[FFmpeg-cvslog] lavc/aarch64: Add neon implementation for pix_abs16_y2
Hubert Mazur
git at videolan.org
Thu Aug 18 12:07:50 EEST 2022
ffmpeg | branch: master | Hubert Mazur <hum at semihalf.com> | Tue Aug 16 14:20:14 2022 +0200| [a2e45ad407c526cd5ce2f3a361fb98084228cd6e] | committer: Martin Storsjö
lavc/aarch64: Add neon implementation for pix_abs16_y2
Provide optimized implementation of pix_abs16_y2 function for arm64.
Performance comparison tests are shown below.
pix_abs_0_2_c: 317.2
pix_abs_0_2_neon: 37.5
Benchmarks and tests run with checkasm tool on AWS Graviton 3.
Signed-off-by: Hubert Mazur <hum at semihalf.com>
Signed-off-by: Martin Storsjö <martin at martin.st>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a2e45ad407c526cd5ce2f3a361fb98084228cd6e
---
libavcodec/aarch64/me_cmp_init_aarch64.c | 3 ++
libavcodec/aarch64/me_cmp_neon.S | 75 ++++++++++++++++++++++++++++++++
2 files changed, 78 insertions(+)
diff --git a/libavcodec/aarch64/me_cmp_init_aarch64.c b/libavcodec/aarch64/me_cmp_init_aarch64.c
index 57722b6a9a..30737e2436 100644
--- a/libavcodec/aarch64/me_cmp_init_aarch64.c
+++ b/libavcodec/aarch64/me_cmp_init_aarch64.c
@@ -29,6 +29,8 @@ int ff_pix_abs16_xy2_neon(MpegEncContext *s, const uint8_t *blk1, const uint8_t
ptrdiff_t stride, int h);
int ff_pix_abs16_x2_neon(MpegEncContext *v, const uint8_t *pix1, const uint8_t *pix2,
ptrdiff_t stride, int h);
+int ff_pix_abs16_y2_neon(MpegEncContext *v, const uint8_t *pix1, const uint8_t *pix2,
+ ptrdiff_t stride, int h);
int sse16_neon(MpegEncContext *v, const uint8_t *pix1, const uint8_t *pix2,
ptrdiff_t stride, int h);
@@ -42,6 +44,7 @@ av_cold void ff_me_cmp_init_aarch64(MECmpContext *c, AVCodecContext *avctx)
if (have_neon(cpu_flags)) {
c->pix_abs[0][0] = ff_pix_abs16_neon;
c->pix_abs[0][1] = ff_pix_abs16_x2_neon;
+ c->pix_abs[0][2] = ff_pix_abs16_y2_neon;
c->pix_abs[0][3] = ff_pix_abs16_xy2_neon;
c->sad[0] = ff_pix_abs16_neon;
diff --git a/libavcodec/aarch64/me_cmp_neon.S b/libavcodec/aarch64/me_cmp_neon.S
index f3201739b8..26490e189f 100644
--- a/libavcodec/aarch64/me_cmp_neon.S
+++ b/libavcodec/aarch64/me_cmp_neon.S
@@ -271,6 +271,81 @@ function ff_pix_abs16_x2_neon, export=1
ret
endfunc
+function ff_pix_abs16_y2_neon, export=1
+ // x0 unused
+ // x1 uint8_t *pix1
+ // x2 uint8_t *pix2
+ // x3 ptrdiff_t stride
+ // w4 int h
+
+ // initialize buffers
+ movi v29.8h, #0 // clear the accumulator
+ movi v28.8h, #0 // clear the accumulator
+ movi d18, #0
+ add x5, x2, x3 // pix2 + stride
+ cmp w4, #4
+ b.lt 2f
+
+// make 4 iterations at once
+1:
+
+ // abs(pix1[0], avg2(pix2[0], pix2[0 + stride]))
+ // avg2(a, b) = (((a) + (b) + 1) >> 1)
+ // abs(x) = (x < 0 ? (-x) : (x))
+
+ ld1 {v1.16b}, [x2], x3 // Load pix2 for first iteration
+ ld1 {v2.16b}, [x5], x3 // Load pix3 for first iteration
+ ld1 {v0.16b}, [x1], x3 // Load pix1 for first iteration
+ urhadd v30.16b, v1.16b, v2.16b // Rounding halving add, first iteration
+ ld1 {v4.16b}, [x2], x3 // Load pix2 for second iteration
+ ld1 {v5.16b}, [x5], x3 // Load pix3 for second iteartion
+ uabal v29.8h, v0.8b, v30.8b // Absolute difference of lower half, first iteration
+ uabal2 v28.8h, v0.16b, v30.16b // Absolute difference of upper half, first iteration
+ ld1 {v3.16b}, [x1], x3 // Load pix1 for second iteration
+ urhadd v27.16b, v4.16b, v5.16b // Rounding halving add, second iteration
+ ld1 {v7.16b}, [x2], x3 // Load pix2 for third iteration
+ ld1 {v20.16b}, [x5], x3 // Load pix3 for third iteration
+ uabal v29.8h, v3.8b, v27.8b // Absolute difference of lower half for second iteration
+ uabal2 v28.8h, v3.16b, v27.16b // Absolute difference of upper half for second iteration
+ ld1 {v6.16b}, [x1], x3 // Load pix1 for third iteration
+ urhadd v26.16b, v7.16b, v20.16b // Rounding halving add, third iteration
+ ld1 {v22.16b}, [x2], x3 // Load pix2 for fourth iteration
+ ld1 {v23.16b}, [x5], x3 // Load pix3 for fourth iteration
+ uabal v29.8h, v6.8b, v26.8b // Absolute difference of lower half for third iteration
+ uabal2 v28.8h, v6.16b, v26.16b // Absolute difference of upper half for third iteration
+ ld1 {v21.16b}, [x1], x3 // Load pix1 for fourth iteration
+ sub w4, w4, #4 // h-= 4
+ urhadd v25.16b, v22.16b, v23.16b // Rounding halving add
+ cmp w4, #4
+ uabal v29.8h, v21.8b, v25.8b // Absolute difference of lower half for fourth iteration
+ uabal2 v28.8h, v21.16b, v25.16b // Absolute difference of upper half for fourth iteration
+
+ b.ge 1b
+ cbz w4, 3f
+
+// iterate by one
+2:
+
+ ld1 {v1.16b}, [x2], x3 // Load pix2
+ ld1 {v2.16b}, [x5], x3 // Load pix3
+ subs w4, w4, #1
+ ld1 {v0.16b}, [x1], x3 // Load pix1
+ urhadd v30.16b, v1.16b, v2.16b // Rounding halving add
+ uabal v29.8h, v30.8b, v0.8b
+ uabal2 v28.8h, v30.16b, v0.16b
+
+ b.ne 2b
+
+3:
+ add v29.8h, v29.8h, v28.8h // Add vectors together
+ uaddlv s16, v29.8h // Add up vector values
+ add d18, d18, d16
+
+ fmov w0, s18
+
+ ret
+endfunc
+
function sse16_neon, export=1
// x0 - unused
// x1 - pix1
More information about the ffmpeg-cvslog
mailing list