Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:32444
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: pass (pb1.pair.com: domain ntlworld.com designates 81.103.221.47 as permitted sender)
To: "'Nuno Lopes'" <nlopess@php.net>,
	"'PHPdev'" <internals@lists.php.net>
Cc: <stas@zend.com>,
	<andi@php.net>,
	<dmitry@php.net>
Date: Tue, 25 Sep 2007 12:01:48 +0100
MIME-Version: 1.0
Content-Type: text/plain;
	charset="us-ascii"
Content-Transfer-Encoding: 7bit
In-Reply-To: <001f01c7f6f0$dbcf5350$4001a8c0@pc07653>
Thread-Index: Acf28SRO690/eFUXRn2/krXLLAW2+AIb/igg
Message-ID: <20070925110139.FPDG29112.aamtaout04-winn.ispmail.ntl.com@p2>
Subject: RE: [PHP-DEV] RFC: mark functions as const for possible optimizations
From: jared.williams1@ntlworld.com ("Jared Williams")
References: <001f01c7f6f0$dbcf5350$4001a8c0@pc07653>

 
Hi,

Just a thought, now dl() has been deprecated and disabled in SAPIs (except
CLI,CGI,embed),  would that mean extension_loaded() would become a
optimizable function?

So something like 

include extension_loaded('gmp') ? 'GMPFoo.php' : 'PHPFoo.php';

Would be optimized to be more APC friendly?

Jared

> -----Original Message-----
> From: Nuno Lopes [mailto:nlopess@php.net] 
> Sent: 14 September 2007 18:01
> To: PHPdev
> Cc: stas@zend.com; andi@php.net; dmitry@php.net
> Subject: [PHP-DEV] RFC: mark functions as const for possible 
> optimizations
> 
> Hi,
> 
> Following my last post on bytecode optimization 
> (http://news.php.net/php.internals/32113), I would like to 
> discuss a few more things.
> The patch in that e-mail allowed the engine itself to do 
> transformations like, e.g.:
> $a = 1*2*3*4*5+1-0;   -->  $a = 121;
> 
> However the patch is now a bit dead because Stas would like 
> to have more advanced things that I didn't have time yet to 
> look at (because the proposal introduces several difficult 
> ambiguities in the grammar).
> 
> So, let's move on for now :P
> 
> My proposal is the following:
> some functions when fed with constant arguments always return 
> a constant value, too. e.g.:
> strlen('abcd') === 4.
> 
> This means that an optimizer can and should do this 
> transformation. (and others like: $a='abcd'; strlen($a); -> 
> 4). I think Ilia created a list of such functions in his 
> optimizer. But I would like to have that list in the core, so 
> that everybody can benefit from it.
> Basically the only thing needed to do is to change PHP_FE() to
> PHP_CONST_FE() in the function entry tables.
> 
> The patch: 
> http://web.ist.utl.pt/nuno.lopes/zend_const_function_entry.txt
> (includes a few function entries changed as an example)
> 
> 
> Nuno
> 
> P.S.: the university semester has already started, so don't 
> worry with the 
> e-mail traffic I'm generating because it'll end pretty soon 
> (until the next 
> vacations :P) 
> 
> -- 
> PHP Internals - PHP Runtime Development Mailing List
> To unsubscribe, visit: http://www.php.net/unsub.php
>