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To: Joe Watkins <pthreads@pthreads.org>
CC: PHP internals <internals@lists.php.net>, Nikita Popov <nikic@php.net>
Thread-Topic: [PHP-DEV] [RFC] Replace "Missing argument" warning with "Too few
 arguments" exception
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Date: Wed, 1 Jun 2016 18:24:16 +0000
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Subject: Re: [PHP-DEV] [RFC] Replace "Missing argument" warning with "Too few
 arguments" exception
From: dmitry@zend.com (Dmitry Stogov)

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In the SSA optimisation framework  (part of opcache), we predict and propag=
ate types of variables.

We also may detect situations when some variables may be undefined.

If variable can't be "undefined", we may avoid unnecessary run-time checks =
(e.g .like in ZEND_ADD_LONG handler).

Local variables almost always initialized before usage, but with exiting be=
havior, function arguments always may be uninitialized.


$ sapi/cli/php -d opcache.opt_debug_level=3D0x400000 2>&1 ../Zend/bench.php=
 | less

...

fibo_r: ; (lines=3D14, args=3D1, vars=3D1, tmps=3D3, ssa_vars=3D9, no_loops=
)
...
        #1.CV0($n) [undef, any] =3D RECV 1
        #2.T1 [bool] RANGE[0..1] =3D IS_SMALLER #1.CV0($n) [undef, any] int=
(2)
        JMPZ #2.T1 [bool] RANGE[0..1] BB2
...


With the patch $n won't include "undef" anymore.


Thanks. Dmitry.

________________________________
From: Joe Watkins <pthreads@pthreads.org>
Sent: Wednesday, June 1, 2016 8:42:49 PM
To: Dmitry Stogov
Cc: PHP internals; Nikita Popov
Subject: Re: [PHP-DEV] [RFC] Replace "Missing argument" warning with "Too f=
ew arguments" exception

Evening,

    Could you expand on the "obvious optimization opportunities" in the doc=
ument ?

    They are not obvious to me, and even if they were, this document is par=
t of the history of this change, so a little more detail would be nice.

Cheers
Joe

On Wed, Jun 1, 2016 at 11:55 AM, Dmitry Stogov <dmitry@zend.com<mailto:dmit=
ry@zend.com>> wrote:
hi,


Please take a look into the proposal.


https://wiki.php.net/rfc/too_few_args


The RFC is extremely simple (both proposal and implementation) and almost c=
ompletely described by the email subject.

I think, this mini-RFC doesn't need 2-weeks discussion period, so I'm going=
 to start the vote on next week.


Thanks. Dmitry.


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