On Mon, 26 Sep 2022, Grzegorz Bernacki wrote:
Provide optimized implementation of vsse8 for arm64.Performance comparison tests are shown below. - vsse_1_c: 141.5 - vsse_1_neon: 32.5 Benchmarks and tests are run with checkasm tool on AWS Graviton 3. Signed-off-by: Grzegorz Bernacki <g...@semihalf.com> --- libavcodec/aarch64/me_cmp_init_aarch64.c | 5 ++ libavcodec/aarch64/me_cmp_neon.S | 70 ++++++++++++++++++++++++ 2 files changed, 75 insertions(+) diff --git a/libavcodec/aarch64/me_cmp_init_aarch64.c b/libavcodec/aarch64/me_cmp_init_aarch64.c index 2c61cfcf63..f247372c94 100644 --- a/libavcodec/aarch64/me_cmp_init_aarch64.c +++ b/libavcodec/aarch64/me_cmp_init_aarch64.c @@ -71,6 +71,9 @@ int nsse8_neon(int multiplier, const uint8_t *s, const uint8_t *s2, int nsse8_neon_wrapper(MpegEncContext *c, const uint8_t *s1, const uint8_t *s2, ptrdiff_t stride, int h); +int vsse8_neon(MpegEncContext *c, const uint8_t *s1, const uint8_t *s2, + ptrdiff_t stride, int h); + av_cold void ff_me_cmp_init_aarch64(MECmpContext *c, AVCodecContext *avctx) { int cpu_flags = av_get_cpu_flags(); @@ -96,6 +99,8 @@ av_cold void ff_me_cmp_init_aarch64(MECmpContext *c, AVCodecContext *avctx) c->vsad[5] = vsad_intra8_neon; c->vsse[0] = vsse16_neon; + c->vsse[1] = vsse8_neon; + c->vsse[4] = vsse_intra16_neon; c->nsse[0] = nsse16_neon_wrapper; diff --git a/libavcodec/aarch64/me_cmp_neon.S b/libavcodec/aarch64/me_cmp_neon.S index 6f7c7c1690..386d2de0c5 100644 --- a/libavcodec/aarch64/me_cmp_neon.S +++ b/libavcodec/aarch64/me_cmp_neon.S @@ -843,6 +843,76 @@ function vsad16_neon, export=1 ret endfunc +function vsse8_neon, export=1 + // x0 unused + // x1 uint8_t *pix1 + // x2 uint8_t *pix2 + // x3 ptrdiff_t stride + // w4 int h + + ld1 {v0.8b}, [x1], x3 // Load pix1[0], first iteration + ld1 {v1.8b}, [x2], x3 // Load pix2[0], first iteration + + sub w4, w4, #1 // we need to make h-1 iterations + movi v16.4s, #0 + movi v17.4s, #0 + + cmp w4, #3 // check if we can make 3 iterations at once + usubl v31.8h, v0.8b, v1.8b // Signed difference of pix1[0] - pix2[0], first iteration + b.le 2f
Why the b.le here, shouldn't it be enough with b.lt? If we're run with h=<unroll amount>, it should be enough to run one round in the unrolled loop.
I see that we've got the same issue in a couple preexisting functions; I'll send a patch to fix that.
Other than that, this looks reasonable to me. // Martin _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
