead for all other methods. I don't see any visible performance change on real-life apps. Thanks. Dmitry. ________________________________ From: Lin Yo-An <cornelius.howl@gmail.com> Sent: Friday, April 1, 2016 19:14 To: Dmitry Stogov Cc: internals; Xinchen Hui; Nikita Popov Subject: Re: [PHP-DEV] Object getter method optimization I submitted my PR here https://github.com/php/php-src/pull/1847 On Fri, Apr 1, 2016 at 11:41 PM, Lin Yo-An <cornelius.howl@gmail.com<mailto:cornelius.howl@gmail.com>> wrote: Hi internals, Here comes the result: Without getter optimization (3 runs): 250.76603889465ms With getter optimization (3 runs) 110.88299751282ms Microbench result: https://gist.github.com/c9s/0273ac21631562724cabf86c42e86e32 On Fri, Apr 1, 2016 at 4:35 PM, Lin Yo-An <cornelius.howl@gmail.com<mailto:cornelius.howl@gmail.com>> wrote: Hi Dmitry, Nikita, Andrea My implementation now is able to get the property offset and fetch object property directly without invoking zend_std_read_property and pushing new call frame onto the stack. The current behavior: 1. In compile-time, the pass_two() function now marks the getter functions in op_array.accessor.type 2. When Zend Engine first time attempt to read the property, it saves the property offset in the accessor field and mark the method as a "getter". 3. When Zend Engine second time invoke the getter method, it checks the accessor field and try to read the property value directly instead a "method call" The implementation did some change: 1. Added accessor struct to op_array to save "accessor" related information (getter or setter, property offset) 2. Added two statement in zend_std_read_property to save property offset. 3. Added op code check in zend_compile (The pass_two() function) to mark a function is a getter) But now I encountered a problem, I can't store the result value in INIT_METHOD_CALL op, the result var is only available in DO_FCALL_* I have an idea for solving this, but I'm not sure if it's good or not: If DO_FCALL_* will always follow a INIT_METHOD_CALL, then I think we can store result var from the next op (DO_FCALL) and skip DO_FCALL directly. Would be great if I can have your advices and suggestion. :-) Thanks, Yo-An Lin On Tue, Mar 22, 2016 at 4:45 PM, Dmitry Stogov <dmitry@zend.com<mailto:dmitry@zend.com>> wrote: Hi Yo-An Lin, This "run-time inlining" approach may work. PHP compiler (or optimizer) may mark functions and methods suitable for "run-time" inlining (e.g. methods without arguments and FETCH_OBJ_R UNUSED, CONST -> TMP; RETURN TMP). Then INIT_METHOD_CALL may check this flag and execute "optimized code sequence" instead of pushing stack frame and real call. However, I'm not sure what kind of performance impact this may make, because we will have to make additional check on each INIT_METHOD_CALL execution. Thanks. Dmitry. ________________________________ From: Lin Yo-An <cornelius.howl@gmail.com<mailto:cornelius.howl@gmail.com>> Sent: Saturday, March 19, 2016 10:08 To: Dmitry Stogov Cc: internals; Xinchen Hui Subject: Re: [PHP-DEV] Object getter method optimization Hi Dmitry, Thanks for your reply! You're correct. let me try to explain your points: If I have a main.php and worker.php And I defined work($worker) { $status = $worker->getStatus(); } inside main.php when main.php is compiled, we don't know what the class entry of $worker is.. What we only know is invoking a method "getStatus" on $worker CV unless we know we have to compile worker.php before main.php and add a type hint on $worker. Is it correct? Since the original approach doesn't work, here comes another new idea: When executing method call on an object, if we found the method body are just 2 op codes (FETCH_OBJ_R and RETURN), we then denote the method is a "getter method" And the next time, when we execute the same method, we found the "getter method" flag, we simply execute FETCH_OBJ_R on that object and return the value to avoid extra op code execution time. Do you think if this could work? Best Regards and Thanks for your work on PHP VM Yo-An Lin On Fri, Mar 18, 2016 at 3:36 PM, Dmitry Stogov <dmitry@zend.com<mailto:dmitry@zend.com>> wrote: Hi Yo-An Lin, Unfortunately, this approach won't work. At first, at compile time we don't know the body of called getter. At second, the called method might be changed even at run-time, because of polymorphism. Tricks like this might be implemented using JIT and polymorphic inline caches. Thanks. Dmitry. ________________________________________ From: Lin Yo-An <cornelius.howl@gmail.com<mailto:cornelius.howl@gmail.com>> Sent: Friday, March 18, 2016 05:23 To: internals Subject: [PHP-DEV] Object getter method optimization Hello Everyone, I am recently trying to write an optimizer that could optimize the getter method call into just one object fetch opcode. I'd like to know thoughts from you guys, here is the note: https://c9s.hackpad.com/INLINE-OP-TVGo9WcshbZ -- Best Regards, Yo-An Lin https://github.com/c9s -- Best Regards, Yo-An Lin -- Best Regards, Yo-An Lin -- Best Regards, Yo-An Lin -- Best Regards, Yo-An Lin