On Sat, Mar 19, 2016 at 4:36 AM, Michael Niedermayer
<mich...@niedermayer.cc> wrote:
> On Fri, Mar 18, 2016 at 07:27:46PM -0700, Ganesh Ajjanagadde wrote:
>> Yields speedup in quantize_bands, and non-negligible speedup in aac encoding
>> overall.
>>
>> Sample benchmark (Haswell, -march=native + GCC):
>> new:
>> [...]
>> 553 decicycles in quantize_bands, 2097136 runs, 16 skips9x
>> 554 decicycles in quantize_bands, 4194266 runs, 38 skips8x
>> 559 decicycles in quantize_bands, 8388534 runs, 74 skips7x
>>
>> old:
>> [...]
>> 711 decicycles in quantize_bands, 2097140 runs, 12 skips7x
>> 713 decicycles in quantize_bands, 4194277 runs, 27 skips4x
>> 715 decicycles in quantize_bands, 8388538 runs, 70 skips3x
>>
>> old:
>> ffmpeg -f lavfi -i anoisesrc -t 300 -y sin_new.aac 4.58s user 0.01s system
>> 99% cpu 4.590 total
>>
>> new:
>> ffmpeg -f lavfi -i anoisesrc -t 300 -y sin_new.aac 4.54s user 0.02s system
>> 99% cpu 4.566 total
>>
>> Signed-off-by: Ganesh Ajjanagadde <gajja...@gmail.com>
>> ---
>> libavcodec/aacenc_utils.h | 33 +++++++++++++++++++++++++--------
>> 1 file changed, 25 insertions(+), 8 deletions(-)
>>
>> diff --git a/libavcodec/aacenc_utils.h b/libavcodec/aacenc_utils.h
>> index 38636e5..0203b6e 100644
>> --- a/libavcodec/aacenc_utils.h
>> +++ b/libavcodec/aacenc_utils.h
>> @@ -62,18 +62,35 @@ static inline int quant(float coef, const float Q, const
>> float rounding)
>> return sqrtf(a * sqrtf(a)) + rounding;
>> }
>>
>> +static inline float minf(float x, float y) {
>> + return x < y ? x : y;
>> +}
>> +
>> static inline void quantize_bands(int *out, const float *in, const float
>> *scaled,
>> int size, float Q34, int is_signed, int
>> maxval,
>> const float rounding)
>> {
>> - int i;
>> - for (i = 0; i < size; i++) {
> [...]
>> + for (int i = 0; i < size; i+=4) {
>
> iam not sure we still support a compiler that has a problem with
> that int placement but its not done anywhere else
No problem, changed.
>
> [...]
>
> --
> Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
>
> In fact, the RIAA has been known to suggest that students drop out
> of college or go to community college in order to be able to afford
> settlements. -- The RIAA
>
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