Re: Windows (Visual Studio) compiler stuff

Hi Anatol, ----- Original Message ----- From: "Anatol Belski" Sent: Monday, November 16, 2015

Hello Matt,

-----Original Message----- From: Matt Wilmas [mailto:php_lists@realplain.com] Sent: Sunday, November 15, 2015 11:31 PM To: internals@lists.php.net; internals-win@lists.php.net Cc: Dmitry Stogov <dmitry@zend.com>; Anatol Belski

<anatol.php@belski.net>;

Pierre Joye <pierre.php@gmail.com> Subject: [PHP-DEV] Windows (Visual Studio) compiler stuff Hi Dmitry, Anatol, Pierre (etc.), and all, I'm back now, I think, after a much longer (unintentional) break than I

expected.

Be coming very soon with what I was doing in the summer (param parsing

stuff)

-- *now* it works with MSVC too, barring any fragility, as I accidentally discovered last month... I've been "discovering" a lot with the wacky Visual Studio compiler! :-)

This

message is about the 2 I found today. The first simple thing was probably just overlooked, but noticed it while

looking

up __declspec. zend_never_inline has always been empty (I guess) for

MSVC,

but there's actually a __declspec(noinline) that can be used (and works as expected). A simple and obvious change to bring it in line with the other compilers?

According to the docs __declspec(noinline) is specific to C++. Also with VS it's always much more tedious to inline something than the opposite. These are the main two reasons it's disregarded ATM. We can add it for compliance with C++, but it'll in best case have no effect in the PHP core. Should be tested before, though.

Yeah, I know what the docs imply ("member function"), which is why I tested it. I guess you missed my "works as expected" part. :-P A test function that just returns a number was automatically inlined (plain C). Using __declspec(noinline) it was call'ed instead. Not sure if any of the "zend_never_inline" PHP stuff is getting inlined when it's desired not to be -- I'll compile PHP in a bit and see what it looks like with "noinline."

The second "issue" is with the zend_always_inline functions, I noticed

this

summer. Did anyone else know that MSVC leaves a *copy* of those functions

in

the output files (DLLs)? What's the point of that? When they've been

inlined,

and not referenced otherwise, there should be no reason to emit code for a standalone function! I remembered after seeing that behavior that a bit of my own

__forceinline'd

code did NOT have extra function code, but forgot to investigate until

today.

What's different about my function definition? No "static" specifier! So that's the key. :-) But... non-static would create duplicate symbols, I thought. But no, it

works!

With just __forceinline, there's no errors. :^) Can something be done about this? It would cut the binary size down a

bit.

A zend_static macro to be used with zend_always_inline...?

I'd ask you for some concrete case for this, as I'm not sure to understand exactly what you mean. The only case where an extra code would be generated is with "__declspec(export) inline", but that's not the case anywhere within PHP.

My concrete case is checking tons of generated code! ;-) It's simple: useless standalone functions are created for every "static __forceinline" definition... Not having static makes it act like GCC/Clang. Again, I'll try to compile PHP with those static's removed and report the effect later.

Regards Anatol

- Matt