[FFmpeg-cvslog] lavc/aarch64: Provide optimized implementation of vsse8 for arm64.
Grzegorz Bernacki
git at videolan.org
Tue Oct 4 13:51:57 EEST 2022
ffmpeg | branch: master | Grzegorz Bernacki <gjb at semihalf.com> | Mon Oct 3 16:10:18 2022 +0200| [bad67cb9fd53885ee2e5fba4db28b1f1bb315a8f] | committer: Martin Storsjö
lavc/aarch64: Provide optimized implementation of vsse8 for arm64.
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 <gjb at semihalf.com>
Signed-off-by: Martin Storsjö <martin at martin.st>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=bad67cb9fd53885ee2e5fba4db28b1f1bb315a8f
---
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 05156627fa..1a0c3e90bb 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 24be05dd18..104e02f495 100644
--- a/libavcodec/aarch64/me_cmp_neon.S
+++ b/libavcodec/aarch64/me_cmp_neon.S
@@ -838,6 +838,76 @@ 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.lt 2f
+
+
+1:
+ // x = abs(pix1[0] - pix2[0] - pix1[0 + stride] + pix2[0 + stride])
+ // res = (x) * (x)
+ ld1 {v0.8b}, [x1], x3 // Load pix1[0 + stride], first iteration
+ ld1 {v1.8b}, [x2], x3 // Load pix2[0 + stride], first iteration
+ ld1 {v2.8b}, [x1], x3 // Load pix1[0 + stride], second iteration
+ ld1 {v3.8b}, [x2], x3 // Load pix2[0 + stride], second iteration
+ usubl v29.8h, v0.8b, v1.8b
+ usubl2 v28.8h, v0.16b, v1.16b
+ ld1 {v4.8b}, [x1], x3 // Load pix1[0 + stride], third iteration
+ ld1 {v5.8b}, [x2], x3 // Load pix1[0 + stride], third iteration
+ sabd v31.8h, v31.8h, v29.8h
+ usubl v27.8h, v2.8b, v3.8b
+ usubl v25.8h, v4.8b, v5.8b
+ sabd v29.8h, v29.8h, v27.8h
+ sabd v27.8h, v27.8h, v25.8h
+ umlal v16.4s, v31.4h, v31.4h
+ umlal2 v17.4s, v31.8h, v31.8h
+ mov v31.16b, v25.16b
+ umlal v16.4s, v29.4h, v29.4h
+ umlal2 v17.4s, v29.8h, v29.8h
+ sub w4, w4, #3
+ umlal v16.4s, v27.4h, v27.4h
+ umlal2 v17.4s, v27.8h, v27.8h
+ cmp w4, #3
+
+ b.ge 1b
+
+ cbz w4, 3f
+
+// iterate by once
+2:
+ ld1 {v0.8b}, [x1], x3
+ ld1 {v1.8b}, [x2], x3
+ subs w4, w4, #1
+ usubl v29.8h, v0.8b, v1.8b
+ sabd v31.8h, v31.8h, v29.8h
+ umlal v16.4s, v31.4h, v31.4h
+ umlal2 v17.4s, v31.8h, v31.8h
+ mov v31.16b, v29.16b
+ b.ne 2b
+
+3:
+ add v16.4s, v16.4s, v17.4s
+ uaddlv d17, v16.4s
+ fmov w0, s17
+
+ ret
+endfunc
+
+
function vsse16_neon, export=1
// x0 unused
// x1 uint8_t *pix1
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