Hi Lester,
On Sat, January 25, 2014 13:32, Lester Caine wrote:
> Anatol Belski wrote:
>
>> On Fri, January 24, 2014 12:29, Dmitry Stogov wrote:
>>
>>>> I would be glad t see any 64-bit performance related improvements.
>>>>
>>>>
>>>> BTW: the performance degradation is expected. Each pointer is
>>>> 64-bit
>>>> instead of 32-bit => more memory consumption => more CPU cache
>>>> pressure => more CPU cache misses.
>>>>
>>>> On the other hand x86-64 uses more CPU registers, MMX, SSE, passes
>>>> arguments in registers, so it's usually faster on small tasks that
>>>> keep working set in CPU caches.
>>>>
>> Wouldn't then the small parts improve the whole? Fixing the small cases
>> laying on the surface like implicit 32 vs 64 bit type conversions,
>> better struct packing and similar measures would already contribute to
>> more efficient processor and memory usage. That would probably turn many
>> things even more upside down though:) As yep, potentially 64 bit should
>> be faster, so it's worth a try to lean PHP towards.
>>
>> Especially as you welcome it, I would put the topic on my todo after
>> properly finishing this RFC. Besides potential improvement that's also
>> an exciting matter.
>
> Much of the 'improved performance' provided by later versions of windows
> is down to faster processors to hide the extra bloat created. They have
> adopted having a 32bit version and a 64bit version. Making PHP super
> efficient on 64bit processors would be useful, but it still misses the
> point of being able to fall back gracefully to run on 32bit machines? Or
> is now the time to introduce the same differentiation in all builds of
> PHP? It is built for the platform?
>
>
> The main problem here is that changing things to be more 64bit efficient
> could then make things even worse on 32bit? Yes we need to be modernising,
> but telling users to 'read the source code' to find out where functions
> are now returning 64 bit values rather than 32bit ones is not the right
> approach?
this RFC has no plans to discriminate 32-bit platforms, but merely to
improve the 64-bit ones. 32-bit platforms are nowadays mature, consistent
and well supported, whereas 64-bit platforms have much more non exhausted
potential and still luck on proper software ports at many places.
Regards
Anatol