[fpc-devel] State of SSE/AVX intrinsics

J. Gareth Moreton gareth at moreton-family.com
Wed Apr 22 12:07:24 CEST 2020

Possibly, but it can become wasteful, especially on systems that might 
be strapped for memory.

Generally, you only want a coarser alignment for specialised 
applications, such as for certain instruction sets (e.g. AVX) and memory 
paging.  The mechanics behind the regular GetMem is more than adequate 
for most applications.  True, it might be useful to have a global 
alignment parameter so you don't have to develop new classes, but I 
think most programmers would be willing to develop their own frameworks 
if a coarse memory alignment is required.

It's also following on from C11 and C++17 that introduced an aligned 
allocation into their standard libraries.

However, I will say that having an additional optional parameter to the 
existing GetMem and ReallocMem routines is definitely a nicer idea than 
brand new functions.

Gareth aka. it

On 22/04/2020 10:59, Tomas Hajny wrote:
> On 2020-04-21 20:47, J. Gareth Moreton wrote:
> Hi,
>> As I mentioned in my future development post,
>> do you think FPC could benefit from
>> GetMemAligned and ReallocMemAligned routines?
>> The internal functions could be used to help
>> control such custom alignment in dynamic
>> arrays.
> Wouldn't it be better to use either some kind of global property or an 
> optional additional argument than completely new routines requiring 
> explicit handling not only from the end-user programs, but also from 
> all units which may in turn be involved in memory allocation 
> (including various containers etc.)?
> Tomas
>> On Tue 21/04/20 19:59 , Florian Klämpfl
>> florian at freepascal.org sent:
>>> Am 21.04.20 um 14:58 schrieb denisgolovan
>> via fpc-devel:
>>> >> I think Gareth meant the address of V
>>> instead (Pointer(@V)).
>>> >>
>>> >> Regards,
>>> >> Sven
>>> >
>>> > Hm. I have no idea why anyone would take
>> pointer
>>> to pointer :)
>>> >
>>> > BTW, Sven, what's your opinion on dynamic
>> arrays
>>> alignment problem?
>>> It should be fixed/there should be a
>> possibility to get them aligned
>>> properly. To be honest though, I did not
>> look into it yet.

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