[fpc-devel] Patch, font rendering on Arm-Linux devices.

[Daniël Mantione]

Op Fri, 29 Feb 2008, schreef Christian Iversen:

> Daniël Mantione wrote:
>> 
>> 
>> Op Fri, 29 Feb 2008, schreef Christian Iversen:
>> 
>>>> Instead "unaligned" will simulate an unaligned load with two loads and 
>>>> some rotation etc. On the ARM, where every mnemonic can rotate operands, 
>>>> this is isn't that bad of a penalty.
>>>> 
>>>> Therefore, I wouldn't be surprised that even on ARM, arrays with packed 
>>>> structures are faster than arrays with unpacked structures.
>>> 
>>> That's possible. Why would it be faster, btw? Better cache coherency?
>> 
>> Like I mentioned, unliek modern x86 processors, ARM processors cannot 
>> detect an array traversal and preload the array into the cache. If the 
>> array is not in cache, you get cache miss after cache miss.
>
> Unlike modern x86 processors?
>
> Granted, I haven't timed it, but most processors since early P4 models are 
> supposed to have "Streaming access detection", which is a fancy way of saying 
> array detection.
>
> Are you sure your information is current?

Please read again. I said modern X86 processors have, ARM processors 
don't have.

Daniël