Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:86521
Mailing-List: contact internals-help@lists.php.net; run by ezmlm
Received-SPF: error (pb1.pair.com: domain realplain.com from 216.33.127.80 cause and error)
Message-ID: <1FAF88D0E2DE433FA299B4FAF7120880@pc1>
To: "Sara Golemon" <pollita@php.net>,
	"Dmitry Stogov" <dmitry@php.net>
Cc: "Stanislav Malyshev" <smalyshev@gmail.com>,
	"PHP internals" <internals@lists.php.net>
References: <CAESVnVr6oyAOCjWRWp7MGio_JNuUryPm=HKeY=fDgKRBcMXJ=Q@mail.gmail.com><55513AA4.7010706@gmail.com><579127CDC1B54040BEEFD4564A6F78B7@pc1> <CAESVnVpDXmLB-Gd_9HTyrdcnuS8g27Gezwgodb1CVLCVo0u2tg@mail.gmail.com>
Date: Tue, 9 Jun 2015 08:05:30 -0500
MIME-Version: 1.0
Content-Type: text/plain;
	format=flowed;
	charset="Windows-1252";
	reply-type=original
Content-Transfer-Encoding: 7bit
Subject: Re: [PHP-DEV] Undefined variables undefined order
From: php_lists@realplain.com ("Matt Wilmas")

Hi all,

----- Original Message -----
From: "Sara Golemon"
Sent: Monday, May 11, 2015

> On Mon, May 11, 2015 at 5:12 PM, Matt Wilmas <php_lists@realplain.com> 
> wrote:
>> ----- Original Message -----
>> From: "Stanislav Malyshev" <smalyshev@gmail.com>
>> Sent: Monday, May 11, 2015
>>
>>>> argument. I'd like to propose making the order of evaluation defined
>>>> by splitting this into separate statements:
>>>
>>> What is the purpose of this? I.e. why is it important that these notices
>>> would be produced in certain order?
>>
>> Logic, consistency, "polish," etc. :-)
>>
> Exactly this. :)
>
> It's just my CDO kicking in.  It's not necessary for the language to
> function. Heck, HHVM already matches PHP 5.1-7.0's out-of-order
> behavior, so fixing PHP only creates double work for me.  I just look
> at these error messages and twitch uncomfortably.

Hah, looks like this just changed last week after barely 3 weeks. :-P  I 
didn't verify, just noticed the code change: 
http://git.php.net/?p=php-src.git;a=commitdiff;h=c09698753e7d1d95299dca54c8ca888c885fd45b

Andi hasn't objected, yet. :-O  And ironically it was part of an 
optimization...

Now CONCAT is consistent, but not others.  Which places need changing 
anyway?  Just binary ops in VM?

A couple/few extra instructions are unavoidable, I guess on any 
architecture, for the intermediate save of op1, but can anyone show that it 
makes ANY measurable difference (other than instruction count)?

For ADD, MUL, IS_[NOT_]IDENTICAL, IS_[NOT_]EQUAL, BW_*, and BOOL_XOR, ops 
can be passed as

... result, op2, op1);

with no ill effects (I think) and still have the same (fewest) instructions 
as now!  That is, if anyone thinks, or can show, that it matters. :-)

Whoops, didn't check first -- I see ADD, MUL, and IS_[NOT_]EQUAL (among 
others) are already consistent/fixed (but extra instructions :-D).

> -Sara

- Matt