[fpc-devel] CompareMem slower in FPC 2.4.4

[Florian Klämpfl]

Am 03.06.2011 03:06, schrieb Michalis Kamburelis:
> Florian Klämpfl wrote:
>> Am 01.06.2011 22:07, schrieb Michalis Kamburelis:
>>> Hi,
>>>
>>> In my tests, FPC 2.4.4 has much slower CompareMem than FPC 2.4.2, at
>>> least for some cases:
>>
>> I've commited an improved version in r17642
> 
> That's great :) I just tested with fpc from SVN (rev 17644), and can
> confirm that CompareMem is much faster now. It beats CompareMem from
> both FPC 2.4.4 and FPC 2.4.2:
> 
> FPC 2.4.2: 2.635s
> FPC 2.4.4: 16.803s
> FPC trunk: 1.931s

I improved CompareDWord as well, for your application it should be even
better.

> 
> Although it's still slightly slower than comparing directly with "(V1[0]
> = V2[0]) and ...", which is ~1.2s for all 3 FPC versions mentioned
> above. I guess there has to be some price for CompareMem being more
> general, and checking size at runtime.

Yes.