Req #78270 [Asn->Csd]: Usage of __vectorcall convention with FFI

Edit report at https://bugs.php.net/bug.php?id=78270&edit=1 ID: 78270 Updated by: cmb@php.net Reported by: lisachenko dot it at gmail dot com Summary: Usage of __vectorcall convention with FFI -Status: Assigned +Status: Closed Type: Feature/Change Request -Package: Unknown/Other Function +Package: *Extensibility Functions Operating System: Windows x64 PHP Version: 7.4.0alpha2 Assigned To: cmb Block user comment: N Private report: N New Comment: Basic __vectorcall support is implemented as <http://git.php.net/?p=php-src.git;a=commit;h=bedbecf56d94353a2bcebc835d14896fd95ce6d7>. Previous Comments: ------------------------------------------------------------------------ [2019-10-22 14:51:09] cmb@php.net Failing to resolve zend_hash_add_or_update() has been tracked as bug #78716; since that bug has been fixed, new builds are available at <https://windows.php.net/downloads/snaps/ostc/ffi-vectorcall/>. ------------------------------------------------------------------------ [2019-10-22 09:54:25] lisachenko dot it at gmail dot com Current patch helps a lot, at least most of __vectorcall functions can be resolved now. Surprisingly, extern zval __vectorcall *zend_hash_add_or_update(HashTable *ht, zend_string *key, zval *pData, uint32_t flag); could not be resolved, could you please check this? ------------------------------------------------------------------------ [2019-10-14 21:19:25] cmb@php.net There is now a dev version available[1], which adds minimal __vectorcall support (should be sufficient for PHP's APIs). It would be great if you could test it. [1] <https://windows.php.net/downloads/snaps/ostc/ffi-vectorcall/> ------------------------------------------------------------------------ [2019-07-25 10:42:08] cmb@php.net Well, the best solution would be to support __vectorcall, since there may be other libraries which use this calling convention. I tried to assess the required effort for this, and found that apparently no name mangling is yet supported by ext/ffi, so that even __fastcall wouldn't work on x86. This has to be resolved anyway. ------------------------------------------------------------------------ [2019-07-22 12:29:29] lisachenko dot it at gmail dot com Unfortunately, recompiling PHP with custom ZEND_FASTCALL doesn't change anything. Nobody will do this for general purposes, so in my opinion, we shouldn't affect overall performance by dropping this call convention, as it is a step back. However I have an interesting idea. What if we could solve this in another way, by defining all internal API functions as ZEND_FASTCALL and removing ZEND_API macros for them, thus they won't be exposed outside. And select some useful methods to work with internal structures with ZEND_API, but without declaring them as ZEND_FASTCALL convention. I can see some conflicts in presence of both ZEND_API and ZEND_FASTCALL. Because in some places the macros ZENA_API is present and in another it is absent, like with ZEND_FASTCALL. ------------------------------------------------------------------------ The remainder of the comments for this report are too long. To view the rest of the comments, please view the bug report online at https://bugs.php.net/bug.php?id=78270 -- Edit this bug report at https://bugs.php.net/bug.php?id=78270&edit=1