Re: [VOTE] 64 bit platform improvements for string length and integer

From: Date: Fri, 31 Jan 2014 11:54:06 +0000
Subject: Re: [VOTE] 64 bit platform improvements for string length and integer
References: 1 2 3 4 5 6 7 8 9  Groups: php.internals 
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Hi,

On Fri, Jan 31, 2014 at 11:34 AM, Derick Rethans <[email protected]> wrote:

> On Thu, 30 Jan 2014, Christopher Jones wrote:
>
> > This is because the implementation touches nearly every source file
> > and alters the string length of the most fundamental data object in
> > PHP's implementation (the zval).
>
> I know in the past we have been really reluctant to increase the zval
> change. F.e. with the GC change we added bitfields. I think it might be
> less of an issue now to increase the size, as Dmitry has I think
> improved the allocator quite a bit, but it is by no means something that
> should be glossed over lightly.
>
> cheers,
> Derick
>

What do you mean by increasing the zval size?

GCC aligns the memory to 64bits on 64bit which means following for the
string in zvalue_value:
- before the patch: 8B (ptr) + 4B (int) + 4B (alignment) = 16B
- after the patch: 8B (ptr) + 8B (size_t) = 16B

That seems like no increase to me. Is there anything else that I missed?

Cheers
Jakub


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