Re: Image scaling performance

[Michael Zimmermann]

your patch still has graphical glitches: http://puu.sh/gcpco/da369f26c7.png
btw it should be legal because modified GPL code still is GPL code.

On Wed, Feb 25, 2015 at 7:56 PM, Vladimir 'φ-coder/phcoder' Serbinenko
<address@hidden> wrote:
> On 25.02.2015 19:46, Michael Zimmermann wrote:
>>
>> oh ok so linux's div/mod/... assembler is as slow/fast as grub's code?
>> Linux uses armv5>= ifdefs. Maybe we could optimized things a little :)
>> About scale_nn,
>> amarullz(https://plus.google.com/u/0/+AhmadAmarullah/about) wrote a
>> optimized version without divs:
>> loops: http://pastebin.com/MaZqWSA9
>> memcpy: http://pastebin.com/iNq0V5Tw
>>
> Please try my patch (reattached here after minor fixes). The patch by
> anonymous source, sent by third-party through pastebin isn't acceptable from
> legal perspective
>
>> this code works a little faster. I'm still questioning the efficiency
>> math operations because on slow devices there are other bottlenecks of
>> the same kind(like de/compression).
>>
>> On Wed, Feb 25, 2015 at 7:41 PM, Vladimir 'phcoder' Serbinenko
>> <address@hidden> wrote:
>>>
>>> ARMv7 doesn't mandate div instructions. It's a separate flag in features.
>>> GRUB supports earlier CPUs as well and we use them for testing. My only
>>> test
>>> machine is armv6
>>>
>>> Le 2015-02-25 19:38, "Michael Zimmermann" <address@hidden> a
>>> écrit
>>> :
>>>
>>>> Why u think the native div code would crash on most devices? I support
>>>> ARMv7+ only anyway.
>>>>
>>>> On Wed, Feb 25, 2015 at 5:23 PM, Leif Lindholm
>>>> <address@hidden>
>>>> wrote:
>>>>>
>>>>> On Wed, Feb 25, 2015 at 03:45:40PM +0000, Leif Lindholm wrote:
>>>>>>>>>
>>>>>>>>> Some technical info:
>>>>>>>>> ARMv7
>>>>>>>>> Linaro GCC 4.9
>>>>>>
>>>>>>
>>>>>> I don't see any calls to any of the __aeabi helpers generated for this
>>>>>> file with current head. Which specific Linaro toolchain are you using?
>>>>>> (mine is"Linaro GCC 4.9-2014.09").
>>>>>
>>>>>
>>>>> Scratch that, I do see them. Just failing to drive the tools properly.
>>>>>
>>>>> /
>>>>>      Leif
>>>>>
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