[FFmpeg-devel] [PATCH] lavc/aarch64: Add neon implementation for sse4
Hubert Mazur
hum at semihalf.com
Fri Jul 29 10:26:11 EEST 2022
Yes, it seems that they are misplaced or each is treated as a new series
and thus can't be applied.
I will send the whole batch again after the first review, so some issues
could be fixed.
Thanks for the feedback!
On Thu, Jul 28, 2022 at 8:51 PM Swinney, Jonathan <jswinney at amazon.com>
wrote:
> > There is one more place to move the sub, cmp and branch instructions
> apart in sse16_neon. It doesn't seem to make any difference to Neoverse N1
> and V1 and it may help A53.
>
> Sorry-- I meant sse4_neon.
>
> --
>
> Jonathan Swinney
>
> On 7/28/22, 1:50 PM, "Swinney, Jonathan" <jswinney at amazon.com> wrote:
>
> Your latest set of patches didn’t get interpreted correctly by the
> patchwork tool. I suspect it took them in the wrong order.
>
>
> https://patchwork.ffmpeg.org/project/ffmpeg/list/?series=&submitter=1479&state=&q=&archive=&delegate=
>
> There is one more place to move the sub, cmp and branch instructions
> apart in sse16_neon. It doesn't seem to make any difference to Neoverse N1
> and V1 and it may help A53.
>
> I didn't see anything else.
>
> Thanks!
> --
>
> Jonathan Swinney
>
> On 7/25/22, 6:16 AM, "Hubert Mazur" <hum at semihalf.com> wrote:
>
> CAUTION: This email originated from outside of the organization.
> Do not click links or open attachments unless you can confirm the sender
> and know the content is safe.
>
>
>
> Provide neon implementation for sse4 function.
>
> Performance comparison tests are shown below.
> - sse_2_c: 74.0
> - sse_2_neon: 24.0
>
> Benchmarks and tests are run with checkasm tool on AWS Graviton 3.
>
> Signed-off-by: Hubert Mazur <hum at semihalf.com>
> ---
> libavcodec/aarch64/me_cmp_init_aarch64.c | 3 ++
> libavcodec/aarch64/me_cmp_neon.S | 65
> ++++++++++++++++++++++++
> 2 files changed, 68 insertions(+)
>
> diff --git a/libavcodec/aarch64/me_cmp_init_aarch64.c
> b/libavcodec/aarch64/me_cmp_init_aarch64.c
> index 3ff5767bd0..72a2062e7e 100644
> --- a/libavcodec/aarch64/me_cmp_init_aarch64.c
> +++ b/libavcodec/aarch64/me_cmp_init_aarch64.c
> @@ -32,6 +32,8 @@ int ff_pix_abs16_x2_neon(MpegEncContext *v,
> uint8_t *pix1, uint8_t *pix2,
>
> int sse16_neon(MpegEncContext *v, uint8_t *pix1, uint8_t *pix2,
> ptrdiff_t stride, int h);
> +int sse4_neon(MpegEncContext *v, uint8_t *pix1, uint8_t *pix2,
> + ptrdiff_t stride, int h);
>
> av_cold void ff_me_cmp_init_aarch64(MECmpContext *c,
> AVCodecContext *avctx)
> {
> @@ -44,5 +46,6 @@ av_cold void ff_me_cmp_init_aarch64(MECmpContext
> *c, AVCodecContext *avctx)
>
> c->sad[0] = ff_pix_abs16_neon;
> c->sse[0] = sse16_neon;
> + c->sse[2] = sse4_neon;
> }
> }
> diff --git a/libavcodec/aarch64/me_cmp_neon.S
> b/libavcodec/aarch64/me_cmp_neon.S
> index 98c912b608..3336d88848 100644
> --- a/libavcodec/aarch64/me_cmp_neon.S
> +++ b/libavcodec/aarch64/me_cmp_neon.S
> @@ -352,3 +352,68 @@ function sse16_neon, export=1
> ret
>
> endfunc
> +
> +function sse4_neon, export=1
> + // x0 - unused
> + // x1 - pix1
> + // x2 - pix2
> + // x3 - stride
> + // w4 - h
> +
> + movi d18, #0
> + movi d17, #0
> + cmp w4, #4
> + b.le 2f
> +
> +// make 4 iterations at once
> +1:
> +
> + // res = abs(pix1[0] - pix2[0])
> + // res * res
> +
> + ld1 {v0.s}[0], [x1], x3 // Load
> pix1, first iteration
> + ld1 {v1.s}[0], [x2], x3 // Load
> pix2, first iteration
> + uabdl v30.8h, v0.8b, v1.8b //
> Absolute difference, first iteration
> + ld1 {v2.s}[0], [x1], x3 // Load
> pix1, second iteration
> + ld1 {v3.s}[0], [x2], x3 // Load
> pix2, second iteration
> + umull v16.4s, v30.4h, v30.4h //
> Multiply vectors, first iteration
> + uabdl v29.8h, v2.8b, v3.8b //
> Absolute difference, second iteration
> + ld1 {v4.s}[0], [x1], x3 // Load
> pix1, third iteration
> + ld1 {v5.s}[0], [x2], x3 // Load
> pix2, third iteration
> + umlal v16.4s, v29.4h, v29.4h //
> Multiply and accumulate, second iteration
> + uabdl v28.8h, v4.8b, v5.8b //
> Absolute difference, third iteration
> + ld1 {v6.s}[0], [x1], x3 // Load
> pix1, fourth iteration
> + ld1 {v7.s}[0], [x2], x3 // Load
> pix2, fourth iteration
> + umlal v16.4s, v28.4h, v28.4h //
> Multiply and accumulate, third iteration
> + uabdl v27.8h, v6.8b, v7.8b //
> Absolue difference, fourth iteration
> + umlal v16.4s, v27.4h, v27.4h //
> Multiply and accumulate, fourth iteration
> +
> + uaddlv d17, v16.4s // Add
> vector
> + add d18, d18, d17
> +
> + sub w4, w4, #4
> + cmp w4, #4
> + b.ge 1b
> +
> + cbnz w4, 2f
> + fmov w0, s18
> +
> + ret
> +
> +// iterate by one
> +2:
> + ld1 {v0.s}[0], [x1], x3 // Load
> pix1
> + ld1 {v1.s}[0], [x2], x3 // Load
> pix2
> + uabdl v30.8h, v0.8b, v1.8b
> + umull v16.4s, v30.4h, v30.4h
> +
> + uaddlv d17, v16.4s
> + add d18, d18, d17
> +
> + subs w4, w4, #1
> + b.ne 2b
> + fmov w0, s18
> +
> + ret
> +
> +endfunc
> --
> 2.34.1
>
>
>
>
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