rfc:jit

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rfc:jit [2019/03/15 09:33]
dmitry 		rfc:jit [2019/04/12 07:15]
laruence
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 ====== PHP RFC: JIT ====== ====== PHP RFC: JIT ======
-  * Version: 0.9+  * Version: 1.0
   * Date: 2019-01-28   * Date: 2019-01-28
   * Author: Dmitry Stogov <dmitry@php.net>, Zeev Suraski <zeev@php.net>   * Author: Dmitry Stogov <dmitry@php.net>, Zeev Suraski <zeev@php.net>
-  * Status: Under Discussion+  * Status: Accepted (to be merged into PHP-8 only)
   * First Published at: https://wiki.php.net/rfc/jit   * First Published at: https://wiki.php.net/rfc/jit
  
 ===== Introduction ===== ===== Introduction =====
-It's no secret that the performance jump of PHP 7 was originally initiated by attempts to implement JIT for PHP. We started these efforts at Zend (mostly by Dmitry) back in 2011 and since that time tried 3 different implementations.  We never moved forward to propose to release any of them, for three main reasons:  They resulted in no substantial performance gains for typical Web apps;  They were complex to develop and maintain;  We still had additional directions we could explore to improve performance without having to use JIT.+It's no secret that the performance jump of PHP 7 was originally initiated by attempts to implement JIT for PHP. We started these efforts at Zend (mostly by Dmitry and Xinchen) back in 2011 and since that time tried 3 different implementations.  We never moved forward to propose to release any of them, for three main reasons:  They resulted in no substantial performance gains for typical Web apps;  They were complex to develop and maintain;  We still had additional directions we could explore to improve performance without having to use JIT.
  
 ===== The Case for JIT Today ==== ===== The Case for JIT Today ====
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 Currently we support x86 and x86_64 on POSIX platforms (tested on Linux with GCC and LVVM) and Windows (both non-ZTS and ZTS builds). We support "Hybrid" and "Call" VM with and without GCC explicit global register variables extension. Currently we support x86 and x86_64 on POSIX platforms (tested on Linux with GCC and LVVM) and Windows (both non-ZTS and ZTS builds). We support "Hybrid" and "Call" VM with and without GCC explicit global register variables extension.
 There are no any restrictions on C compiler and OS any more. There are no any restrictions on C compiler and OS any more.
- 
-===== Open Issues ===== 
-Make sure there are no open issues when the vote starts! 
  
 ===== Future Scope ===== ===== Future Scope =====
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 Support for JIT is more a strategic PHP question. JIT definitely requires a lot of work, but it may be actively developed only as a part of PHP, with common effort. Support for JIT is more a strategic PHP question. JIT definitely requires a lot of work, but it may be actively developed only as a part of PHP, with common effort.
  
-This project requires a 2/3+1 majority.+This project requires a 2/3+1 majority. Voting opened 2019-03-21 and closes 2019-03-28. 
  
 <doodle title="Include JIT into PHP 8?" auth="user" voteType="single" closed="true"> <doodle title="Include JIT into PHP 8?" auth="user" voteType="single" closed="true">
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 As PHP 7.4 is already branched and its engine is not expected to be significantly changed (consequently requiring corresponding changes to the JIT implementation), we can also consider including JIT in PHP-7.4 as an experimental feature (disabled by default), to provide early access and receive more feedback. This also requires a 2/3+1 majority. As PHP 7.4 is already branched and its engine is not expected to be significantly changed (consequently requiring corresponding changes to the JIT implementation), we can also consider including JIT in PHP-7.4 as an experimental feature (disabled by default), to provide early access and receive more feedback. This also requires a 2/3+1 majority.
 +
 +In case JIT is not included in PHP-7.4 and PHP-8 introduces language compatibility breaks (it already does), existing applications couldn't be tested with JIT without porting to PHP-8.
  
 <doodle title="Include JIT into PHP 7.4 (experimental)?" auth="user" voteType="single" closed="true"> <doodle title="Include JIT into PHP 7.4 (experimental)?" auth="user" voteType="single" closed="true">
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 ===== Implementation ===== ===== Implementation =====
-After the project is implemented, this section should contain  +Merged into PHP master by [[https://github.com/php/php-src/commit/9a06876072b9ccb023d4a14426ccb587f10882f3|9a06876072b9ccb023d4a14426ccb587f10882f3]] commit
-  - the version(s) it was merged into +
-  - a link to the git commit(s) +
-  - a link to the PHP manual entry for the feature +
-  - a link to the language specification section (if any)+
  
 ===== References ===== ===== References =====
   - [[https://luajit.org/dynasm.html|DynAsm page]]   - [[https://luajit.org/dynasm.html|DynAsm page]]
 +  - [[https://github.com/LuaJIT/LuaJIT/tree/master/dynasm|DynASM Source codes]]
   - [[https://corsix.github.io/dynasm-doc/|The Unofficial DynASM Documentation]]   - [[https://corsix.github.io/dynasm-doc/|The Unofficial DynASM Documentation]]
- 
-===== Rejected Features ===== 
-Keep this updated with features that were discussed on the mail lists. 
- 
rfc/jit.txt · Last modified: 2020/08/01 23:41 by carusogabriel

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