[x265] [PATCH 2 of 2] asm:intra pred planar32 sse2 high bit

[dave]

On 03/10/2015 08:56 AM, Steve Borho wrote:
> On 03/10, dave wrote:
>> On 03/09/2015 11:40 PM, Steve Borho wrote:
> <snip>
>>> No, but the command line option --cu-stats does show how much it is
>>> called (but not how long it took)
>>>
>> This produces some interesting numbers.
>>
>> Without using registers for constants
>>
>> x265 [info]: I32: Intra 100%(DC 0% P 40% Ang 58%)
>>
>> encoded 2000 frames in 95.98s (20.84 fps), 1020.04 kb/s
>>
>> With using registers for constants
>>
>> x265 [info]: I32: Intra 99%(DC 39% P 16% Ang 43%)
>>
>> encoded 2000 frames in 93.10s (21.48 fps), 1008.63 kb/s
>>
>> I just added --cu-stats to the same command options that I used
>> previously and I ran it several times and got exactly the same
>> percentages.  Times varied by less than a second for each build.  So
>> how can simple register usage in one primitive affect intra pred
>> decisions?
> it shouldn't, the behavior must be wrong in one of the cases. no change
> in performance should be able to impact the encoder output (or any
> coding decisions)
>
So execution time isn't directly measured for decision making?

The output is also different.

ls -l bridge-close*
-rw-r--r-- 1 shakezula shakezula 8432204 Mar 10 09:25 bridge-close1.y4m
-rw-r--r-- 1 shakezula shakezula 8527219 Mar 10 07:49 bridge-close.y4m

  bridge-close1.y4m was generated without the use of registers to hold 
constants.