Hey: On Wed, Jan 28, 2015 at 11:22 AM, Xinchen Hui <xinche...@zend.com> wrote: > 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? I mean, dropping both ZEND_FE_RESET and FE_FETCH share one ZEND_OP_DATA.
the previously example should be: > 0 FE_RESET > 1 JMP 3 > 2 ....statements > 3 FE_FETCH success->2 4 ZEND_OP_DATA > 5 .... thanks > > 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/ -- Xinchen Hui @Laruence http://www.laruence.com/ -- PHP Internals - PHP Runtime Development Mailing List To unsubscribe, visit: http://www.php.net/unsub.php
