RE: [PHP-DEV] RFC: mark functions as const for possible optimizations
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)
>
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Thread (11 messages)