Hey: On Wed, Jan 28, 2015 at 12:55 AM, Dmitry Stogov <dmi...@zend.com> wrote: > Hi, > > I'm working on a PoC, implementing the proposed behavior - > https://gist.github.com/dstogov/a311e8b0b2cabee4dab4 > > Only few PHPT tests had to be changed to confirm new behavior and actually > they started to behave as HHVM. > 2 tests are still unfixed XFAILed. Foreach by reference is still need to be > improved to support different array modifications. > > The patch makes ~1% improvement on Wordpress-3.6 (saving duplication and > destruction of 200 arrays on each request)
I just have got an idea: Droping use of ZEND_OP_DATA make it possible to generate better foreach loop opcodes previously FE_RESET and FE_FETCH share one same OP_DATA based on offset. 0 FE_RESET 1 FE_FETCH fail-> 5 2 OP_DATA 3 ..... statements 4 JMP 1 5.... without depending on that OP_DATA, we can change this to 0 FE_RESET 1 JMP 3 2 ....statements 3 FE_FETCH success->2 4 .... that will reduce on JMP in every foreach loop could you please also try this? thanks > > Thanks. Dmitry. > > > > On Thu, Jan 22, 2015 at 1:38 PM, Benjamin Coutu <ben.co...@zeyos.com> wrote: >> >> Hi Nikita, >> >> I would suggest using the proposal for the by-value case and sticking with >> the current behavior for the by-reference case as you suggested. Granted, we >> then cannot remove the internal pointer all together, but we would just use >> it for the less common by-reference case as well as for the legacy >> reset/next functions, of course. This would still improve most for-each >> traversals. At least we then wouldn't have to find a replacement solution >> for rest/prev/next/end. Moreover we can then move the internal position >> pointer out of the hashtable structure into zend_array because it is only >> used for userland arrays, not other hash tables (such as object properties >> or internal structures that build upon the hashtable struct). >> >> Thanks, >> >> Ben >> >> ========== Original ========== >> From: Nikita Popov <nikita....@gmail.com> >> To: Benjamin Coutu <ben.co...@zeyos.com> >> Date: Thu, 22 Jan 2015 10:53:19 +0100 >> Subject: Re: [PHP-DEV] Improvements to for-each implementation >> >> Doing this was the idea I had in mind as well, i.e. change the semantics >> of >> foreach to say that it will always work on a copy for by-value iteration >> (which ironically avoids having to actually copy it). Note that this will >> differ from the current behavior in a number of ways. In particular it >> means that changes to arrays that were references prior to iteration will >> not influence the iteration. >> >> The real question is what we should do in the by-reference case. Given >> that >> we need to acquire references to elements of the original array we can't >> reasonably work with copy-semantics (at least I don't see how). So would >> we >> just stick with the previous behavior (using the hash position hack) for >> that? >> >> Nikita >> >> >> -- >> PHP Internals - PHP Runtime Development Mailing List >> To unsubscribe, visit: http://www.php.net/unsub.php >> > -- Xinchen Hui @Laruence http://www.laruence.com/ -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
