On Tue, 13 Apr 2021, Mikhail Nitenko wrote:
Benchmarks: pred16x16_dc_10_c: 124.0 pred16x16_dc_10_neon: 97.2 pred16x16_horizontal_10_c: 71.7 pred16x16_horizontal_10_neon: 66.2 pred16x16_top_dc_10_c: 90.7 pred16x16_top_dc_10_neon: 71.5 pred16x16_vertical_10_c: 64.7 pred16x16_vertical_10_neon: 61.7
When posting benchmark numbers, it's nice if you'd mention what CPU it was benchmarked on, as the numbers sometimes differ quite a bit between various CPUs.
Some functions work slower than C and are left commented out. --- libavcodec/aarch64/h264pred_init.c | 12 +++ libavcodec/aarch64/h264pred_neon.S | 117 +++++++++++++++++++++++++++++ 2 files changed, 129 insertions(+) diff --git a/libavcodec/aarch64/h264pred_init.c b/libavcodec/aarch64/h264pred_init.c index fc8989ae0d..9a1f13910d 100644 --- a/libavcodec/aarch64/h264pred_init.c +++ b/libavcodec/aarch64/h264pred_init.c @@ -45,6 +45,11 @@ void ff_pred8x8_0lt_dc_neon(uint8_t *src, ptrdiff_t stride); void ff_pred8x8_l00_dc_neon(uint8_t *src, ptrdiff_t stride); void ff_pred8x8_0l0_dc_neon(uint8_t *src, ptrdiff_t stride); +void ff_pred16x16_top_dc_neon_10(uint8_t *src, ptrdiff_t stride); +void ff_pred16x16_dc_neon_10(uint8_t *src, ptrdiff_t stride); +void ff_pred16x16_hor_neon_10(uint8_t *src, ptrdiff_t stride); +void ff_pred16x16_vert_neon_10(uint8_t *src, ptrdiff_t stride); + static av_cold void h264_pred_init_neon(H264PredContext *h, int codec_id, const int bit_depth, const int chroma_format_idc) @@ -78,6 +83,12 @@ static av_cold void h264_pred_init_neon(H264PredContext *h, int codec_id, codec_id != AV_CODEC_ID_VP7 && codec_id != AV_CODEC_ID_VP8) h->pred16x16[PLANE_PRED8x8 ] = ff_pred16x16_plane_neon; } + if (bit_depth == 10) { + h->pred16x16[DC_PRED8x8 ] = ff_pred16x16_dc_neon_10; + h->pred16x16[VERT_PRED8x8 ] = ff_pred16x16_vert_neon_10; + h->pred16x16[HOR_PRED8x8 ] = ff_pred16x16_hor_neon_10; + h->pred16x16[TOP_DC_PRED8x8 ] = ff_pred16x16_top_dc_neon_10; + } } av_cold void ff_h264_pred_init_aarch64(H264PredContext *h, int codec_id, @@ -88,3 +99,4 @@ av_cold void ff_h264_pred_init_aarch64(H264PredContext *h, int codec_id, if (have_neon(cpu_flags)) h264_pred_init_neon(h, codec_id, bit_depth, chroma_format_idc); } +
Stray newline added
diff --git a/libavcodec/aarch64/h264pred_neon.S b/libavcodec/aarch64/h264pred_neon.S index 213b40b3e7..5ce50323f8 100644 --- a/libavcodec/aarch64/h264pred_neon.S +++ b/libavcodec/aarch64/h264pred_neon.S @@ -359,3 +359,120 @@ function ff_pred8x8_0l0_dc_neon, export=1 dup v1.8b, v1.b[0] b .L_pred8x8_dc_end endfunc + +.macro ldcol.16 rd, rs, rt, n=4, hi=0 +.if \n >= 4 || \hi == 0 + ld1 {\rd\().h}[0], [\rs], \rt + ld1 {\rd\().h}[1], [\rs], \rt +.endif +.if \n >= 4 || \hi == 1 + ld1 {\rd\().h}[2], [\rs], \rt + ld1 {\rd\().h}[3], [\rs], \rt +.endif +.if \n == 8 + ld1 {\rd\().h}[4], [\rs], \rt + ld1 {\rd\().h}[5], [\rs], \rt + ld1 {\rd\().h}[6], [\rs], \rt + ld1 {\rd\().h}[7], [\rs], \rt +.endif +.endm + +// slower than C +/* +function ff_pred16x16_128_dc_neon_10, export=1 + movi v0.8h, #2, lsl #8 // 512, 1 << (bit_depth - 1) + + b .L_pred16x16_dc_10_end +endfunc +*/ + +function ff_pred16x16_top_dc_neon_10, export=1 + sub x2, x0, x1 + + ld1 {v0.8h, v1.8h}, [x2] + + addv h0, v0.8h + addv h1, v1.8h + + add v0.4h, v0.4h, v1.4h + + rshrn v0.4h, v0.4s, #4 + dup v0.8h, v0.h[0] + b .L_pred16x16_dc_10_end +endfunc + +// slower than C +/* +function ff_pred16x16_left_dc_neon_10, export=1 + sub x2, x0, #2 // access to the "left" column + ldcol.16 v0, x2, x1, 8 + ldcol.16 v1, x2, x1, 8 // load "left" column + + addv h0, v0.8h + addv h1, v1.8h + + add v0.4h, v0.4h, v1.4h + + rshrn v0.4h, v0.4s, #4 + dup v0.8h, v0.h[0] + b .L_pred16x16_dc_10_end +endfunc +*/ + +function ff_pred16x16_dc_neon_10, export=1 + sub x2, x0, x1 // access to the "top" row + sub x3, x0, #2 // access to the "left" column + + ld1 {v0.8h, v1.8h}, [x2] + ldcol.16 v2, x3, x1, 8 + ldcol.16 v3, x3, x1, 8 // load pixels in "top" row and "left" col + + addv h0, v0.8h + addv h1, v1.8h + addv h2, v2.8h // sum all pixels in the "top" row and "left" col + addv h3, v3.8h // (sum stays in h0-h3 registers) + + add v0.4h, v0.4h, v1.4h + add v0.4h, v0.4h, v2.4h + add v0.4h, v0.4h, v3.4h // sum registers h0-h3
Instead of doing ((v0+v1)+v2)+v3, try doing (v0+v1)+(v2+v3). That reduces the latency chain by one instruction, when the v2+v3 addition can start independent of the v0+v1 addition.
+ + rshrn v0.4h, v0.4s, #5 + dup v0.8h, v0.h[0] +.L_pred16x16_dc_10_end: + mov v1.16b, v0.16b + mov w3, #8 +6: st1 {v0.8h, v1.8h}, [x0], x1 + subs w3, w3, #1 + st1 {v0.8h, v1.8h}, [x0], x1 + b.ne 6b + ret +endfunc + +function ff_pred16x16_hor_neon_10, export=1 + sub x2, x0, #2 + add x3, x0, #16 + + mov w4, #16 +1: ld1r {v0.8h}, [x2], x1 + subs w4, w4, #1 + st1 {v0.8h}, [x0], x1 + st1 {v0.8h}, [x3], x1 + b.ne 1b + ret +endfunc + +function ff_pred16x16_vert_neon_10, export=1 + sub x2, x0, x1 + add x1, x1, x1 + + ld1 {v0.8h, v1.8h}, [x2], x1 + + mov w3, #8 +1: subs w3, w3, #1 + st1 {v0.8h, v1.8h}, [x0], x1 + st1 {v0.8h, v1.8h}, [x2], x1 + + b.ne 1b + ret +endfunc +
Stray newline at the end of the file, git complains about it. Other than that, the code looks straightforward and ok 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".