[FFmpeg-devel] [PATCH] avodec/hevcdsp: optimize pixel comparison in sao_edge_filter

[James Almer]

On 16/02/15 5:45 PM, Michael Niedermayer wrote:
> On Mon, Feb 16, 2015 at 05:06:20PM -0300, James Almer wrote:
>> GCC 4.9.2 on a Core i5-4200U @ 1.60GHz, Linux x86_64
>>
>> Before
>> 715487 decicycles in sao_edge_filter_8, 262144 runs, 0 skips
>>
>> After
>> 672104 decicycles in sao_edge_filter_8, 262144 runs, 0 skips
>>
>> Signed-off-by: James Almer <jamrial at gmail.com>
>> ---
>> Not like the C versions of these functions matter to a CPU like the above, but 
>> this could very well mean a couple extra fps for pre-SSSE3 CPUs with 8bit hevc 
>> content.
>>
>> Thanks to Zhaoxiu Zeng for inspiring this :P
>>
>>  libavcodec/hevcdsp_template.c | 2 +-
>>  1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/libavcodec/hevcdsp_template.c b/libavcodec/hevcdsp_template.c
>> index 9ce7bf2..aeb142c 100644
>> --- a/libavcodec/hevcdsp_template.c
>> +++ b/libavcodec/hevcdsp_template.c
>> @@ -325,7 +325,7 @@ static void FUNC(sao_band_filter_0)(uint8_t *_dst, uint8_t *_src,
>>      }
>>  }
>>  
>> -#define CMP(a, b) ((a) > (b) ? 1 : ((a) == (b) ? 0 : -1))
>> +#define CMP(a, b) ((a > b) - (a < b))
> 
> LGTM

Pushed, thanks.